New Pham paper re: Occult Hepatitis C

"Hepatitis C Virus Replicates in the Same Immune Cell Subsets in Chronic Hepatitis C and Occult Infection."

"BACKGROUND & AIMS: Infection of the lymphatic system by hepatitis C virus (HCV) appears to be an intrinsic characteristic of chronic hepatitis C (CHC) and low-level (occult) HCV infection, but the subsets of immune cells involved were not defined. The aim of this study was to characterize HCV replication status and to assess virus compartmentalization in CD4+ and CD8+ T lymphocytes, B cells, and monocytes in CHC, and silent infection persisting after resolution of hepatitis C. METHODS: Immune cell subtypes isolated from 7 patients with CHC and 7 individuals with occult infection were analyzed for HCV-RNA-positive and -negative strands and, in selected cases, nonstructural protein 5A display and HCV variants. RESULTS: All subtypes of immune cells investigated support HCV replication in both forms of infection, although significant differences were found between patients, and virus loads in the cells were greater in CHC than in occult infection. Although HCV RNA occurred at a comparable frequency in all cell subtypes in CHC, monocytes contained the greatest loads. In contrast, B cells tended to carry the highest virus quantities in occult infection, whereas monocytes appeared to be the least frequently infected. Detection of HCV nonstructural protein 5A and HCV variants that were not found in plasma confirmed virus replication in different immune cell types. CONCLUSIONS: This work documents that the immune system supports HCV replication regardless of clinical appearance of infection and identifies immune cells that are reservoirs of HCV in symptomatic and occult infections."


TnHepGuy

[TnHepGuy_]

Here's the link to the paper:

http://www.ncbi.nlm.nih.gov/pubmed/18243182?dopt=AbstractPlus


TnHepGuy

[Ginger12521]

This is one topic that makes me sit back and say hummm? I have to wonder if everyone in the U.S. got tested for occult HCV, how many would indeed be reactive with a positive PCR?

I suppose there's no way to know unless everyone recieved a liver biopsy and tested it for +PCR RNA.

Crazy virus to say the least!

Thanks for the article.

[DoubleDose]

Thanks for the up to date information, on a subject that we have been discussing a good bit lately on the forum.  This is exactly why I have long had concerns about 'atypical transmission',  symptoms in close contacts, and also have hypothesized that the reason so many 'alcohol abusers' seem to develop HCV, in spite of not having other risk factors, might just be that many people already 'carry' an undetected, non-blood form of the virus, in a somewhat dormant, or carrier state.

  If there is truth to this immune system low level infection, then I could not imagine why it would not be able to also replicate in similar tissues and cells in almost anyone.  My take is that the researchers now need to look at two groups, and determine what the percentage of positive HCV infection is within immune and lymphatic cell structures among these groups.  Those groups would first be those close or intimate contacts of persons who have had true, blood borne, chronic HCV infections.  The second group would be the general population, in order to see what the real rate of 'underlying immune system HCV infection' might look like.  It could be on the lower side, like 2% (reflecting chiefly those who also concurrently have the full blown CHC infection,  or even up to 5% or 10%, reflecting mostly those infected AND their close contacts, etc.  Or, there could already, over the many hundreds of years, be a large percentage of the population that has become a 'silent carrier' of this lymphatic form of infection. (as are many other  viruses...EBV, HPV, HSV, etc.)  Who knows, this could be present as Ginger stated above, in much of the population.  

The first thing they need to absolutely determine though is this:  whether this form of infection is able to exist in those who have never had the full blown HCV chronic blood liver infection.  They need to test for this 'lymphatic infection' in those who have absolutely no viral load on PCR testing in the blood, and no reactivity to the HCV antibody test using the typical blood testing.   If it turns out that there are populations out there harboring ONLY this 'silent' form of HCV infection, then we have an entirely new ballgame.  We would then need to learn what this form of infection might do, or what problems might develop, and also to understand what, if anything, could provoke this low level, in-check, immune system infection to cross over the humoral immune system barriers, and become a chronic HCV blood borne infection.  I want to know more about this subject, and I bet the researchers are really whetting their appetites after these study findings.  We learn more every year about HCV!

DoubleDose

[TnHepGuy_]

Yes, some of the questions that get raised in my mind re occult are:

The current assumption is that the virus is assumed to be 'controlled/contained' via the immune system. If that's the case, then by definition it (the virus) is generating an immuno-response. And more to the point, it's generating a chronic immuno-response to maintain containment. The question then becomes what systemic negative effects (if any) might this constant immune stimulation/response lead to?

Also, how many other low-level 'contained' viral infections (be they hepatitis or non-hepatitis) might each of us have? And are they generally considered benign - or might each 'ramp-up' the immune system in it's own particular manner, thereby leading to potential long-term damage and/or other concerns?

And of course, how much is anyone with any form of occult viral infection at risk for viral rebound should the immune system become compromised in any fashion (e.g. - through immuno-suppressants, auto-immune concerns, age-related immune issues, etc)?


TnHepGuy

[DoubleDose]

Those are exactly the questions on my mind!  This idea of viral containment to me generates a picture of an immune system constantly churning and reacting, which in turn would have a huge potential to create some sort of 'autoimmune' disturbance or illness over the long term.  At the very least, it would seem to create a chronic immune system adjustment that would not be very normal.  Each virus under containment would probably have a particular profile, and level of 'effort' necessary for the immune system to effectively deal with it.  The greater the number of latent, chronic viruses, and the more potent and aggressive of the viruses pushing on the immune system, would provoke the greatest level of bodily and systemic reactions, I would think.  

I wonder if any of this could play into the underlying causes or mechanisms for cause-undetermined illnesses like CFS, Fibromyalgia, or even Sjogren's, and other autoimmune diseases?  Could it be a silent, or 'invisible' form of HCV, or even a combination of this and other viruses, causing the chronic immune system malfunction in these entities?

Great thought provoking article, which when added to the other seemingly unrelated 'gray area' studies, may begin to paint a new picture of HCV viral behavior.  The "other modes of HCV invection" theory could go from conjecture to reality very quickly if some of these studies ultimately have substance, and support the additional implications that each raises.

DoubleDose

[kcrandy]

point made.  

since your first post dd i have read at least 12 others post that have concerns now to have thier spouses checked because he or she has kissed them.

i said earlier that this could leed to confusion and taken out of context leed to hysteria in the public venue.  

you stated i was foolish thinking that this could happen.  i will sit back and watch the mass confusion and hysteria that will surely come.

i am making this statement and a rebuttal to this study you sight and that itnhep sights.
you sight a study that only says it is lmyphatic in nature, but were are the facts that it is from saliva and how it gets into the lymphs system?
were in this study does it say the means of transmission.
were does it say in the study how many of the people that had it in there lymph system was or never had hcv, and or if said persons got it from their spouses, and not somewhere else, or for that case that they had hcv already.
if what you state according to the study then i would have to come to the conclusion that 90%+ people just in the u.s. have hcv in their lymph system.

do i want to see this study continue, NO. the only way i would like to see such a study continue is if it provides way of finding a cure.

arguing symantics over kissing you spouse or friend,  loved one, etc  is useless  and only continues ( in my opinion ) to create fear, and for me i am tired of living in fear.
i know you two are not going to like my opinion but thats ok we can at least agree to disagree.


  p.s.       i promise i will not let anyone have any of my blood.

[DoubleDose]

I certainly respect your opinion, and for myself do not really think anyone is going to be going into a panic because this potential form of infection is being 'looked at' by researchers.  We are certainly not going to have ANY impact on their studies, nor are we going to answer these questions among ourselves on the forum.  I don't think any of us are going to fear kissing anyone else, and as I stated numerous times (that you keep overlooking), we do not know whether this Lymphatic version of the infection is a valid concern, whether it is transmissable, or whether it poses any health concerns.  

The comments relayed by HR also seem to point to a potential for all our intimate contacts having this 'immune system' manifestation....and many of us have wondered aloud about these issues before.  So if you want to work yourself into a frenzy, and scream that the sky is falling, that is you perogative.  

I don't think either the people who don't want to know any more about the virus, or the people who are asking provocative questions about the virus are going to have more than a 'gnat's impact' on the continuing research and dissemination of new findings about the virus.  
I guess if we don't talk about any of this on the forum, it will all just go away, and no one will ever notice.  But, I really don't think so.  I also think you grossly underestimate the maturity and intelligence of the people discussing issues on the forum, and out there in the general society. Our asking questions about the 'what ifs' are in no way a declaration of what is.   I really do not think we will be seeing any stampedes.  And even if there were negative reactions to news about HCV, I don't think our discussing it will affect it one way or the other.  Knowledge and truth is like a ten thousand ton rockslide coming down the mountain....nobody can stop it.

But I really do respect your concerns and opinion.  We all have our own ways of dealing with the virus, and all the issues surrounding it.  

DoubleDose

[pigeonca]

Although any given person's experiences mean little or nothing compared to the results of a properly conducted scientific study, I can state that in my case, all of the autoimmune problems that I experienced before and during tx (cutaneous scleroderma) seem to have disappeared with my SVR.  

If my immune system was amped up from the virus, and if I still had occult virus in other bodily compartments, one would expect the scleroderma to persist.  Of course, it's possible that the autoimmune situation could return; only time will tell, but it's been almost a year since SVR and there have been no further exacerbations of my skin problems.

[DoubleDose]

You are fortunate indeed that your HCV related problems resolved as a result of SVR.  I think it is really a **** shoot!  Some feel better after SVR, some develop problems that they never had before, and some get rid of some problems after tx, and develop new but different ones.  I sure can't explain why or how it works the way it does.  I guess we all respond in a unique way.  You also may be one of the very lucky ones that really did eradicate ALL of the virus, even the low level 'persistent' stuff in compartments that most SVR's seem to maintain.

DoubleDose

[DoubleDose]

And here is a case where for Pigeonca, doing the tx, and using interferon ended up getting rid of the physical symptoms and autoimmune related problems that were manifested before doing tx.  So, it really is impossible to tell what the interferon will confer, as far as physical effects, and we cannot assume that treatment alone causes our problems.  As far as a possible 'occult infection' I do not think we yet know enough about what it is, or what it does, to even entertain any sort of treatment...except for maybe those that have it in their livers, and nowhere else, and seem to be experiencing liver degradation.  They should probably treat like anyone else.

[merryBe]

I think I'll just give everyone in here a big wet kiss  : ))))))))))))))))))))

but seriously, I've been actually willing to forego all kissing would prefer that until more is known.....but has anyone ever tried to convince a horny non-infected spouse of that???

good luck!

I like what DD said......we can't blame everything on one tx....not at our ages, hello.

The one case in here...where Florida Mouse got "let go" from her office job because someone would not share the same aisle with her.....let alone bathroom.
that's maybe where the concerns come in.

It's not like every one of us doesn't walk past 50 upteen HIV and Hep cases a day and not know it.......and not touch what they've touched....how many times???

but when you see thousands of uninfected spouses and people still thrown out of work for basically breathing the same air....well somewhere lies sanity.

and Fleetwood wafts Landslide somewhere in the distance.............
meanwhile Mary plants her tulips and yells....here's spit in yer eye!!!!!
sorry.....just one of my moods.......y'get's it or ya don'ts
MB

[mikesimon]

From: Hepatitis C Virus Replicates in the Same Immune Cell Subsets in Chronic
Hepatitis C and Occult Infection Pham et al.

"Persistent HCV replication after clinical recovery would lead
to continuous antigenic stimulation of the immune system,
as evidenced by sustained HCV-specific T-cell responses for
years after resolution of hepatitis C. On the other
hand, it also is conceivable that endogenous presentation
of HCV antigens by infected B cells and monocytes, as
shown in our current work, may contribute to the immune
tolerance of HCV, hence, favoring its persistence
even further. At present, it is not known how infection of
the immune cells by HCV may affect functions of immune
cells. However, the allostimulatory capacity of
HCV-carrying dendritic cells from patients with CHC has
been shown to be impaired.
Although occult HCV infection might be beneficial to
immunocompetent hosts in whom persistent antigenic
stimulation may help keep the virus under relative control,
on the other hand, it might be a source of virus
reactivation in certain situations, including immunosuppressive
therapy. In this regard, recurrent HCV infection
also has been reported in liver transplant recipients who
had been found to be HCV-RNA negative before transplantation,
as judged by serum and explanted liver tissue
negativity. Also, HCV RNA was detected in anti-HCV–
positive patients receiving an HCV-negative kidney or
bone marrow. At this stage, the data on pathogenic
consequences of occult HCV infection remain very sparse.
This research area is of significant clinical relevance in
which, as our current study shows, an involvement of the
infected immune system needs to be taken under consideration"

Mike

[nygirl7]

It's like trying to read Chinese to me.  Am i the only one who gets so confused at all the big words and such? I feel like a bonehead. I am a bonehead. Too much peroxide dumped on my head over the years I guess.

[moahunter]

I doubt many people understand the words nygirl7. It's the same with any job/proffession, unless you are educated in it, and also have applied experience of it, you don't understand it. I can read as many biology books as I want, and others can too, but without proper training and experience I think the interpretation is all pretty much meaningless gobbledygook.

[DoubleDose]

The Pham comments are interesting and provocative, to say the least.  At this point I will treat them like a 'hot potato' since 'my' discussing this subject seems to call out the attack dogs far beyond when the actual researchers themselves describe the viral behaviors and possible implications , etc.  I noticed their references to 'possible reactivation'....  No comment on my part at this time.  I have commented out in recent posts!  Thanks for the additional reference Mike.

DoubleDose

[mikesimon]

I think this is a very hot issue and we probably should tread lightly. The article says enough that there probably isn't much left to say other than to theorize what the impact could be. I'll pass right now but I may speculate a little bit later. Mike

[Proactive]

In the "My doctor said" category..We discussed occult hep c for a little bit the other day...interesting tibit. They have had 2 patients who had a biopsy shortly after treatment...Liver tissue samples came back negative for hcv, yet both relapsed.

[mikesimon]

Who is "we"? My first thought is that I would question the biopsy  - either the pathologist or the methodology. Maybe willing will see this and respond because he knows much more than I do about the methodology to detect HCV on biopsy but that just doesn't sound right to me.
Mike

[sldb]

18mths post tx (svr), did 96 wks peg and copeg.  ALL pre tx symptoms disappeared during tx, and have not returned post tx.  No new symptoms have surfaced.  My question is, could i have totally eradicated the virus from my system?  If this were true  how could someone come up with a neg liver bx and relapse. (proactives post). Now  totally confused.  Due for another liver bx at 2 yr mark post tx (end of 2008). Should i ask for a lymph node bx instead of a liver bx? Not looking forward to having another needle stuck in my liver, easier to have a lymph node tested.  Maybe a stupid ? but has anyone done this?

[Proactive]

Near as I can figure most probably the same serum pcr/tma tests are used on the core that are used on a blood draw.So maybe it shouldn't be that shocking, people do get neg pcr's after tx and then latter relapse...The biopsies were done shortly after finishing tx(not 6 months post), but don't know how the samples were tested....the bottomline I think is, as long as the detectability limit of the various VL tests are above absolute zero...people will relapse.

[sldb]

Thanks, What do you think about a lymph node bx as opposed to a liver bx for occult results?  Ive read such much on the virus hiding in the lymphatic system.

[mikesimon]

Sldb, I wouldn't think that a lymph node biopsy would be appropriate and, in fact, I have never heard of one being performed in an HCV setting.

Proactive, I think the testing on tissue is not the same as a serum test. I really wish willing would pop in and elucidate this issue because he knows about it.
It would probably be better if I just quoted willing regarding my biopsy report in a discussion that he and I were having regarding the methodology.

willing: "I believe an important clue is the disclaimer that starts "The following
statement applies to all immunohistochemistry, InsituHybridization
Assays (ISH & FISH), Molecular Anatomic Pathology, and
"Immunofluorescent Testing". These assays, in particular IH and ISH,  
are the very ones that would be used to bind to HCV proteins and/or RNA
in a way that would make their presence visible on a slide.....These are in fact lab-type tests and would  not have formal FDA approval  for routine clinical use. I suspect the presence of that disclaimer coupled with the coordinator's assertion  that staining indicated HCV suggests they ran one or more of those tests, but the report is not indicating which (though perhaps the lines with the text HHE,  H&E and TC1 are relevant - could TC1 be trichrome?)"

If you see language similar to the quoted language regarding immunohistochemistry, InsituHybridization Assays (ISH & FISH), Molecular Anatomic Pathology, and
"Immunofluorescent Testing in willing's discussion then it is likely that this methodology was employed. I am not sure how frequently this type of testing is performed in liver biopsies. I suspect it may not be routine with most biopsies but I really don't know.

Mike

[Proactive]

Mike, I will try and get some more details on the testing at my next appointment, My next appt isn't for another 3 months (actually they handed me a stack of lab slips for blood draws and were going to set an appt. @ 6 months, thought I'd feel more comfortable seeing them in 3(g))
.. I'd suspect they are using the latest and greatest testing,whatever that might be,they certainly can afford it. Heck, they have a donated baby grand piano in the lobby and alumni throwing cash at them and their 200 yo medical school..(vbg)
Hopefully willing will add to the subject...,pro

[mikesimon]

Are you sure you really want to know? I am beginning to believe that, in some cases, what you don't know can't hurt you. This might be one of those cases. Mike

[nygirl7]

Agree - sometimes ignorance IS bliss.  Deb

[willing]

well, it's hard to argue with the view that knowledge of bad news you can't do anything about is not necessarily worthwhile (part of my thinking in delaying my post-eot test for about 2.5 years). However..  post-SVRs facing a biopsy for whatever reason may want to ask about also  having the pathologist treat the tissue with stains specific for HCV RNA and proteins. These techniques, which have names that are variants on immunohistochemistry (IHC) and in-situ hybridization (ISH) allow the pathologist to view the viral components on the slide, much as they use trichrome and other staisn to check for iron and fibrotic tissue.

Most of the occult papers in tn's list analyze hcv rna in cells (liver, pbmc, etc. ) in much the same way as the standard serum-based pcrs. The main difference is that cells are first broken up and total rna extracted. From there, the cells vs serum protocols are similar and yield a quantitative copies/ml (which may be collapsed to a qualitative yes/no).

ISH however works by having stain molecules diffuse into the cells (here those obtained from the biopsy ) and attach to either hcv rna or proteins thus making them visible. This is a variant on a standard bio technique and I didn't know it had been adapted to hcv until Mike called my attention to it. A recent application is here:

http://www.ncbi.nlm.nih.gov/pubmed/16879909

I would suspect the pathology dept. of any large research hospital set up for liver transplants should be equipped to run these techniques and there seems to be no problem doing so on paraffin-protected bx tissue collected elsewhere. Also, these techniques are qualitative and less reliable than standard  rna extraction pcrs.

dd : yeah, I'm a bit puzzled that discusussion of occult tends to be taken as a challenge to the svr = cure equation. As far as I can see, there's no reason not to believe  both are  true.

[mikesimon]

Thanks for helping us understand this subject.
And I agree with your suggestion that SVR can be a "cure" notwithstanding the distinct possibility that occult virus may persist in some, if not most, SVRs. I sure hope so anyway.
And by the way, I didn't call your attention to this biopsy approach, though it is kind of you to say that I did. I asked you you a question and you called this methodology to my attention.  I always try to site my sources so, you get the credit here.
Mike

[Bill1954]

Hi gents; while I’ve caught you both on the same thread, I thought I’d take the opportunity to thank all the participants in these discussions regarding occult/ persistent HCV RNA in sera or other compartments. While this subject is definitely intriguing from an intellectual and probably a research standpoint, I’m still puzzled by the possible clinical applications this matter might represent. Unless it somehow involves unraveling the process of relapse/ non-response during treatment, I’m not sure what clinical applications might come of this topic. It appears to me that no amount of intellectual debate will change the (apparent) fact that SVR continues to remains durable in well over 99.5% of patients as reported in most published, peer reviewed studies that *I’m* personally familiar with.

I have *no* problem with this concept challenging the current view of SVR; I just don’t understand the effort put forth by many here that continue to explore this phenomena. I wish I could contribute more to these discussions; I’m somewhat treatment weary lately, and struggle a little from time to time; I admit that I haven’t been closely following these discussions. If someone could explain the significance of this topic, I’d appreciate it.

Thanks, and have a great day—

Bill

[mikesimon]

I believe that willing's interest - and mine as well - in part centers around the mechanism(s) of relapse. If being serum undetectable means complete eradication then, how do we explain relapse? I have entertained the notion that time spent undetectable might be an important factor (I used to think we could eradicate the last traces with enough time undetectable while still treating) but I have seen too many cases in which a person tested serum undetectable for quite a while only to relapse following the cessation of treatment drugs. I also believe that once SVR is achieved it appears to be durable and if, in fact, there is still replicating virus in at least some SVRs, albeit at very low levels, then this too prompts the question what mechanism(s) accounts for this "control". It is obviously immune system related and that's what we're dancing around in these discussions. I don't think that any of us participants think for a second that we will solve this issue but we are fascinated with trying to gain insight into it. And, in my case, since I am immunosuppressed with anti rejection drugs, it becomes even more fascinating and perplexing. I have come to realize that our immune system is an incredibly complex system and I cannot help but think about it and want to discuss it when new information becomes available. Maybe for me it has a lot to do with being a transplant recipient who is SVR. There aren't a lot of us and I strive to gain even a tiny bit of insight into why people can achieve SVR if, in fact, there is still low level virus in us.
Along this line I found this statement form the article particularly relevant.

"Although occult HCV infection might be beneficial to immunocompetent hosts in whom persistent antigenic stimulation may help keep the virus under relative control,
on the other hand, it might be a source of virus reactivation in certain situations, including immunosuppressive therapy."

I apologize if the discussion of this subject has become tedious but I must say that there are many subjects frequently discussed here which I find extremely tiresome. I try to ignore them and, fortunately for me, that seems to be getting easier and easier to do.

All my best to you Bill,
Mike

[DoubleDose]

I agree with everything Mike said above.  I will add, from my perspective, that the reason why this 'persistent virus' issue holds so much interest, and provokes so much research, is precisely the question of what happens when a low level virus like this is being constantly 'held in check by' the immune system.  I think that many of us, researchers included, are trying to determine if this 'immune system control' contributes to ongoing symptoms after achieving SVR, possibly autoimmune in nature, and also if the low level virus might insinuate itself into other systems, like CNS, immune, or skeletal, and provoke either cytokine immune responses, or even slow, degenerative damage.  All of this may be potential outcomes, EVEN THOUGH the SVR is very durable, and even though SVR might be considered a 'cure' as Mike and Willing have intimated.  I believe we are trying to determine just how 'complete' this 'cure' really is, not just in terms of being durable, which it seems to be, but in terms of 'is there residual damage, or ongoing symptoms' stemming from this low level residual virus?

I think that the researchers make these questions pretty clear in many of the listed papers, and surface their own concerns and questions about this immune system stimulation, and its impact on the body, and in a few papers they ask questions, as just quoted above by Mike, about the 'possibility' of viral reactivation, under some extreme circumstance, etc.

I don't think we should all just 'assume' that this residual virus must be totally 'benign', even if our SVR's are fully durable.  Its like saying someone got rid of Cancer, but did two years of chemo and radiation.  Would we not want to discover what the effects of all the therapy might be?  And with HCV we might want to look at two issues:  The effects of long term interferon use, and the impact of a lingering, reproducing, low level, immune system controlled virus remaining in our bodies after SVR.  I think we need to sort out both questions to determine what each of the above are responsible for, and what the long term possibilities might be.  We want to know these things for any disease, and its treatment, I think.  HCV is no different.

DoubleDose

[willing]

Bill - I hope you are faring well on your  long-distance hike..

all: the concerns DD raises may be quite valid, but I continue to believe the group that should be most concerned with occult/persistent hcv are not svrs but relapsers. In both groups the ifn stimulated immune system was able to keep viral proliferation   at low enough a level to yield serum und for 36 weeks or more. In both groups infected cells remained at eot, yet in one group those remaining infected cell were capable of re-establishing full-blown infection and in the other group not - why?

We know it's not an entirely random process because otherwise the success rate for simple re-tx following relapse would be approximately equal to that of naive tx, while in fact it's much lower.  Is it the number of infected cells, the type of cells, characteristics of the remaining virus or deficiencies in the host immune system? We don't know yet but I believe all relapsers have a stake in following this  area closely.

Why? In the next few years, say by 2015,  it's a safe bet the arsenal for re-tx will include at least ntz, some polymerase inhibitor like r1626 and some protease inhibitor like 750 or boceprevir in addition to soc. Unfortunately, relative to the millions being spent on development of these drugs, I suspect relatively little will be spent on strategies for optimally combining them. Currently, once tx starts, the only controls available are duration and dose. With three or more anti-viral drugs in the mix, additional controls will involve when to take what  and for how long. The more is understood about the population of surviving virus, in particular how much virus is resistant to what, the better those decisions are likely to be.

PS -for those interested in what the stained bx slides might look like,  there's a nice picture of RNA visualization in drosophila embryos in the wikipedia ISH article

http://en.wikipedia.org/wiki/In_situ_hybridization

[Trish77]

A couple of comments on the points you've made, if you will:

"We know it's not an entirely random process because otherwise the success rate for simple re-tx following relapse would be approximately equal to that of naive tx, while in fact it's much lower.  Is it the number of infected cells, the type of cells, characteristics of the remaining virus or deficiencies in the host immune system? We don't know yet but I believe all relapsers have a stake in following this  area closely. "
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Only comment is in this particular part - With regards to your submission that "success rate for simple re-tx following relapse would be approximately equal to that of naive tx" I don't see that.  I keep reading about the acquired resistance to treatment drugs as one goes through tx each time....and those that don't do well on Pegasys doing better on Peg-intron and others doing better on Infergen.  It seems HCV is such an individual thing for all of us, as we can all do the same SOC and yet have very different results from each other.  It seems that if one is a non-responder OR relapser to SOC, the approach is then to do something different next time - double dose for a time, extend, use a different INF, add something else to the mix .. with success for some and not so successful for others.  The question then becomes if one relapses and then SVR's next time around using a different treatment method and stays that way, if HCV immune system is responsible for this, why would another round of treatment work when the same supposed immune system factor remains as the last time?  

Granted, it leaves open the question to those for whom treatment does not work after repeated tries as to the reason why it does not for some people, which is what the balance of your comment is aimed at.  

-----------------------------------------------------------------------------------------------------------------  

Willing:  Why? In the next few years, say by 2015,  it's a safe bet the arsenal for re-tx will include at least ntz, some polymerase inhibitor like r1626 and some protease inhibitor like 750 or boceprevir in addition to soc. Unfortunately, relative to the millions being spent on development of these drugs, I suspect relatively little will be spent on strategies for optimally combining them. Currently, once tx starts, the only controls available are duration and dose. With three or more anti-viral drugs in the mix, additional controls will involve when to take what  and for how long. The more is understood about the population of surviving virus, in particular how much virus is resistant to what, the better those decisions are likely to be.
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I'm not sure I quite agree with little being spent on optimally combining polymerase/protease inhibitors with SOC, being in a 7 Arm trial! :)  

When the Phase II R1626 trial I and others are in has 7 arms, with only one of them that doesn't have the trial drug and the other 6 have various combinations of SOC drugs and trial drug, specifically designed to determine optimal combination.  This is Phase 2b and Phase 2a came before.  Isn't that the whole idea of Phase II trials of Telaprevir and any drug, to determine optimal dosage combinations?  And then Phase III follows afterwards still.  Perhaps I miss your point somewhat?

Trish

[Bill1954]

Thank you all for taking the time to explain your efforts. I assumed that all this was essentially an analysis of the mechanics of relapse, but I just haven’t devoted much time to it. I’ve been on treatment for most of the last three years, and while I find the subject fascinating, it does give me a headache now and then :o). I seem to have developed a rather short attention span lately, so I’m unable to contribute anything of substance. Keep up the good work- it’s appreciated more than you can imagine.

Take care—

Bill

[willing]

my point was that the low sucess rate for re-tx on the same regime indicates that the importance of the  random component can't be very large. Though the mechanism of relapse remains largely unknown three factors that are believed to play a role include viral (what sequences are you dealing with) host (what does your personal biochem look like) and random (roll the dice). The success rate for simply re-rolling the dice is not zero, so the random effect plays some role, but it seems to be the least important of the three.

As you point out, re-tx with a different regime, some variant of more-time, more-ifn and (slighly) different ifn, generally has a better outlook. However, with the exception of cases  where under-dosing is apparent, the absence of any understanding of what led to the relapse makes designing  re-tx approach pretty much a guessing game.  

The quote Mike included above is very much on point. We don't know whether infected cells continue to present HCV antigen, thus leading to an ongoing low-level guerilla action ("persistent antigenic stimulation may help keep the virus under relative control") which, though quite possibly responsible for secondary complications as suggested by DD, enables sufficient control to establish SVR, thus solving the major problem. Relapse may be due to failure of antigen presentation by dendritic cells, as discussed by HR,  which would effectively shut down that low-level containment of infected cell.

With regards to your 2nd point, yes it's true all the new meds are being tested in conjunction with soc. However, I was referring to a suspicion that it'll be a long while before anyone investigates whether your R1626 (+ - soc  ) tx would also have benefitted from inclusion of  a non-Roche drug (say vx or ntz) and at what point.  I also have a nagging hunch that if relapse is in fact due to a failure of infected cells to announce their status via antigen presentation, all the new hcv-targeted meds are likely to play a much more important role at the *end* of tx, not the beginning. In other words, let immune-dependent soc eliminate as much virus as it can, and at the point where it starts to fail to detect residual infection, introduce the hcv-targeted drugs, serine or polymerase inhibitors that don't depend on any immune activity.

[mikesimon]

Regarding your statement: "I keep reading about the acquired resistance to treatment drugs as one goes through tx each time....and those that don't do well on Pegasys doing better on Peg-intron and others doing better on Infergen."
I treated 3 times before achieving SVR. I attribute my success to adequate ribavirin dose my 3rd treatment and extending TX duration but, I took plenty of Peg during my first two TXs to suggest that if interferon resistance was a common effect of exposure I shouldn't have been able to reach SVR. I haven't seen any convincing evidence that treatment resistance is at play here.
Mike

[Myown]

"I haven't seen any convincing evidence that treatment resistance is at play here."

I hope you're right about that. My doctor should know,being he deals with so many patients and he doesn't see that as the problem in my case. I am a problem as far as my immune system it seems, but not the interferon because I wouldn't have been RVR if that was the case.

MO

[GoofyDad]

just to stick my nose it here for a sec: With regard to this stetement:

Currently, once tx starts, the only controls available are duration and dose.

I get you point, and not to split nits, but for anyone treating who may be reading this far down into the thread  - I think it's worth mentioning that the patient does have contol over diet, rest, exercise, weight control, med compliance, and OTC compounds like PPC, all of which may influence outcome.

  

[Trish77]

MikeSimon: Regarding your statement: "I keep reading about the acquired resistance to treatment drugs as one goes through tx each time....and those that don't do well on Pegasys doing better on Peg-intron and others doing better on Infergen."
I treated 3 times before achieving SVR. I attribute my success to adequate ribavirin dose my 3rd treatment and extending TX duration but, I took plenty of Peg during my first two TXs to suggest that if interferon resistance was a common effect of exposure I shouldn't have been able to reach SVR. I haven't seen any convincing evidence that treatment resistance is at play here.
-------------------------------------------------------------------------------------------------------------------
Fair enough, and I should qualify what I mean by "reading".  I am not talking about studies or I would have said as such but also I don't clarify.  I mean simply reading other posts over time and I had a number of people warn me that one of the risks I would encounter if I didn't clear successfully on my drug trial is building up a resistance to the drugs - however, to be honest, it could have been the polymerase inhibitor drug - although I remember it as building up a resistance to any of the SOC drugs.  I thought also I've seen it mentioned here a number of times that each time you treat, your success rate drops.  

Honestly, in your treatment example, I don't see that it conclusively proves the non-existence of drug resistance in my own simple opinion and this is why I think so.  From what I understand, ribavirin and interferon are synergistic.  You increased your ribavirin AND you extended.  While you maintained the interferon dosage, there's no way of knowing if you developed any kind of resistance to interferon OR ribavirin that wasn't overcome with the extra ribavirin and extension of treatment.  Is there?  

Anyway....I should have been more clear on what I meant by "I've been reading" so thank you for pointing that out and giving me the opportunity to do so.  Not a scientific observation by any means, simply one based on what has seemed to be the experiences and opinions of others going and having gone through treatment.

Trish

[willing]

goofy: all true, but whereas factors such as diet and exercise, or for that matter "rescue drugs" like epogen/procrit may  make a huge difference in how bearable tx is and in adherence to dose, I don't believe any have been correlated with outcome (assuming full adherence is met without them).

trish/mike: the issue of "ifn resistance" comes up pretty often. I may be totally wrong about this, and if so I hope someone posts the relevant data, but I don't believe there's support for this. All the new hcv-targeted drugs directly interact with the virus and it's relatively easy for the virus to mutate away from the problem (apparently harder for r1626 than for vx).  Ifn on the other does not directly interact with hcv but stimulates cells via a large number of ancient and general anti-viral pathways. The  existence of chronic infection means hcv was already "ifn resistant" at some level long before tx started and the existence of non-responders indicates that in some host/virus combinations that resistance is much deeper than in others. However I've never seen anything indicating that relapsers on their nth tx can turn into non-responders.

[zazza]

"Tibotec is also conducting a Phase 2 viral kinetics study in Europe to evaluate telaprevir in patients infected with genotype 2/3 HCV. Interim on-treatment data are expected to be available in late 2008."

Found this in a link on HCV Advocate. Thought it might interest you.

http://www.hcvadvocate.org/news/newsRev/2008/News_alert_VX950.htm

[mikesimon]

I gave my history as one example of why I don't believe that interferon resistance is a factor. Of course, it really doesn't constitute proof. I have read members refer to interferon resistance here too but I have never seen any evidence of it. But in my case, when I increased my ribavirin dose to 1000 per day from 800 mg per day I became undetectable by week 12 and remained undetectable throughout the remaining 61 weeks of treatment per Heptimax < 5IU/ml. It does not appear that any degree of interferon/ribavirin resistance resulted from my previous 2 years of interferon/ribavirin treatment and thus your speculation that perhaps I overcame a resistance to interferon/ribavirin through dose and/or duration modification seems extremely unlikely. During my second treatment I did become undetectable quite late in treatment and I relapsed immediately upon discontinuation of TX.
Mike

[DoubleDose]

I do not believe that with interferon the question involves 'development of resistance' at all, but only that each individual has his or her own degree of interferon 'reactiveness' to coin a term.  I think that some need more, some less, and some, the non-responders, seem to need far more of the drug than is given in typical dosing, to show a response.
Some don't see a viral response at all to interferon.

But in just about all cases, just redoing the same therapy usually produces the same result, and same viral reduction curve.  This LACK OF a 'development of resistance' to interferon is what allows slow responders, and relapsers to finally achieve SVR by either going longer, or doing higher doses, or both.  I see no evidence of  'interferon resistance' at all, from the cases that I have seen and read about.  My own case bears that out as well.\

I do think that each individual has his or her own specific 'set point' as in dieting, where the quantity of the interferon must exceed the 'setpoint' in order to be therapeutic, and to get them to undetected, and eventually SVR in a reasonable, doable period of time.  Unfortunately for the very slow responders, that setpoint is often much higher than the average, and may also call for much longer dosing, to get to the final viral eradication point.

Thats my opinion anyway.  

With the inhibitor class drugs, I am also not sure that you would call it classical 'resistance' when the drugs allow viral rebound.  I think that the virus just becomes more adaptive, and goes 'around' the drug, at some point.  That may be a little bit different than classical drug resistance, and maybe it is not.  I am not sure how resistance is medically defined in drug research.

DoubleDose

[willing]

resistance is an important part of the larger question of how to mix and match that is looming for all those waiting to combine multiple stat-c meds with soc. Here’s an excerpt from an editorial by Pawlotsky on publication of (in the same issue) of a study of vx resistance

http://www.ncbi.nlm.nih.gov/pubmed/17680654

“Another study to be published in the May issue of Gastroenterology19 provides a detailed molecular analysis of HCV resistance to telaprevir over 2 weeks of administration of different treatment schedules used in the clinical trial reported by Reesink et al.7 The authors carefully describe the dynamics of HCV quasispecies populations during therapy. They show that relapse related to selection of resistant variants mainly occurred in patients with lower exposure to the drug. Telaprevir had to be administered every 8 hours precisely, at a dose of 750 mg, to induce a sustained biphasic decline in viral replication. A higher dose administered every 12 hours, or a lower dose administered every 8 hours, was associated with frequent relapses or with a lack of second-phase viral decline. Both these phenomena could be due to selection of telaprevir-resistant variants. The principal mutations were V36M/A, T54A, R155K/T and A156S/T/V, and some patients harbored double-mutant populations. Interestingly, however, the most resistant virus (A156V/T) was also the least fit in vivo. The other variants that were intrinsically less resistant to telaprevir had better replication fitness and predominated in the patients in whom high-level replication resumed upon telaprevir administration. After treatment cessation, resistant variants were slowly replaced by the wild-type, sensitive virus.19 Resistance selection with STAT-C is not surprising: HCV bears all the characteristics required for the generation of mutant viruses, including rapid viral kinetics, large population sizes, and a quasispecies distribution of viral populations.20 In addition, antiviral drugs are, by definition, drugs that select for resistance.21 The most surprising finding in the study by Sarrazin et al.19 is the frequency and timing of the emergence of resistance: indeed, it occurred during the first week of administration in 21 of 28 treated patients. These results, together with the recent observations that valopicitabine can select for the RdRp S282T substitution after several weeks of administration, and that HCV 796 selects for the RdRp C316Y substitution in the vast majority of treated patients after only 3 days of administration (Villano S, et al, presented at the 1st International Workshop on Hepatitis C Resistance and New Compounds, Boston, Massachusetts, October 25–26, 2006), suggest that resistant variants are preexisting, fit, and ready to be selected by any specific HCV inhibitor. These findings disqualify HCV inhibitor monotherapy and raise major ethical issues as to whether naive or nonresponder patients should now be included in trials of STAT-C monotherapy, as there is a risk that they will be disqualified from future trials and therapies with drug combinations.”

His observation that resistant variants are “preexisting fit and ready to be selected” was confirmed in a letter published last month in hepatology:

http://www.ncbi.nlm.nih.gov/pubmed/18220300

“We describe here, for the first time to our knowledge, a case of natural presence of the arginine-to-lysine substitution at residue 155 (R155K) in HCV NS3 sequences from a patient chronically infected with HCV, but who never received any anti-HCV drug.

A 39-year-old human immunodeficiency virus (HIV)--seronegative man was admitted to our center in June 2007 for decompensated liver cirrhosis related to chronic HCV infection of presumed old evolution but diagnosed 4 months earlier. Serum HCV RNA was 5.04 log10 international units (IU)/mL (as determined by Cobas TaqMan assay, Roche). Liver transplantation was performed in August 2007, and HCV recurrence was diagnosed 1 month later (HCV RNA, 7.8 log10 IU/mL). No anti-HCV therapy has been introduced either before liver graft or thereafter. The HCV genotype was 1a, as determined by phylogenetic analysis of the NS3-protease coding region sequence using in-house protocols with primers that were chosen using the SVARAP program.[3] Outer primers were MarsNS3F2: 5-ATCACsTGGGGrGCrGAyAC/MarsNS3R1: 5 -AAyTTGCCrTAkGTGGAGTAyGT; inner primers were MarsNS3F3: 5-ACsGCrGCrTGygGGGACAT/MarsNS3R2: 5-GTGCTCTTrCCGCTrCCrGT. Surprisingly, aa Lysine-155 (codon AAA) was found within NS3-protease and confirmed on another serum collected 2 months later (1 month after liver transplantation). Clonal analysis, performed as described,[4] revealed that codon 155-AAA was harbored by 100% of 15 clonal sequences. In addition, after selecting the 100 BLAST hits with the highest score on sequences from our patient (www.ncbi.nlm.nih.gov/BLAST/), we did not find any other NS3-protease sequence that harbors this codon.”

The take-home messages I see in this are (1) the stat-c soc synergy is critical; for ifn non-responders the new drugs may not help that much as they amount to (inadequate) montherapy (2) be careful about when you take the new stat-c drugs. Unlike ifn, they’re effectively a gun loaded with a single bullet. Once you’ve selected the resistant varieties it won’t do much good to take them again.

zazza: thanks! that same editorial by Pawlotsky underscored that the initial vx results were not as dramatic in g2/3 but I think this predated some of the soc fine-tuning. Hopefully it'll turn out to be useful across multiple genotypes.