New Occult Hep C paper from Pham et al

Chronic hepatitis C and persistent occult hepatitis C virus infection are characterized by distinct immune cell cytokine expression profiles.

"Hepatitis C virus (HCV) replicates in immune cells in both chronic hepatitis C (CHC) and occult HCV infection, but the extent of virus replication in this compartment in these opposing infection forms varies greatly. It was unknown whether this could be linked to HCV genotype or to differences in host gene expression shaping the immune response, and whether HCV replication in immune cells is sensitive to endogenous antiviral cytokines. In this study, we uncovered that significantly greater HCV load in peripheral blood mononuclear cells (PBMC), but not in plasma, coincided with HCV genotypes 2 and 3 in CHC, but with genotype 1 in residual occult infection after clinical resolution of hepatitis C. Moreover, PBMC from individuals with occult infection transcribed significantly greater levels of IFN-alpha, IFN-gamma and TNF-alpha, but less interleukin (IL)-10 than those from CHC. In CHC, PBMC with low HCV load expressed significantly more IFN-gamma but less IL-12 than did cells with high virus content. In occult infection, HCV RNA detection in PBMC was associated with much lower IFN-alpha and IL-12 expression. Further, HCV replication in T lymphocytes could be completely eliminated by activation of endogenous IFN-gamma in CHC, but of IFN-alpha in occult infection. In conclusion, CHC and persistent occult HCV infection are characterized by clearly different profiles of antiviral cytokine response in circulating immune cells which are also different from those of healthy individuals. Higher expression of IL-10, combined with lower transcription of IFN-alpha, IFN-gamma and TNF-alpha, is associated with a more robust HCV replication in immune cells."

http://www.ncbi.nlm.nih.gov/pubmed/19215578?ordinalpos=1&itool=Email.EmailReport.Pubmed_ReportSelector.Pubmed_RVDocSum


TnHepGuy

[susan400]

I wish that this would translate into the researchers developing a drug for those of us who seem to be failing at every treatment that's been tried!  AND, I don't want to have to wait another 10 years for that to take place, since I've already been doing treatments on and off since 1997...12 yrs!!!   I'm just a wee bit impatient.  :)

Susan400

[apache1]

Thanks for posting this brand new study from feb 09. It coincides with past studies.

Need some help here guys.
So, not sure I have interpreted this study correctly.

g1 infects the plasma more than g2 g3 which favor residing in the pmbc instead of plasma both AFTER SVR ?

Does it mean only g1 gets the occult HCV and g2 g3 do not get occult hcv ???

confused

apache

[mikesimon]

I believe this is the sentence that you are referring to.
"In this study, we uncovered that significantly greater HCV load in peripheral blood mononuclear cells (PBMC), but not in plasma, coincided with HCV genotypes 2 and 3 in CHC, but with genotype 1 in residual occult infection after clinical resolution of hepatitis C."

I understand that to mean that in CHRONIC HEPATITIS genotypes 2 & 3 show greater viral load in PBMC's but not in plasma. In OCCULT HEPATITIS C genotype 1's after SVR shows the same profile - greater viral load in PBMC's but not in plasma.

I didn't understand it to say that GT 2 & 3 do not get occult virus.

That's the way I read it and, as always, I could very well be wrong. The good thing is that if I am wrong someone will correct me shortly.

Mike

[Bobby1952]

  For us lay people what exactly does it mean ??

I understand that to mean that in CHRONIC HEPATITIS genotypes 2 & 3 show greater viral load in PBMC's but not in plasma. In OCCULT HEPATITIS C genotype 1's after SVR shows the same profile - greater viral load in PBMC's but not in plasma.

??

[apache1]

Thanks Mike. Yes that is the sentence. A lot of info...

For a lowly engineer, that sentence is hard to understand. To me, that sentence needed a little clarification. Still not real sure of the conclusion of this study, or its relevance to us.

=========================================================
In this study, we uncovered that significantly greater HCV load in peripheral blood mononuclear cells (PBMC), but not in plasma, coincided with HCV genotypes 2 and 3 in CHC, but with genotype 1 in residual occult infection after clinical resolution of hepatitis C.
==========================================================

"but with genotype 1 in residual occult infection after clinical resolution of hepatitis C"
This is the only reference I see to SVR
( or in their terms "clinical resolution of hepatitis C"),
and it looks to only refer to  Genotype1.... maybe ?

apache

[mikesimon]

The title of the article and it's conclusion pretty much sums it up - that occult hep c and chronic hep c have different cytokine expression profiles.

Chronic hepatitis C and persistent occult hepatitis C virus infection are characterized by distinct immune cell cytokine expression profiles.
                                              
"In conclusion, CHC and persistent occult HCV infection are characterized by clearly different profiles of antiviral cytokine response in circulating immune cells which are also different from those of healthy individuals. Higher expression of IL-10, combined with lower transcription of IFN-alpha, IFN-gamma and TNF-alpha, is associated with a more robust HCV replication in immune cells."

It's relevance to us is probably purely academic. This article assumes that persistent occult hepatitis is real. We can and have argued about the issue of whether occult hepatitis truly exists. But the topic most vigorously discussed/debated has been: if it does exist what does it mean for SVRs in terms of liver health - ongoing damage -  and health in general and is there the possibility of recurrence or re-emergence of detectable virus.

My personal opinion is that SVR is durable and confers a great benefit and may improve liver histology. I think that is pretty well settled..
For my purposes anything beyond that is purely academic. I suppose it's nice to know that the anti viral cytokine response in immune cells are different for CHC and occult hepatitis but I don't really know what to do with that information

Mike

[Hepatitis Researcher]

here is the conclusion of the authors;

In summary, our study revealed that HCV replication in lymphoid cells in CHC and occult persistent infection is accompanied by evidently distinct expression profiles of the genes involved in antiviral and proinflammatory cytokine responses. Expression levels of some of the genes were found to be closely related to the virus loads in circulating immune cells.

The fact that the gene transcription profiles in low-level HCV infection were different from those of healthy individuals also argues that the virus replicating at low levels in immune cells is not ignored by the cell innate defence but continues to trigger its response for many years after clinically apparent clearance.

Further work is required to determine whether the status of virus replication in immune cells and the expression profiles of the genes induced, including those identified in this study, could serve to predict the patient's response to antiviral therapy and the likelihood of establishing CHC.


My note; this is further evidence that in some SVR this ongoing innate immune stimulation will have the consequence of increased inflammation, over the level that this person would have had, as a simple age related phenomenon, if never HCV infected. There is not much that can be done about this. It most likely serves to stabilize SVR.

[Rockerforlife]

Although occult HCV infection generally appears to be mild, some patients have shown evidence of serious chronic liver injury. In addition, occult infection raises the possibility of disease spread via blood donations, hemodialysis and other procedures. Fortunately, the study also suggests a minimally invasive approach to detect occult infection.


http://www.innovations-report.com/html/reports/medicine_health/report-24439.html

[TnHepGuy_]

Very good to see you here again!  And thanks for taking the time to comment on this paper.

"My note; this is further evidence that in some SVR this ongoing innate immune stimulation will have the consequence of increased inflammation, over the level that this person would have had, as a simple age related phenomenon, if never HCV infected. There is not much that can be done about this. It most likely serves to stabilize SVR."


As 'mikesimon' mentioned above, and what you have stated, this is the practical 'crux' of any discussion re occult: the potential negative effects of having an ongoing immune response to replicative RNA. The price some (all?) SVR's may have to pay to remain so is a chronic increase in their immune system - but at what cost?


So I would ask you (HR) this:

- In general terms, what are the known clinical consequences of patients w/ similar such long-term conditions (i.e. - chronic over-stimulation)?

-  Increases in autoimmune concerns?

-  A lowered or lessened ability of the immune system to properly respond when called upon to do so?

-  Would it be a reasonable assumption that in this particular type of chronic immune response (to occult Hep C) a fibrotic response would not be unusual?


And while there may not be much that can be done in regards to having and 'treating' an overly stimulated immune system, I believe a patient in such a circumstance benefits greatly when knowing what their current condition truly is. Such knowledge can eliminate unnecessary testing, false diagnoses and wrong treatments to symptoms and ailments that might otherwise be incorrectly attributed to unrelated sources.


TnHepGuy

[DoubleDose]

HR, thank you very much for your clarifying comments on this research study.  I also concur with your conclusion, and feel that this post-SVR, cytokine reaction to the now suppressed, persistent virus after SVR, may just be the missing link in our pursuit of just what causes so many post-tx, long term after effects.  Certainly the Interferon itself may be responsible for a good portion, but my contention is that much of the ongoing, and often 'auto-immune' in nature responses that many of us experience, is exactly this phenomenon...a post-tx cytokine response to low level virus.  So we are SVR, but still a little like smoldering coals....or maybe like radio-active, half-life victims....  Thanks for being a part of the forum again!!!

TnHepGuy - Thanks for your follow up questions and comments regarding HR's reply.  I also second your questions!!!  This subjest still deserves much attention, and not to be 'blown off' by those that would prefer to assume that it is a very benign phenomenon...or even a non-existent issue.

DoubleDose

[Rockerforlife]

Im pretty sure a large % people who SVR will go on to live normal lives...providing they dont go on and party like its 1999....my nurse says in her 28 years of treating patients that all are still SVR...and in good health...who knows if the "occult patients,"  (who show the slow  progression of damage) is not caused by life style or even things we dont even know...just my thoughts....ill take the SVR  if a can and from then on....just do the regular check ups for damage...to me im not too worried about no occult bug....yet

[Hepatitis Researcher]

To the questions;
In general terms, what are the known clinical consequences of patients w/ similar such long-term conditions (i.e. - chronic over-stimulation)?

-  Increases in autoimmune concerns?

Very likely in some SVR, but the individual variability precludes definite conclusions for any particular patient:

1. Remnant HCV ("PseudoHCV, since most will be crippled mutants") will vary widely in amount.

2. Innate response to this remnant amount will vary and the types of remnant will matter as well.

3. Any increased innate stimulation that persists is typically followed by counter-regulative measures "immunosuppressive regulatory machanisms' if you will, that are just as complex as the activations of the defense machinery and badly needed for the stability of the organism. Thus the degree of these "response suppressive" mechanisms is itself genetically variable and typically starts to deteriorate with age, that is among the reasons why so many older people are chronically inflamed.
Thus some counterbalance their HCV remnant induced cytokine elevations fairly well and feel good, others suffer dearly.




-  A lowered or lessened ability of the immune system to properly respond when called upon to do so?

Chronic innate induced inflammation is both a call to action for the immune system as well as a reason for exhaustion and chronic molecular damage to the delicate machinery needed to properly and optimally operate the adaptive immune responses. Thus a decrease for example in Bcell diversity can be caused by chronic inflammation.
This is however a very broad concept. For example myocardial fatigue and insufficiency/failure can be hastened/caused by chronic Gingivitis/Periodontitis, because the inflammatory signals sent out body-wide activate the hidden defense system/eg TNFalpha production of the cardiomyocytes themselves, causing long term molecular damage to the contraction machinery. Similar mechanisms are likely at play in the immune system, but much harder to separate in the setting of ever variable activity.

-  Would it be a reasonable assumption that in this particular type of chronic immune response (to occult Hep C) a fibrotic response would not be unusual?
NOT LIKELY, SINCE THE FIBROTIC RESPONSE REQUIRES A FAIRLY STRONG LIVER SPECIFIC INNATE RESPONSE.

Again the actual degree of a system-wide cytokine level elevation caused by HCV remnant stimulation as described in that paper would need to be investigated in each individual by cytokine level measurements, serially, since these tend to fluctuate. Unfortunately these tests are not yet well standardized and the prime example, TNF alpha, is not even typically used by rheumatologists to test their patients before initiating anti TNF alpha therapy - which is used in increasing numbers lately for various immune mediated disorders.

[DoubleDose]

You just commented on something which connects with another problem which I have developed in the past year, now that I am 5 years post-tx, and SVR.  I have developed Peyronies Disease, which is in effect, a fibrotic, or scar tissue affliction in the penis, causing a curving.  In recent research studies published by the Urologists Association, it seems that increased levels of circulating cytokines, and specifically TNF-Alpha, have recently been correlated to a very high degree with those who have Peyronies.  This is a disease with no currently understood cause, and only lately is getting lots of research attention.  Of course, I have to consider my post-tx auto-immune reactions, and plethora of symptoms after SVR, in thinking about the potential catalyst for this Peyronies condition.  I am certain there is a relationship.

My question to you is:  Should I consult with a rheumatologist about the TNF-Alpha therapy that you alluded to, as a possible treatment for the Peyronies???  If an increase in this cytokine is indeed responsible for the PD, as some new research suggests....might there be a way to mitigate this ongoing imbalance in TNF-Alpha???

Your comments above really 'turned on a light bulb' for me.  I would bet quite a large sum that my cytokine levels are grossly out of whack since treatment, just by the numerous autoimmune like sx that I seem to display.

Thanks for any thoughts you might have on this possibly related issue!!

DoubleDose

[Rockerforlife]

Dont know if this is any help,but there is a natural product out there that modulates and balances the immune system....its called 'moducare"

[Hepatitis Researcher]

While TNF alpha might have a role in the progression/promotion  of Peyronie's disease it does not seem to be the primary player. This fairly frequent syndrome (5%) might be caused by a genetically predetermined propensity of excessive TGF beta expression under conditions where the body tries to heal by scarring even minor traumatic injuries. Thus minor traumatic injuries to the tunica albuginea are responded to with excessive progressive scar tissue formation. TGF beta is a critical 'cytokine' or tissue hormone that acts to "heal" injuries by promoting scar formation

Certain cytokines levels will have a promoting role in that setting, however the effect of inhibiting specific ones like TNF alpha is hard to predict and you will have a difficult time finding a doctor prescribing one of the TNF alpha inhibitors for this purpose, since regression is - even if there is a positive effect- going to take substantial time. There will also be the argument that TNF alpha inhibitors shall not be used in patients with hepatitis, even if SVR, I presume.  There is literature describing an inhibitory effect of trans Resveratrol on TGF beta expression and Curcumin might be useful in reducing the intensity of the profibrotic pathway signaling that results from increased TNF alpha levels, but of course there are no trials to prove any effectiveness of these in this particular disorder.

[geterdone]

Laymen here,

So what you are saying is that while treating the virus with high doses of interferon these strands of RNA are cleaved up, but all are not totally destroyed by the t cells and are floating around in the peripheral blood and organs and are still giving off a signal in a mutated state by which the now altered natural interferon is still attacking anything with its signature in an undetected state?

Could it be that during the duration of treatment with the synthetic interferon and its “additives” that it by some chance altered the natural gamma interferon from its natural state in which it has left it in an overstimulation state there by causing just as much long term damage as the virus itself but on a lower chronic level?  

jasper

[DoubleDose]

Thank you so much for your informative reply.  You have provided more specifics and insights on how PD works than the specialists that I have seen.  I may conduct my own trial with the Curcumin over a long period.  I have already added daily Vitamin E, Acetyl-L-Carnitine, Primrose Oil, L-Arginine, L-Citrulline, and assorted other supplements, for the last nine months....and am seeing some slight improvement which may or may not be a result of the supplements.  Thanks again for your interest.

DoubleDose

[geterdone]

Laymen question here and maybe on the boarder of deep space but here goes.

Can the in coded gamma interferon and immune system changed over time to be stronger in fighting the virus as it evolves and changes its tactics to evade the immune system?  Does the immune system become even stronger while fighting the evasion or is there a Plato which is reached and the immune system is unable to get stronger?

If our immune system has been fighting this virus for the last 20, 30, 40 years and the immune system is “adaptive” to the ever changing tactics and evolution of the virus with in our bodies and the immune system gets stronger as time goes on while fighting the virus then the immune system has to change also to meet the needs, right? Then when the synthetic interferon is added to that for a long duration, what happens when the synthetic interferon is gone and the gamma interferon dips below the natural threshold what ever that may be because I am sure it has lost its original coding level of 20, 30, 40 years ago. So is it possible that the new level of the gamma interferon after the prolong use of the synthetic interferon has changed or altered the immune system to a higher level than that of a more suitable level for our biological needs and if this is the case, would it be more sensitive to pick up on the signaling process of the persistent mutated virus causing it to stay in the attack mode causing much of the post treatment symptoms experienced?

jasper

[Hepatitis Researcher]

The molecular structure of the natural Interferons does not change or adapt with time. The huge functional network of cells that produce IFN and numerous other molecules that interact with virus infected cells changes, becomes more activated with external Interferon added. HCV producing cells then die off in huge numbers, some might be cleared of the virus without cell death (noncytolytic clearance). At all these phases the large number base of the virus will contain certain variants that are less visible to the critical Tcell response by having, by chance, changed their critical recognition epitopes. Such mutants, albeit much less fit, might be able to survive the immune elimination process, but have lost their power to rapidly replicate or turn off the innate responses in the cell that they infect to some degree. Thus some very slowly replicating and otherwise functional incapacitated HCV mutants will stay in the system, but elicit enough recognition to trigger the production of cytokines in the dendritic and macrophage cells that they still infect. This is essentially the finding of the above paper. But this cannot be interpreted as a now stronger immune system. It is a response to a remnant antigenic trigger.

[geterdone]

Appreciate the follow up and as with the rest here and glad to see you post, Thanks! I do have one additional question that being does polyethylene glycol, ethylene glycol used to extend the half life of the interferon have any adverse effects on the body long term or is it in such a low state that there are no effects to worry about?

I am one year post as of March 12th and considered a SVR’er < 2, < 2, and < 5 insurance change, lol! For me, the taper worked tho slightly modified, thank you!

jasper

[Hepatitis Researcher]

The Polyethylenglykol (PEG) that is attached to the IFN molecule exists in minute amounts only and you can expect no negative effects from it.

[apache1]

HR, got a few questions, if you got the time.

How large does this mutant occult infection does it take to elicit cytokines response ?
Or will one incapacitated HCV mutant viron in one dendritic or macrophage cell make that cell produce cytokines.
And how much cytokines production does it take to effect a patient ?

What was the significance of the genotype differentiation in the above paper ?

Is it possible for occult mutant infection to blossom into a full blown HCv infection ?
Or is it probable to intermittently test positive at very low levels (50 IU/mL) then negative on a follow up test from remnant replicating occult... all years after SVR,  ?

Sorry for all the questions HR, I find this part of microbiology extremely fascinating. And you have a way of making a laymen understand. I really appreciate you being here for us.

Thanks
apache

[geterdone]

Recht schönen Dank!

jasper

[alagirl]

this is further evidence that in some SVR this ongoing innate immune stimulation will have the consequence of increased inflammation, over the level that this person would have had, as a simple age related phenomenon, if never HCV infected. There is not much that can be done about this. It most likely serves to stabilize SVR.
-------------------------------------------------------------------------------------------------------------
Fabulous.

Good to see you btw

[willing]

thanks for posting the article and for the interesting  discussion. I'm a big fan of the work being done by Pham and others at the Michalak lab. The overall conclusion from their data, borne out by many others, is that  SVR is simply a different and stable equilibrium point in the struggle between virus and host. While much of the rest of the research community seems to have decided that this is not an interesting area of research, Pham has been systematically exploring the parameters of this new equilibrium.
The main point of the article was comparison of expression levels between chronic and residual infection, but the comparison with healthy subjects is pretty striking. Cytokine activity in PMBCs reminds me a bit of those stories of isolated Japanese troops fighting long after the end of WWII - no one's told them the war's over. Among the 6  cytokines,  3 IFN-induced genes and 4 CD proteins whose mRNA they quantified, statistically significant differences between healthy and chronic-HCV subjects showed up in four: IFN-a, IP-10, OAS, and CD19. So what happens after chronic infection is resolved (either spontaneously or through SVR)? Of the four, only  OAS returns close enough to normal levels that the differences are no longer significant.  The health effects, if any,  of the continuing elevated cytokine levels seem likely to remain unclear for a long time to come and none of this diminishes the good news in
http://www.ncbi.nlm.nih.gov/pubmed/19072828
but it's interesting background, and what's special about OAS?

The other major news here, poorly summarized in that unhappy sentence in their abstract, seems to be that genotype  plays a significant role in determining viral replication in immune cells and post-resolution infection. While for g2/g3s the ratio of plasma to pbmc vl looks similar pre/post SVR, with the major difference being the reduction in volume of vl from millions of copies/ml to mere tens, for g1s that ratio is reversed with higher pbmc infection, relative to plasma, post svr. Maybe  g1 virions  reproduce relatively poorly in pbmcs (relative to hepatocytes), but those that do manage the feat are more tenacious post tx?


HR: once again this paper shows a very clear effect of mitogen and PHA/IL2 stimulation of PBMCs on measured HCV RNA. On the other hand, papers like
http://www.ncbi.nlm.nih.gov/pubmed/18593587
which argue for eradication, have not applied this step in their protocol. Any thoughts on why? Even if the stimulation is non-physiologic it seems to be essential to measuring low levels of replication.

[TnHepGuy_]

Thanks for all of your thoughts and comments on this paper. I, too, am fascinated by Pham's work in this area. He is a virtual lone wolf (along w/ Castillo et al) in the area of occult/post-SVR research - and I, for one, certainly hope his funding continues into the future and other researchers begin to pay closer attention.

HR - I know this is purely speculative, but I hope you don't mind if I ask your thoughts here:

- What are the possibilities of occult SVR's being able to transmit the virus?

- And if the majority of occult infection is made of 'unfit' viral remnants, how might the immune system of an uninfected individual who became exposed (via transfusion, IV drug use, needle stick, etc) respond? Would you expect their immune system to 'trap' and treat it in the same way - creating a low level 'balance' with a chronic infection remaining? Or might a healthy immune system be able to fully 'knock back' the occult infection to the point where negative strand replication no longer takes place?

And on a personal note, as a post-SVR (4 years and counting), I was wondering what immune enhancement supplements you might think be in order for someone who: a.) may be experiencing negative effects of post-peginterferon exposure, and b.) could possibly be occult-positive. Thank you.


TnHepGuy

[DoubleDose]

If there is a more fascinating, important, and yet-to-be fully understood aspect of HCV infection and treatment than the Occult/Persistent viral infection research that is being led by Pham, Castillo, etc. then I would love to hear about it!!

This research could potentially answer many questions about how the immune system works in chronic viral infection, and what different forms of chronic infection might mean to the person who is affected by them.  Our simplistic view of SVR meaning "gone baby gone' will probably be replaced by a newer version of some sort of 'viral stasis' in the body, with a host of consequent symptoms, reactions, and internal system alterations reflecting these ongoing attempts at maintaining viral stasis.  

This is exactly why I think we often see the random Post-TX, Post SVR PCR test that comes back in the 40 IU, 60 IU, 90 IU viral load range.  Possibly not a false positive at all, but just the body figuring out how to permanently keep the residual virus under control, and under the current limits of detection.  Too many of these odd, very low level PCR results occur to just be 'false positives!', at least I believe this is the case.

The occult/persistent research also forms a basis for many of my intra-familial observations over the years, where I believe that I have seen typical "HCV extra-hepatic" symptoms in family members, and former partners, who do NOT test positive for the virus.  Maybe the 'cytokine reaction' to having come in contact with spurious HCV virions in saliva, sexual fluids, etc. over many years of contact.

Maybe there is a 'cellular based' occult viral infection that takes residence in others, in salivary glands, sexual organs, or even systemically in CNS, but just like SVR's is always held to a very minute, sub-detectable, and maybe localized infection....nonetheless, triggering continuing cytokine reactions in the host...thus causing a range of observable, and chronic HCV-like symptoms!!!  This form of infection might never trigger humoral cytoking reactions, and thus the blood based anti-HCV tests would always produce a Negative result!  Although there have been a few research articles alluding to this scenario, there has been little interest overall in pursuing these subjects in the wider HCV research community.

You could project this possibility out into the general population, and see how a sizable portion of the population could be impacted by this 'cellular level infection' thus causing an increase in many of the unexplained health trends that we see today in the populace.  Far more chronic inflammatory, allergic, hypertensive, diabetic, depressive, cases, etc. than ever before in history.  I know, its just the fast food chains causing all of it!!! ( I don't buy that theory at all.)

Thanks to all of you for keeping an important issue front and center. Thank you HR for your scientific and clinical input, and professional demeanor.   Occult and Persistent HCV, and Post SVR viral status are the next generation of HCV challenges that need to be met head on, and fully understood.  The implications might be more severe than currently believed, and of wider impact than we suspect.  Sorry for the divergence from the main issue, in my tag-on speculative commentary, but I think there is a connection, so I will continue to discuss my concerns.

Best wishes to all of you!!!

DoubleDose

[Hepatitis Researcher]

"   once again this paper shows a very clear effect of mitogen and PHA/IL2 stimulation of PBMCs on measured HCV RNA. On the other hand, papers like
http://www.ncbi.nlm.nih.gov/pubmed/18593587
which argue for eradication, have not applied this step in their protocol. Any thoughts on why? Even if the stimulation is non-physiologic it seems to be essential to measuring low levels of replication

Well if you think friendly you may argue, that they only wanted to check for Vl levels that are of any relevance..

If you are critical you could say that the inconvenience or unavailability of the stimulation procedure in their labs or the places where they send the material for testing was the real cause for not using it.
It has to be clarified that the stimulation by itself does not produce false pos results, but holds the capacity to enhance extremely minute amounts to the level of very small amounts, possibly by providing enough of the transcription and translation co-factors that the unfit virus needs to manage a few rounds of replication in an otherwise non-conducive cellular environment...
We must keep in mind that "infection" of dendritic cells and macrophages by viruses is not a surprising phenomenon limited to HCV. After all these cells need to take up all those infectious particles intracellularly, so as to present their epitopes to the lymphocytes that need specific education and stimulation. Somehow they manage not to become breeding grounds of virions themselves, again quite an essential feature considering their role in the defense process.

[Hepatitis Researcher]

"    - What are the possibilities of occult SVR's being able to transmit the virus?

Most likely negligible, since not even full blown VLs with fit virus in the 5o Million/ml range are very transmissible in the sexual context.


"- And if the majority of occult infection is made of 'unfit' viral remnants, how might the immune system of an uninfected individual who became exposed (via transfusion, IV drug use, needle stick, etc) respond? Would you expect their immune system to 'trap' and treat it in the same way - creating a low level 'balance' with a chronic infection remaining? Or might a healthy immune system be able to fully 'knock back' the occult infection to the point where negative strand replication no longer takes place? "

Such an infection will probably not take hold to any degree that matters. It has become a "non-pathogenic' virus, a lame and tame dog out of a Wolfe....

Questions like that will also have a very low chance of being investigated, since they are very difficult to examine and have a clinical impact too low to matter in a world filled with more obvious diseases and dilemmas.

[willing]

HR : many thanks for clarifying that point - I had been wondering for some time whether this could be construed as  introducing contamination; interesting that though detection via lab protocols is quite challenging, the infected cells, as evidenced by their ifn-a expression, seem to have no such problem

all: Here's a quote re occult from D. Nelson, a speaker at a recent HCV CME roundtable, posted by Mike a while back:
"If you look though at low-level persistence in a number of these articles, as a clinician there are a lot of perplexing issues that just do not make sense. So you have to ask yourself, is this clinically relevant? We have all had patients that are cured who developed a cancer and get chemotherapy; they do not reactivate hepatitis C. Patients who are undergoing transplant do not reactivate hepatitis C. So if there is a reservoir, it does not appear to become reactivated under the classic reactivation scenarios. Histology improves in almost all patients, and as we showed the negative outcomes are dramatically reduced, and transmission has really never been documented in the post-SVR state. I think to try to bring these 2 pieces of information together, there has been a lot of concern that this has not been well-validated data. We really cannot find the virus protein very often and it brings up the only way that this could really exist is you would have to envision a defective hepatitis C replication that is at such a low level that it is not picked up in most patients. So it is a challenging but I think more likely a nonexistent issue."

this seems to echo a viewpoint many here have heard from their drs. on this topic.  The above paper doesn't contradict this view but suggests a possible cause  for post svr inflammation-related issues. The interesting point, IMHO, is how the virus (permanently) lost its groove, falling from superfit to  barely tolerated has-been.

[jmjm530]

Wow, for anyone reading who has been around, that post of yours is quite a turnaround :) Of course, I'm one of those whose t doctors have said for years that these studies have no clinical relevance and whatever may have been found is not viable virus that should cause any alarm. In fact, I've quoted Nelson several times on this from the C.C. Options web site where he has addressed the issue several times.Your response has always been that you're less interested in opinions and more in the study data. Apparently, HR's opinion has swayed you more than that of other eminent hepatologists, so be it. Must say, his "lame dog/wolf analogy" is great and I plan on stealing it (with attribution of course :)

-- Jim

[apache1]

Yes Jim, I agree 100% on  HR's "lame dog/wolf analogy".

I got a better understanding of the virus/immune systems ongoing war, from HR's 'crippled mutated viron like a vacuum cleaner with out a handle' analogy in his past post about virus mutation making virons undetectable to our Dendritic cells and Macrophages.

HR's explanations of microbiology lets laymen like me get a better idea of what is really going on in papers like this. Is HR also a professor/lecturer at Universities ?

apache

[willing]

sorry to disappoint, but there's no turnaround. I quoted Dr. Nelson above because it was a good summary of what many here have said they've heard from their Drs, as you have, and I believe it probably represents a 'prevailing view'.  To argue that there's available evidence of significant health effects from residual virus would be a hopeless task and I've never heard anyone make that claim (though there are spotty case reports here and there about cryo and elevated alts).

What I *have* argued about in the past, is dismissal of  post-svr virus as a spurious artefact (contamination, sloppy pcrs, it's not viable, replicating virus, etc. ); there's simply too much data, as tn has documented, for that to be a likely explanation. As to health effects, the issue remains open, and this paper in fact provides evidence that the residual virus *does* affect the cells it infects, though it's pretty clear by now those effects can't be as serious as those facing non-SVRs.

Unfortunately, many discussions on this forum tend to argue for black and white extremes (tx is/is-not good; alcohol is/is-not permissible; occult virus does/does-not exist). When Pham's first paper appeared in 2000 there was considerable stress and skepticism over his find;  accumulating evidence since then has shown he likely was right, yet SVR is still a cure.

Also, loss of viability because of mutation in the virus (the wolf->chihuahua analogy) is an attractive hypothesis but as far as I know it is still hypothesis - there's no sequence data for residual virus nor has anyone yet extracted it and monitored it in a replicon system or tested infectivity in chimp (which seem like  straightforward experiments to try). It could be that suppression of the virus is largely due to host factors (the wolf is still a wolf, but kept under control by high-powered ammo). Given the error rate of the hcv polymerase,  it wouldn't take too long for that chihuahua to start growing fangs again, but that doesn't happen.

[DoubleDose]

Thank you for your clarification of what you were actually saying.  Our comments are often taken out of context, or used to prove something we did not mean at all.  I happen to agree entirely with your post, and feel that there is absolutely NO proof of just what this residual viral infection really involves.  ie.  is it a twisted, crippled, badly damaged mutant virus that is totally benign?  if so, why would it continue to exist and replicate over the years?  How do we know it causes no harmful effects?  Have there been long term studies?  OR, could this remaining, replicating virus be exactly the same form of virus as in the chronic, active infection, but simply now held under immuno-suppression tightly by a now-trained immune system?  We just don't know yet.  And, in deference to HR, I respect his opinion that the virus is a mangled mutant form, but I still do not see the real-world research confirming this to be the case.  Is this residual virus infectious under some circumstances?  Let's find out...using chimps and direct blood injections, to see if they  either  develop a chronic active HCV infection.. .or if they develop a 'persistent, low level, infection, similar to what we are left with...or if they develop no indication of any virus at all.  It would just be nice to know what the infectious potential is for this remaining persistent virus.

I also really do NOT believe that we have seen any solid evidence yet that there are definitely no possible health consequences for this persistent virus, and in light of the recently posted study on demonstrable cytokine response changes in SVR's, with persistent virus, it seems that we might want to better understand what that will mean for our health and well being.  Just because something is subtle does not mean it won't eventually kill you!  The tobacco companies still claim that smoking is not proven to kill you.

I have frequently raised an eyebrow at the post-SVR, low level positive PCR's test results that seem to sometimes occur, and that many on the forum respond to by ASSUMING that they must be false positives...and that a follow up negative PCR proves that position.  I disagree, and feel that the post-SVR positive PCR's that we see, can be more easily explained by the persistent virus research model, and our more recent understanding of what happens during and after SVR.  If the immune system is becoming trained to keep a permanent 'lock-grip' on the virus, then the early period positive PCR's may just be reflective of that final process, and adjustment period.  But, to assume that they mean nothing, or must be false test results, is not very scientific, nor logical.

I still believe that the terms Persistent, and Occult are used confusingly, and inconsistently by different researchers, and that they need to clearly define what each means.  If they want them to be synonomous terms, then say it.  Some articles claim Occult to be an active ongoing liver infection, without a positive PCR for the blood.  I see that as very different than post-SVR persistence.  I think the researchers each use their own terms, and interpretations for different situations, thus causing a lack of clarity.

Overall, I am in favor of MORE understanding, and knowledge, thus more research, rather than to gloss over these issues, claim that they are of little importance (we just don't really know that yet), and then just go on assuming everything is just fine.  Persistence MAY end up being a small, benign issue...OR...maybe something more serious.  Claiming that we know the answers yet, is way premature.

DoubleDose

[willing]

agree that the alleged false-positive rate one sees on this forum immediately post-eot seems a bit suspicious. From a recent test evaluation paper
http://www.ncbi.nlm.nih.gov/pubmed/18692434

the specifity of roche's taqman2 came in at 99% and the older monitor v2 at 100%. I assume other tests have a similarly low false positive rate, yet reports of  post-eot vl among those who later reach svr seem more frequent than that.

As to the health effects of persistence, my impression is that there are very few researchers and  little funding. Even Pham/Michalak seem more interested in the issue from the perspective of  virology than because of any possible clinical impact.