Two-Day Results Predict Ultimate Response to Therapy in Chronic Hepatitis C
Two-Day Results Predict Ultimate Response to Therapy in Chronic Hepatitis C
A new study suggests that previously noted low rates of successful hepatitis C virus (HCV) therapy in African Americans are in large part due to very early differences in the antiviral activity induced by interferon. The study is published in the April 15 issue of The Journal of Infectious Diseases, now available online.
More than 3 million Americans are infected with HCV, and in some countries more than 10 percent of the population is infected. Chronic HCV infection is the leading cause of liver failure worldwide. Response to standard therapy with peginterferon and ribavirin varies widely. Those infected with one strain of the virus—genotype 1—are the least likely to have a successful response to therapy, known as a sustained virological response (SVR). About one-half of patients infected with genotype 1 do not achieve SVR.
Studies have shown that African Americans have consistently lower rates of SVR to interferon-based therapy, compared to Caucasian Americans. A recent study of those with chronic genotype 1 HCV infection found that only 28 percent of African American patients attained SVR, compared with 52 percent in Caucasian Americans. This new study shows that the variation in therapy responsiveness between African Americans and Caucasian Americans can be partly explained by differences in viral response noted as early as one to two days after the first dose of peginterferon.
The study, conducted by a collaborative group of eight medical centers throughout the United States, monitored 341 patients with chronic HCV, genotype 1, who underwent therapy with peginterferon and ribavirin for at least 24 weeks. It focused on response rates to interferon therapy within the first 28 days of therapy, noting viral factors such as HCV RNA levels and host factors such as race, gender, and weight.
Results showed that HCV RNA levels decreased in almost all patients, and that the degree and pattern of decrease, as expected, was different between African and Caucasian Americans. Most important was the new finding that these differences were statistically significant by day 2 of treatment, and that this early viral kinetic measurement was a reliable predictor of ultimate SVR rates. After 28 days of treatment, 22 percent of Caucasian Americans, but only 12 percent of African Americans, were HCV RNA negative.
These findings are particularly important because they point toward the presence of some block or defect in the immediate antiviral response of those who do not respond to therapy. As the authors summarize, “The underlying cause of virological non-response and the reasons why it is more common among African Americans than Caucasian Americans are not clear. [But] the current analyses demonstrated that these differences are fundamentally biologic and become apparent within 24 to 48 hours of starting therapy.” As a next step, future research should focus on these host biologic factors that are induced by interferon in an attempt to improve therapy response rates.
In an accompanying editorial, Andrew W. Tai, MD, PhD, and Raymond T. Chung, MD, of Massachusetts General Hospital agree that the findings will prove vital for future research into HCV, remarking, “[this study] demonstrates that the low rates of SVR in African American patients in response to IFN-based therapy appear to result, in large part, from impaired early viral kinetics. Further studies are necessary to uncover the relevant mechanisms that underlie this defect in IFN signaling… with the hope that such mechanisms can be manipulated to restore interferon responsiveness in the otherwise nonresponsive host.”
Founded in 1904, The Journal of Infectious Diseases is the premier publication in the Western Hemisphere for original research on the pathogenesis, diagnosis, and treatment of infectious diseases; on the microbes that cause them; and on disorders of host immune mechanisms. Articles in JID include research results from microbiology, immunology, epidemiology, and related disciplines. JID is published under the auspices of the Infectious Diseases Society of America (IDSA). Based in Arlington, Va., IDSA is a professional society representing more than 8,600 physicians and scientists who specialize in infectious diseases. For more information, visit www.idsociety.org.
I won't be shocked if we shortly have a study posted on the prevleance of diabetes and/or IR in the Afro American population LOL and honestly do not know if that was screened out or not. But the other point, is once again the importance of very early viral kinetics in the treatment process.
Actually Jim, Latinos have a higher response rate to treatment than African Americans but also have a significantly higher rate of IR/Diabetes. Studies are just starting to appear regarding some of these differences.
I need to clarify....just looked at my notes. It is latinos from Puerto Rico that have the highest rate of type 2 diabetes, about 14% diagnosed. African Americans have approximately 11.5% when both genders are looked at.
??? I'm confused. Are you saying you posted a study in this thread and had it deleted? Well, my ex-girlfriend told me I had certain powers, but one of them is not the ability to delete posts on a forum I do not run. Nor did I contact MH to remove any post regarding diabetes? Why would I. If you had a post deleted, the appropriate thing would be to contact MH and ask why instead of throwing allegations around.
I said previously: "....if that was screened out..."
Maybe the phrase above is what disturbs you? I was not talking about a post being "screened out", I was talking about IR/diabetes screened out of the study. In other words did the study screen out IR/diabetes as an active factor in the study. You will note that in my next post I mention that apparently that is not the case and posted the full-text. I think you had best read a little more carefully or ask for clarification before jumping down someone's throat.
And btw the person I was referring to who in terms of "we shortly have a study posted" was not you, it was CO (she has posted before on IR and Afro Americans) and it was a lighthearted joke with no offense intended to her and absolutely no reference to you.
Apology accepted and frankly I have no idea why that post would have been deleted. We post links all the times here to studies. In fact, I just did earlier. LOL. Do us all a favor and nicely ask MH why they deleted your post and let us know. No harm. No foul. Let the band play on :)
Is it possible to discuss the other matter in a new thread and keep this one on topic. It's a good topic and I really don't feel like reposting everything because this thread no doubt will be deleted the way it's going.
interesting does that mean we should get a viral load test after the first week of tx to see how we respond sorry I did not read the link but that would seem resonable to have a test done on the onset of the treatment for possibilities or am I not understanding
Most studies still revolve around the week 4 test in terms of predictive power. That said, smaller studies have been coming out of years where testing has been done as early as 24 hours after the first injection and indeed I believe some of the PI trials test that early but not sure. This study deals with DAY 2, not "week 2" . FWIW when I treated three years ago I tested for viral load weekly from week 1 until I was UND at week 6. Very few here test that often but my doc suggested it and frankly I was thrilled he was being so thorough. And frankly, if I had to treat again, I'd probably ask for the both the 24 hour test as well as the day 2 test as well, but this does not mean it would have a solid current clinical signifcance nor am I suggesting anyone test viral load other than week 4 or weekly until UND if they really want to follow things closely.
At my first meeting with my Gastro, he told me what the SVR percentage rates are. Later he told me that African Americans have a lower SVR percentage than Caucasians. I asked him if the SVR percentage rates are based with African Americans and Caucasians lumped together, he said yes. I asked, “If this is the case how can this percentage rate be accurate? He looked at me with “the deer in the headlight look”.
Jim, what has me confused is that I was always told Gen.1 SVR rate is 50%. This study shows African Americans have a 28% chance while Caucasians have a 52% chance. If the old studies have us lumped together, by separating the statistics it seems that 52% is low. I am not being argumentive; it is just that the numbers don’t add up. Unless the old studies do not have us lumped together and African Americans were excluded.
I see your point and it may be that Afro Americans were under represented in the previous studies, really dont know and btw I never thought you were being "argumentative" and hopefully I did not come across that way.
It might make sense anyway, as the whole population is not only based on African Americans and Caucasians... They don't mention Asians. Asians seem to have better SVR rates than Caucasians.... And then % wise, there are more Caucasians than African Americans, so it is not 50 / 50, if you guys know what I mean. I'm not very good at expressing myself these days, as tx seems to be making me more and more stupid...
"I see your point and it may be that Afro Americans were under represented in the previous studies, "
I've written on this topic here before and that is indeed the reason. In fact, the participation rate of Afro-Americans in clinical trials is extremely low and as such doesn't skew numbers in any significant way.
For an explanation for low enrollee rates in clinical trials by Afro-Americans Google "Tuskegee Experiments".
At first, I wrote off you comment to that sharp cynicism that in part makes you "Mr. Liver". But a quick "google" shows some truth although as I suspected minority participation in trials is more complex with socio/economic factors at play. This does however appear to confirm some of the number(s) discrepancy that has been discussed.
I recall an article from at least a year ago which also stated that a 48 hour test can be highly predictive. I don't have the time to search for it now but I am sure that I read it and I likely have it somewhere.l
For the record, I don't believe I have ever responded to a post of yours with cynicism, or even skepticism. Not that I wouldn't if I had reason to. lol ;)
It's been shown that socio-economic factors are directly correlated to HCV infection for all ethnicities. I can't remember all of the stats but those with HCV are in general poorer, less educated, more likely to abuse substances, and come from dysfunctional families significantly greater than the population-at-large.
I'm not sure how these facts would influence minorities more than caucasians when it comes to enrolling in HCV trials. It is somewhat counter-intuitive that those with the least amount of medical care and financial resources wouldn't take advantage of the free medicines and monitoring that a trial offers.
Many African-Americans that I have interacted with over the years concerning HCV have expressed horror at even the simple mention of enrolling in a trial. Some remember Tuskegee----or have been raised by those who do and the spectre of a trial (especially one funded or controlled with the help of the US gov't) has produced a lingering fear that is a quantifiable cultural phenomenon. I have known a researcher with SP for years. She helps to develop trials and has often mentioned over the years how hard it is to get minority participation especially amongst African-Americans, this despite earnest attempts to recruit this population. As a company that sells medicine they would love to have much more data on a segment of the population with high prevalence rates.
It's my belief that the lack of data pertaining to the HCV tx of African-Americans can only be overcome by allaying the fears and sense of mistrust of those who remember Tuskegee or waiting until the clouds of time obscure their collective memory.
I can't believe we did this to US citizens while at the same time we were trying to hunt down Mengele. (Gratuitous cynical remark) ;)
Jim its always nice to see you post and I too hope all is well where you are.
You're right, we've always been cool, and good to see you posting as well.
Other than the Tuskegee Horror, to help reconcile the "counter-intuitive" nature of minority participation, I do remember a study/survey -- something -- a year or so ago that showed that minorities were more apt to be sent home from the ER as opposed to non-minorities who might have been given a hospital bed and therefore more enhanced care. And for the same diagnosis. So I do wonder if perhaps a prejudice, subconscious or not, exists within the medical community that may give preferential trial assignments to non-minorities.
Another factor no doubt is that because Afro Americans have a significantly lower SVR rate, many trials may have excluded them on that basis because the results would be skewed differently.
Miss Evers' Boys (1997) Excellent movie about the the Tuskegee chronic syphilitics experiment. It's an HBO produced drama and very compelling. Stars Alfre Woodard, Lawrence Fishborne. I saw it again a couple of weeks ago, worth watching if you can access it somehow.
I think the current speed record for predicting whether it's likely to work is a recent, rather remarkable (and free access ) paper out of the Heim lab
By collecting bx tissue four hours after the 1st ifn injection and analyzing expression levels of ifn-stimulated genes in liver cells they were able to clearly distinguish rapid responders from non-RRs (See Figure 4 on the 3rd page of the paper).
Of course there's also a growing number of tests that will tell you *before* that 1st shot, but that seems like cheating.
I vaguely remember the four-hour paper, but the 24 and 48 testing predictors have been around for a few years. Too bad more research isn't poured into that because it could probably help tailor plans very early-on and/or significantly limit one's exposure to the drugs if the test comes out with an unlikely to SVR result.
Now think about it. You do the four-hour or 24-hour test on regimen 1. The result is not very promising, so you stop treatment. Maybe wait a month and then try ad different combo of drugs, regiment number 2. Still not promising. You wait another month and now try regiment number 3. Voila. You found the magic coctail for this particular indivdual. Of course this would mean that docs and their busy offices would actually have to think and plan as opposed to write rx and quickly hand-off patients to nurses running a mill. Still...
A couple of years ago, in the Prove 1 and Prove 2 teleprivir trials (in the tx era of Mremeet, PLN, PDS, APK etc) the trial protocol called for very frequent pcr in those early hours, days and weeks. I think that some were as soon as 8 hours after initial dosing. I'm not sure if the latter Phases of tvr trials included all that early tx testing, but I recall that the tvr test pioneers had a lot of early test they needed to be available for. And, I assume that the placebo group did as well making early response between the groups highly comparative.
a distinguishing point about
is that it did not base predictions on vl drop but on analysis of changes in gene expression 4 hours after the shot. There have been a lot of papers along the lines of
by Neumann, Perelson and others showing a correlation between the steepness of early vl drop and outcome, but the above is something new. The flip side of this is
which predicts tx success by looking at the changes the virus is/is-not able to make. Correlating the list of human genes predictive of outcome in Sarasin-Filipowicz with the viral genes whose changes are predictive of outcome in Aurora'09 should give some pretty good clues - sort of like getting to see all the cards in a poker tournament..
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