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What Do You Think About This Scary Study?
Study: Patients With Resolved Hepatitis C Likely Still Contagious
Patients with chronic hepatitis C that has been resolved through therapy or immune response may still be able to infect others with the virus. That finding is from a new study in the May issue of Hepatology, a journal published by John Wiley & Sons on behalf of the American Association for the Study of Liver Diseases (AASLD). The article is also available online at Wiley Interscience (www.interscience.wiley.com).
About 170 million people worldwide are infected with hepatitis C virus, which can progress to chronic hepatitis, cirrhosis and even liver cancer. In some individuals, the infection seems to resolve, either spontaneously from the efforts of the immune system, or after treatment with interferon and ribavirin.
Patients who achieve a sustained viral response show no clinical or biochemical evidence of liver disease and standard tests can no longer detect the virus in their blood. However, more sensitive research tests are finding that such patients often still have miniscule amounts of the virus in their bodies. No one knows if these trace remainders are infectious.
Researchers led by Tomasz I. Michalak of Memorial University of Newfoundland, Canada examined this question using a system that allows for propagation of HCV in human T cells in vitro.
They began with nine patients with HCV who had achieved a sustained viral response that persisted for at least two years after treatment. HCV RNA was detectable in their blood only with the more sensitive tests.
The researchers set up twelve cultures of lymphoid cells from healthy donors, and exposed them to plasma or to supernatants of cultured circulating lymphoid cells from the HCV patients. Eleven of the cell cultures became HCV RNA positive. Furthermore, HCV from three of the nine patients was able to establish active HCV replication in the cultures.
“These findings provide in vitro evidence that trace quantities of HCV persisting in the circulation for a long time after therapeutically induced resolution of CHC can remain infectious,” the authors report.
Interestingly, HCV replication in the T cells was prevented after neutralization of the virus, and by treatment with interferon.
This study is the first to investigate the infectivity of HCV traces that remain when the infection is occult. It agrees with previous animal studies of the same question.
“Our present findings reveal that HCV circulating in some individuals with resolved hepatitis C is capable of inducing productive infection in vitro at doses of 20 to 50 copies,” the authors conclude. “This can be interpreted as a strong indication of potential virus infectivity in vivo.”
Article: “Hepatitis C Virus Persisting at Low Levels after Clinically Apparent Sustained Virological Reponse to Antiviral Therapy Retains Its Infectivity in Vitro.” MacParland, Sonya A.; Pham, Tram N.Q.; Guy, Clifford S.; Michalak, Tomasz I. Hepatology; May 2009.
Patients with chronic hepatitis C that has been resolved through therapy or immune response may still be able to infect others with the virus. That finding is from a new study in the May issue of Hepatology, a journal published by John Wiley & Sons on behalf of the American Association for the Study of Liver Diseases (AASLD). The article is also available online at Wiley Interscience (www.interscience.wiley.com).
About 170 million people worldwide are infected with hepatitis C virus, which can progress to chronic hepatitis, cirrhosis and even liver cancer. In some individuals, the infection seems to resolve, either spontaneously from the efforts of the immune system, or after treatment with interferon and ribavirin.
Patients who achieve a sustained viral response show no clinical or biochemical evidence of liver disease and standard tests can no longer detect the virus in their blood. However, more sensitive research tests are finding that such patients often still have miniscule amounts of the virus in their bodies. No one knows if these trace remainders are infectious.
Researchers led by Tomasz I. Michalak of Memorial University of Newfoundland, Canada examined this question using a system that allows for propagation of HCV in human T cells in vitro.
They began with nine patients with HCV who had achieved a sustained viral response that persisted for at least two years after treatment. HCV RNA was detectable in their blood only with the more sensitive tests.
The researchers set up twelve cultures of lymphoid cells from healthy donors, and exposed them to plasma or to supernatants of cultured circulating lymphoid cells from the HCV patients. Eleven of the cell cultures became HCV RNA positive. Furthermore, HCV from three of the nine patients was able to establish active HCV replication in the cultures.
“These findings provide in vitro evidence that trace quantities of HCV persisting in the circulation for a long time after therapeutically induced resolution of CHC can remain infectious,” the authors report.
Interestingly, HCV replication in the T cells was prevented after neutralization of the virus, and by treatment with interferon.
This study is the first to investigate the infectivity of HCV traces that remain when the infection is occult. It agrees with previous animal studies of the same question.
“Our present findings reveal that HCV circulating in some individuals with resolved hepatitis C is capable of inducing productive infection in vitro at doses of 20 to 50 copies,” the authors conclude. “This can be interpreted as a strong indication of potential virus infectivity in vivo.”
Article: “Hepatitis C Virus Persisting at Low Levels after Clinically Apparent Sustained Virological Reponse to Antiviral Therapy Retains Its Infectivity in Vitro.” MacParland, Sonya A.; Pham, Tram N.Q.; Guy, Clifford S.; Michalak, Tomasz I. Hepatology; May 2009.
For those that missed it, here is what "HR" had to say about "occult" tramission by SVRs....
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" - What are the possibilities of occult SVR's being able to transmit the virus?
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(HR): 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? "
(HR): 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.
http://www.medhelp.org/posts/Hepatitis-C/New-Occult-Hep-C-paper-from-Pham-et-al/show/763749?post_id=post_4022709
-------------------------
" - What are the possibilities of occult SVR's being able to transmit the virus?
-----------------------------
(HR): 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? "
(HR): 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.
http://www.medhelp.org/posts/Hepatitis-C/New-Occult-Hep-C-paper-from-Pham-et-al/show/763749?post_id=post_4022709
What Do You Think About This Scary Study?
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Honestly, unless you're a healthy specimen of serum in one of MacParland's petri dishes, I don't think there's anything at all to be scared about :) Did you read what they had to do to those poor serum specimens to "infect" them !
Regardless of what you think about the study and its methods, the fact remains that hepatitis C is very inefficiently transmitted. For that reason, the CDC doesn't even recommend condoms for monogamous couples excluding anal or rough sex. Even needle stick accidents only account for around a 3% transmission risk. And keep in mind this is for someone with full-blown HCV were viral load can be in the TENS OF MILLIONS..
So where does that leave the real-real world transmission risk for an SVR where viral load is either zero or under the radar of the most sensitive commercial tests, depending on who you read?
For those interested, the complete study is available for free online at the "Hepatology" website. Simply scroll down, find the article, then click on "HTML Full Text".
-- Jim
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Honestly, unless you're a healthy specimen of serum in one of MacParland's petri dishes, I don't think there's anything at all to be scared about :) Did you read what they had to do to those poor serum specimens to "infect" them !
Regardless of what you think about the study and its methods, the fact remains that hepatitis C is very inefficiently transmitted. For that reason, the CDC doesn't even recommend condoms for monogamous couples excluding anal or rough sex. Even needle stick accidents only account for around a 3% transmission risk. And keep in mind this is for someone with full-blown HCV were viral load can be in the TENS OF MILLIONS..
So where does that leave the real-real world transmission risk for an SVR where viral load is either zero or under the radar of the most sensitive commercial tests, depending on who you read?
For those interested, the complete study is available for free online at the "Hepatology" website. Simply scroll down, find the article, then click on "HTML Full Text".
-- Jim
"I doubt there have been many SVR-donated organs used....because of the possibility of interferon treatment having caused autoimmune problems, etc. "
"It's just my opinion. I've actually never seen any studies on SVR liver transplants. "
Autoimmune diseases can be detected by tests. Thyroid, AIH, etc. Not every person going through treatment picks up an autoimmune problem - it happens to be in the minority. I don't see any issue whatsoever with an SVR liver on those grounds if the presence of autoimmune issues have been ruled out by testing.
Your comparison of lingering hep C remnants to chickenpox and shingles was brilliant I think.
Course I'm not one of the brighter bulbs on the forum but still, it was a great analogy!
However, I have to point out that although shingles is more prevalent in older people, young adults and children are also susceptible, (my daughter had shingles in the fifth grade.)
Course I'm not one of the brighter bulbs on the forum but still, it was a great analogy!
However, I have to point out that although shingles is more prevalent in older people, young adults and children are also susceptible, (my daughter had shingles in the fifth grade.)
It's just my opinion. I've actually never seen any studies on SVR liver transplants.
"HCV positive organs have been transplanted and I would assume that an SVR liver would be preferable to HCV+ liver. I could go on but I won't. "
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Not necessarily. Several studies have shown that the survival rates using hepatitis-C-infected or uninfected livers are comparable.
The Optimal Liver for Transplant in Hepatitis-C Patients: Presented at DDW
By Bruce Sylvester
WASHINGTON, DC -- May 22, 2007 -- New research suggests that hepatitis-C- (HCV) infected patients receiving livers from HCV-infected donors have a slower rate of fibrosis progression at 1 year than those receiving uninfected livers.
The findings were presented at a press briefing here at Digestive Diseases Week (DDW).
"The implications are potentially highly important," said presenter and investigator Paul Kwo, MD, associate professor of medicine and medical director of liver transplantation, Indiana University School of Medicine, Indianapolis.
"Many people live 'peacefully' with hepatitis C infection, but when they die of other causes, their livers have not been considered to be eligible for transplantation. Our study suggests that survival rates for recipients are at least as good with cadaveric hepatitis-C-infected, noncirrhotic livers as with uninfected livers. This could mean the availability of many more cadaveric livers for transplant, where there is a critical shortage now," said Dr. Kwo.
The investigators compared transplant outcomes for liver recipients from HCV-infected donors to those for standard, nonextended criteria (ECD) donors. They analyzed data from 38 liver recipients and 76 ECD donors, data extracted from a transplant center registry, UNOS (United Network for Organ Sharing), and original on-site donor data charts.
Thirty percent of all donors met non-ECD criteria (standard donors) and were included as potential matches for the case-control study. The researchers matched each HCV-positive liver donor recipient to 2 standard donor recipients
They then analyzed recipient data for graft survival and patient survival at 3 months, 1 year, and 2 years. They also noted perioperative death, HCV recurrence, and 4-month and 1-year fibrosis.
The researchers discovered that when HCV-positive livers were used, there was no difference in survival rates compared with patients receiving uninfected livers. And they reported that the rate of fibrosis appeared to be slower in recipients of HCV-infected livers.
"The use of HCV-positive donors may be considered as a first-line therapy to increase the available donor pool of organs in those undergoing OLT for HCV-related cirrhosis," the authors concluded.
"We need more organ options for hepatitis-C patients," added press briefing moderator John Vierling, MD, professor of medicine, chief of hepatology, and director of Baylor Liver Health, Baylor University College of Medicine in Houston, Texas. "This could go a long way to meeting the need for more donors."
Here's one more.....
"In addition, the study showed that, among the patients receiving an HCV-positive liver, those in whom the donor strain of the virus prevailed remained disease-free for a significantly longer period of time than patients who retained their original viral strain. "Disease-free" was defined as patients showing no recurrence of hepatitis and no significant liver disease."
http://www.gastro.org/wmspage.cfm?parm1=474
Co
"How many cases of HCV transmission from SVR-donated organs have been recorded? "
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"I doubt there have been many SVR-donated organs used....because of the possibility of interferon treatment having caused autoimmune problems, etc."
You may be right that few SVR organs have been transplanted but I strongly doubt that the reason is "the possibility of autoimmune problems". It's more likely due to scarcity of SVR livers. If you have any evidence to support that statement please post what you have. HCV positive organs have been transplanted and I would assume that an SVR liver would be preferable to HCV+ liver. I could go on but I won't.
Mike
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"I doubt there have been many SVR-donated organs used....because of the possibility of interferon treatment having caused autoimmune problems, etc."
You may be right that few SVR organs have been transplanted but I strongly doubt that the reason is "the possibility of autoimmune problems". It's more likely due to scarcity of SVR livers. If you have any evidence to support that statement please post what you have. HCV positive organs have been transplanted and I would assume that an SVR liver would be preferable to HCV+ liver. I could go on but I won't.
Mike
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