Reuters Health Information (2004-06-04): HCV diversity after liver transplant predicts 1-year outcome
HCV diversity after liver transplant predicts 1-year outcome
Last Updated: 2004-06-04 15:35:54 -0400 (Reuters Health)
NEW YORK (Reuters Health) - In patients who undergo liver transplantation for hepatitis C cirrhosis, the dynamics of hepatitis C virus quasi-species can predict the severity of recurrence.
In an international multicenter study led by Dr. Juan I. Arenas of the Mayo Clinic Scottsdale in Arizona, the dynamics of hepatitis C virus quasi-species in the HVR1/E2 region were evaluated in 29 liver transplant recipients with hepatitis C. Serum and liver biopsy samples were obtained before transplant and at 1 week, 4 months, and 1 year after transplant.
In the June 1st issue of The Journal of Infectious Diseases, the researchers explain that to estimate viral complexity, they counted the number of bands in a single-strand conformational polymorphism assay. To quantify viral diversity, they performed heteroduplex mobility assays and derived Shannon entropy and median mobility shift values.
The researchers divided their patients into two groups depending on whether their Knodell/Ishal fibrosis stage at 1 year posttransplant was equal to or greater than 2, or less than 2.
Before transplant and 1 week afterward, complexity was higher in the patients who eventually had the lower fibrosis stage. In these patients, both of the diversity values decreased between the pretransplant and 1-week posttransplant analyses, but then increased during the period between 1 week and 1 year after transplant.
In contrast, the researchers report, in the patients in whom fibrosis was more advanced at 1 year posttransplant, "the trend was reversed." The mean diversity values increased between the pretransplant and 1-week posttransplant measurements and then decreased over the rest of the year.
Eighty-three percent of patients with Shannon entropy values that either rose or remained stable between the pre- and early post-transplant measurements were in the more advanced fibrosis group at 1 year.
Of the patients with decreased diversity during this early phase, however, 88% were in the group with the lower fibrosis stage at 1 year. Specifically, for patients with decreased Shannon entropy values, between the pre- and early post-transplant measurements, the odds ratio of a fibrosis stage less than 2 by 1 year after transplant was 37.5.
"The clinical outcome for hepatitis C virus-positive patients who undergo transplantation is closely correlated with virus variability in the HVR1/E2 region, which is most likely a reflection of the immune system response of the host," the researchers conclude.
Given that quasi-species analyses at 1 week may predict the outcome at 1 year, the authors add, such observations "may help to determine the amount of immunosuppression and need for antiviral therapy."
J Infect Dis 2004;189:2037-2046.