Genomic variability associated with the presence of occult hepatitis B virus in HIV co-infected individuals.

Occult hepatitis B virus (O-HBV) infection is characterized by the presence of HBV DNA without detectable hepatitis B surface antigen (HBV DNA+/HBsAg-) in the serum. Although O-HBV is more prevalent during HBV/HIV co-infection, analysis of HBV mutations in co-infected patients is limited. In this preliminary study, HBV PreSurface (PreS) and surface (S) regions were amplified from 33 HIV-positive patient serum samples - 27 chronic HBV (C-HBV) and six O-HBV infections. HBV genotype was determined by phylogenetic analysis, while quasispecies diversity was quantified for the PreS, S and overlapping polymerase regions. C-HBV infections harboured genotypes A, D and G, compared to A, E, G and one mixed A/G infection for O-HBV. Interestingly, nonsynonymous-synonymous mutation values indicated positive immune selection in three regions for O-HBV vs one for C-HBV. Sequence analysis further identified new O-HBV mutations, in addition to several previously reported mutations within the HBsAg antigenic determinant. Several of these O-HBV mutations likely contribute to the lack of detectable HBsAg in O-HBV infection by interfering with detection in serologic assays, altering antigen secretion and/or decreasing replicative fitness.

Characterization of hepatitis E-specific cell-mediated immune response using IFN-gamma ELISPOT assay.

In developing countries, hepatitis E (HEV) and hepatitis A (HAV) are the major causes of acute viral hepatitis with similar feco-oral modes of transmission. In contrast to the high seroprevalence of hepatitis A infection, a low seroprevalence of HEV among children in endemic areas has been reported. These data suggest the possibility that silent HEV infection is undiagnosed by the current available methods. Many of the serological tests used for HEV diagnosis have poor specificity and are unable to differentiate among different genotypes of HEV. Moreover, the RT-PCR used for HEV isolation is only valid for a brief period during the acute stage of infection. Cell-mediated immune (CMI) responses are highly sensitive, and long lasting after sub-clinical infections as shown in HCV and HIV. Our objective was to develop a quantitative assay for cell-mediated immune (CMI) responses in HEV infection as a surrogate marker for HEV exposure in silent infection. Quantitative assessment of the CMI responses in HEV will also help us to evaluate the role of CMI in HEV morbidity. In this study, an HEV-specific interferon-gamma (IFN-gamma) ELISPOT assay was optimized to analyze HEV-specific CMI responses. We used peripheral blood mononuclear cells (PBMC) and sera from experimentally infected chimpanzees and from seroconverted and control human subjects to validate the assay. The HEV-specific IFN-gamma ELISPOT responses correlated strongly and significantly with anti-HEV ELISA positive/negative results (rho=0.73, p=0.02). Moreover, fine specificities of HEV-specific T cell responses could be identified using overlapping HEV ORF2 peptides.

Management of hepatitis B virus in HIV-positive patients.

High rates of coinfection with human immunodeficiency virus-1 (HIV) and the hepatitis B virus (HBV) are commonly found in at risk populations due to their shared parenteral route of transmission. Although the increasingly widespread use of highly active antiretroviral therapy (HAART) has prolonged survival for those with HIV, it has also increased the potential for morbidity and mortality from other diseases and opportunistic infections. Liver-related illness is a leading cause of morbidity and mortality in those infected with HIV and HBV is responsible for a vast proportion of this, especially in regions of high HBV prevalence. HIV/HBV coinfected patients may exhibit atypical serological markers of HBV infection, hindering appropriate diagnosis. They may experience faster progression to cirrhosis, decompensation, and hepatocellular carcinoma than HBV-monoinfected patients. Rates of response to vaccine against HBV are abrogated in those with HIV, facilitating the spread of the virus. Treatment of HBV must be monitored for resistance, although newer agents appear to have less risk of resistance development. Moreover, treatment of HIV with antivirals must be monitored closely for liver toxicity. Because liver damage with HBV occurs via the immune response to the virus, liver damage is possible with HAART-mediated immune reconstitution. Although liver transplant is not commonly undertaken in HIV-positive patients, centers undertaking transplantation report improved survival and low rates of HBV recurrence.

Topical testosterone treatment for chronic allograft failure in liver transplant recipients with recurrent hepatitis C virus.

INTRODUCTION: Liver transplant recipients with allograft failure due to recurrent hepatitis C virus (HCV) infection often develop marked muscle wasting and ascites prior to death and are denied repeat liver transplantation. We sought to determine whether topical testosterone therapy is associated with improved muscle mass and survival in patients with chronic allograft failure post-liver transplant. METHODS: We performed a retrospective review of liver transplant recipients with chronic allograft failure. Group 1 patients were treated for >6 months with testosterone gel 1%; group 2 patients were untreated. RESULTS: Fourteen patients were identified with stage 3 or 4 fibrosis, muscle wasting, and allograft failure due to recurrent HCV. Group 1 (n=9) patients had statistically significant improvement in albumin, testosterone, muscle strength, well-being, and MELD/CTP scores, while there was no improvement seen for any of these parameters in group 2 (n=5). There were no deaths in group 1, while four of five patients in group 2 died on average 84 days posttransplant. Adverse effects of testosterone treatment included lower extremity edema (which resolved upon dose adjustment), hypertension, and pruritus. CONCLUSIONS: Topical testosterone gel appears to increase muscle strength, stimulate albumin synthesis, and improve survival in patients with allograft failure post-liver transplant.

Response rates to pegylated interferon and ribavirin in HCV/HIV coinfection: a research synthesis.

Several recent trials have determined varying rates of response to pegylated interferon plus ribavirin (peg-IFN + RIB) in hepatitis C virus (HCV)/human immunodeficiency virus-coinfected patients. We sought to identify a pooled response rate and sources of interstudy variability. A literature search was conducted to identify randomized or prospective studies evaluating response rates to peg-IFN + RIB in coinfected patients. A Bayesian hierarchical model was used to estimate overall response rate. Between-study variance was calculated and sensitivity analyses were conducted. Meta-regression was employed to identify sources of between-study variability. The literature search yielded seven studies of 146, which matched keywords and inclusion criteria. The combined patient total was 784. Individual intention-to-treat response rates ranged from 27.3% to 44.2%. The pooled Bayesian estimate of percent response was 33.3%. Significant interstudy heterogeneity was detected. Meta-regression yielded no significant effects of covariates on response rate. Subanalyses by CD4+, HCV viral load and genotype yielded sustained virological response (SVR) odds ratios of 0.73 for low CD4+, 0.41 for high viral load and 0.30 for genotype 1/4. The pooled response rate is not attributable to any one study. Response is poor compared with HCV-monoinfected patients. Interstudy variability is not satisfactorily explained by factors influencing individual response, but may be due to differences between studies unavailable for inclusion in this analysis. However, both genotype 1/4 and high HCV viral load at baseline were significantly associated with a reduction in odds of SVR in pooled subanalysis. Improved treatments are needed in coinfected patients, especially with genotype 1/4 and high viral load.

Human immunodeficiency virus-infected patients with prior Pneumocystis pneumonia exhibit increased serologic reactivity to several major surface glycoprotein clones.

Recombinant clones of the carboxyl terminus of the major surface glycoprotein (MsgC) of Pneumocystis jirovecii are useful for analyzing serologic responses in humans. However, there is no standardized set of antigens in general use, which could lead to conflicting results. We have previously shown that human immunodeficiency virus type 1 (HIV-1)-infected patients with prior Pneumocystis pneumonia (PcP+) responded more frequently and more strongly to a clone of MsgC than did HIV-1-infected patients without PcP (PcP-). Here we test three new clones of MsgC to determine the effect of antigenic sequence variation on immune reactivity in blood donors and HIV-infected patients previously analyzed for reactivity to our original MsgC clone. In Western blot analyses, PcP+ patients exhibited the highest frequency of reactivity to each MsgC clone, and the frequency of reactivity with all four MsgC clones together was significantly higher in sera from PcP+ patients than in sera from the other patient groups. Furthermore, in an enzyme-linked immunosorbent assay we found that the PcP+ population had the highest level of reactivity to two of the four clones tested. One of the new clones could distinguish between PcP+ and PcP- populations, and two MsgC clones could distinguish blood donors from the other patient populations. The results show that inherent differences in MsgC amino acid sequence can affect recognition by antibodies independently of variations in protein length or patient population, and the utility of a clone depends on its sequence and on the populations tested.