Hepatitis: Shrestha MP

Shrestha MP, Scott RM, Joshi DM, Mammen MP, Thapa GB, Thapa N, Myint KS, Fourneau M, Kuschner RA, Shrestha SK, David MP, Seriwatana J, Vaughn DW, Safary A, Endy TP, Innis BL. · Walter Reed-Armed Forces Research Institute of Medical Sciences Research Unit Nepal, Kathmandu, Nepal. · N Engl J Med. · Pubmed #17329696 links to  free full text

Abstract: BACKGROUND: Hepatitis E virus (HEV) is an important cause of viral hepatitis. We evaluated the safety and efficacy of an HEV recombinant protein (rHEV) vaccine in a phase 2, randomized, double-blind, placebo-controlled trial. METHODS: In Nepal, we studied 2000 healthy adults susceptible to HEV infection who were randomly assigned to receive three doses of either the rHEV vaccine or placebo at months 0, 1, and 6. Active (including hospital) surveillance was used to identify acute hepatitis and adverse events. The primary end point was the development of hepatitis E after three vaccine doses. RESULTS: A total of 1794 subjects (898 in the vaccine group and 896 in the placebo group) received three vaccine doses; the total vaccinated cohort was followed for a median of 804 days. After three vaccine doses, hepatitis E developed in 69 subjects, of whom 66 were in the placebo group. The vaccine efficacy was 95.5% (95% confidence interval [CI], 85.6 to 98.6). In an intention-to-treat analysis that included all 87 subjects in whom hepatitis E developed after the first vaccine dose, 9 subjects were in the vaccine group, with a vaccine efficacy of 88.5% (95% CI, 77.1 to 94.2). Among subjects in a subgroup randomly selected for analysis of injection-site findings and general symptoms (reactogenicity subgroup) during the 8-day period after the administration of any dose, the proportion of subjects with adverse events was similar in the two study groups, except that injection-site pain was increased in the vaccine group (P=0.03). CONCLUSIONS: In a high-risk population, the rHEV vaccine was effective in the prevention of hepatitis E. (ClinicalTrials.gov number, NCT00287469 [ClinicalTrials.gov].).

Myint KS, Endy TP, Shrestha MP, Shrestha SK, Vaughn DW, Innis BL, Gibbons RV, Kuschner RA, Seriwatana J, Scott RM. · Department of Virology, Armed Forces Research Institute of Medical Sciences, 315/6 Rajvithi Road, Bangkok 10400, Thailand. · Trans R Soc Trop Med Hyg. · Pubmed #16542692 No free full text.

Abstract: A cohort of 62 Nepalese adults with acute hepatitis E was identified and total Ig as well as IgM levels to hepatitis E virus (HEV) capsid protein were determined using the Walter Reed Army Institute of Research (WRAIR) immunoassay. An antibody profile was constructed from serial serum specimens collected up to 14 months following the onset of illness. The decline in total Ig was rapid for the first 3 months. There followed a slow, sustained decline, but antibodies remained above the seropositive level of 20 WRAIR units. The decline of IgM was steeper than total Ig for the first 3 months, but IgM remained detectable after 14 months in 25% of cases. Study data contribute to an understanding of the pathophysiology of human hepatitis E and set an antibody response pattern to be targeted as a part of HEV vaccine development.

Seriwatana J, Shrestha MP, Scott RM, Tsarev SA, Vaughn DW, Myint KS, Innis BL. · Department of Virus Diseases, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, USA. · Clin Diagn Lab Immunol. · Pubmed #12204962 links to  free full text

Abstract: Diagnosis of acute hepatitis E by detection of hepatitis E virus (HEV)-specific immunoglobulin M (IgM) is an established procedure. We investigated whether quantitation of HEV IgM and its ratio to HEV total Ig furnished more information than conventional IgM tests that are interpreted as positive or negative. A previously described indirect immunoassay for total Ig against a baculovirus-expressed HEV capsid protein was modified to quantitate HEV-specific IgM in Walter Reed (WR) antibody units by using a reference antiserum and the four-parameter logistic model. A receiver-operating characteristics curve derived from 197 true-positive specimens and 449 true-negative specimens identified 30 WR units/ml as an optimum cut point. The median HEV IgM level in 36 patients with acute hepatitis E fell from 3,000 to 100 WR units/ml over 6 months, suggesting that 100 WR units/ml would be a more appropriate cut point for distinguishing recent from remote IgM responses. Among three hepatitis E case series, determination of the HEV IgM-to-total-Ig ratio in acute-phase serum revealed that most patients had high ratios consistent with primary infections whereas a few had low ratios, suggesting that they had sustained reinfections that elicited anamnestic antibody responses. The diagnostic utility of the new IgM test was similar to that of a commercially available test that uses different HEV antigens. In conclusion, we found that HEV IgM can be detected specifically in >95% of acute hepatitis E cases defined by detection of the virus genome in serum and that quantitation of HEV IgM and its ratio to total Ig provides insight into infection timing and prior immunity.

Innis BL, Seriwatana J, Robinson RA, Shrestha MP, Yarbough PO, Longer CF, Scott RM, Vaughn DW, Myint KS. · Department of Virus Diseases, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, USA. · Clin Diagn Lab Immunol. · Pubmed #11986273 links to  free full text

Abstract: We developed a quantitative enzyme immunoassay (EIA) for antibody to hepatitis E virus (HEV) by using truncated HEV capsid protein expressed in the baculovirus system to improve seroepidemiology, to contribute to hepatitis E diagnosis, and to enable vaccine evaluations. Five antigen lots were characterized; we used a reference antiserum to standardize antigen potency. We defined Walter Reed antibody units (WR U) with a reference antiserum by using the four-parameter logistic model, established other reference pools as assay standards, and determined the conversion factor: 1 WR U/ml = 0.125 World Health Organization unit (WHO U) per ml. The EIA performed consistently; median intra- and inter-test coefficients of variation were 9 and 12%, respectively. The accurate minimum detection limit with serum diluted 1:1,000 was 5.6 WR U/ml; the test could detect reliably a fourfold antibody change. In six people followed from health to onset of hepatitis E, the geometric mean antibody level rose from 7.1 WR U/ml to 1,924.6 WR U/ml. We used the presence of 56- and 180-kDa bands by Western blotting as a confirmatory test and to define true-negative and -positive serum specimens. A receiver-operating characteristics plot identified 30 WR U/ml as an optimum cut-point (sensitivity, 86%; specificity, 89%). The EIA detected antibody more sensitively than a commercially available test. The EIA was transferred to another laboratory, where four operators matched reference laboratory results for a panel of unknowns. Quantitation of antibody to HEV and confirmation of its specificity by Western blotting make HEV serology more meaningful.

Clark KL, Howell RM, Scott RM, Vaughn DW, Shrestha MP, Longer CF, Innis BL. · Department of Virus Diseases, Walter Reed Army Institute of Research, Washington, District of Columbia 20307-5100, USA. · Am J Trop Med Hyg. · Pubmed #10497999 links to  free full text

Abstract: Hepatitis E disease is responsible for substantial morbidity in Nepal. A socioeconomic analysis was performed to describe the costs and the effects of hepatitis E disease (HE) on health status in a Nepalese population living in the Kathmandu Valley. A modified health status index was used to quantify healthy days lost associated with HE. One hundred thirty-four individuals recently recovered from HE were interviewed in June 1998. The median age was 22 years and 60% were female. Study participants were sick and bedridden for a median of 22 and 10 days, respectively. The median healthy days lost per individual was 35 (768,000 total per region). The median cost of illness per individual, including direct and indirect, was $37 ($1,238,676 total per region). The percentage of yearly income lost for wage earners totaled 19.4%. Hepatitis E disease is associated with significant costs and loss of healthy days in Nepal. Further research is warranted to understand and limit this common disease.

He J, Innis BL, Shrestha MP, Clayson ET, Scott RM, Linthicum KJ, Musser GG, Gigliotti SC, Binn LN, Kuschner RA, Vaughn DW. · Walter Reed Army Institute of Research, Silver Spring, Maryland, USA. · J Clin Microbiol. · Pubmed #16517936 links to  free full text

This publication has no abstract.

He J, Innis BL, Shrestha MP, Clayson ET, Scott RM, Linthicum KJ, Musser GG, Gigliotti SC, Binn LN, Kuschner RA, Vaughn DW. · Walter Reed Army Institute of Research, Silver Spring, Maryland, USA. · J Clin Microbiol. · Pubmed #12454141 links to  free full text

Abstract: Hepatitis E virus (HEV) is an important cause of enterically transmitted hepatitis in developing countries. Sporadic autochthonous cases of hepatitis E have been reported recently in the United States and other industrialized countries. The source of HEV infection in these cases is unknown; zoonotic transmission has been suggested. Antibodies to HEV have been detected in many animals in areas where HEV is endemic and in domestic swine and rats in the United States. There is evidence supporting HEV transmission between swine and humans. Nevertheless, HEV has not been detected in wild rodents. We tested murid rodents and house shrews trapped in Nepal's Kathmandu Valley, where hepatitis E is hyperendemic, for HEV infection. The most commonly trapped species was Rattus rattus brunneusculus. Serum samples from 675 animals were tested for immunoglobulin G against HEV by enzyme-linked immunosorbent assay; 78 (12%) were positive, indicating acute or past infection. Antibody prevalence was higher among R. rattus brunneusculus and Bandicota bengalensis than in Suncus murinus. Forty-four specimens from 78 antibody-positive animals had sufficient residual volume for detection of HEV RNA (viremia) by reverse transcription-PCR. PCR amplification detected four animals (9%; three were R. rattus brunneusculus and one was B. bengalensis) with viremia. Phylogenetic analysis of the four genome sequences (405 bp in the capsid gene) recovered showed that they were identical, most closely related to two human isolates from Nepal (95 and 96% nucleotide homology, respectively), and distinct from HEV sequences isolated elsewhere. These data prove that certain peridomestic rodents acquire HEV in the wild and suggest that cross-species transmission occurs, with rodents serving as a virus reservoir for humans.