title: Detection of serum anti-NV-F antibodies in the convalescent phase of severe hepatitis in patients positive for tissue NV-F antigen and novel virus-like particles.
abstract: Previously, a non-human DNA fragment named NV-F was isolated from a patient with non-A-E fulminant hepatitis. This sequence encoded an incomplete open reading frame (the NV-F antigen). In this study, we developed a western blot assay to detect serum anti-NV-F antibodies. Serum samples from 347 patients with severe hepatitis (ALT > fivefold ULN) were analyzed to understand the prevalence and distribution of the NV-F associated virus (HnFV) infection. Of these patients, acute HnFV infection was diagnosed (by positive serum NV-F DNA) in 34 patients (9.8%). However, none of these 34 serum samples were positive for serum anti-NV-F antibodies. In the remaining patients negative for serum NV-F DNA, 62 (17.9%) were positive for serum anti-NV-F antibodies. Liver biopsy samples from 35 severe hepatitis patients were submitted for immunohistochemistry and electron microscopy examination. Of them, seven were positive for hepatic NV-F antigen expression. Electron microscopy identified a novel virus-like particle in all of the seven NV-F antigen-positive liver tissues but not in the remaining 28 NV-F antigen-negative liver tissues. Longitudinal serum sample analysis revealed transient positivity of serum NV-F DNA in three of the seven patients during the clinical courses. Seroconversion of anti-NV-F antibody from negative to positive was found in four of the seven patients and all positive anti-NV-F antibodies were detected in the convalescent phases. In conclusion, in patients with severe hepatitis, a novel hepatotropic virus, temporarily named HnFV, was found in liver tissues expressing the NV-F antigen. Serum anti-NV-F antibodies were detected in the convalescent serum samples.
authors: Liver Research Center, Department of Hepato-Gastroenterology, Chang Gung Memorial Hospital, Taipei, Taiwan.|Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan.
authors: Chau-Ting
authors: CT
authors: Yeh
authors: Liver Research Center, Department of Hepato-Gastroenterology, Chang Gung Memorial Hospital, Taipei, Taiwan.
authors: Mei-Lin
authors: ML
authors: Tsao
mesh_terms: D000208:Acute Disease; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000276:immunology*; D015153:Blotting, Western; D003289:Convalescence; D004279:DNA, Viral / Q000097:blood / Q000235:genetics / Q000276:immunology*; D006525:Hepatitis, Viral, Human / Q000276:immunology* / Q000821:virology*; D006801:Humans; D008099:Liver / Q000276:immunology / Q000821:virology; D008297:Male; D008854:Microscopy, Electron
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D004279:DNA, Viral
keywords: co-infection; electron microscopy; hepatotropic; seroconversion