Identification of a Novel Single-Stranded DNA Fragment Associated with Human Hepatitis

By performing nonspecific polymerase chain reaction followed by elimination of chromosome-derived sequences, foreign DNA fragments were obtained from the serum of a patient with non–A–E hepatitis. One of the sequences, named NV-F, contained a partial open reading frame and was detected in 17 (24.6%) of 69 patients with non–A–E hepatitis, including 1 with fulminant hepatitis (vs. in 5 [2.8%] of 180 healthy individuals). A peptide was synthesized accordingly, to detect serum anti–NV-F antibody, which was found in 49 (75.4%) of 65 patients positive for NV-F. This DNA fragment was sensitive to S1 nuclease digestion. Cesium chloride gradient analysis revealed that the NV-F–associated particles had buoyant densities of 1.33–1.39 and 1.22–1.25 g/mL. Immunofluorescence analysis revealed that the novel antigen was present in the hepatocytes of patients infected with NV-F. In conclusion, we have identified a novel single-stranded DNA fragment derived from a virus-like agent associated with human hepatitis