SEN virus infection in patients with hepatocellular carcinoma

Summary.  Although most cases of hepatocellular carcinoma (HCC) are associated with either the hepatitis B or C viruses (HBV, HCV), about 10–20% of HCCs occur in patients with chronic hepatitis that is aetiologically undefined. The aim of the present study was to determine the prevalence of the transfusion-transmitted SEN virus (SEN-V) in patients with HCC, including those patients who do not otherwise appear to be infected with HBV or HCV. Fragments of SEN-V subtypes D and H were amplified separately by PCR from the sera of 50 patients with HCC (31 from Canada and 19 from Japan) as well as from HCC and adjacent nontumourous liver tissues from eight of the Canadian patients. SEN-V DNA was found in the serum of 10 of 31 (32%) Canadian patients and eight of 19 (42%) Japanese patients [overall, 18 of 50 (36%) HCC patients]. SEN-V DNA was detected in the serum of 10 of 23 (43%) HCC patients with antibody to HCV (anti-HCV), six of 11 (55%) with hepatitis B surface antigen (HBsAg), and two of 16 (12%) without detectable anti-HCV or HBsAg. Twenty-three HCC patients in this study had ‘silent HBV,’ characterized by the detection of HBV DNA in the absence of HBsAg; eight of these (35%) also had SEN-V infections. SEN-V DNA was detected in HCC patients most typically in those with coexistent HBV or HCV infection. SEN-V was found in only one of seven HCC patients without HBV (without HBsAg or HBV DNA) or HCV and thus does not appear to be an important cause of ‘cryptogenic’ HCC.