The presence of nucleotide sequences of the hepatitis B virus in the serum of HBsAg-negative blood donors in Sardinia]

The presence of HBV DNA was assessed in the serum samples from 878 HBsAg negative Sardinian blood donors. They were composed of 481 (55%) donors selected because of abnormal serum alanine aminotransferase (ALT) levels during routine testing of their blood donation, and of 397 donors (45%) selected on the basis of normal serum ALT activities. HBV DNA sequences were detected in 37 (7.7%) out of 481 subjects with abnormal ALT and in 2 (0.5%) out of 397 subjects with normal ALT. Anti-HBc was detected in 199 (41%) of the 481 subjects with abnormal ALT and in 81 (20%) out of 397 subjects with normal ALT. Among the 39 subjects positive for serum HBV DNA, 12 (31%) were positive for anti-HBc, while 27 (69%) were negative for all serological HBV markers. These data show in Sardinia, where HBV infection is endemic, there is a high frequency of HBsAg negative HBV DNA positive individuals in whom multiplication of HBV may occur without conventional serological HBV markers, suggesting the possible existence of HBV-like viruses which may be responsible for some of the presumed non-A non-B hepatitis.