Molecular characteristics of occult hepatitis B virus from blood donors in southeast China

Abstract

The characteristics of 30 carriers with occult hepatitis B virus (HBV) infection (OBI) were compared with those of 30 individuals diagnosed as being HBV carriers at the time of blood donation, 60 asymptomatic carriers, and 60 chronic hepatitis patients. The prevalence of genotype C was significantly higher in carriers with OBIs than in any other HBsAg-positive (HBsAg(+)) group (P < 0.001). Specific amino acid substitutions in the regions from amino acids 117 to 121 and amino acids 144 to 147 located in the major hydrophilic region of the S gene were associated with carriers with OBIs (P < 0.01 for carriers with OBIs versus HBsAg(+) donors, carriers with OBIs versus HBsAg(+) asymptomatic carriers, and carriers with OBIs versus HBsAg(+) chronic hepatitis patients). G145R was the major variation in the HBV isolates responsible for local occult HBV infections.

FIG. 1.

Amino acid variability of S-protein MHR (aa 110 to aa 165) in individuals with occult HBV infection and controls. The consensus amino acid sequences of genotypes B and C were deduced from the sequences with GenBank accession numbers AB073826 and AF286594, respectively. Strains whose amino acid sequences were identical to the wild-type sequence are not represented in the figure. These nonrepresented strains included the following: OBI 9 to 11, 13 and 14, and 23; HBsAg⁺ donors 1, 5 to 8, 10 to 14, 18 and 19, 21, 25, 27 and 28, and 30; asymptomatic chronic carriers (ASC) 2 and 3, 5 to 8, 12 to 14, 16, 19 to 23, 25 to 27, 29, 31 to 35, 37, 41, 43 to 45, 47 to 49, 51, 54, and 57 to 60; patients with chronic hepatitis 1, 3 to 7, 9, 11, 15, 17 to 20, 23, 25 to 27, 31 and 32, 34 to 40, 42 to 46, 49, 57, and 60 (genotype B, adw2); donors with OBIs 20, 22, 24, and 26 to 28; HBsAg⁺ donors 15, 22, and 23; asymptomatic chronic carriers 4, 10, 11, 17, 24, 36, 39, 42, and 53; and patients with chronic hepatitis 22, 29, 33, 47 and 48, 51, 53, 55, and 59 (genotype C, adrq positive).