01 Set Occult HBV infection in HCC and cirrhotic tissue of HBsAg-negative patients: a virological and clinical study
Aim: To evaluate the virological and clinical characteristics of occult HBV infection (OBI) in 68 consecutive HBsAg-negative patients with biopsy-proven cirrhosis and HCC.
Methods: HBV DNA was sought and sequenced in plasma, HCC tissue and non- HCC liver tissue by PCRs using primers for HBV C, S and X regions. OBI was identified by the presence of HBV DNA in at least two different PCRs.
Results: OBI was detected in HCC tissue of 13 (20%) patients and in non-HCC liver tissue of 3 of these 13. OBI was detected in HCC tissue of 54.5% of 11 anti- HBs- negative/anti-HBc-positive patients, in 29.4% of 17 anti-HBs/anti-HBc-positive and in 5% of 40 anti-HBs/anti-HBc-negative (p < 0.0005). The 13 patients with OBI in HCC tissue more frequently than the 55 without showed Child-B or -C cirrhosis (53.9% vs. 5.5%, p < 0.0001) and BCLC-B or -C stages (46.1% vs. 1.8%, p < 0.0001). The pre-S1, pre-S2 and S region sequences in HCC tissue showed amino acid (AA) substitutions (F19L, P24L, S59F, T131I, Q129H) and deletions in the S region, AA substitutions (T40S, P124K, L54P, G76A, N222T, I273L) in pre-S1 region and in pre-S2 region (P41H, P66L). In the 3 patients showing OBI also in non-HCC liver tissue the S, pre-S1 and pre-S2 sequencing displayed different patterns of mutations.
Conclusions: The study showed a significant correlation between OBI and the severity of liver damage, several patterns of mutations in the S, pre-S1 and pre-S2 regions in HCC tissue, some at their first description.