Type 2 hepatitis B virus (HBV-2) in carriers and patients with malignancy in Saudi Arabia.

Four cases of type 2 hepatitis B virus (HBV-2) infection were demonstrated in the Gizan area of Saudi Arabia during the hepatitis B marker ELISA screening of the 152 native pregnant females, 42 cases of primary hepatocellular carcinoma, 19 cases with an epithelial but non-hepatic malignancy, 16 with a non-epithelial and non-hepatic malignancy and eight with chronic hepatitis. HBV-2 infection diagnosis was based on HBsAg positivity without anti-HBc, anti-HBs and HBeAg in one pregnant female and one patient each with a primary hepatocellular carcinoma, lymphocytic lymphoma and metastatic adenocarcinoma. During neutralisation of HBsAg ELISA reactivity, the respective reduction in absorbance values in sera from the pregnant female and the patient with primary hepatocellular carcinoma were 21% and 76% respectively. HBV-2 specific gene probes would be needed to define its role in pathogenesis of malignant neoplasms and chronic hepatitis. Incorporation of pre-S2 sequences in future hepatitis B vaccines is likely to protect against both, HBV-2 and conventional hepatitis B (HBV-1) exposures.