[Detection and characterization of pre-core mutants of hepatitis B virus (HBV) in chronically infected patients].

Hepatitis B virus infection is responsible of an important number of world morbimortality. This is associated to severe liver outcome such as cirrhosis and hepatocellular carcinoma. Diverse factors influence the severity of liver injury produced by Hepatitis B Virus (HBV): the emergence of HBV mutants unable to secrete "e" antigen (pre-core mutants), the virus and host genetic heterogenicity and immune system competence. Particularly, the presence of pre-core mutants in chronic carriers is associated a low response to interferon therapy. We present paper is to present evidence as to the presence of these mutants in chronically infected, HBeAg negative patients (HBsAg positive) in Argentina. Viral DNAs were extracted from sera of nine patients, amplified by PCR and characterized by restriction enzyme assay. All of them appear to be pre-core mutants according with serological markers and a very low level of viral DNA detected in serum. Further genetic characterization of one of them by nucleotide sequence analysis of the pre-core region let allowed us to show modifications at codon 15 and 28 both of them previously described for pre-core mutants.