ABSTRACT
Hepatitis B surface antigen (HBsAg) is considered the best marker for the diagnosis of hepatitis B virus (HBV) infection. Mutations of the s gene involving amino acid substitutions within the a determinant could affect the sensitivity of diagnostic tests. In the present study, HBsAg mutants were detected in 3 immunocompromised patients, previously found to be HBsAg negative and anti-HBs positive. All patients had high levels of HBV-DNA, whereas HBsAg tests gave discordant results. Immunosuppression can cause viral reactivation of occult HBV infection in these patients and favour the selection of HBsAg a determinant mutants.
Subject(s)
Hepatitis B Surface Antigens/blood , Hepatitis B Surface Antigens/genetics , Hepatitis B virus/genetics , Hepatitis B virus/isolation & purification , Hepatitis B/diagnosis , Mutation, Missense , Aged , DNA, Viral/blood , Female , Hepatitis B Antibodies/blood , Humans , Immunoassay , Immunocompromised Host , Male , Middle Aged , Sensitivity and SpecificityABSTRACT
Lamivudine can select resistant hepatitis B virus (HBV) tyrosine-methionine-aspartate-aspartate aminoacid motif (YMDD) mutants, which usually disappear in few months after lamivudine withdrawal. We report an unusual case of a male adult patient who showed a prolonged persistence of the M204I mutation up to 24 months after lamivudine withdrawal followed by the emergence of new distinct YMDD mutants (namely M204V, V207L). Only 42 months after lamivudine withdrawal wild-type YMDD motif became dominant over the YMDD mutants. To our knowledge, a so prolonged persistence of a YMDD mutant and also the emergence of new YMDD mutants many months after drug withdrawal are unusual.
