OBJECTIVETo see the HBV DNA detection instance in the HBsAg negative people and to study the serological method detection strategy for detecting hepatitis B virus large surface protein (HBLP) to filtrate the occult HBV infection.

METHODSThe HBsAg negative serum samples were divided into HBsAb negative and positive two species according to the hepatitis B virus markers (HBVM) in daily work excepting the special HBVM modes. Total 2000 stochastic serum samples with 1000 HBsAb negative results and 1000 HBsAb positive results were collected from the copy tubes to detect HBVM with national ELISA reagent kits and put them -20 degrees C frostily. Mixed samples (8 x 30 microl) were analyzed with fluorescence quantitative PCR (FQ-PCR) and filtrated the individual positive samples. The filtrated samples were doubly tested again with American MONOLISA HBsAg ULTRA reagents.

RESULTSNo HBV DNA positive results were found out from the 1000 HBsAb positive samples and 19 cases HBV DNA positive results were found out from the 1000 HBsAb negative samples. On these 19 samples, the HBsAg results from the American MONOLISA HBsAg ULTRA reagents were all positive and the HBLP results were all positive, too. The 19 HBV DNA quantitative results were divided into 2 cases more than 500 copies/ml, 3 cases between 400-500 copies/ ml, 3 cases between 300-400 copies/ml, 7 cases between 200-300 copies/ml and 4 cases between 100-200 copies/ml.

CONCLUSIONThe leaked samples tested HBsAg with national reagents are mostly from the HBsAb negative people. HBLP results may be positive on these samples and detecting HBLP marker is propitious to filtrate the occult HBV infection. This study provided a kind of serological reference for actively searching for the detecting strategy in occult HBV infection field.