WESTERN-BLOT-ANALYSIS OF THE REACTIVITY BETWEEN ENVELOPE PROTEINS OF HEPATITIS-B VIRUSES FROM BRAZILIAN CARRIERS AND ANTIBODIES RAISED AGAINST RECOMBINANT HEPATITIS-B VACCINES

A Western blot assay was standardized to evaluate the antigenic reacti vity of hepatitis B virus (HBV) strains circulating in Brazilian popul ation with antibodies raised against recombinant hepatitis B (HB) vacc ines. In this assay, HBV envelope proteins from infected human blood w ere detected by antibodies from rabbits immunized with either of two r ecombinant vaccines. These were Engerix B (Smith Kline Beecham, Belgiu m) containing exclusively S protein particles and TGP-943 (Takeda Chem ical Industries, Japan) containing M protein particles. Forty-seven se rum samples, presenting HE surface antigen. (HBsAg) reverse passive ha emagglutination assay (RPHA) titers ranging from 1:32 to greater than or equal to 1:4096 after HBV particles concentration, were tested. Twe nty-seven samples were from acute hepatitis cases and 20 were from chr onic cases (11 from cirrhotic patients and 9 from asymptomatic carrier s). Four HBV serotypes, adw2, adw4, ayw2 and ayw3, were identified in these samples. Infectivity of these sera was evaluated by HBV DNA dete ction by polymerase chain reaction (PCR). HBV DNA was present in 62% o f samples from acute cases and in all samples from chronic cases. Desp ite the differences between serotypes, genotypes, forms of infection, and infectivity of the samples, antibodies against both vaccines react ed with HBV envelope proteins from all but one sample. In one sample f rom cirrhotic patient, only a small protein of unexpected size reacted with TGP-943 antibodies.