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Serum and liver HBsAg bear an inverse relation to each other during the evolution of chronic hepatitis B virus infection and the quantity of HBsAg in tissue rises gradually with time. In this study, intracellular and extracellular levels of HBsAg were measured by radioimmunoassay in primary culture of hepatocytes from 30 patients with chronic hepatitis B virus infection to determine a possible relationship with hepatitis B virus replication. Serum levels of HBsAg correlated with markers of active viral replication (serum hepatitis B virus DNA, p less than 0.005, and tissue HBcAg, p less than 0.02) but inversely with tissue HBsAg (p less than 0.05). In similar fashion, in vitro export of HBsAg was also related to the presence of active viral replication markers (serum hepatitis B virus DNA, p less than 0.02, and tissue HBcAg, p less than 0.05) and negatively with tissue HBsAg (p less than 0.001). Export of HBeAg also correlated positively with markers of active viral replication (serum hepatitis B virus DNA, p less than 0.05 and tissue HBcAg, p less than 0.05). Further experiments indicated that intrahepatic pre-S1 and pre-S2 correlated closely with intrahepatic HBsAg, indicating that a failure to export HBsAg was unlikely to be attributable to deficient intracellular expression of pre-S1 or pre-S2. These data indicate that in vitro primary hepatocyte culture of hepatitis B virus-infected cells provides an accurate reflection of in vivo export of HBsAg and that this is closely related to the presence of active viral replication.

Most of the sera from patients with primary biliary cirrhosis contains antimitochondrial antibodies, which react with four proteins of the mitochondrial inner membrane. We reported in a previous paper that when beef heart mitochondrial inner membrane proteins were digested by trypsin, a new reactive 36 kDa fragment with antimitochondrial antibody was obtained. This 36 kDa fragment derives from original 70 kDa protein because the monoclonal antibody specific to 70 kDa protein reacts with the 36 kDa band equivalent to 70 kDa band. The 36 kDa fragment was purified using an affinity column conjugated with an immunoglobulin-rich fraction of primary biliary cirrhosis serum containing antimitochondrial antibody, preparative electrophoresis and high-performance liquid chromatography using a reverse phase column. The final preparation showed a single band in sodium dodecyl sulfate polyacrylamide gel electrophoresis. Its amino acid composition is in good agreement with that of the subunit binding domain of the pyruvate dehydrogenase complex E2 from bovine heart.

A new complement-fixing antimitochondrial antibody--anti-M8--was detected in patients with primary biliary cirrhosis. Anti-M8 was only found in association with anti-M2, however, not all anti-M2 positive patients had anti-M8. Thus, among 66 anti-M2 positive patients, 29 were also positive for anti-M8, whereas sera from patients who had the complement-fixing anti-M2 and anti-M4 antibodies in parallel always strongly reacted with the M8 antigen. This group was previously described as mixed form. The M8 antigen was isolated either from human liver mitochondria or pig kidney microsomes and could be clearly distinguished from the M4 antigen. In contrast to M4, M8 was trypsin sensitive and banded at sucrose densities from 1.16 to 1.24, while M4 was found at densities from 1.08 to 1.14. Like M4, the M8 antigen also co-purified with outer mitochondrial membranes. Fifty-three patients with primary biliary cirrhosis have been followed over a period of up to 16 years and were classified according to their complement-fixing antimitochondrial antibody profile. At the time of the first diagnosis, 95% of 31 patients being anti-M2 positive, but anti-M8 negative (antimitochondrial antibody Profile I) were in Stage I or II. In contrast, only 61% of 13 patients being anti-M2 and anti-M8 positive (antimitochondrial antibody Profile II) and 44% of 9 patients with anti-M2, anti-M8 and anti-M4 in parallel (antimitochondrial antibody Profile III) belonged to Stage I or II.(ABSTRACT TRUNCATED AT 250 WORDS)