During acute type B hepatitis, the proportion of inducer to cytotoxic/suppressor T-cells is decreased due to an increase in the concentration of suppressor cells. Similar changes are seen in chronically infected subjects with evidence of active viral replication (HBeAg positive) and chronic hepatitis of varying severity. This imbalance of the regulatory cells returns to normal when viral replication decreases during the recovery phase of acute hepatitis and in patients who become chronic carriers with minimal liver disease (HBeAb positive patient). Patients in whom viral replication has subsided (HBeAb positive) but who continue to exhibit chronic active liver disease have increased inducer to cytotoxic/suppressor cell ratios due to a decrease in the concentration of the cytotoxic/suppressor cell population. Further studies are needed to determine whether these alterations of the regulatory cells of the immune system are a causal factor influencing the duration of active hepatitis B virus replication and the degree of inflammatory liver damage, or merely changes secondary to the presence of a replicating virus.

Acute Disease↗

PubMedDate not supplied

A comparative study of the biliary secretion of human dimeric and monomeric IgA in the rat and in man.

In the rat, dimeric immunoglobulin A (dIgA) is cleared rapidly from the systemic circulation into bile by vesicular transport through the hepatocyte. Whether such transfer of dIgA occurs in man is controversial. The fate of dIgA and monomeric IgA (mIgA) was studied in rats with biliary drainage, and in parallel in 4 patients, 3 of whom had biliary drainage. Human dIgA and mIgA were prepared from myeloma sera and labeled with radioisotopes of iodine. Ten microcuries each of 125I-dIgA and 131I-mIgA (2 to 4 microgram protein) were given i.v. simultaneously. In the four patients, 125I-dIgA disappeared more rapidly from the serum than did 131I-mIgA. Biliary recovery of 125I-dIgA (expressed as per cent total dose given) was only 0.2 to 0.9% in 8 8 hr while that of 131I-mIgA was 0.1 to 0.2%. In contrast, biliary recovery over the same period in rats was 21 to 32% for 125I-dIgA and 3.0 to 4.6% for 131I-mIgA. The data show that in man after injection of a trace amount of human myeloma IgA, rapid transport of dIgA into bile, as observed in the rat, was not seen. Although selective transport of dIgA over mIgA into bile occurred in man, the total amount of dIgA transported was small, and it is suggested that under physiological conditions, the major part of human biliary IgA is derived from local synthesis.

Adult↗

PubMedDate not supplied

Hepatitis B virus infection: the impact of molecular biology.

Assays for the detection of nucleic acid in serum are likely to be better systems for determining infectivity than indirect ones dependent on detection of virus-encoded proteins such as HBeAg. The hybridization assays are particularly useful in monitoring spontaneous or treatment-related conversion from the "replicative" to "nonreplicative" phase of HBV infection. The simplified technology described in the papers reported in this issue of Hepatology (9, 14) and their future adaptation to nonisotopic systems will rapidly bring these techniques into everyday clinical practice.

DNA, Viral↗