John Vnek

A New Reversed Passive Hemagglutination Test for Detection of HBsAg

Abstract. A new reversed passive hemagglutination test for HBsAg, termed Raphadex B, has been developed using immunochemically purified chimpanzee anti‐HBs bound to stabilized human erythrocytes. The test has been found to have equivalent sensitivity to the Ausria 125I radioimmunoassay, and detected a similar number of HBsAg‐containing specimens in screening of volunteer blood donors. This method offers an economical approach to third generation methodology for hepatitis B screening of blood donors.

Delayed hypersensitivity and arthus reaction to purified hepatitis B surface antigen (HBsAg) in immunized chimpanzees

Abstract To further investigate the specific immunopathogenic role of hepatitis B surface antigen (HBsAg), we have histologically documented the sequential appearance of both delayed hypersensitivity and Arthus reactions following skin testing with purified HBsAg of chimpanzees. These findings were correlated with anti-HBs and anti-HBc antibody titers and with results of lymphocyte migration inhibition (LMI) tests to purified HBsAg. Positive cutaneous delayed hypersensitivity (DH) reaction developed in all six recently immunized chimpanzees, with evidence of in vitro DH to HBsAg by LMI in five of six. Arthus reactions following skin testing with HBsAg were observed in all seven animals immunized l yr earlier, which had high circulating anti-HBs titers. The LMI test was positive in only two of these. No cutaneous reactions, LMI, or anti-HBs were detected in two healthy chronic HBsAg carrier chimpanzees. By contrast, anti-HBc was detected only in this latter group. These data suggest that specific cellular as well as humoral response to HBsAg can develop in immune chimpanzees. In contrast, chronic carriers do not react in these tests, suggesting a form of immunologic paralysis.