Linda A. Smallwood

Subtyping of Hepatitis B Surface Antigen and Antibody by Radioimmunoassay

The hepatitis B surface antigen (HBSAg) has been shown to possess distinct subtypes adw, ayw, adr, and ayr). A commercially available solid phase radioimmunoassay for antibody to HBSAg (Ausab, Abbott Laboratories North Chicago, Ill.) has been modified to detect the subtypes of HBSAg as well as the subtype-specific anti-HBS reactivities to detect the subtypes of HBSAg as well as the subtype-specific anti-HBS reactivities (anti-d, anti-y, and anti-w). This method has the advantages of general availability, ease of performance, and increased sensitivity over conventional subtyping methods of agar gel diffusion and counterelectrophoresis.

Studies of Donors Who Transmit Posttransfusion Hepatitis

Sera and questionnaires were evaluated retrospectively from 128 volunteer blood donors whose blood had been implicated in cases of clinically recognized posttransfusion hepatitis in recipients of one‐ or two‐unit blood transfusions between 1971 and 1977. Serologic markers of hepatitis B virus (HBV) infection were found in 23 per cent, compared to 9.7 per cent of 3,230 prospective blood donors. The prevalence of antibody to hepatitis A virus was similar among implicated donors (44%), prospective donors (58%), and among those implicated donors with (41%) and without (44%) HBV markers. Among implicated donors, none had a history at the time of donation of having had clinically recognizable hepatitis, 93 per cent had no history of prior blood transfusion, and 80 per cent had normal hepatic enzymes. Data from this study confirm that non‐A, non‐B hepatitis has been a common form of posttransfusion hepatitis in recent years, since 77 per cent of these implicated donors had no HBV serologic markers. In addition, these donors could not be distinguished by age, race, sex, history of clinical hepatitis or of prior blood transfusion, or in most cases by hepatic enzyme levels.

Concomitant Hepatitis B Surface Antigen and Antibody in Thirteen Patients

Both hepatitis B surface antigen (HBsAg) and its antibody (anti-HBs) were found in 13 patients. Nine patients had HBsAg subtype ad, and 7 had anti-HBs monotypic subtype anti-y. Nine patients had HBsAg before detectable levels of anti-HBs were present. Of the 6 patients whose serum contained subtypes of both HBsAg and anti-HBs, 4 had HBsAg before development of the monotypic antibody. All patients have remained positive for HBsAg and anti-HBs (mean duration, 55.5 weeks). Nine patients were positive for HBeAg, and 7 had renal disease. Six of these seven patients are on hemodialysis. Because of the differing subtype specificities of the circulating HBsAg and anti-HBs, we conclude that HBsAg and anti-HBs occur concomitantly. The presence of HBeAg, which indicates infectivity, is common in our study group, suggesting that these patients are a reservoir for transmission of hepatitis-B-virus infection. Therefore, the presence of anti-HBs alone does not indicate a noninfectious serum. Concomitant HBsAg and anti-HBs seems to be particularly common in patients with renal disease who are on hemodialysis.

Antibody to Hepatitis B Core Antigen in Blood Donors with a History of Hepatitis

Sera and questionnaires from 3,230 prospective U.S. volunteer blood donors were obtained in an earlier study to determine the prevalence of serologic markers of hepatitis B virus (HBV) and hepatitis A virus (HAV) among prospective blood donors with or without a history of either hepatitis or blood transfusion. These sera were reevaluated using a radioimmunoassay for antibody to hepatitis B core antigen (anti‐ HBc). Anti‐HBc in the absence of hepatitis B surface antigen (HBsAg) or its antibody (anti‐HBs) was detected in 30 of 1,151 (2.6%) prospective donors with a history of hepatitis, compared to four of 1,086 (0.4%) with no history of hepatitis (p < 0.001). Although end‐point dilution titers of anti‐HBc ≥ 1:100 and the presence of IgM anti‐HBc were more frequently detected among donors with a history of hepatitis than among donors with no history of hepatitis, the difference was not statistically significant. Unlike a history of hepatitis, a history of transfusion or a history of exposure to persons with hepatitis had no significant association with the detection of anti‐HBc in the absence of other HBV serologic markers.

Chromatographic removal of hepatitis B virus from a factor IX concentrate. Experimental studies in chimpanzees

Non‐A, non‐B hepatitis virus can be removed from a factor IX concentrate by a hydrophobic chromatographic step added to the ordinary fractionation process. The efficacy of this procedure for removal of hepatitis B virus (HBV) was evaluated in chimpanzees. A well‐defined hepatitis B virus (HBV) inoculum was added to a factor IX preparation and this preparation was subjected to chromatography with octanohydrazide‐Sepharose 4B at a high salt concentration and then injected intravenously into two chimpanzees. A control chimpanzee was inoculated with the part of the factor IX/HBV preparation that had not been chromatographed. The two chimpanzees that received the treated material remained free of any serologic or biochemical evidence of hepatitis B infection during a 12‐month follow‐up, whereas the control chimpanzee had hepatitis B. After a later HBV challenge, the two healthy animals also had hepatitis B. The hydrophobic binding procedure seems to be useful for the adsorption of viral agents in blood components.