e Antigen and antibody in outbreaks of hepatitis B in two renal dialysis units

SUMMARY In two renal dialysis units which had outbreaks of hepatitis B, patients were studied for the presence of e antigen and antibody. In one unit, in which the illness was mild and most of the patients (78 %) became carriers of HBsAg, all but one patient had e antigen. Most of the HBsAg carriers had persisting e antigen and most of the transient patients had also transient e antigen. In the other unit, in which the illness was more severe, none of the patients became a carrier. Only 30 % had e antigen during the acute phase of illness and 40 % developed anti-e just before clearing HBsAg. It seems possible that the differences between these two units may reflect strain differences in the infectivity of hepatitis B virus. The e antigen/antibody system was first described by Magnius and Espmark (1972), who suggested that the presence of e antigen might indicate infectivity while the antibody occurred only in non-infectious HBsAg positive sera. The correlation of e antigen with large numbers of 'Dane ' particles, and its absence in sera containing no 'Dane ' particles (Nielsen et al., 1974; Neurath et al., 1976), also seems to suggest a relationship to infectivity. Neurath et al. (1976) suggested that e antigen is present as an additional antigenic site on the surface of the 'Dane' particles and tubular forms of HBsAg as well as in the form of a soluble antigen. Nielsen et al. (1974) suggested that it might be a valuable prognostic marker because it was present in the sera of 58 % of cases of acute hepatitis B which progressed to chronic hepatitis or cirrhosis. In the present study, the presence was determined of e antigen and antibody in sera from patients in two renal dialysis units in which the outbreaks of hepatitis B (during 1969-71) were quite different (Polakoff et al., 1972). In dialysis unit A, 32 of the infected patients became carriers of HBsAg. Of these, consecutive serum samples were available from 27. In dialysis unit B, none of the infected patients became a carrier. Consecutive serum samples were available from all 10 individuals. Material and methods Sera taken from patients with hepatitis B infection in the two renal dialysis units were examined for