Abstract: | Anti-HBs was undetectable in the plasma of 303 HBsAg-positive blood donors. The apparent reactivity of anti-HBs in the chromatographically isolated IgG fractions of these antigen-positive donors was shown to be nonneutralizable by HBsAg. The false-positive antiHBs reactions were apparently due to the isolation and concentration of IgG from the plasma which was initially nonreactive for anti-HBs. |