Recovery and turnover rate of hepatitis B immunoglobulin in volunteers.

: Hepatitis B Immunoglobulin with an antibody content of 2 300 IU was injected i.m. into five healthy female volunteers without Hepatitis B markers in serum (HBsAg, anti-HBs, anti-HBc). The uptake of anti-HBs after i.m. injection was calculated by measuring the concentration of antibody in plasma. An international standard (WHO) containing 100 IU/ml was used as reference. The serum concentration of anti-HBs was analysed on day 1, 3, 5, 7, 9, 11, 13, 28 and 56 after the single i.m. injection. The peak serum concentrations after one single injection were observed between day 5 and 11. The mean recovery rate was calculated according to a compartment model where the plasma volume was estimated to be 45 ml/kg body weight. The mean recovery rate expressed as percentage of injected dose was 19.2% with a range of 14.2-28.2%. The mean biological half life of anti-HBs was 21.7 days. The recovery rate of Hepatitis B Immunoglobulin injected i.m. seems to be somewhat lower than expected but is within the same range as i.e. Ig anti-D (Eklund et al, BMJ 1982, 284: 854-855). The peak serum concentration of anti-HBs was reached comparatively late after the injection. This finding may in part explain the discouraging protection of Hepatitis B Immunoglobulin in the post-exposure situation. Intravenous administration of anti-HBs with an immediate peak concentration followed by vaccination will possibly be a better alternative for post-exposure prophylaxis against Hepatitis B.