The problem of purification of HBs antigen.

Purification techniques utilized until now do not allow to obtain an HBs antigen totally free from one or more protein constituents of the serum. The authors describe the method which has given the best results; this method combines the utilization of silicate, Sephadex G200 and ultracentrifugation. The authors then determined the nature of the relations between HbsAg and the serum proteins. They have perfected a screening technique allowing to detect the immune complexes by means of a tetanus antigen-tetanus antitoxin model. Sixty-nine patients with viral hepatitis A and B were tested. It was observed that the immune complexes are in relation with the IgM which are themselves correlated with the rheumatoid factor: the mu chains found in purified HBsAg could correspond to the rheumatoid factor reacting with the Fc of IgG bound to HBsAg.