[Hepatitis A antibodies in young hemophiliacs].

The proof of antibodies against the hepatitis A-virus (anti-HAV) is a frequent finding in substituted haemophiliacs. Anti-HAV is apparently not the expression of an actively acquired immunity, but might have been transmitted above all passively by means of the plasma preparations. Among 68 haemophilic children and adolescents anti-HAV was proved 22 times, in 33 boys of about the same age with undisturbed blood coagulation only twice. Of 40 cryoprecipitate 22 were anti-HAV-positive. Thus as a side-effect of the substitution therapy a protective effect against a hepatitis A-virus infection develops--at least partly.