Serum samples taken from 73 patients with haemophilia A were tested fo
r the presence of total antibody against hepatitis A (antiHAV) by radi
oimmunoassay. 29 (39.7%) were antiHAV positive and 44 (60.3%) were ant
iHAV negative. These figures are comparable with local prevalence figu
res for immunity (40.3%) and susceptibility (59.7%) to HAV in adults.
30 patients were subsequently exposed to Scottish National Blood Trans
fusion Service High-Purity Factor VIII (SNBTS HPVIII). They were re-te
sted for the presence of antiHAV at a median of 5 months after exposur
e. Of these, 25 (83.3%) were antiHAV negative (16.7%) were antiHAV pos
itive. All five antiHAV-positive patients were positive on samples tak
en prior to exposure. No cases of seroconversion to hepatitis A occurr
ed.