Antibodies toPneumocystis cariniiin Danish blood donors and AIDS patients with and withoutPneumocystis cariniipneumonia

Sera from 1) 8 AIDS patients with Pneumocystitis carinii pneumonia, 2) 13 HIV antibody-positive patients, 9 with AIDS and 4 with AIDS-related symptoms, all 13 without Pneumocystis carinii pneumonia, and 3) 36 healthy male blood donors, all HIV antibody negative, were examined for antibodies against Pneumocystis carinii using the indirect immunofluorescence antibody technique. Seven (87%) out of eight sera from group 1, 12 (92%) out of 13 sera from group 2, and 35 (97%) out of 36 sera from group 3 were positive. There was no significant difference between group 1 and 2, and group 2 and 3. The difference between group 1 and group 3 was significant (p = 0.03).