Blood groups and HLA antigens in paracoccidioidomycosis.

The frequencies of blood groups, Rh and HLA antigens were studied in a series of patients with paracoccidioidomycosis as well as in control subjects. Statistical analysis of the results showed that only 2 antigens (HLA-A9 and HLA-B13) had a significantly increased frequency among patients with paracoccidioidomycosis compared with healthy controls. Among patients with paracoccidioidomycosis antigen HLA-A9 was significantly more prevalent in progressive pulmonary forms of the disease than in patients with extra pulmonary involvement. These observations suggest that HLA-A9 may influence susceptibility to the mycosis as well as its course.