SUSCEPTIBILITY TO IDIOPATHIC AZOOSPERMIA IN JAPANESE MEN IS LINKED TOHLA CLASS-I ANTIGEN

Purpose: Approximately 15 to 20% of infertile men have azoospermia. In the Y chromosome a deletion, termed the azoospermic factor, has been found in some cases of idiopathic azoospermia. We investigate the rela tionship of factors in autosomal chromosomes (HLA class I antigens) to spermatogenesis failure in idiopathic azoospermia. Materials and Meth ods: We evaluated 65 infertile Japanese men with idiopathic azoospermi a. The frequency of the HLA allele reported in 1,216 healthy Japanese men was used as a control. HLA class I typing was performed by the Nat ional Institutes of Health standard serological method or polymerase c hain reaction-sequence specific primer analysis. Allele frequencies we re calculated. We determined statistical significance in the frequency of each allele in patients and controls using the chi-square test. Th e relationship of HLA antigens to idiopathic azoospermia was expressed as relative risk. Results: In Japanese men with idiopathic azoospermi a the frequency of HLA-A33, B13 and B44 was significantly increased co mpared with controls. The relative risk of HLA-B44 was 8.4, an extreme ly high value compared with that of other diseases and HLA antigens. C onclusions: We suggest that HLA class I antigens are important genetic markers that represent a risk factor for idiopathic azoospermia.