Human leucocyte antigen I expression in spermatozoa from infertile men

The expression of class I human leucocyte antigen (HLA) has been investigat ed by reverse transcription polymerase chain reaction (RT-PCR) and flow cyt ometry on human purified ejaculated spermatozoa from an infertile populatio n. Similar investigation in a control fertile population has been performed . Among 22 fertile and 20 infertile men, 17 were selected for the study bec ause they showed no contamination with non-sperm cells. HLA I molecules wer e expressed in four of nine fertile subjects (44.4%) and three of eight inf ertile subjects (37.5%), with no significant difference between groups. The se data demonstrate for the first time the presence of class I HLA antigens on spermatozoa of infertile subjects. In addition, considering that simila r results have been obtained in both fertile and infertile populations, the hypothesis that the fertilizing capacity of the spermatozoon is independen t of class I HLA-antigen expression on their surface may be advanced.