Cytofluorographic identification of activated T-cell subpopulations in the semen of men with spinal cord injuries

Abstract

The semen of most men with spinal cord injury (SCI) contains an abundance of leukocytes. It is not known if this leukocytospermia contributes to the abnormally low sperm motility observed in many of these men. Our study used flow cytometry to identify the leukocyte population in the semen of 12 men with SCI compared to 8 healthy age-matched control subjects. The results showed that, compared to control subjects, the semen of men with SCI had increased numbers of mature granulocytes and lymphocytes. The largest proportion of the leukocytes consisted of lymphocytes, and immunophenotypic analysis showed that the greater fraction were T cells, many of which coexpressed human leukocyte antigen HLA-DR and CD25, suggesting they were in an "activated" state. No significant B-cell population was evident. Our finding of immunologically active leukocytes is a significant step in understanding the relationship of leukocytospermia and decreased sperm motility in the semen of men with SCI.