The removal of morphologically abnormal sperm forms by phagocytes: a positive role for seminal leukocytes?

A preliminary investigation was undertaken further to determine the function of the leukocytic cells found in semen. We performed semen analysis and quantified leukocyte subsets using immunocytochemical staining techniques in ejaculates of 351 patients. Leukocyte profiles were examined in relation to sperm morphological data for evidence of a sperm removal/selection process. Three types of seminal phagocytic cell were found to contain spermatozoa: small polymorphonuclear leukocytes (∼ 10–12 μn), monocytes of similar size and much larger (30–40 μm) macrophages capable of engulfing multiple sperm heads. The total leukocyte count (P < 0.01), the numbers of phagocytic cells i.e. polymorphonuclear leukocytes (P < 0.05), monocyte/macro-phages (P < 0.01) and HLA-DR positive cells (P < 0.01), were significantly higher in those samples with > 50% ideal sperm forms. Significantly fewer of these same cell types were observed in samples with > 50% head defects. There was no difference in the number of tail or midpiece defects between leukocytospermic (