Nonsperm cells in human semen: with special reference to seminal leukocytes and their possible influence on fertility

Nonspermatozoal cells (NSC) in semen, including immature germ cells, leukocytes (WBC) and epithelial cells, are normally found in a concentration less than 15% of the sperm concentration. Cytological staining methods and immunoenzymatic assays for characterization of seminal WBC and methods for detection of various enzymes from WBC are evaluated. Criteria for abnormally high levels of WBC in semen, caused by exogenic factors (e.g., infection) and possibly by endogenic factors (e.g., abnormal sperm), are discussed. Leukocytospermia is associated with reduced in vitro fertilization rate, and experimentally-measured sperm functions (e.g., motility) are inhibited by high concentrations of certain WBC products (e.g., reactive oxygen species and interferon-gamma). At the present stage, the following procedures could be used to evaluate WBC in ejaculates from infertile patients: (1) count the number of NSC using a hemocytometer. (2) Determine the number of WBC in percentage of NSC in smears using the Papanicolaou staining technique, or an immuno-enzymatic assay using monoclonal antibodies to the different kinds of WBC. (3) If, abnormally high levels of WBC (according to the WHO criteria or based on a percentile determined from examination of normal, fertile men) is detected, a second ejaculate should be examined 3 months later. (4) Persistent leukocytospermia should indicate physical and microbiological examinations, after which antibiotic treatment may be indicated.