Effects of White Blood Cells on the In Vitro Penetration of Zona‐free Hamster Eggs by Human Spermatozoa

Abstract

The presence of white blood cells in semen has been associated with male infertility. Previous studies indicate that pyospermia occurs in conjunction with decreases in sperm motility, number of normal sperm forms, and penetration rates in the zona-free hamster egg sperm penetration assay. We have evaluated the relationship of seminal white blood cells and sperm function, as reflected in the zona-free hamster egg penetration assay, and have investigated the possible mode of action of the white cells. Egg penetration rates decreased when white blood cells from fertile or potentially fertile donors were added to their sperm suspensions prior to preincubation and at insemination in the in vitro assay. Zona-free hamster egg penetration assay results were also inhibited when the supernatant from white blood cells incubated in Biggers, Whitten, and Whittingham (BWW) medium overnight were introduced to sperm-oocyte suspensions at insemination. Conversely, egg penetration rates were enhanced in samples from hypofertile individuals when white blood cell concentrations in the semen or WBC/sperm ratios were reduced, either by physical removal or as a result of antibiotic therapy. The physical presence of leukocytes, and possibly, the extracellular release of lysosomal enzymes may be responsible for the inhibitory effects in vitro. Although the mechanism(s) by which white blood cells interfere with the fertilizing capacity of spermatozoa are not clear, it is quite obvious that their presence in the in vitro environment is undesirable and can mask an individual's actual fertilizing potential.

Nonsperm Cells in Human Semen: With Special Reference to Seminal Leukocytes and their Possible Influence on Fertility

“…In unstained wet preparations it is difficult to distinguish immature germ cells from WBC: Immature germ cells may be recorded as WBC. This might explain why Maruyama et al [58] found that among 243 ejaculates from infertile couples 134 contained high concentrations of WBC, i.e., >3 x 106/mL, and 42 ejaculates contained >I0 x 106/mL. Using cytological staining procedures the different kinds of NSC are distinguishable by morphological criteria.…”

Prevalence of sexually transmissible pathogens in semen from asymptomatic male infertility patients with and without leukocytospermia

“…The prevalence of LCS in male infertility patients varies from 2% to 40% in published reports (9,(11)(12)(13), and elevated concentrations of WBC in semen have been associated with reduced sperm function and quality (9,(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23).…”

Reactive Oxygen Species in Human Semen in Relation to Leukocyte Contamination

“…The contribution of leukocytospermia to impairming the fertilizing ability of sperm was first studied in the mid-nineteen eighties 12 , but since then conflicting opinions have been expressed. For instance, Ochsendorf 8 stated that only very high numbers of leukocytes, at least >2.0x10 6 PMN per ml, generate excessive ROS which can not be counteracted by the antioxidant capacity of seminal plasma.…”