Percoll density gradient centrifugation and consecutive flow cytometry do not identify leukocytes and leukocyte subtypes in ejaculate specimens

Effects of leukocytospermia on the outcomes of assisted reproductive technology

Leukocytospermia is one of the common causes of male infertility, and its effects on the clinical outcomes of assisted reproduction are controversial. There are no recommendations for the management of leukocytospermia in cases of assisted reproductive technology (ART). To investigate the impact of leukocytospermia on ART, we retrospectively compared the clinical outcomes in ART couples with or without leukocytospermia and further analysed the impact of the insemination method itself by split insemination treatment in ART couples with leukocytospermia. In this study, leukocytospermia was detected in 133 patients, namely 63 in the conventional in vitro fertilization (IVF) group, 38 in the intracytoplasmic sperm injection (ICSI) group and 32 in the split insemination group. Leukocytospermia has a negative influence on the parameters of semen samples; however, leukocytospermia did not affect the clinical outcomes of IVF or ICSI. Different insemination methods did not affect the fertilization, clinical pregnancy or live birth rates. In the split insemination study, no significant differences in clinical pregnancy and live birth rates between the IVF and ICSI groups were found; however, the numbers of two pronuclei (2PN), available embryos and good‐quality embryos in the ICSI group were higher than those in the IVF group. Leukocytospermia may be a risk factor affecting semen parameters, and more attention should be given to IVF insemination. Leukocytospermia has no significant negative effect on the outcomes of ART. ICSI may obtain better embryos than IVF, but it cannot improve the clinical pregnancy and live birth rates.

Influence of autogenous leucocytes and Escherichia coli on sperm motility parameters in vitro

Urogenital infections are considered important factors in male infertility. In this in vitro study we have evaluated the impact of leucocytes in association with an artificial infection with Escherichia coli on the motility of human spermatozoa. Ejaculates and blood samples were obtained from healthy donors with normal semen parameters. Ejaculates were prepared by swim-up technique and five fractions were isolated for incubation. Leucocyte subtypes were separated from blood samples by gradient centrifugation. Purified sperm suspensions were adjusted to a concentration of 20 x 106 ml-1 and incubated with lymphocytes/ monocytes, polymorphonuclear granulocytes (PMN), and E. coli. Samples were incubated for up to 6 h at 37 degrees C. Motility analysis was performed using a computer-assisted sperm analyzer (CASA). Spermatozoa incubated with 3 x 106 PMN ml-1 revealed a significant (P=0.003) decrease in progressive motility after 2 h. This decrease remained weakly significant (P=0.024) after 4 and 6 h. Lymphocytes and monocytes had no effect on sperm motility. Spermatozoa incubated with granulocytes and E. coli demonstrated highly significant alterations in motility after 4 and 6 h of incubation (P < 0.001). The PMN indicate an effect on motility of spermatozoa under experimental conditions. However, the results suggest that bacteria are the primary agents that interfere with sperm motility.

Leukocyte detection in human semen using flow cytometry

This study set out to establish a new method, using flow cytometry, to evaluate leukocytes in semen. Ejaculates of 59 males, asymptomatic for genitourinary infections, were examined. Routine semen analyses were carried out as well as peroxidase and polymorphonuclear granulocyte-elastase detection. Leukocytes were detected combining flow cytometry and monoclonal antibodies (anti-CD45, anti-CD53). This technique reliably assessed the total number of leukocytes and differentiated subpopulations even at low concentrations. The peroxidase test and elastase determination showed good specificity, but only moderate sensitivity versus flow cytometry combined with monoclonal antibodies. No significant association was observed between semen parameters and leukocytospermia whether evaluated by conventional methods or flow cytometry except for a moderate correlation between spermatozoa and CD53-positive cell concentrations. A first comparison of data from patients grouped on the basis of leukocytospermia (>10(6) white blood cells, WBC/ml) or non-leukocytospermia revealed no significant differences in semen parameters; lowering the threshold value for leukocytospermia to 2x10(5) WBC/ml, sperm concentration was reduced in the group with a low number of WBC identified by monoclonal antibodies. Flow cytometry using monoclonal antibodies was seen to be a simple, reproducible method that enables leukocytes in semen to be accurately detected and to identify WBC subpopulations without preliminary purification procedures.