Application of leukocyte subsets and sperm DNA fragment rate in infertile men with asymptomatic infection of genital tract

Abstract

Background: About 15% of male infertility is due to genital tract infection and inflammation, some of them have no clinical symptoms, but manifested as leukocytospermia (LCS). Leukopenia will lead to functional impairment of male sperm and integrity damage of sperm morphology. A large amount of reactive oxygen species (ROS) produced by leukocytes can damage sperm nuclear DNA. The aim of this study was to investigate the correlation between leukocyte subsets and sperm DNA fragmentation rate in semen of infertile men with asymptomatic infection of genital tract.

Methods: One hundred and eight cases of infertile men were enrolled, who were admitted to our hospital from May 2016 to September 2018, and all had genital tract infections. After routine sperm analysis, realtime PCR was performed for detecting the infection of chlamydia trachoma (CT) and Ureaplasma urealyticum (UU). Furthermore, total leukocyte count in semen was evaluated by detection of CD45 molecules using immunocytochemistry. Flow cytometry was used for subset analysis, monocyte/macrophages were evaluated by CD14, and activated macrophages were evaluated by HLA-DR antigen. Sperm DNA fragmentation index (DFI) were evaluated by SCD method and 8-hydroxydeoxyguanosine (8-OHdG) expression were evaluated by chromatin diffusion method and TUNEL method; the correlation analysis was conducted between semen leukocyte subsets, sperm DNA fragment rate and conventional semen parameters.

Results: There was a significant correlation among the concentrations of cells expressing HLA-DR antigen and those expressing CD14 (P<0.01), but the concentrations of differential leukocyte subsets all had no significant correlation with sperm DFI, the percentage of 8-OHdG-expressing cells and routine semen parameters. The percentage of 8-OHdG-expressing sperm was positively correlated with the percentage of sperm fragments (r=0.42, P<0.01), and negatively correlated with sperm concentration (r=-0.32, P<0.01). After adjustment for possible confounders including age, abstinence time and smoking, the percentage of 8-OHdG-expressing sperms independently associated with sperm concentration (β=-0.30; P=0.006) and DFI (β=0.180, P=0.06).

Conclusions: Among infertile men with genital tract infection, the sperm DFI is associated with decreased semen quality and not the concentration of differential leukocyte subsets.

Keywords: 8-hydroxydeoxyguanosine (8-OHdG); Leukocyte subset; genital tract infection; infertile men.