Dendritic Cells in Semen of Infertile Men: Association with Sperm Quality and Inflammatory Status of the Epididymis

Objective: To determine whether dendritic cells (DCs) are present in semen and whether their abundance and activation correlate with sperm quality and inflammatory status of the male genital tract.

Design: In vitro prospective study.

Setting: University hospital laboratory.

Patient(s): Eighty infertile men and twelve control fertile men were enrolled in this study.

Intervention(s): None.

Main Outcome Measure(s): The percentages of DCs, intracellular staining of cytokines, and spermatozoa DNA fragmentation index were assessed by flow cytometry. Seminal cytokines, neutral α-glucosidase, zinc, and fructose were measured with commercial kits.

Result(s): A significant number of CD11c(+) HLA-DR(+) DCs were detected in ejaculates from patients with chronic inflammation of genital tract, which was negatively correlated with spermatozoa motility, vitality, and DNA integrity. Intracellular staining of cytokines of seminal DCs showed enhanced ability to secrete inflammatory cytokines (interleukin [IL] 23p19, tumor necrosis factor [TNF]-related apoptosis-inducing ligand [TRAIL], and TNF-α). Furthermore, a significant correlation was found between DCs and the seminal concentrations of IL-6, IL-17, IL-23, TRAIL, and neutral α-glucosidase, the marker of epididymal function, in the inflammatory group but not in the noninflammatory and fertile groups.

Conclusion(s): The abundance and activation of seminal DCs of infertile men may be closely associated with poor epididymal function and sperm quality.