Acute epididymitis induces alterations in sperm protein composition

ObjectiveTo use a proteomic approach to evaluate possible postinflammatory alterations in the protein composition of motile sperm in patients 3 months after acute epididymitis.DesignProspective case-control study.SettingUniversity medical school research laboratory.Patient(s)Eight patients 3 months after acute unilateral epididymitis and 10 healthy controls.Intervention(s)None.Main Outcome Measure(s)Proteome analysis of sperm samples collected by swim-up from control and acute epididymitis patients analyzed by two-dimensional gel electrophoresis and subsequent protein identification by matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry; immunofluorescence staining for mitochondrial ATP synthase subunit β (ATP5B), α-tubulin (TUBA1A), and tubulin-β2c (TUBB4B) for validation purposes.Result(s)Proteome analysis identified 35 proteins in sperm from epididymitis patients that were down-regulated, irrespective of subcellular localization and biologic function. Furthermore, immunofluorescence microscopy confirmed ATP5B, TUBA1A, and TUBB4B were less abundantly expressed in epididymitis samples compared with controls.Conclusion(s)Despite normal semen parameters observed by conventional semen analysis in patients after epididymitis, significant changes to sperm protein composition were observed. These changes may be implicated as additional factors contributing to subfertility/infertility in men after episodes of epididymitis.