Epididymitis: revelations at the convergence of clinical and basic sciences

• Published in: Asian journal of andrology Vol. 17; no. 5; pp. 756 - 763
• Main Authors: Michel, Vera, Pilatz, Adrian, Hedger, Mark P, Meinhardt, Andreas
• Format: Journal Article
• Language: English
• Published: China Medknow Publications and Media Pvt. Ltd 01.09.2015; Medknow Publications & Media Pvt. Ltd; Medknow Publications & Media Pvt Ltd; Wolters Kluwer Medknow Publications
• Subjects: acute epididymitis; animal models of bacterial epididymitis; epididymal duct; epididymal immune environment; fertility; Animals; Anti-Infective Agents - therapeutic use; Apoptosis; Azoospermia - etiology; Bacteria; Care and treatment; Causes of; Convergence; Cytokines; Dendritic cells; Diagnosis; Disease Models, Animal; E coli; Epididymis - pathology; Epididymitis; Epididymitis - complications; Epididymitis - drug therapy; Epididymitis - pathology; Health aspects; Humans; Infections; Invited Review; Lymphocytes; Male; Male infertility; Motility; Oligospermia - etiology; Prevention; Quality; Risk factors; Rodents; Sperm; Spermatogenesis; Spermatozoa - pathology; T cell receptors; Germany
• ISSN: 1008-682X; 1745-7262
• DOI: 10.4103/1008-682x.155770

Acute epididymitis represents a common medical condition in the urological outpatient clinic. Mostly, epididymitis is caused by bacterial ascent through the urogenital tract, with pathogens originating either from sexually transmitted diseases or urinary tract infections. Although conservative antimicrobial therapy is possible in the majority of patients and is usually sufficient to eradicate the pathogen, studies have shown persistent oligozoospermia and azoospermia in up to 40% of these patients. Animal models of epididymitis are created to delineate the underlying reasons for this observation and the additional impairment of sperm function that is often associated with the disease. Accumulated data provide evidence of a differential expression of immune cells, immunoregulatory genes and pathogen-sensing molecules along the length of the epididymal duct. The evidence suggests that a tolerogenic environment exists in the caput epididymidis, but that inflammatory responses are most intense toward the cauda epididymidis. This is consistent with the need to provide protection for the neo-antigens of spermatozoa emerging from the testis, without compromising the ability to respond to ascending infections. However, severe inflammatory responses, particularly in the cauda, may lead to collateral damage to the structure and function of the epididymis. Convergence of the clinical observations with appropriate animal studies should lead to better understanding of the immunological environment throughout the epididymis, the parameters underlying susceptibility to epididymitis, and to therapeutic approaches that can mitigate epididymal damage and subsequent fertility problems.