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To the Editor: Legionnaires' disease is a systemic infection caused by gram-negative bacteria belonging to the genus Legionella. The primary clinical manifestation is pneumonia. Legionella spp. are typically found in [...]

Background: It has been identified that human epididymal protease inhibitor (EPPIN) plays a critical role in sperm function and male fertility. The aim of this study was to determine whether variants of the EPPIN gene are risk factors for idiopathic male infertility.Methods: All subjects, including 473 idiopathic infertile men and 198 fertile controls, underwent complete historical and physical examinations. Each subject donated 5 ml of peripheral blood for genomic DNA extraction and serum testosterone evaluation and an ejaculate for semen analysis. The semen analysis was performed by computer-assisted semen analysis system. The serum testosterone level was evaluated by radioimmunoassay. Four tagging single-nucleotide polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism.Results: We have demonstrated a significant decreased risk of idiopathic infertility with abnormal semen parameters in association with the variant rs2231829, and an increased risk of idiopathic infertility with abnormal semen parameters in association with the variant rs11594. However, among men with normal semen parameters, there were no differences in risk for these genotypes. Furthermore, no significant differences were found for the other variants, rs6124715 and rs2227290, on the risk of male infertility with normal or abnormal semen parameters. Similar serum testosterone levels among different EPPIN genotypes were observed for each group.Conclusions: These results suggest that different variants in the EPPIN gene may have different relationships with idiopathic male infertility and men carrying these variants have a decreased or increased risk of abnormal semen parameters associated with male infertility. [ABSTRACT FROM AUTHOR]

Background: Before a spermatozoon can fertilize an oocyte it must undergo a cascade of biochemical and physiological changes that facilitate its binding and penetration into the oocyte. Epididymal protease inhibitor (eppin) has been found to play a critical role in male fertility through an immunological approach.Methods: In this study, we used an anti-eppin antibody to clarify the effect of eppin on human sperm functions during fertilization. Immunofluorescence studies were performed on ejaculated human spermatozoa in uncapacitated, capacitated and ionophore-treated states. Human spermatozoa were incubated in the presence or absence of anti-eppin antibody under capacitating conditions and with A23187. The effects of the antibody were evaluated on sperm motility, protein phosphotyrosine content and free intracellular calcium.Results: Immunofluorescence results demonstrated that eppin is located on the acrosome and tail. After the acrosome reaction eppin is found on the equatorial segment and tail. We found that blocking eppin with antibodies significantly inhibited the human sperm acrosome reaction induced by A23187 in a dose-dependent manner. Finally, fluo-3 analysis demonstrated that the A23187-induced elevation of sperm intracellular calcium concentration was markedly reduced after incubation with anti-eppin antibody. However, the tyrosine phosphorylation of sperm proteins did not change.Conclusion: These results demonstrate that eppin can modulate intracellular calcium concentrations and subsequently affect the calcium ionophore A23187-induced acrosome reaction. [ABSTRACT FROM AUTHOR]