Semen polymorphonuclear neutrophil leukocyte elastase as a diagnostic and prognostic marker of genital tract inflammation--a review.

Elastase is a protease released by polymorphonuclear neutrophils (PMN) during the inflammatory process. Since 1987, seminal elastase-inhibitor complex (Ela/alpha1-PI) has been proposed as a marker of male silent genital tract inflammation. Measured by immunoassay in seminal plasma, Ela/alpha1-PI at a cut-off level of > or = 230 microg/l, is useful in the detection of genital tract inflammation. The prevalence of increased seminal Ela/alpha1-PI in infertile men is significantly higher than that observed in fertile men. The Ela/alpha1-PI level is positively correlated with other seminal fluid markers of male genital tract inflammation: reduced semen volume, citric acid, fructose, and increased albumin, complement component C3, caeruloplasmin, immunoglobulins IgG and IgA, and cytokines interleukins-8 and -6. A higher seminal Ela/alpha1-PI level is significantly associated with tubal damage in female partners. After antibiotic therapy, a decrease of Ela/alpha1-PI level is observed. The presence of tubal damage in the partner may negatively affect the response to antibiotic treatment. A higher seminal Ela/alpha1-PI is associated with lower percentage of sperm with single-stranded deoxyribonucleic acid (DNA) and better fertilization rate in in vitro fertilization. Besides infertility, the determination of Ela/alpha1-PI is useful to confirm the presence of prostate and other male accessory gland bacterial inflammation. Screening for PMN Ela/alpha1-PI is easy to perform and reproducible and is a reliable quantitative test for diagnosis and prognosis of silent genital tract inflammation of couples. Moreover, sequential determinations allow the follow-up of inflammation during and after therapy.