Evaluation of Leukocyte Threshold Values in Semen to Detect Inflammation Involving Seminal Interleukin-6 and Interleukin-8

Abstract

To evaluate leukocyte threshold values in semen to detect inflammation involving seminal interleukin (IL)-6 and IL-8. The levels of leukocytes, IL-6, and IL-8 in semen were determined. The 75th and 90th percentiles of seminal IL-6 and IL-8 were considered as "high" and "very high" concentrations, respectively. Inflammatory semen was defined based on high levels of IL-6 (≥86.75 pg/mL) or IL-8 (≥4460 pg/mL). Very high levels of IL-6 (≥228 pg/mL) or IL-8 (≥12,480 pg/mL) were used to define acute seminal inflammation. On the basis of high and very high levels of IL-6 or IL-8, receiver operating characteristic curves were generated to evaluate leukocyte threshold values. Leukocytes at a cutoff level of 1 × 10(6)/mL had 51% sensitivity and 95% specificity to detect high levels of IL-6, whereas on the basis of very high levels of IL-6, the same cutoff level revealed 82% sensitivity and 90% specificity. Similarly, leukocytospermia demonstrated low sensitivity (56%) to detect high levels of IL-8 but acceptable sensitivity (94%) and specificity (92%) to predict very high levels of IL-8. The cutoff level of 0.315 × 10(6) leukocytes/mL had optimal sensitivity and specificity for predicting high levels of inflammatory cytokines. Leukocytospermia demonstrated poor sensitivity to detect seminal inflammation, as defined by high levels of inflammatory cytokines. The optimal threshold value to detect inflammation was found to be 0.315 × 10(6) leukocytes/mL. On the basis of very high levels of IL-6 or IL-8, leukocytospermia is a sensitive and specific marker to predict acute seminal inflammation.