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

Objective: To evaluate leukocyte threshold values in semen to detect inflammation involving seminal interleukin (IL)-6 and IL-8.

Materials And Methods: 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.

Results: 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.

Conclusion: 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.