Detection and quantitation of soluble B7-H3 in expressed prostatic secretions: a novel marker in patients with chronic prostatitis

Abstract

Purpose: We determined the soluble B7-H3 level and its clinical significance in serum and expressed prostatic secretions of patients with chronic prostatitis, including chronic bacterial prostatitis (type II) and chronic pelvic pain syndrome.

Materials and methods: Using enzyme-linked immunosorbent assay we measured soluble B7-H3 in 11 patients with chronic prostatitis (type II), and 26 with inflammatory (type IIIA) and 54 with noninflammatory (type IIIB) chronic pelvic pain syndrome, and healthy donors. We assessed differences between these groups using Student's t test. As determined by the National Institutes of Health-Chronic Prostatitis Symptom Index, we correlated soluble B7-H3 with clinical pain using the Pearson test.

Results: We found no significant difference between serum soluble B7-H3 in healthy donors and patients with chronic prostatitis (p = 0.897). However, soluble B7-H3 in expressed prostatic secretions was statistically significantly decreased in patients with chronic prostatitis vs controls (p <0.001). ROC using soluble B7-H3 greater than 38.82 ng/ml in expressed prostatic secretions distinguished patients with chronic prostatitis from healthy donors with 90.9% sensitivity and 83.5% specificity. Also, soluble B7-H3 levels in expressed prostatic secretions correlated negatively with the Chronic Prostatitis Symptom Index and the pain subscore. Compared to the pretreatment level soluble B7-H3 in expressed prostatic secretions was significantly increased in patients with a greater than 25% decrease in the Chronic Prostatitis Symptom Index total score (p = 0.016).

Conclusions: Data indicate that the soluble B7-H3 level in expressed prostatic secretions is a novel chronic prostatitis marker that correlates negatively with subjective symptoms.