NLRP3 inflammasome in expressed prostatic secretions as a potential biomarker of chronic prostatitis/chronic pelvic pain syndrome.

Background: Pyroptosis has been implicated in the progression of chronic prostatitis (CP)/chronic pelvic pain syndrome (CPPS).

Objectives: The present study was performed to explore the diagnostic value of the levels of the pyroptosis-related protein nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome in the expressed prostatic secretions (EPS) of patients with CP.

Material and methods: A total of 167 CP patients, including 85 National Institutes of Health (NIH)-IIIA CP patients and 82 NIH-IIIB CP patients, as well as 80 benign prostatic hyperplasia (BPH) patients and 80 healthy controls, were enrolled. The levels of NLRP3, interleukin 1 beta (IL-1β), and interleukin 18 (IL-18) in EPS were detected using an enzyme-linked immunosorbent assay (ELISA). Disease severity was assessed using the Bergman CP scale. Differences in EPS NLRP3 inflammasome levels between the groups were analyzed, and receiver operating characteristic (ROC) curves were used to investigate the clinical value of the NLRP3 inflammasome in the diagnosis of CP. The numerical rating scale (NRS), the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) and the Danish Prostatic Symptom Score (DAN-PSS-1) were applied to evaluate symptom severity. The cutoff value of NLRP3 expression was calculated using R language.

Results: NLRP3 inflammasome levels in EPS were significantly higher in CP patients of NIH-IIIA and NIH-IIIB compared to the BPH patients and controls. NLRP3 levels in EPS were positively associated with Bergman grade. In addition, NRS levels were in a positive relationship with NIH-CPSI and DAN-PSS-1. The ROC curve analysis demonstrated that NLRP3 in EPS may act as a decent indicator for the diagnosis of CP/CPPS. The cutoff value of EPS NLRP3 expression was ≥55.25 ng/mL.

Conclusions: NLRP3 levels in EPS were significantly higher in NIH-IIIA and NIH-IIIB patients compared to BPH patients and healthy controls. NLRP3 inflammasome levels in EPS may be valuable as diagnostic indicators, and targeting chemokines may present a promising approach to treatment for those suffering from CPPS.