Nerve growth factor level in the prostatic fluid of patients with chronic prostatitis/chronic pelvic pain syndrome is correlated with symptom severity and response to treatment

Abstract

Objective: • To explore whether levels of nerve growth factor (NGF) in expressed prostatic secretions (EPS) are correlated with symptom severity in chronic prostatitis (CP) and chronic pelvic pain syndrome (CPPS).

Patients and methods: • All patients with CP/CPPS underwent a complete history and physical examination, and were scored according to the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI). • Expressed prostatic secretion samples from 20 patients with CP/CPPS and from four asymptomatic control patients were collected and frozen, and NGF levels in EPS were measured by enzyme-linked immunosorbent assay. • Patients were asked to complete NIH-CPSI questionnaires at baseline and 8 weeks after treatment and patients with at least a 25% decrease in total NIH-CPSI score from the baseline values were classified as responders to treatment.

Results: • The mean (± sd) NGF levels in EPS of patients with CP/CPPS and asymptomatic control patients were 7409 (± 3788) pg/mL and 4174 (± 1349) pg/mL, respectively. The NGF level in patients with CP/CPPS correlated directly with pain severity (P= 0.014, r= 0.541). • There were no significant differences between NGF levels in EPS before and after treatment. However, successful treatment significantly decreased NGF levels in responders (P= 0.001).

Conclusion: • Nerve growth factor might contribute to the pathophysiology of CP/CPPS as changes in NGF level in EPS occurred in proportion to pain severity. Therefore, these results suggest that NGF could be used as a new biomarker to evaluate the symptoms of CP/CPPS and the effects of treatment.