Development and validation of a clinical nomogram to predict prostatic inflammation in men with lower urinary tract symptoms

Background: Prostatic inflammation is an important etiological component of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). The Prostatic Inflammation Nomogram Study (PINS) aimed to develop and validate a nomogram for predicting the presence of prostatic inflammation in men with LUTS. Methods: This non-interventional, cross-sectional, prospective study was conducted in six secondary/tertiary centers across Cyprus, Greece, Italy, Portugal, and Spain. Men (≥40 years) with BPH/LUTS scheduled to undergo prostatic surgery or transrectal ultrasound-guided (TRUS) prostate biopsy were included. Fifteen demographic and clinical participant characteristics were selected as possible predictors of prostatic inflammation. The presence of inflammation (according to Irani score) in the prostatic tissue samples obtained from surgery/TRUS biopsy was determined. The effect of each characteristic on the likelihood a prostate specimen demonstrated inflammation (classified by Irani score into two categories, 0–2 [no/minimal inflammation] or 3–6 [moderate/severe inflammation]) was assessed using multiple logistic regression. A nomogram was developed and its discriminatory ability and validity were assessed. Results: In total, 423 patients (mean age 68.9 years) were recruited. Prostate volume ultrasound (PVUS) > 50 mL, history of urinary tract infection (UTI) treatment, presence of diabetes, and International Prostate Symptom Score (IPPS) Storage score were statistically significant predictors of Irani classification. Logistic regression demonstrated a statistically significant effect for leucocytes detected via urine dipstick, presence of diabetes, PVUS > 50 mL, history of UTIs, and higher IPSS Storage score for the odds of an inflammatory score category of 3–6 versus 0–2. The nomogram had a concordance index of 0.71, and good internal validity. Conclusions: The nomogram developed from PINS had good predictive ability and identified various characteristics to be predictors of prostatic inflammation. Use of the nomogram may aid in individualizing treatment for LUTS, by identifying individuals who are candidates for therapies targeting prostatic inflammation.