Diagnostic accuracy of urinary prostate protein glycosylation profiling in prostatitis diagnosis

INTRODUCTION: Although prostatitis is a common male urinary tract infection, clinical diagnosis of prostatitis is difficult. The developmental mechanism of prostatitis is not yet unraveled which led to the elaboration of various biomarkers. As changes in asparagine-linked-(N-)-glycosylation were observed between healthy volunteers (HV), patients with benign prostate hyperplasia and prostate cancer patients, a difference could exist in biochemical parameters and urinary N-glycosylation between HV and prostatitis patients. We therefore investigated if prostatic protein glycosylation could improve the diagnosis of prostatitis. MATERIALS AND METHODS: Differences in serum and urine biochemical markers and in total urine N-glycosylation profile of prostatic proteins were determined between HV (N = 66) and prostatitis patients (N = 36). Additionally, diagnostic accuracy of significant biochemical markers and changes in N-glycosylation was assessed. RESULTS: Urinary white blood cell (WBC) count enabled discrimination of HV from prostatitis patients (P < 0.001). Urinary bacteria count allowed for discriminating prostatitis patients from HV (P < 0.001). Total amount of biantennary structures (urinary 2A/MA marker) was significantly lower in prostatitis patients compared to HV (P < 0.001). Combining the urinary 2A/MA marker and urinary WBC count resulted in an AUC of 0.79, 95% confidence interval (CI) = (0.70–0.89) which was significantly better than urinary WBC count (AUC = 0.70, 95% CI = [0.59–0.82], P = 0.042) as isolated test. CONCLUSIONS: We have demonstrated the diagnostic value of urinary N-glycosylation profiling, which shows great potential as biomarker for prostatitis. Further research is required to unravel the developmental course of prostatic inflammation.