Pre-Procedural Gamma-Glutamyltransferase-To-Lymphocyte Ratio as an Adjunctive Biomarker for Differentiating Hunner-Type Interstitial Cystitis From Bladder Pain Syndrome.

OBJECTIVES

To evaluate the potential role of the pre-procedural gamma-glutamyltransferase-to-lymphocyte ratio (GLR) as an adjunctive biomarker for differentiating Hunner-type interstitial cystitis (HIC) from bladder pain syndrome (BPS).

METHODS

Consecutive patients who underwent cystoscopic evaluation with hydrodistension for suspected interstitial cystitis/bladder pain syndrome between April 2016 and September 2025 were retrospectively analyzed. HIC and BPS were diagnosed by expert adjudication based on cystoscopic, clinical, and histopathological findings. GLR was calculated as serum gamma-glutamyltransferase divided by peripheral lymphocyte count. Diagnostic performance was assessed using receiver operating characteristic analysis, and associations with HIC were evaluated using logistic regression.

RESULTS

Among 106 patients, 62 had HIC and 44 had BPS. GLR was significantly higher in HIC than BPS (21.4 ± 14.7 vs. 14.2 ± 15.2, p = 0.016) and correlated with total histological activity score (ρ = 0.606, p < 0.001). GLR showed an AUC of 0.759, while GGT showed similar discrimination (AUC 0.776; p = 0.592 vs. GLR). Adding GLR to a clinical model did not improve discrimination (AUC 0.948 vs. 0.949; p = 0.879). In the covariate-adjusted multivariable analysis, GLR remained associated with HIC (odds ratio 1.04, 95% confidence interval 1.01-1.10, p = 0.032).

CONCLUSIONS

Pre-procedural GLR may serve as a practical blood-based adjunct reflecting bladder-inflammatory histopathology and supporting early phenotyping across the IC/BPS spectrum, although prospective external validation is required.