Increased urinary hyaluronic acid and interstitial cystitis

Purpose: We compared urinary levels of hyaluronic acid in patients who met the National Institute for Diabetes, and Digestive and Kidney Diseases criteria for interstitial cystitis and in age matched healthy female controls. Materials and Methods: Urinary hyaluronic acid was measured by solid phase radiometric assay using hyaluronic acid binding protein. Hyaluronic acid and symptom scores were compared in interstitial cystitis patients who gave multiple urine samples during treatment. Since hyaluronic acid changed with treatment in some patients, 17 samples from untreated interstitial cystitis patients were selected and compared with 17 control samples. Results: Mean plus or minus standard deviation urinary hyaluronic acid concentrations were similar in the 2 groups (interstitial cystitis group 574 ± 496, controls 512 ± 324 ng./ml., p = 0.77). When normalized to creatinine urinary hyaluronic acid was significantly higher in interstitial cystitis patients (interstitial cystitis group 674 ± 220, controls 446 ± 220 ng./mg. creatinine, p = 0.0019). Urinary creatinine concentrations did not differ significantly (interstitial cystitis group 842 ± 715, controls 1,162 ± 516 mg./l., p = 0.12). Conclusions: Urinary hyaluronic acid was higher in interstitial cystitis patients than healthy controls. Since bladder hyaluronic acid is below the epithelium, this finding may indicate leakage across the epithelium into the urine in interstitial cystitis patients.