Nitric oxide as an objective marker for evaluation of treatment response in patients with classic interstitial cystitis

Nitric oxide (NO) has previously been shown to be a marker for inflammatory disorders in the bladder. We investigated if the measurement of NO can be used to evaluate the treatment response in classic interstitial cystitis (IC). Materials and Methods: A total of 15 patients diagnosed with classic IC were included. The patients were treated with oral prednisolone for 8 weeks. We evaluated patient symptoms/ problems with the IC index, and we measured NO formation in the bladder. Results: Seven patients were classified as responders with a 4 point or more decrease in symptom score after 8 weeks of treatment. In this group the mean symptom score was +/- SEM decreased from 15 +/- 1 to 7 +/- 2 at the end of therapy (p <0.05). The problem score was also significantly reduced. Responders showed a clear decrease in bladder NO. The 8 nonresponders did not show any improvement in symptom/problem score and there was no change in bladder NO during steroid treatment. Furthermore, the study showed a statistically significant correlation between changes in symptom/problem score and changes in luminal bladder NO in each patient. Conclusions: The study shows that NO can be used not only to measure inflammation in patients with IC, but also to evaluate objectively the treatment response in individuals. This makes NO formation a useful marker in the assessment of classic interstitial cystitis.