Histamine content and mast cell count of detrusor muscle in patients with interstitial cystitis and other types of chronic cystitis.

The quantitative mast cell count in the detrusor muscle, the histamine content and the degree of collagen staining material in the bladder wall have been evaluated in order to elucidate their value in distinguishing between patients with interstitial cystitis and other types of chronic cystitis. The number of mast cells in the detrusor muscle was statistically significantly increased in patients with interstitial cystitis compared with the control group (P less than 0.0001). With a proposed level of greater than 20 mast cells/sq mm of muscle tissue the diagnostic specificity was 88% and the diagnostic sensitivity 95%. The histamine content in the bladder wall was significantly increased in patients with interstitial cystitis (P less than 0.05) but not useful as a diagnostic test. The amount of collagen staining material was significantly increased in the intra- and inter-fascicular muscle tissue of the bladder in patients with interstitial cystitis (P less than 0.0005, P less than 0.001) and might be used as a support for the histological diagnosis, even in patients with uncontracted bladders.