A DIAGNOSTIC IN-VITRO URINE ASSAY FOR INTERSTITIAL CYSTITIS

Objectives. A low molecular weight urine factor that inhibits the prol iferation of normal bladder epithelial cells in vitro was previously s hown to be present significantly more often in the urine of patients w ith interstitial cystitis (IC) than in the urine of asymptomatic age-, race-, and sex-matched control subjects. We sought to determine the s pecificity of this finding for IC by determining whether the urine of patients with other urogenital inflammatory disorders also contains a factor that inhibits bladder epithelial cell proliferation. Methods. U rine was collected from women with IC, acute bacterial cystitis, or vu lvovaginitis, as well as from asymptomatic control women. The prolifer ation of primary normal adult bladder epithelial cells was determined by measuring H-3-thymidine incorporation in vitro. Results. Osmolality - and pH-corrected urine specimens from 50 (86%) of 58 women with IC s ignificantly inhibited human bladder epithelial cell proliferation com pared with 3 (8%) of 36 asymptomatic control women, 7 (12%) of 58 wome n with bacterial cystitis, and 0 (0%) of 12 women with vulvovaginitis (P < 0.001 for the comparison of mean percent change in H-3-thymidine incorporation with IC urine versus urine from each of the control grou ps). Optimal sensitivity and specificity values of 91.4% and 90.6%, re spectively, were achievable at a cutoff of 25% inhibition of H-3-thymi dine incorporation, using all three control groups. Conclusions. The m easurement of urine antiproliferative activity may be a useful noninva sive means for diagnosing IC in women. (C) 1998, Elsevier Science Inc. All rights reserved.