Novel NMP22 quick qualitative analysis (BladderChek NMP22) for the diagnosis of urothelial tumor]

The BladderChek NMP22 test was studied to determine whether it could be a useful diagnostic tool for urothelial tumor.During the period from April to May 2004, a total of 50 patients who visited Nagano Municipal Hospital were subjected to analysis with the BladderChek NMP22 test. They consisted of 25 patients with microscopic or gross hematuria and 25 patients with urothelial tumor who were being followed after surgery. The clinical diagnosis was made by cystoscopy, abdominal CT scanning, ultrasonography or intravenous urography. BladderChek NMP22 was used in all of the patients and the test was judged to be positive when a line appeared on the glass at 30 minutes after a drop of urine was added to the sample well. Cytological examination of the urine was also done. It was defined as negative if the result was I, II or III, while it was positive if the result was IV or V.Seven patients who were not eligible were excluded and the remaining 43 patients were studied. Eleven of the 43 patients were diagnosed as having urothelial tumor. The sensitivity, specificity, and accuracy of BladderChek NMP22 for making a correct diagnosis was 63.6%, 62.5%, and 62.7%, respectively (p = 0.1703). As for urine cytology, the sensitivity, specificity, and accuracy was 36.3%, 100%, and 83.7%, respectively (p = 0.0027). BladderChek NMP22 was positive in all the patients whose urine cytology was positive and in three patients with low-grade, low-stage, and small tumors, although urine cytology was negative. On the other hand, false-positive BladderChek NMP22 results were obtained in patients undergoing follow-up after removal of urothelial carcinoma and in patients with urinary stones. The sensitivity of BladderChek NMP22 was superior to that of urine cytology, but its specificity was inferior.The combined use of BladderChek NMP22 and cystoscopy may be useful for the diagnosis and follow-up of urothelial tumor. On the other hand, the results obtained with BladderChek NMP22 need to be interpreted carefully because the test can yield a false-positive outcome in the presence of marked hematuria, pyuria or cytolysis of normal urotherium. When the result of BladderChek NMP22 in the monitoring of recurrent urotherial tumor following surgery was positive in spite of negative findings of cystoscopy, it is necessary to consider the presence of a tumor in the upper urinary tract or a high tendency toward tumor recurrence. In such a case, careful followup may be necessary.