THE BTA STAT TEST IS NONSPECIFIC FOR HEMATURIA: AN EXPERIMENTAL HEMATURIA MODEL

PURPOSE: An experimental hematuria model was designed to determine whether the bladder tumor antigen (BTA) stat test (Bion Diagnostics, Redmond, Washington) is influenced by microscopic or macroscopic hematuria. MATERIALS AND METHODS: A total of 25 healthy subjects provided urine and blood samples for the study. All subjects had a negative BTA stat test initially. Normal urine was mixed with autologous blood to cause hematuria of 3 degrees of severity. The test was performed in each sample after the creation of hematuria. RESULTS: BTA stat assay specificity in the presence of microscopic and gross hematuria was 80% and 24%, respectively. Results varied depending on the severity of hematuria, that is 20% for microscopic and 76% for gross hematuria. CONCLUSIONS: The results of the BTA stat test in the presence of microscopic hematuria must be interpreted in regard to the degree of hematuria. The test is not reliable in urine samples with gross hematuria due to a high false-positive rate.