BTA TRAK assay specificity by patient type and GU disease status.
As expected, the effect of using cytology as a confirmatory test for the BTA TRAK assay, that is, requiring that both tests be positive to report a positive result, produced a lower overall sensitivity than using cytology alone with a specificity equivalent to that of cytology (Table 4).
The primary goal of this study was to better define the potential roles of the BTA TRAK assay and cytology in the diagnosis and management of bladder cancer.
The overall specificity of the BTA TRAK assay in these 120 patients was 69% (83 of 120; 95% CI, 60-77%; Fig.
Because the group with no previous history of bladder cancer contained a higher percentage of patients with GU disease (47%, 22 of 47) than that with previous bladder cancer (12%, 9 of 73; Table 3), the specificity of the BTA TRAK assay appeared to be better in the latter (80%, with 95% CI, 68-88% vs 53%, with 95% CI, 38-68%).
Because cytology had an exquisite specificity, calling the overall result positive if either the BTA TRAK assay or cytology were positive yielded a specificity equivalent to that of the BTA TRAK test alone.
We found that the presence of FHR-1 caused a reduction in the FH-dependent test signal in the BTA TRAK assay. These results suggest that this diagnostic assay recognizes FH, whereas FHR-1 decreases the signal in the test samples.
We subjected increasing amounts of purified FH to the BTA TRAK assay and found a clear dose-dependent positive signal (Fig.
In contrast, our finding that the presence of FHR-1 reduced the binding of FH to X52.1 in the BTA TRAK assay indicates that the presence of FHR-1 in a patient's urine sample can affect the BTA TRAK test result.
It is therefore likely that the observed competition between FH and FHR-1 in the BTA TRAK assay does not compromise the sensitivity of the assay in clinical diagnosis of BC.
Multicenter trial of the quantitative BTA TRAK assay in the detection of bladder cancer.