The use of natural killer cell activity and PPD test in the prediction of results in intravesical BCG treatment of patients with nonmuscle-invasive bladder cancer.

Purpose: To predict the efficacy of intravesical BCG therapy in patients with nonmuscle-invasive bladder tumors (NIBC) by using components of the cellular immune response such as the tuberculin skin test (PPD) and natural killer (NK) activity measurement.

Methods: Ninety-nine patients who were started on intravesical BCG therapy for NIBC were evaluated prospectively. Patients who were included in the intermediate, high, and very high-risk groups according to the EAU NMIBC Scoring System and who had never received intravesical BCG therapy previously were included. The clinical and demographic characteristics of the patients (age, gender, EAU NMBIC risk group, EORTC progression and recurrence scores, CUETO progression and recurrence scores, presence and types of comorbidity) were recorded. NK activity was measured and the PPD test was applied 3 days before the start of intravesical BCG therapy. The results of PPD were measured in millimeters 72 h after the test.

Results: PPD values measured before BCG treatment, as an independent variable, were found to be significantly lower in patients with recurrence. A significant correlation was detected between NK activity results obtained before BCG treatment and recurrence after treatment, when the cutoff was 200-500 pg/dl. There was no significant relationship between the time to recurrence and PPD and NKA measurements.

Conclusion: We conclude that the results of PPD test and NK activity measurement performed before starting intravesical BCG therapy in NIBC may be a marker that can be used to predict the risk of recurrence under treatment.