The booster phenomenon in 2-step tuberculin skin testing of patients receiving long-term hemodialysis

Tuberculosis remains a significant health problem for patients receiving long-term hemodialysis (HD). The tuberculin skin test (TST) is an important method for detecting Mycobacterium tuberculosis infection. This study examined the significance and frequency of the booster phenomenon in serial TST of HD patients. Fifty-three outpatients in a hospital-based HD center in Turkey were screened for tuberculosis with the TST between August and October 1999. To determine the frequency of booster phenomenon, patients with less than 10 mm indurations to the initial TST were given a second test 7 days later. Nineteen (35.8%) of 53 patients had a significant tuberculin reaction (≥ 10 mm) on the initial TST. The booster effect was detected in 10 (29.4%) of 34 patients who had a negative reaction (< 10 mm) to the initial test. Overall, 29 (54.7%) patients showed a significant reaction on both tests. These results showed significant rates of TST positivity and the booster effect in this HD center.