Correlation Between the Tuberculin Skin Test and T-SPOT.TB in Patients with Suspected Tuberculosis Infection: A Pilot Study

T-SPOT.TB is a novel screening method for infection. However, it is controversial whether T-SPOT.TB should become an alternative method to the tuberculin skin test (TST) for screening infections. The present study aimed to evaluate this issue based on the retrospective analysis of clinical cases. TST and T-SPOT.TB tests were used on patients with suspected infection on admission. Demographic data and clinical information, including previous history of infection, were collected. A total of 118 patients were included in the analysis, among whom 30 (25.4%) were diagnosed with active infection, and seven patients (5.9%) were currently receiving immunosuppressive treatment. The overall sensitivity and specificity of the TST were 76.7 and 77.3%, respectively, while they were 88.3 and 68.1%, respectively, for the T-SPOT.TB test. Patients with large TST indurations had a higher number of gamma interferon-producing T cells among peripheral blood mononuclear cells compared with those of TST-negative patients. In conclusion, the T-SPOT.TB test had a higher sensitivity than the TST, but the difference was not statistically significant. Neither the T-SPOT.TB test nor the TST was sufficiently accurate to detect active infection.