Tuberculin skin test and Interferon-gamma release assay agreement, and associated factors with latent tuberculosis infection, in medical and nursing students in Bandung, Indonesia.

BACKGROUND: No gold standard diagnostic test exists for latent tuberculosis infection (LTBI). The intra-dermal tuberculin skin test (TST) has known limitations and Interferon-gamma release assays (IGRA) have been developed as an alternative. We aimed to assess agreement between IGRA and TST, and risk factors for test positivity, in Indonesian healthcare students. METHODS: Medical and nursing students starting their clinical training were screened using IGRA and TST. Agreement between the two tests was measured using Cohen's Kappa coefficient. Logistic regression was used to identify factors associated with test positivity. RESULTS: Of 266 students, 43 (16.2%) were IGRA positive and 85 (31.9%) TST positive. Agreement between the two tests was 74.7% (kappa 0.33, 95% CI 0.21-0.45, P<0.0001). Students who had direct contact with family or friends with TB were less likely to be test positive using IGRA (AOR 0.18, 95% CI 0.05-0.64) and using TST (AOR 0.51, 95% CI 0.26-0.99). CONCLUSION: Test positivity for LTBI was lower when measured by IGRA than by TST, with poor agreement between the two tests. Known close TB contact was unexpectedly negatively associated with positivity by either test. Longitudinal studies may be required to help determine the best test for LTBI in healthcare students in Indonesia.

High risk of Mycobacterium tuberculosis infection among medical and nursing students in Indonesia: a 1-year prospective study.

BACKGROUND: Medical and nursing students entering their clinical programmes are at increased risk for tuberculosis (TB) in TB-endemic settings. Relatively little is known about Mycobacterium tuberculosis infection among such students in high-endemic countries. METHODS: We examined M. tuberculosis infection among medical and nursing students starting clinical training in Bandung, Indonesia using interferon-γ release assay (IGRA) QuantiFERON-TB Gold Plus. IGRA-negative students had a repeat test after 1 y and logistic regression was used to identify factors associated with IGRA positivity or conversion. RESULTS: There were 379 students included in this study: 248 (65.4%) were medical students and 131 (34.6%) were nursing students. Of 379 students, 70 (18.5%) were IGRA positive at baseline. Of 293 IGRA-negative students with 1-y results, 26 (8.9%) underwent IGRA conversion. Being a medical student (adjusted relative risk [ARR] 5.15 [95% confidence interval {CI} 1.82 to 14.59], p=0.002) and participation in sputum collection or bronchoscopy were associated with IGRA conversion (ARR 2.74 [95% CI 1.29 to 5.79], p=0.008). CONCLUSIONS: Medical and nursing students entering clinical training are at high risk of M. tuberculosis infection and need improved infection prevention and control strategies.

Activity Disease in SLE Patients Affected IFN-γ in the IGRA Results.

PURPOSE: Highly active systemic lupus erythematosus (SLE) causes a high risk of tuberculosis (TB) infection in SLE patients in Indonesia, a country in which the disease, especially extrapulmonary TB, is endemic. Interferon (IFN)-γ releasing assay (IGRA) can detect latent or previous TB infection. This study sought to determine latent TB infection and levels of IFN-γ, a key player in various inflammation and autoimmune disease, in patients with SLE and relate findings to disease activity. PATIENTS AND METHODS: This experimental study included 79 female subjects distributed into three groups of active SLE, quiescent SLE and healthy controls. We used SLE Disease Activity Index-2000 (SLEDAI-2K) scores to stratify the subjects. Each group underwent IGRA testing using the QuantiFERON-TB Gold Plus kit. RESULTS: We recruited 59 female patients with SLE. The patients had a median age and disease duration 30 and 5 years, respectively. Statistical analysis using the Kruskal-Wallis test showed that active condition, high SLEDAI-2K score and immunosuppressive therapies affect IGRA results. Specifically, healthy controls (n=20) were most likely to have negative IGRA results (67.09%), whilst 27.27% of active cases (n=33) and 3.85% of quiescent cases (n=26) had indeterminate results (p=0.02). The number of immunosuppressant therapies was significantly negatively correlated with IFN-γ (p=0.004). No difference in IFN-γ concentration was detected amongst the active and other groups (p>0.05). CONCLUSION: High-activity SLE and immunosuppressive therapies cause dysregulation of the immune response, which, in turn, influences IGRA results. Thus, additional testing is necessary to detect TB infection in patients with SLE.