Comparison of single and dual latent tuberculosis screening strategies before biologic and targeted therapy in patients with rheumatic diseases: a retrospective cohort study

Abstract

Before biologic and targeted synthetic disease-modifying antirheumatic drug (b/tsDMARD) treatment, latent tuberculosis infection (LTBI) screening by tuberculin skin test (TST) or interferon gamma release assay (IGRA) is recommended. However, both tests have reduced reliability in immunosuppressed patients. We investigated whether dual LTBI screening with both tests could reduce the incidence of tuberculosis. Methods: Consecutive patients receiving b/tsDMARDs for rheumatic diseases in a regional hospital were recruited. All patients underwent either TST/IGRA or both. They were categorised into a single or dual testing group and were followed up for at least 6 months. Isoniazid was prescribed if any one test was positive. Results: In total, 217 patients were included in this study; 121 underwent single LTBI testing and 96 underwent dual testing. Tuberculosis occurred in nine patients in the single testing group and one patient in the dual testing group (7.4% vs 1.0%, P=0.045). However, the difference was not statistically significant when follow-up duration was considered (log rank test). In total, 71 patients tested positive for LTBI with isoniazid treatment (28.9% in the single testing group and 45.8% in the dual testing Comparison of single and dual latent tuberculosis screening strategies before biologic and targeted therapy in patients with rheumatic diseases: a retrospective cohort study

2022 EULAR recommendations for screening and prophylaxis of chronic and opportunistic infections in adults with autoimmune inflammatory rheumatic diseases

“…From this point of view, IGRA should be preferred over TST for TB screening. Given the low agreement between TST and IGRA,42 44 52–71 performing both tests can also be considered in cases of high suspicion for latent TB and/or in high-endemic countries 58 70 72. Concordance between different IGRAs (Quantiferon and EliSPOT) is good thus one is not recommended over the other 47 73–75.…”

Systematic literature review informing the 2022 EULAR recommendations for screening and prophylaxis of chronic and opportunistic infections in adults with autoimmune inflammatory rheumatic diseases

“…Several studies have shown that agreement between TST and IGRA is moderate (agreement range: 61%–88%)14 15 17 18 33–50 (table 2). Disagreement between TST and IGRA has led some authors to suggest that both tests should be performed in high-risk patients (travelling or coming from endemic regions) and/or in countries with high TB-burden 39 49 51.…”

Approaches to screening for latent tuberculosis infection in patients with immune-mediated disease prior to commencement of biologics

“…As illustrated by the study from Tang et al in this issue of the Hong Kong Medical Journal, 11 there were significantly more patients with tuberculosis in the single test group (mostly TST) than in the dual test group (9 [7.4%] vs 1 [1.04%]; P=0.045). Another report has raised the concern that TST as the only screening test for LTBI prior to anti-TNF therapy was likely inadequate.…”