Risk of latent tuberculosis in the cohort of patients with rheumatoid arthritis in Slovakia

This study aims to determine the prevalence of latent tuberculosis infection (LTBI) in patients with moderate to severe rheumatoid arthritis (RA) who receive conventional and anti-cytokine therapy, to identify possible risk factors for tuberculosis (TB) and to evaluate the prophylactic treatment in positively screened patients.

We conducted an observational, retrospective study in patients with RA, who underwent LTBI screening (chest X-ray, tuberculin skin test and interferon gamma release assay test - IGRA test).

Out of 124 patients included, 7.25% of patients were diagnosed with LTBI during the treatment with conventional synthetic anti-rheumatic drugs in combination with glucocorticoids before initiation of anti-cytokine therapy. Another 21.77% were diagnosed during treatment with biologics or Janus kinase inhibitors. We confirmed the highest incidence of LTBI in TNF-treated group (66.66% LTBI positive patients), but also found positive screening in patients treated with other modalities. The mean LTBI detection time since the initiation of anti-cytokine therapy was 39.5 months (12-134 months). Active TB with clinical manifestation has occurred in one patient. Statistical analysis did not show an association between risk of LTBI and age, sex or treatment modality.

The results of this study confirm the necessity of LTBI screening and long-term monitoring in RA patients treated with any kind of anti-cytokine therapy. The currently used national recommendations are sufficiently sensitive to identify TB in these patients. There remains a question of screening and prophylactic antituberculosis therapy in patients treated with conventional synthetic anti-rheumatic drugs in combination with glucocorticoids.