[Incidence of latent tuberculosis and disease in patients with rheumatoid arthritis]

Immunosuppression in rheumatoid arthritis (RA) treatment is associated with an increased risk of tuberculosis (TB). The objective was to determine the incidence of latent tuberculosis (LTBI) and TB in a cohort of RA patients receiving immunosuppressive therapy and to identify which drugs cause the tuberculin test conversion or the disease.

Retrospective observational study. A cohort of RA patients from a public hospital in the Autonomous City of Buenos Aires between 2020 and 2024 was examined. They underwent LTBI screening to determine who underwent tuberculin conversion or had TB. The drug they were being treated with at diagnosis was also determined.

A total of 438 patients were analyzed. The 14.2% (n=62) was diagnosed with LTBI, 24.2% (n=15) were treated with conventional disease modifying antirheumatic drugs (cDMARD) alone, 38.7% (n=24) with combined cDMARD, 14.5% (n=9) with cDMARD associated with corticosteroids, 17.7% (n=11) with cDMARD and a biological DMARD, and 4.8% (n=3) with high-dose corticosteroids alone. The highest incidence of LTBI was observed in those treated with cDMARD, which was statistically significant (p=0.0006). TB was detected in 2.3% (n=13) of the patients.

Although several studies have shown that the risk of LTBI is higher under treatment with biologic DMARD, in our study we observed a higher risk in those treated with cDMARD. Therefore, it is essential to rigorously reevaluate and repeat LTBI screening in patients treated with immunosuppressants for long periods of time.