The Risk of Tuberculosis with TNF Inhibitors Save

A study from Turkey shows that among 2117 patients treated with a TNF inhibitor (TNFi) the risk of developing TB was 6 fold higher in those treated with a TNFi compared to non-users.

This retrospective cohort study included patients with rheumatoid arthritis (RA), ankylosing spondylitis, juvenile idiopathic arthritis or psoriatic arthritis (PsA) that treated with or without TNFI. The calculated the 2-year RR of TB after TNFi.

Among 413 500 rheumatic patients, 2117 received TNFi. Four patients among anti-TNF-α users developed TB compared to 128 patients in anti-TNF-α-naïve group (189 vs 31 cases per 100 000 patients, respectively). The 2-year risk of TB (RR) was  6.07 (95% CI, 2.25-16.42).

The risk was higher in men (RR 5.39; 1.69-7.17), adults (6.12; 2.26-16.55) and RA (5.70; 1.41-23.08) and PsA (13.46; 1.58-114.40).

These findings are similar to other studies showing a higher risk of TB with TNFi users. 

Another report from Romania assessed the incidence of active TB and the efficacy of TB prevention measures. (Citation source:https://buff.ly/2vYGpHj) 

Patients were divided into 3 groups according to LTBI screening: tuberculin skin test (TST) with a positive threshold of either 10 mm (group TST1), or 5 mm (group TST2), and QuantiFERON®-TB Gold test (group QFT).

Among 550 patients included (305 RA, 42 PsA, 203 AS). The number of TB cases/time of exposure to TNFi (person-years, PY) was 8/593.5, 9/1044.0 and 3/555.3, respectively, accounting for an incidence of 1348.0, 862.1 and 540.2 cases per 105 PY.

The number of active early TB cases (in the first year of TNFi) was relatively few - only 3/8, 1/9 and 1/3.

Overall there were less TB cases in the QFT group, probably due to the reduced duration of exposure to TNFi.

In this cohort study, TB was more likely to occur after 1 year of TNFi treatment, rather than early, suggesting the need for ongoing monitoring and TB prevention measures, especially in high risk areas and populations.