Screening for acquired latent tuberculosis in rheumatoid arthritis patients on tumor necrosis factor inhibition therapy in Southern California

Background: There are no studies assessing the development of latent tuberculosis infection (LTBI) in patients on tumor necrosis factor inhibitors (TNFα-I) in high TB prevalence areas of the USA. Our objective was to assess the rate of LTBI development in rheumatoid arthritis (RA) patients on TNFα-I therapies in San Bernardino and Riverside Counties of California, high TB prevalence areas in the US.

Methods: Data were extracted from the electronic health record for 217 adult RA patients across three health centers from January 2010 to January 2017 who have had at least 1 year of TNFα-I use and negative initial QuantiFERON Gold status. Demographics, TNFα-I type, duration of use, TB risk factors, QuantiFERON results, rates of re-screening, TB test seroconversion, and its association with drug use and other factors were assessed.

Results: Of the 217 patients, 115 (53%) received baseline and annual screening for LTBI. LTBI was diagnosed in 9.4% (10) of patients. Four patients were on infliximab, three on golimumab, two on adalimumab, and one on etanercept. Hispanic patients tended to have a greater than 200% increase in odds of seroconversion compared to non-Hispanic patients. Infliximab and golimumab were associated with a 92% and 400% increase in odds of seroconversion, respectively.

Conclusion: The LTBI developed in 9.4% of the patients. This is higher than what is reported for previous US studies. Screening for LTBI in the US should take into consideration TB prevalence, ethnicity, drug type, and duration of use. For our local population and similar populations, annual screening should be practiced. Key Points • Although patients on TNFα inhibitor (TNFα-I) therapy are at high risk of latent tuberculosis infection (LTBI), few studies report the rate of LTBI in patients living in high prevalence areas of the US. • The rate of LTBI was 9.4% in patients on TNFα-I therapy in Southern California. The risk of seroconversion was higher in patients of Hispanic ethnicity and also higher for those on infliximab and golimumab compared to those on other TNFα-I therapies. • Screening guidelines for LTBI screening on TNFα-I should consider local TB prevalence, drugs used, duration of use and ethnicity for cost efficient, and optimal healthcare.