Screening for latent tuberculosis in patients with inflammatory bowel disease under antitumor necrosis factor: data from a Portuguese center

Abstract

Portugal is one of the countries with the highest tuberculosis (TB) burden in the European Union. Patients who are receiving antitumor necrosis factor (TNF) treatment should be screened and treated for latent tuberculosis infection (LTBI). This study aimed to evaluate the prevalence of LTBI and the number of active TB cases in patients with inflammatory bowel disease (IBD) treated with anti-TNF agents. This was a retrospective study from a Portuguese center that included patients with IBD who started anti-TNF treatment between 2013 and 2017. LTBI screening was considered positive in case of positive tuberculin skin test, positive/indeterminate interferon gamma release test, or history of exposure to TB irrespective of the results of the screening. One hundred and seventeen patients were included, 56% female, mean age 40 years; 91% had Crohn's disease; infliximab was initiated in 79%, adalimumab in 21%, and golimumab in 1%. Of these, 37 (32%) presented LTBI - tuberculin skin test was positive in 18 (49%) patients; interferon gamma release test was positive in 14 (38%) patients and undetermined in seven (19%); and there was a history of exposure in 12 (32%) patients. All patients screened with LTBI were on isoniazid for 9 months. During follow-up (mean 21.6 months), one patient under infliximab developed pleural TB 5 years after receiving treatment with isoniazid. None of the patients with negative LTBI screening developed active TB. In this sample of patients with IBD, the prevalence of LTBI before starting anti-TNF treatment was significant (32%), but only one patient had active TB after LTBI treatment.