Risk factors for active tuberculosis in patients with inflammatory bowel disease: A case-control study

Background: Patients with inflammatory bowel disease (IBD) who receive anti-tumor necrosis factor (antiTNF) therapy are at increased risk of active tuberculosis (TB), mainly by reactivation of latent TB infection. Methods: A retrospective, case-control, multicenter study was conducted. Patients who developed active TB after the IBD diagnosis were identified from the IBD databases of four hospitals in Northern Spain. Results: A total of 34 cases and 102 matched controls were included, (15 cases associated to antiTNF therapy). In the univariate analysis, hospitalization and exposure to corticosteroids, IMM or anti TNF in the previous 3, 6 or 12 months, were associated to higher risk for active TB; In the multivariate analysis, only antiTNF therapy in the previous 12 months (OR 8.34 [2.46-28.22], p: 0.001), hospitalization in the previous 3 months (OR 6.25 [1.45-26.90], p: 0.014), and albumin level at the TB diagnosis (OR 0.90 [0.82-0.98], p: 0.013), were significantly associated to active TB. IMM therapy in the previous 12 months and extrapulmonary presentation were more frequent among TB cases associated to antiTNF treatment (80% vs 37%, p: 0.017; 63% vs 32%, p: 0.03, respectively). Active TB was diagnosed an average of 13 months after starting antiTNF therapy, and only 47% took place after 12 months of starting antiTNF. Conclusions: In addition to the antiTNF treatment, hospitalization Is associated with increased risk of active TB in IBD patients. Less than 50% of active TB associated with antiTNF occur in the first 12 months after starting this treatment; TB screening should be mandatory after starting treatment with antiTNF.