Background: According to the WHO the incidence of active tuberculosis (TB) in Spain is high 13 cases per 100.000 inhabitants, reaching in Galicia (a region located in the North-west of Spain 20 cases per 100.000 inhabitants. Otherwise patients on anti-TNF treatment have an increased risk of active TB too. We aimed to analyze the clinical features of active tuberculosis infection in inflammatory bowel diseases (IBD) patients on anti-TNF drugs.
Methods: We perform a case-control study. Our database was searched for IBD patients on anti-TNF who developed active TB from 2000 to 2014. Controls were selected among patients with active TB infection matched for sex, age and year of diagnosis of tuberculosis. All their clinical features were analyzed and in the statistical analysis p values below 0.05 were considered significant.
Results: The incidence of active TB in IBD patients on anti-TNF drugs was 3.4% (10/290). The median time to the development of active TB after initiation of anti-TNF therapy was 6 months range (2–60). TB skin test (TST) was performed in 90% cases, but only 50% had two-step TST. Three patients had a positive TST and received anti-TB prophylaxis. Prior antiTNF chest radiographies do not suspected TB. Previous TB exposition, time from symptoms to TB diagnosis and hospital stay were similar to controls. IBD patients had a higher laboratory identification of mycobacterium TB prior antiTB treatment (p=0.03) and had previous 3 months exposition to steroids or inmunodepressant (p=0.01) than controls. They suffered from more extrapulmonary TB (p=0.01) with primary resistances to antiTB drugs (p=0.03), had to receive TB treatment for a longer time (p=0.04) and had more complications related to TB p=0.008) than controls.
Conclusions: IBD patients on anti-TNF drugs suffer from more complicated extrapulmonary and drug-resistant TB infections, needing longer course of TB treatment.
In these patients two-step TST must be performed and positive findings must be treated.