Risk of tuberculosis in a large sample of patients with coeliac disease - a nationwide cohort study.

Background Research suggests a positive association between coeliac disease and tuberculosis (TB), but that research has often been limited to in-patients and small sample size. We examined the relationship between TB and coeliac disease. Aim To examine the association of TB and coeliac disease. Methods We collected biopsy data from all pathology departments in Sweden (n = 28) to identify individuals who were diagnosed with coeliac disease between 1969 and 2007 (Marsh 3: villous atrophy; n = 29 026 unique individuals). Population-based sex- and age-matched controls were selected from the Total Population Register. Using Cox regression, we calculated hazard ratios (HRs) for TB from data in the Swedish national health registers. Results Individuals with coeliac disease were at increased risk of TB (HR = 2.0; 95% CI = 1.3-3.0) (during follow-up, 31 individuals with coeliac disease and 74 reference individuals had a diagnosis of TB). The absolute risk of TB in patients with coeliac disease was 10 / 100 000 person-years with an excess risk of 5 / 100 000. Risk estimates were the highest in the first year. Restricting our outcome to a diagnosis of TB confirmed by (I) a record of TB medication (HR = 2.9; 95% CI = 1.0-8.3), (II) data in the National Surveillance System for Infectious Diseases in Sweden (HR = 2.6; 95% CI = 1.3-5.2) or (III) positive TB cultivation (HR = 3.3; 95% CI = 1.6-6.8) increased risk estimates. The positive association between coeliac disease and TB was also observed before the coeliac disease diagnosis (odds ratio = 1.6; 95% CI = 1.2-2.1). Conclusion We found a moderately increased risk of tuberculosis in patients with coeliac disease. [ABSTRACT FROM AUTHOR]