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

Abstract

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.