No association between biopsy‐verified celiac disease and subsequent amyotrophic lateral sclerosis – a population‐based cohort study

Abstract

Earlier data suggest an association between amyotrophic lateral sclerosis (ALS) and autoimmune disease, but data on its association with celiac disease (CD) are limited. The risk of ALS in 29093 individuals with CD, according to small intestine biopsy (villous atrophy, Marsh 3) carried out at Sweden's 28 pathology departments in 1969-2008, was compared with that in 144515 age- and sex-matched reference individuals from the general population. ALS was defined as a hospitalization or outpatient visit with ALS according to the Swedish Patient Register. We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for ALS. During follow-up 12 (3.7/100000 person-years) individuals with CD and 56 (3.5/100000 person-years) reference individuals had a diagnosis of ALS. This corresponded to an HR of 1.0 (95% CI0.5-1.8). HRs were significantly higher in the first year of follow-up (4.1; 1.2-13.4) than 1-5years after first CD diagnosis (0.8; 0.2-2.7) or after more than 5years of follow-up (0.5; 0.2-1.5). Relative risk estimates were similar in men and women but were higher at the end of the study period [HR for ALS in patients diagnosed with CD in year 2000 or later was 2.1 (95% CI0.9-4.8)]. This study found no association between CD and ALS. Earlier reports of a positive association may be due to surveillance bias just after CD diagnosis or expedited diagnostic work-up of ALS.