Goal: To determine the risk of future biopsy-verified IgA nephropathy (IgAN) among individuals with biopsy-verified celiac disease (CD).
Background: Individuals with CD suffer increased risk of end-stage renal disease. An association between CD and IgAN has been suggested; however, results have been inconclusive and no previous study has considered the risk of IgAN in biopsy-verified CD.
Study: We performed a population-based prospective cohort study. We identified 27,160 individuals with CD (Marsh stage III) and no previous renal disease through small-intestinal biopsy reports obtained between July 1969 and February 2008 in all (n=28) Swedish pathology departments. Individuals with IgAN were identified by biopsy reports acquired at the 4 Swedish pathology departments specialized in renal pathology. Cox regression analysis was used to determine the risk of future IgAN among individuals with CD compared with 133,949 age-matched and sex-matched reference individuals.
Results: Seven (0.026%) individuals with CD and 11 (0.008%) reference individuals developed IgAN. We found an increased risk of biopsy-verified IgAN among individuals with CD [hazard ratio, 3.03; 95% confidence interval, 1.22-7.56]. The risk increase remained statistically significant after adjustment for prior liver disease and country of birth.
Conclusions: Individuals with CD suffer a 3-fold increased risk of future IgAN. Our findings warrant awareness of renal function in individuals with CD.