To Örebro University

BACKGROUND: Previous studies investigating the prevalence of celiac disease (CD) in individuals with autoimmune hepatitis (AIH) have shown highly variable results. We therefore aimed to examine the prevalence of CD in individuals with AIH.

METHODS: Two professional librarians searched PubMed, EMBASE, Cochrane and Web of Science Core Collection up until 7 February 2020. The search terms included 'celiac disease', 'celiac', 'transglutaminases', 'gluten', 'gliadin', 'EMA', 'TTG' and 'villous' combined with 'autoimmune', 'hepatitis', 'ANA', 'SMA' and 'LKM'. This search yielded 2419 unique publications. A systematic review based on the PRISMA guidelines resulted in 31 articles eligible for full text review. Fifteen articles were deemed relevant, with 8 being included in our main analysis. A fixed-effect inverse variance-weighted model was used, and heterogeneity was calculated.

RESULTS: Our main analysis included 567 individuals with AIH from eight studies, where biopsy-verified CD (equivalent to Marsh III) was seen in 23 individuals (4.1%). The pooled prevalence of CD in AIH was 3.5% (95% CI = 1.6%-5.3%) (heterogeneity: P = .874; I²  = 0.0%), which is clearly higher than the 1% CD seen in most general populations. When also including studies where CD had been diagnosed through positive serology without biopsy (15 studies: n = 1817 individuals with AIH), the pooled prevalence of CD was 2.9% (95% CI = 2.1%-3.8%) (heterogeneity: P < .001; I²  = 66.8%).

CONCLUSION: Our results demonstrate a higher prevalence of CD in individuals with AIH compared to the general population. CD screening may be considered in patients with AIH.