Prevalence and clinical features of patients with autoimmune pancreatitis and inflammatory bowel disease: A systematic review and meta‐analysis

Abstract

Background and Aim Autoimmune pancreatitis (AIP) and inflammatory bowel disease (IBD) are categorized into immune‐mediated inflammatory disorders (IMIDs). While AIP is a pancreato‐biliary IMID with an increased incidence and prevalence among patients with IBD, its features are still unclear. This systematic review and meta‐analysis aims to assess the prevalence and clinical characteristics of AIP‐IBD patients. Methods Electronic databases were searched to identify observational studies assessing AIP and IBD. The primary outcome was the prevalence of IBD among AIP patients, and vice versa. Secondary outcomes included clinical findings and outcomes of each IMID in AIP‐IBD patients. The pooled rate of each outcome was determined using a random effects model. Results For primary outcomes, 40 observational studies with 4031 AIP patients were included and the pooled prevalence of IBD was 10.5% (95% CI 7.2–15.0%). Meanwhile, five studies with 10,551 IBD patients were included and the pooled prevalence of AIP was 0.6% (95% CI 0.2–1.9%). For secondary outcomes, 53 observational studies with 469 AIP‐IBD patients were assessed. The rates of type 2 AIP and ulcerative colitis were 79.2% (95% CI 69.1–86.6%) and 74.8% (95% CI 68.2–80.4%), respectively. We also demonstrated AIP‐IBD patients were at a significant increased risk of AIP recurrence and colectomy compared with patients with either AIP or IBD (RR = 1.9, 95% CI 1.1–3.1 and P = 0.014 and RR = 3.7, 95% CI 1.9–6.9, P < 0.001, respectively). Conclusions Our meta‐analysis reported the prevalence of AIP‐IBD patients and demonstrated patients with both IMIDs had a high risk of poor outcomes.

Autoimmune pancreatitis associated with inflammatory bowel diseases: A retrospectively bidirectional case–control study in China

“…In our study, the crude rate of AIP in IBD patients was 0.39%, compared to 0.57% in UC patients; previous studies in East Asia reported a crude rate of 0.40%–0.60% and 0.52%–0.54%, respectively 12–14 . Taken together, the prevalence of AIP in IBD patients is essentially similar in East Asia.…”

“…In our study, the crude rate of AIP in IBD patients was 0.39%, compared to 0.57% in UC patients; previous studies in East Asia reported a crude rate of 0.40%-0.60% and 0.52%-0.54%, respectively. [12][13][14] Taken together, the prevalence of AIP in IBD patients is essentially similar in East Asia. On the other side, the crude rate of IBD was 2.91% in patients with AIP and 36.67% in patients with type 2 AIP, which are lower than previously reported (5.6%-29.4% and 42.9%-58.3%, respectively).…”

“…There have been several reports on the prevalence of AIP‐IBD and its associated factors, particularly in Western countries. A meta‐analysis showed that the prevalence of AIP was 0.6% (95% confidence interval [CI] 0.2%–1.9%) in 10 551 patients with IBD 12 . Among AIP patients, the prevalence of UC in western countries ranged from 30% to 35%, while in Korea and Japan, the prevalence of UC is 5.8% and 16%, respectively 13,14 .…”

“…A metaanalysis showed that the prevalence of AIP was 0.6% (95% confidence interval [CI] 0.2%-1.9%) in 10 551 patients with IBD. 12 Among AIP patients, the prevalence of UC in western countries ranged from 30% to 35%, while in Korea and Japan, the prevalence of UC is 5.8% and 16%, respectively. 13,14 In France and Belgium, a study including 91 cases showed that the independent factors associated with AIP in UC patients were proctitis and colectomy, while in CD patients such factors included fewer perianal lesions, non-stricturing nonpenetrating CD and a higher rate of colectomy.…”

Type 2 autoimmune pancreatitis associated with ulcerative colitis

“…The association between AIP and IBD is well established, particularly between UC and type 2 AIP ( 52 – 55 ). The prevalence of IBD is significantly higher in patients with AIP (approximately 11%–30%) ( 54 , 56 , 57 ). Approximately 30%–48% of type 2 AIP cases are associated with IBD ( 9 , 58 , 59 ).…”