Suggestive causal associations between 17 autoimmune diseases and pancreatitis

The relationship between different autoimmune diseases (ADs) and pancreatitis has been reported in epidemiological studies. This study systematically investigated the causal effects of ADs factors on pancreatitis using Mendelian randomization (MR). We selected 17 common ADs as exposures from the largest genome-wide association study dataset in Europe. The outcome variables included acute pancreatitis (AP), chronic pancreatitis (CP), alcohol-induced acute pancreatitis, and alcohol-induced chronic pancreatitis. A variety of analytical methods were used to comprehensively evaluate the causal relationship between ADs and various types of pancreatitis, with sensitivity analyses, including Cochran’s Q test and MR-Egger intercept test performed to verify the reliability of the results. Finally, a reverse MR analysis was performed to evaluate the possibility of reverse causation. Genetically predicted type 1 diabetes (OR = 1.032, 95% CI = 1.008–1.056, P = .0086) and ulcerative colitis (OR = 1.065, 95% CI = 1.012–1.121, P  = .0151) were associated with an increased risk of AP. primary sclerosing cholangitis (OR = 1.080, 95% CI = 1.013–1.153, P = .0194) increased the risk of CP. Reverse MR analysis suggested a potential protective causal association between alcohol-induced acute pancreatitis and hashimoto’s thyroiditis (OR = 0.962, 95% CI = 0.936–0.989, P  = .0056), although this finding should be regarded as suggestive because it did not remain statistically significant after Bonferroni correction. Sensitivity analysis did not detect horizontal pleiotropy or heterogeneity. Genetic evidence supports a causal link between type 1 diabetes, ulcerative colitis , and AP, as well as between primary sclerosing cholangitis and CP. This analysis provides new insights into ADs as risk factors for pancreatitis, but further experimental research is needed to explore the potential causal relationships between these factors.