The Clinical Phenotype of Chinese Patients With Autoimmune Pancreatitis Differs Significantly From Western Patients

AIM: To characterize the clinical features of autoimmune pancreatitis (AIP) in China and compare differences between our Chinese cohort and Western cohorts. METHODS: This was a retrospective study of patients with AIP that was carried out in the China-Japan Friendship Hospital between January 2010 and April 2021. We included a total of 50 patients (46 males and 4 females) aged between 27 and 86 years who fulfilled the international Consensus Diagnostic (ICD) Criteria. For comparative purposes, we included data from seven representative Western cohorts. RESULT: When comparing Chinese and Western patients, we found that obstructive jaundice was the most frequent initial symptom (68 vs. 43%, P < 0.001). Extra-pancreatic organ involvement was more common in Chinese patients (68 vs. 30%, P < 0.001). Sclerosing cholangitis was the most frequent extrapancreatic lesion (48 vs. 24%, P = 0.001). The elevation of serum IgG4 was more obvious in our cohort (86 vs. 49%, P < 0.001). Conversely, the rates of ANA-positivity were significantly higher in Western populations (17 vs. 50%, P = 0.006). With regards to imaging, diffuse swelling was significantly more common in China (44 vs. 27%, P = 0.021). Steroid therapy was used more frequently in our Chinese patients (84 vs. 59%, P = 0.001). The steroid-response rate was also significantly higher in our Chinese patients (85 vs. 54%, P = 0.001); However, the rate of resection was higher in Western cohorts (2 vs. 31%, P < 0.001). There was no significant difference between the two populations with regards to recurrence rate (33 vs. 33%, P = 1.000). CONCLUSION: This study identified significant differences between Chinese and Western populations of patients with AIP. Within the Chinese population, AIP was more likely to have jaundice and extra-pancreatic organ involvement, and elevated serum IgG4 levels. Chinese patients were also showed favorable responses to treatment with glucocorticoids.