Clinical Features and Comprehensive Diagnosis of Autoimmune Pancreatitis in China

Abstract

Aim: To search for the key factors of autoimmune pancreatitis (AIP) in China and to improve the early identification of AIP in order to avoid misdiagnosing it as pancreatic carcinoma. Methods: Clinical, imaging, laboratory, and pathological data about AIP were collected and analyzed from 1996 to 2011 in The Chinese People's Liberation Army General Hospital. Results: A total of 33 patients (male 29, female 4) aged 35-76 years (52.3 ± 9.3 years) meeting the International Consensus Diagnostic Criteria for type 1 (n = 32) or type 2 (n = 1) AIP were included. With improved understanding of AIP, the misdiagnosis rate and unnecessary laparotomy rate was decreased from 95.7% (22/23) and 91.3% (21/23) before 2006, to 20.0% (2/10) (p = 0.001) and 0.0% (p = 0.001) respectively after 2006. The major symptoms were jaundice in (24/33, 72.7%) and abdominal pain (12/33, 36.4%). Half of the patients had other accompanied autoimmune disorders. Laboratory tests showed an elevated level of serum IgG in 9 out of 11 patients (81.8%) and an increased eosinophil count in 16 out of 33 patients (48.5%). The serum IgG4 levels were twice the upper limit of the normal value. CT scan showed a low-contrast margin characterized by a capsule-like rim in 24 of 32 patients (75.0%). Pathologic examinations showed fibrosis and infiltration of massive lymphocytes and plasma cells in the pancreas. Prednisone was given to the patients and proved to be quite effective for all of them (12/12, 100%). Conclusion: Type 1 AIP shows a sex predilection compared with type 2 AIP in China. In order to diagnose AIP exactly, a comprehensive strategy, especially including imaging and pathological examination, should be used. With growing awareness, fewer AIP patients with this diagnosis would be misdiagnosed and incorrectly treated.

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

“…We found that the mean onset age of AIP was similar to western cohorts with a predominance in elderly people. However, the proportion of males (92%) was significantly higher in our cohort than in the Western population, this feature is also showed in other Chinese studies ( 29 – 31 ). Furthermore, we also found that the proportion of male patients in our center was higher than that in other Asian countries, such as in Japan.…”

“…In this case, clinicians rely on clinical manifestations and increased serum IgG4 levels to improve the diagnostic rate. Nevertheless, histological findings remain the gold standard for the diagnosis of AIP, as documented in other studies ( 31 ). The main histological findings were interstitial fibrosis and the infiltration of lymphocytes and plasma cells.…”

Serological characteristics of autoimmune pancreatitis and its differential diagnosis from pancreatic cancer by using a combination of carbohydrate antigen 19-9, globulin, eosinophils and hemoglobin

“…However, the severity of histological infiltration did not correlate with peripheral eosinophilia[34]. We reported that 52% patients showed elevated serum eosinophil percentage, which is relatively high compared to the previous reports of 12–45% measured by periphery eosinophil counts[32, 35, 36]. Eosinophil percentage at an optimal cut-off level 4.15% diagnosed AIP with the sensitivity of 60% and specificity of 88%, which indicated a relatively high diagnostic performance.…”

Clinical Features and Expressions of Foxp3 and IL-17 in Type 1 Autoimmune Pancreatitis in China

“…In North America, among CP cases, the prevalence of AIP is 5–6% [ 3 ]. According to the morbidity in these countries, it is estimated that there are thousands of patients with AIP in China, but only few cases are reported because most AIP patients in China have been misdiagnosed and consequently not correctly treated [ 4 , 5 ]. In a report of 36 AIP patients in China, 18 (50%) cases were misdiagnosed as pancreatic cancer and 10 (28%) as non-AIP pancreatitis.…”