Abstract: Objective:To investigate the diagnosis and treatment of autoimmune pancreatitis (AIP).
Methods:The clinical data of 25 patients with AIP who were admitted to the Cancer Hospital of Tianjin Medical University between January 2009 and December 2013 were retrospectively analyzed. Patients received the test of serum γglobulin and IgG4 and abdominal imaging examination. The revised HISORt or results of postoperative pathological examination were performed as diagnostic criteria. Patients who were unable to tolerate surgery were treated by oral prednisone. The focal masses were apparent in the pancreas by imaging examination, which cannot exclude the possibility of malignancy because of ambiguous pathologic characters of  masses. Patients who received ineffective hormonal therapy and were able to tolerate surgery underwent surgery. All the patients were followed up by outpatient examination and telephone interview up to December 2014.
Results:Primary symptoms: jaundice was detected in 16 patients, obvious weight loss (weight loss>10% standard body mass) in 4 patients, chronic diarrhea (duration of diarrhea>2 months or 2 weeks<duration of intermittent diarrhea<4 weeks) in 3 patients and  abdominal pain in 2 patients. Abnormal level of serum γglobulin and increasing level of IgG4 were detected in 13 and 1 pateints. The results of imaging examinations showed that pancreatic masses, stenosis of bile duct and extrapancreactic organ involvement were detected in 19, 6 and 11 patients. Of 25 patients with AIP, 10 underwent conservative treatment without adverse reaction and 15 underwent surgical treatment, including 13 of 15 patients undergoing pancreaticoduodenectomy and 2 of 15 patients undergoing resection of the body and tail of the pancreas+splenectomy. The operation time, volume of intraoperative blood loss and postoperative recovery time of gastrointestinal function in 15 patients undergoing surgery were (271±59)minutes, (268±109)mL and (3.8±1.2)days.After operation, 2 patients were complicated with abdominal infection and had remission of symptoms by sympto matic treatment, including 1 with pancreatic fistula and 1 with delayed gastric emptying. The duration of hospital stay of 15 patients undergoing surgery was (11.5±2.9)days. The results of postoperative pathological examination showed that there were central acinar atrophy, extensive fibrosis, lymphoplasmacytic cell infiltration, nerve tissue surrounded by the plasma cell lymphoma and obstructive phlebitis. The absolute value of positive cells of IgG4 was more than 50 high power field and number of positive cells of IgG4 was more than positive cells of 40% IgG. Twentyfive patients were followed up for a median time of 27 months (range, 6-47months). Nineteen patients had remission of symptoms at month 6 after treatment with normal level of serum γglobulin and IgG4 and without recurrence of pancreatic masses, including 7 receiving conservative treatment and 12 receiving surgical treatment.
Conclusions:The clinical signs of AIP are jaundice, abnormal serum γ globulin and pancreatic masses which are found by imaging examination. Surgery is safe and effective for the treatment of AIP, while surgical indications should be strictly followed because of the surgical trauma.