Japan Pancreas Society criteria for diagnosis of autoimmune pancreatitis mandate presence of characteristic imaging.
Autoimmune pancreatitis has unique histologic features associated with infiltration of tissues of affected organs with abundant immunoglobulin G4-positive cells.
Dr Suresh Chari and colleagues from Minnesota expanded diagnostic criteria for autoimmune pancreatitis.
The team assessed a cohort of histologically confirmed autoimmune pancreatitis from the Mayo Clinic.
The investigative team reviewed the pancreatic imaging findings on computed tomography scans.
The team measured serum immunoglobulin G4 levels, other organ involvement, and response to steroids in 29 consecutive patients.
The patients met histologic criteria for autoimmune pancreatitis.
The investigators found that 22 computed tomography scans showed diffuse pancreatic enlargement in 6 patients.
|Serum immunoglobulin G4 levels were elevated in 15 of 21 patients|
|Clinical Gastroenterology & Hepatology|
The team noted that the remainder of patients had focal enlargement, distinct mass, normal pancreas, or focal acute pancreatitis.
Serum immunoglobulin G4 level was elevated in 15 of 21 patients, and other organ involvement was noted in 11 of 29 patients.
The investigators observed that 17 patients treated with steroids exhibited resolution or marked improvement of pancreatic or extrapancreatic manifestation.
On the basis of this experience the team proposed that diagnosis of autoimmune pancreatitis can be made in these patients.
Diagnostic histology was identified as a criterion for this diagnosis.
Characteristic imaging on computed tomography and pancreatography with elevated serum immunoglobulin G4 level was a diagnostic criteria.
The team found response to steroid therapy of pancreatic or extrapancreatic manifestations of autoimmune pancreatitis was another diagnostic criteria.
In addition, 20 other patients met expanded diagnostic criteria for autoimmune pancreatitis.
The investigators noted that these patients' demographic and clinical profiles were similar to that of the 29 patients meeting histologic criteria.
Dr Chari's team concluded, “Autoimmune pancreatitis defined by histological criteria shows a wide spectrum of radiologic features, with characteristic imaging seen only in a minority.”
“Incorporation of additional features into current diagnostic criteria can identify the full spectrum of clinical presentations of autoimmune pancreatitis.”