Autoimmune pancreatitis: current concepts. Sci China Life Sci. 2013;56:246-253. [PMID: 23526391 DOI: 10.1007/s11427-013-4450-z]

Autoimmune pancreatitis masquerading as carcinoma head of pancreas: A case report and review of literature

Introduction

Autoimmune pancreatitis (AIP) is a rare form of chronic inflammatory pancreatic disease secondary to an underlying autoimmune mechanism. It is now considered as pancreatic manifestation of IgG4 related disease, which is a multisystem disease.

Case report

We are reporting a patient who presented with obstructive jaundice and mass head of pancreas on Computed Tomography (CT) scan. Considering a strong clinical suspicion of pancreatic cancer, Whipple procedure was done. Histopathological report revealed intense lymphoplasmacytic infiltrate and fibrosis with collagenisation, so possibility of AIP was suggested. Serum IgG4 levels were advised and found to be increased. Diagnosis of AIP was made and patient responded to steroids.

Discussion

Pre-operative core biopsy of the pancreas and Serum IgG4 levels are sufficient to make the diagnosis and resection is usually not recommended in AIP.

Conclusion

Awareness of the entity and use of ancillary techniques in making the pre-operative diagnosis could have saved the patient from an extensive surgical procedure.

•

Autoimmune Pancreatitis is a pancreatic manifestation of IgG4 related disorders.

•

It can clinically and radiologically present as pancreatic malignancy.

•

Resection is not required in Autoimmune Pancreatitis.

•

Pre-operative investigations can save the patient from morbidity due to Whipples.

•

Whipples procedure is undesired in these patients.

•

This entity should be kept in mind while dealing with mass lesions in head of pancreas.

A non-invasive screening technique for type 1 autoimmune pancreatitis

Introduction

Type 1 autoimmune pancreatitis (AIP) is the pancreatic manifestation of a systemic fibroinflammatory IgG4-related disease. Accurate diagnosis of AIP can avoid major hepatobiliary and pancreatic surgery as it respond dramatically to corticosteroid therapy.

Aim

This research investigated the feasibility of using peripheral blood cell immunohistochemistry, serum IgG4, T-cell receptor (TCR) and serum isoelectric focusing electrophoresis in the screening of type 1 autoimmune pancreatitis (AIP).

Material and methods

The peripheral blood from 3 type 1 AIP patients, 10 pancreatic cancer patients and 40 normal controls was collected. Sediment smears were jointly incubated with anti-IgG4 and anti-IgG. The percentage of IgG4/IgG positive cells was counted and serum TCR and IgG4 were detected through the whole process. After serum isoelectric focusing electrophoresis, anti-IgG4 and anti-IgG were used to confirm the components of serum.

Results

In the serum isoelectric focusing electrophoresis, IgG4 and IgG strips showed mirrored distribution in type 1 AIP patients, while there were no strips in the normal controls and pancreatic cancer. Compared with pancreatic tumor patients and healthy controls, serum TCR was significant increased in AIP. The percentage of IgG4/IgG positive cells of peripheral blood cell immunohistochemistry was related to serum IgG4 and hormone therapy reactions.

Conclusions

Peripheral blood cell immunohistochemistry, serum IgG4, TCR and serum isoelectric focusing electrophoresis is suitable for the screening of type 1 AIP and monitoring its response assessment.

[Autoimmune pancreatitis in a patient with ulcerative colitis simulating a pancreatic tumor]

Pancreatic endocrine and/or exocrine functional disorders can be commonly detected in patients with inflammatory bowel diseases. Autoimmune pancreatitis is a rare disease and its co-existence with inflammatory bowel disease has been rarely reported. The diagnosis of autoimmune pancreatitis is difficult due to variable nonspecific symptoms, and the high rate of asymptomatic cases. The conventional imaging scans (ultrasonography, computed tomography, retrograde cholangiography) are usually not sensitive enough and they are frequently not able to differentiate between inflammatory and malignant tumorous diseases of the pancreas. The authors present the case history of a patient who developed both ulcerative colitis and autoimmune pancreatitis. The morphological changes of the pancreas detected by ultrasonography suggested the presence of pancreatic cancer, and this diagnosis was supported by the elevated level of serum CA19-9. Computed tomography failed to identify abnormalities in the pancreas and, finally, endoscopic ultrasound combined with fine needle aspiration cytology confirmed the diagnosis of autoimmune pancreatitis.

Current status of research on autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis characterized clinically by frequent presentation with obstructive jaundice, histologically by lymphoplasmacytic infiltration with fibrosis, and therapeutically by a dramatic response to steroids. AIP have recently been classified into two subtypes, lymphoplasmacytic sclerosing pancreatitis (LPSP) and idiopathic duct centric pancreatitis (IDCP). The pathogenesis of AIP may involve genetic susceptibility, autoantibodies, molecular mimicry, imbalance of T-cell-mediated immune regulation, and gene mutation. In this article, we will systematically review typical and atypical clinical, imaging and histopathological features of AIP, with an emphasis placed on the advances in the diagnosis and treatment of this disease.