Autoimmune pancreatitis and hepatitis: an uncommon association

Autoimmune liver disease and concomitant extrahepatic autoimmune disease

AIM

To assess the frequency and clinical impact of associated extrahepatic autoimmune diseases (EAD) on autoimmune liver diseases (ALD).

PATIENTS AND METHODS

We investigated 608 patients with ALD (327 autoimmune hepatitis - AIH and 281 primary biliary cirrhosis - PBC) for concomitant EAD.

RESULTS

In both AIH and PBC, we observed a high prevalence of EAD (29.9 and 42.3%, respectively); both diseases showed a significant association with autoimmune thyroid disease, followed by autoimmune skin disease, celiac disease, and vasculitis in AIH patients and sicca syndrome, CREST syndrome, and celiac disease in PBC patients. At diagnosis, AIH patients with concurrent EAD were more often asymptomatic than patients with isolated AIH (P<0.01).

CONCLUSION

Our study confirms the strict association between ALD and EAD, in particular with autoimmune thyroid disease. In the light of our results, all patients with an EAD should be assessed for the concomitant presence of an asymptomatic ALD.

Concurrent autoimmune diseases in patients with autoimmune hepatitis

BACKGROUND

Although the pathomechanisms of autoimmune diseases in various organs remain unresolved, an accumulation of autoimmune diseases in individual patients has been observed. An overlap of autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) or primary sclerosing cirrhosis has been well documented. However, the overlap of autoimmune diseases other than PBC or PSC has not yet been investigated in a large cohort.

GOAL

The goal of our analysis was to investigate the incidence of concurrent autoimmune diseases in patients with AIH.

STUDY

We analyzed our cohort of 278 patients with AIH for concurrent autoimmune diseases.

RESULTS

A total of 111 patients (40%) were diagnosed with additional autoimmune diseases. Besides overlap syndromes for PBC and PSC, autoimmune thyroiditis was the most common concurrent disease (28 patients, 10%). Other concurrent autoimmune diseases comprised vitiligo (5 patients), rheumatoid arthritis (5 patients), Sjogren syndrome (4 patients), ulcerative colitis (4 patients), conjunctivitis (4 patients), celiac disease (3 patients), systemic lupus erythematodes (2 patients), type I diabetes (2 patients), multiple sclerosis (2 patients), polymyalgia rheumatica (2 patients), and urticaria (2 patients). One patient each was diagnosed with Crohn's disease, autoimmune gastritis, collagenous colitis, hypophysitis, and sarcoidosis. Investigating 100 patients with polyglandular syndrome and autoimmune thyroid disease for the occurrence of autoantibodies associated with AIH, we identified AIH-associated antibodies only in 1 patient.

CONCLUSIONS

Concurrent autoimmune diseases are common in patients with AIH and mirror the full range of known autoimmune diseases. Therefore, an extended diagnostic screening for accumulating autoimmune diseases, especially autoimmune thyroiditis, seems reasonable in patients with AIH.

[Autoimmune pancreatitis]

Autoimmune pancreatitis has been established as a special entity of pancreatitis. It is an enigmatic disease since it is adding an autoimmune etiology to the existing causes of pancreatitis. Morphological hallmarks of the disease are narrowing of the pancreatic duct system and the bile duct by periductal lymphoplasmocytic inflammation. This results in many cases in obstructive jaundice due to a mass-forming lesion in the pancreatic head mimicking pancreatic ductal adenocarcinoma. Therefore, patients will frequently undergo surgery. Histopathologically, the disease can be diagnosed by IgG4-positive plasma cells. Serologically, patients may present with elevated serum IgG and IgG4 levels. Other autoantibodies are also described. Association with other autoimmune manifestations in a wide range of organs is frequent. Autoimmune pancreatitis will respond to steroid treatment, which is of specific importance because pancreatic cancer is one of its clinical differential diagnoses. It is important to positively diagnose autoimmune pancreatitis, especially if the bile ducts are affected, since cholangitis may be or become a prominent problem before or after surgery.

Usefulness of serum IgG4 in the diagnosis and follow up of autoimmune pancreatitis: A systematic literature review and meta-analysis

High circulating serum immunoglobulin G4 (IgG4) levels have been proposed as a marker of autoimmune pancreatitis (AIP). The aim of the present study was to review the data existing in the English literature on the usefulness of the IgG4 serum levels in the diagnosis and follow up of patients with AIP. A total of 159 patients with AIP and 1099 controls were described in seven selected papers reporting the usefulness of serum IgG4 in diagnosing AIP. In total, 304 controls had pancreatic cancer, 96 had autoimmune diseases, and the remaining 699 had other conditions. The summary receiver-operating characteristic curve analysis was carried out by means of Meta-DiSc open-access software. Serum IgG4 showed good accuracy in distinguishing between AIP and the overall controls, pancreatic cancer and other autoimmune diseases (area under the curve [+/- SE]: 0.920 +/- 0.073, 0.914 +/- 0.191, and 0.949 +/- 0.024, respectively). The studies analyzed showed significantly heterogeneous specificity values in each of the three analyses performed. The analysis of the four studies comparing AIP and pancreatic cancers also showed significantly heterogeneous values of sensitivities and odds ratios. Regarding the usefulness of IgG4 as a marker of efficacy of steroid treatment, a decrease in the serum concentrations of IgG4 was found in the four available studies. The serum IgG4 subclass is a good marker of AIP, and its determination should be included in the diagnostic workup of this disease. However, the heterogeneity of the studies published until now means that more studies are necessary in order to better evaluate the true accuracy of IgG4 in discriminating AIP versus other autoimmune diseases.

Autoimmune pancreatitis

Autoimmune pancreatitis is a type of idiopathic pancreatitis. It is also referred to as sclerosing pancreatitis, lymphoplasmatocytic sclerosing pancreatitis, chronic pancreatitis with irregular stenosis of the main pancreatic duct and as sclerosing pancreatocholangitis. Clinical characteristics of autoimmune pancreatitis are jaundice, abdominal pain, weight loss and diabetes mellitus. Radiologically, there is diffuse enlargement of pancreas with stenosis of pancreatic duct without calcifications in the pancreatic parenchyma. In autoimmune pancreatitis, antibodies against lactoferrin and carbonic anhydrase have been detected, but they are not specific because they are present in some other autoimmune diseases too. Also in autoimmune pancreatitis, there are increased levels of gammaglobulins and characteristically high titres of IgG4, which are a subtype of IgG. Autoimmune pancreatitis is usually treated successfully by prednisolone.

Autoimmune pancreatic disease: preparation of pancreatic juice for proteome analysis

The identification of pancreatic proteins is generally hampered by the high content and activity of proteases produced by this organ. The aim of this work was the development of a protocol for the analysis of pancreatic juice by two-dimensional (2-D) gel electrophoresis allowing consistent and reproducible protein analysis encompassed by high-resolution protein 2-D maps and subtle protein spot recognition without substantial losses due to proteases. Immobilized pH gradient (IPG) strips were used for the first dimension, the second dimension was performed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). However, the key step was the sample preparation technique. Improvements were achieved by using several protease inhibitors (phenylmethylsulfonyl fluoride, aprotinin, L-1-chloro-3-[4-tosyl-amido]-7-amino-2-heptanine (TLCK)-HCI, Complete) to prevent degradation of the proteins. The application of different pH-ranges was a valuable step for getting an overview of the expressed protein pattern. These investigations resulted in well-resolved 2-D maps with a high reproducibility.