Clinical significance of extrapancreatic lesions in autoimmune pancreatitis

Diagnostic criteria for IgG4-related sclerosing cholangitis based on cholangiographic classification

BACKGROUND

IgG4-related sclerosing cholangitis (IgG4-SC) needs to be differentiated from pancreatic cancer (PCa), primary sclerosing cholangitis (PSC), and cholangiocarcinoma (CC). We attempted to establish diagnostic criteria for IgG4-SC based on cholangiographic classification by comparison with several diagnostic modalities.

METHODS

We classified 62 IgG4-SC patients into three groups on the basis of cholangiographic findings to allow differentiation from PCa, PSC, and CC: Group A IgG4-SC showed features similar to PCa (Type 1, n = 32), Group B showed similarity to PSC (Type 2, n = 15), and Group C showed similarity to CC (Type 3, 4, n = 15). Thirty-five patients with PCa, 40 with PSC, and 32 CC were enrolled as controls. We retrospectively compared the clinical, imaging, serological, and histopathological features and involvement of other organs between Group A and PCa, Group B and PSC, and Group C and CC.

RESULTS

Association with autoimmune pancreatitis (AIP) (P < 0.001) and involvements with other organs (specificity 100%) were common useful diagnostic parameters in all three IgG4-SC groups. A high serum IgG4 level was a useful parameter in Groups A and B (P < 0.001). Discriminant analysis of cholangiograms (P < 0.001), liver biopsy (specificity 100%), and exclusion of inflammatory bowel disease (specificity 100%) were useful parameters in Group B. Intraductal ultrasonography findings (P < 0.001) and exclusion of malignancy by bile duct biopsy (specificity 100%) were useful parameters in Group C. We established diagnostic criteria for IgG4-SC (sensitivity 100%, specificity 96.3%) by incorporating parameters that showed P < 0.001 or 100% specificity.

CONCLUSIONS

Diagnostic criteria for IgG4-SC based on cholangiographic classification are useful for distinguishing it from PCa, PSC, and CC.

Benign biliary strictures: a current comprehensive clinical and imaging review

OBJECTIVE

There is a wide spectrum of nonneoplastic causes of biliary stricture that can pose a significant challenge to clinicians and radiologists. Imaging plays a key role in differentiating benign from malignant strictures, defining the extent, and directing the biopsy. We describe the salient clinical and imaging manifestations of benign biliary strictures that will help radiologists to accurately diagnose these entities.

CONCLUSION

Accurate diagnosis and management are based on correlating imaging findings with epidemiologic, clinical, and laboratory data. Cross-sectional imaging modalities permit precise localization of the site and length of the segment involved, thereby serving as a road map to surgery, and permit exclusion of underlying malignancy.

Diagnostic procedures for IgG4-related sclerosing cholangitis

BACKGROUND/PURPOSE

IgG4-related sclerosing cholangitis (IgG4-SC) is one of several diseases associated with autoimmune pancreatitis (AIP). However, diffuse cholangraphic abnormalities seen in association with AIP may resemble those seen in primary sclerosing cholangitis (PSC), and the presence of segmental stenosis suggests cholangiocarcinoma. IgG4-SC responds well to steroid therapy, whereas in contrast, liver transplantation is the only effective therapy for PSC, and surgical intervention is also needed for cholangiocarcinoma. The aim of this review was to establish the diagnostic procedures for IgG4-SC.

METHODS

A literature search was conducted, covering English-language articles dealing with IgG4-SC published between 1991 and March 2010. As clinical data on IgG4-SC are limited, the author also took into consideration his own clinical experience with the treatment of IgG4-SC over a period of more than 19 years.

RESULTS

When intrapancreatic stenosis is detected, pancreatic cancer should be ruled out. If multiple intrahepatic stenosis is evident, PSC should be discriminated on the basis of cholangiographic findings and liver biopsy with IgG4 immunostaining. An association with inflammatory bowel disease (IBD) is suggestive of PSC. If stenosis is demonstrated in the hepatic hilar region, cholangiocarcinoma should be discriminated by US, EUS, IDUS, and bile duct biopsy.

CONCLUSION

For diagnosis of IgG4-SC, coexistence of AIP is the most useful finding. However, the most important consideration for clinicians is to be aware of IgG4-SC when encountering patients with obstructive jaundice.

Serologic issues in IgG4-related systemic disease and autoimmune pancreatitis

PURPOSE OF REVIEW

IgG4-related systemic disease (ISD) is a recently recognized syndrome affecting multiple organs. Autoimmune pancreatitis (AIP) is the pancreatic manifestation of ISD and mimics pancreatic cancer. Current data show frequent association with serum IgG4 elevation and other serologic abnormalities. Here we explore the diagnostic and possible prognostic utility and pathogenetic implications of serologic abnormalities in ISD.

RECENT FINDINGS

Serum IgG4 elevations (>140 mg/dl) are seen in 70-80% of AIP patients and also in 5% of normal population and 10% of pancreatic cancer making it an unsuitable single marker for diagnosis. However, when combined with other features of AIP, it can be of great diagnostic value though its utility in monitoring of therapy or as a marker or predictor of relapse is limited. Several other antibodies have been identified in AIP against pancreas-specific antigens like trypsinogens I and II, pancreatic secretory trypsin inhibitor (PSTI) and plasminogen binding protein (PBP) and other nonpancreas-specific antigens. Anti-PBP antibodies appear to have potential diagnostic utility but require further validation.

SUMMARY

No single serologic marker is diagnostic of ISD. Serum IgG4 elevation has convincing diagnostic utility when combined with other disease features although its value in disease monitoring may be limited.

A case of sclerosing cholangitis without pancreatic involvement thought to be associated with autoimmunity

Sclerosing cholangitis (SC) is one of the lesions frequently seen in IgG4-related systemic diseases, causing biliary stricture and mimicking bile duct carcinoma and primary sclerosing cholangitis (PSC). Although it often accompanies autoimmune pancreatitis (AIP), autoimmune-related SC without a pancreatic lesion is very rare. A 79-year-old woman was referred to our institution with suspected diagnosis of bile duct carcinoma in the previous hospital. The patient was not icteric and fever free, but with an elevated level of serum biliary enzyme, which lead us to detect this disease. Clinical images including computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP) and intraductal ultrasonography (IDUS) demonstrated multiple strictures at the intrahepatic bile duct and enhanced wall thickness at the upper common bile duct, however her pancreas was normal. Repeated endoscopic procedures with multiple biopsies from the biliary strictures demonstrated fibrous ductal tissues with lymph-plasma cell infiltration (>10 IgG4(+) cells/HPF). By positron emission tomography using (18)F-fluorodeoxyglucose (FDG-PET), the uptake of FDG was not remarkable in areas other than the biliary lesions. Additional laboratory tests showed elevated levels of serum IgG (2,571 mg/dL), and γ-globulin (29%), and positive autoantibodies, but normal IgG4 (53.2 mg/dL). Together with clinical images, laboratory and histological findings, we diagnosed this patient as sclerosing cholangitis which was thought to be associated with autoimmunity. After one year of follow-up without steroid therapy, idiopathic thrombocytopenic purpura (ITP) developed with an increased level of serological markers. We encountered a rare case of sclerosing cholangitis expected to be associated with autoimmunity, which showed biliary strictures mimicking bile duct carcinoma and needed careful diagnosis. Unlike the typical AIP, the current case demonstrated distinct serological findings and no other organ involvement. Further study is needed to clarify the characteristics of sclerosing cholangitis associated with autoimmunity with a large number of cases.

Clinical analysis of high serum IgE in autoimmune pancreatitis

AIM

To clarify the clinical significance of high serum IgE in autoimmune pancreatitis (AIP).

METHODS

Forty-two AIP patients, whose IgE was measured before steroid treatment, were analyzed. To evaluate the relationship between IgE levels and the disease activity of AIP, we examined (1) Frequency of high IgE (> 170 IU/mL) and concomitant allergic diseases requiring treatment; (2) Correlations between IgG, IgG4, and IgE; (3) Relationship between the presence of extrapancreatic lesions and IgE; (4) Relationship between clinical relapse and IgE in patients treated with steroids, and (5) Transition of IgE before and after steroid treatment.

RESULTS

IgE was elevated in 36/42 (86%) patients. Concomitant allergic disease was observed in seven patients (allergic rhinitis in three, bronchial asthma in three, and urticaria in one). There were no significant correlations between IgG, IgG4, and IgE (r = -0.168 for IgG, and r = -0.188 for IgG4). There was no significant difference in IgE in the patients with and without extrapancreatic lesions (526 ± 531 IU/mL vs 819 ± 768 IU/mL, P = 0.163), with and without clinical relapse (457 ± 346 IU/mL vs 784 ± 786 IU/mL, P = 0.374). There was no significant difference in IgE between before and after steroid treatment (723 ± 744 IU/mL vs 673 ± 660 IU/mL, P = 0.633).

CONCLUSION

Although IgE does not necessarily reflect the disease activity, IgE might be useful for the diagnosis of AIP in an inactive stage.

Comparative evaluation of the Japanese diagnostic criteria for autoimmune pancreatitis

OBJECTIVES

The aim of the study was to clarify the problems of the Japanese criteria for autoimmune pancreatitis (AIP) in comparison with the other criteria.

METHODS

We retrospectively investigated the clinical, imaging, serological, and histopathogic features, together with other organ involvement and response to steroid, in 50 patients with AIP diagnosed on the basis of the Japanese, Korean, HISORt, and Asian criteria. Thirty-five patients with pancreatic cancer were enrolled as a control group.

RESULTS

Forty (80%) of 50 patients received a diagnosis of AIP on the basis of the Japanese criteria. Imaging findings and serological parameters fulfilled the Japanese criteria in 40 (80%) and 50 (100%) of the patients. Pathological findings fulfilled the Japanese criteria in 6 (43%) of 14 patients. All of the 10 patients who did not have a diagnosis of AIP did not fulfill the imaging criteria. Serological parameters fulfilled the Japanese criteria in 8 (23%) of 35 patients with pancreatic cancer. The sensitivities of the Japanese, Korean, HISORt, and Asian criteria for AIP were 80%, 86%, 92%, and 82%, respectively. The specificities of those 4 criteria were 89%, 89%, 97%, and 89%, respectively.

CONCLUSIONS

The low sensitivity of imaging criteria and low specificity of serological criteria were the problems in the Japanese criteria.

Clinicopathological characteristics of patients with IgG4-related tubulointerstitial nephritis

IgG4-related disease is a recently recognized multi-organ disorder characterized by high levels of serum IgG4 and dense infiltration of IgG4-positive cells into several organs. Although the pancreas was the first organ recognized to be affected by IgG4-related disorder in the syndrome of autoimmune pancreatitis, we present here clinico-pathological features of 23 patients diagnosed as having renal parenchymal lesions. These injuries were associated with a high level of serum IgG4 and abundant IgG4-positive plasma cell infiltration into the renal interstitium with fibrosis. In all patients, tubulointerstitial nephritis was the major finding. Although 14 of the 23 patients did not have any pancreatic lesions, their clinicopathological features were quite uniform and similar to those shown in autoimmune pancreatitis. These included predominance in middle-aged to elderly men, frequent association with IgG4-related conditions in other organs, high levels of serum IgG and IgG4, a high frequency of hypocomplementemia, a high serum IgE level, a patchy and diffuse lesion distribution, a swirling fibrosis in the renal pathology, and a good response to corticosteroids. Thus, we suggest that renal parenchymal lesions actually develop in association with IgG4-related disease, for which we propose the term 'IgG4-related tubulointerstitial nephritis.'