Yayoi Ozaki

Prevalence and distribution of extrapancreatic lesions complicating autoimmune pancreatitis

BackgroundAutoimmune pancreatitis is a unique form of chronic pancreatitis characterized by high serum IgG4 concentrations and abundant IgG4-bearing plasma cell infiltration in the pancreatic lesion, and it has been reported to be associated with a variety of extrapancreatic lesions, leading us to postulate the concept of a systemic inflammatory disease. To confirm this, we clarified the exact distribution of these extrapancreatic lesions and provide a panoramic view of them.MethodsThe frequency, distribution, clinical characteristics, and pathology of five extrapancreatic lesions were determined in 64 patients with autoimmune pancreatitis by examining clinical and laboratory findings.ResultsThe most frequent extrapancreatic lesion was hilar lymphadenopathy (80.4%), followed by extrapancreatic bile duct lesions (73.9%), lachrymal and salivary gland lesions (39.1%), hypothyroidism (22.2%), and retroperitoneal fibrosis (12.5%). No patients had all five types of lesions. Patients with hilar lymphadenopathy or lachrymal and salivary gland lesions were found to have significantly higher IgG4 levels than those without (P = 0.0042 and 0.0227, respectively). Patients with three lesions were found to have significantly higher IgG4 levels than those with no lesion, suggesting that patients with multiple extrapancreatic lesions have active disease. Similar to pancreatic lesions, extrapancreatic lesions have a characteristic histological finding of abundant IgG4-bearing plasma cell infiltration, and they respond favorably to corticosteroid therapy.ConclusionsAutoimmune pancreatitis was recognized as a systemic inflammatory disease. Furthermore, recognition of these characteristic findings will aid in the correct diagnosis of this disease.

Differentiation of autoimmune pancreatitis from suspected pancreatic cancer by fluorine-18 fluorodeoxyglucose positron emission tomography

BackgroundFluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has been widely used for the diagnosis of pancreatic cancer. Because autoimmune pancreatitis is easily misdiagnosed as pancreatic cancer and can be tested for by FDG-PET analysis based on the presence of suspected pancreatic cancer, we attempted to clarify the differences in FDG-PET findings between the two conditions.MethodsWe compared FDG-PET findings between 15 patients with autoimmune pancreatitis and 26 patients with pancreatic cancer. The findings were evaluated visually or semiquantitatively using the maximum standardized uptake value and the accumulation pattern of FDG.ResultsFDG uptake was found in all 15 patients with autoimmune pancreatitis, whereas it was found in 19 of 26 patients (73.1%) with pancreatic cancer. An accumulation pattern characterized by nodular shapes was significantly more frequent in pancreatic cancer, whereas a longitudinal shape indicated autoimmune pancreatitis. Heterogeneous accumulation was found in almost all cases of autoimmune pancreatitis, whereas homogeneous accumulation was found in pancreatic cancer. Significantly more cases of pancreatic cancer showed solitary localization, whereas multiple localization in the pancreas favored the presence of autoimmune pancreatitis. FDG uptake by the hilar lymph node was significantly more frequent in autoimmune pancreatitis than in pancreatic cancer, and uptake by the lachrymal gland, salivary gland, biliary duct, retroperitoneal space, and prostate were seen only in autoimmune pancreatitis.ConclusionsFDG-PET is a useful tool for differentiating autoimmune pancreatitis from suspected pancreatic cancer, if the accumulation pattern and extrapancreatic involvement are considered. IgG4 measurement and other current image tests can further confirm the diagnosis.

A Novel Immunoglobulin-Immunoglobulin Interaction in Autoimmunity

Well over six decades since its first description, the Rheumatoid Factor (RF)—autoantibodies recognizing Fc (constant) portion of IgG through their own Fab (antigen binding variable segments)—is believed to have come of age. Autoimmune pancreatitis is a unique form of pancreatitis, biologically characterized by an elevated serum IgG4 concentration. Given the fact that IgG4 myeloma proteins can act as RF, we initially hypothesized that IgG4 in autoimmune pancreatitis might do likewise, hence potentially contributing to disease pathogenesis. Indeed Western blotting clearly showed that IgG4 binds to IgG1 κ, IgG2 κ, IgG3 κ myeloma proteins, as well as to IgG Fc, in line with a typical RF activity. Further experiments however unraveled the unexpected fact that unlike hitherto known RF, IgG4 does not engage IgG Fc through its Fab, but its very own Fc. These data therefore collectively describe a Novel RF (NRF) in autoimmune pancreatitis. In the future, the relevance of NRF, beyond autoimmune pancreatitis, in both diagnosis/prognosis as well as pathophysiology of autoimmune and other systemic diseases where IgG4s role seems paramount, needs to be systematically assessed.

Clinical features of a new disease concept, IgG4-related thyroiditis

Objectives: Immunoglobulin (Ig)G4-related disease is a recently proposed systemic disorder that includes autoimmune pancreatitis (AIP), Mikulicz’s disease, and various other organ lesions. In the present retrospective study, we examined whether thyroid lesions should also be included in IgG4-related disease (Ig4-RD) under the new term IgG4-related thyroiditis. Method: We enrolled 114 patients with Ig4-RD, including 92 patients with AIP, 15 patients with Mikulicz’s disease, and seven patients with IgG4-related cholangitis, and analysed clinical findings, function, serum values of activity markers, computed tomography (CT) images, and histology of the thyroid gland. Results: Among the 22 patients (19%) in our cohort who were found to have hypothyroidism [thyroid stimulating hormone (TSH) > 4 mIU/L], 11 patients had clinical hypothyroidism [free thyroxine (FT4) < 1 ng/dL] and 11 patients had subclinical hypothyroidism (FT4 ≥ 1 ng/dL). Serum concentrations of IgG, IgG4, circulating immune complex (CIC), and β2-microglobulin (β2-MG) were significantly higher in the hypothyroidism group compared with the remaining 92 euthyroid patients, and serum C3 concentration was significantly lower. After prednisolone treatment, TSH values had decreased significantly (p = 0.005) in this group and FT4 values had increased significantly (p = 0.047). CT images showed that the thyroid glands of patients with clinical hypothyroidism had a significantly greater volume than those of the euthyroid and other groups. Pathological analysis of one resected thyroid gland disclosed a focused lesion with infiltration of lymphocytes and IgG4-bearing plasma cells and loss of thyroid follicles. Conclusions: Thyroid lesions associated with hypothyroidism can be considered as a new disease termed IgG4-related thyroiditis. Awareness of this condition should lead to appropriate corticosteroid treatment that may prevent progression to a fibrous state.

Long-Term Follow-Up of Autoimmune Pancreatitis: Characteristics of Chronic Disease and Recurrence

Autoimmune pancreatitis is a unique disease, characterized by lymphoplasmacytic inflammation in the acute stages. However, the active clinical features are unlikely to persist for long periods. Through long-term follow-up, we investigated the disease course in 51 patients with autoimmune pancreatitis. We found recurrence in 21 (41%) patients and pancreatic stone formation in 9 (18%) patients. Pancreatic stone formation was significantly more frequent in the recurrence group (7/21, 33%), compared with the nonrecurrence group (2/30, 7%). Moreover, we found high serum immunoglobulin G4 concentrations in 13 of 175 (7.4%) patients with ordinary chronic pancreatitis. This suggested that pancreatic stone formation is closely associated with recurrence and that autoimmune pancreatitis might transform into ordinary chronic pancreatitis after several recurrences. We found that the immune complex level, with a cutoff value of 10 microg/dL, served as a good predictor of recurrence, with high sensitivity (61.9%), specificity (70.0%), and efficacy (66.7%). We also confirmed that HLA and cytotoxic T-lymphocyte antigen-4 polymorphisms were useful predictors for AIP recurrence.

Efficacy of preoperative endoscopic nasobiliary drainage for hilar cholangiocarcinoma

BACKGROUND/PURPOSE Although percutaneous transhepatic biliary drainage has previously been recommended as a primary preoperative step, endoscopic nasobiliary drainage (ENBD) is prevalent as an alternative procedure. Few reports assess the efficacy and safety of ENBD in a substantial patient cohort. METHODS Of 116 patients with hilar cholangiocarcinoma who underwent surgery, 62 (43 men and 19 women, median age 69 years) underwent preoperative ENBD. After classification of lesions according to Bismuth-Corlette (B-C) criteria, we evaluated efficacy and safety with respect to B-C type. RESULTS Patients were classified as B-C types I (n = 5), II (n = 21), IIIa (n = 23), IIIb (n = 5), and IV (n = 8). Preoperative single ENBD was effective in 46/62 patients (74%) including 5/5 (100%) B-C type I, 20/21 (94%) type II, 16/23 (70%) type IIIa, 4/5 (80%) type IIIb, and 1/8 (13%) type IV. Sixteen cases (26%) required additional drainages with ENBD or endoscopic biliary stenting (EBS) in 8/16 (50%), and with PTBD in 8/16 (50%). Mild acute pancreatitis (n = 1, 2%), segmental cholangitis (n = 2, 3%), and acute cholangitis with catheter obstruction (n = 7, 11%) occurred with ENBD. CONCLUSIONS Preoperative single ENBD in the future remnant lobe is effective treatment for B-C type I-III hilar cholangiocarcinoma. Preoperative ENBD was rarely complicated with segmental cholangitis.

Type 1 Autoimmune Pancreatitis Can Transform into Chronic Pancreatitis: A Long-Term Follow-Up Study of 73 Japanese Patients

Some patients with autoimmune pancreatitis (AIP) form pancreatic stones suggestive of transformation into chronic pancreatitis (CP). The present study examined the underlying risk factors and mechanism of AIP progression to confirmed CP. We compared the clinical and laboratory parameters of subjects who progressed to confirmed CP with those of the subjucts who did not in a cohort of 73 type 1 AIP patients. A total of 16 (22%) AIP patients progressed to CP. Univariate analysis revealed that relapse was significantly more frequent in the progression group, and multivariate analysis indicated that pancreatic head swelling (OR 12.7, P = 0.023) and nonnarrowing of the main pancreatic duct in the pancreatic body (OR 12.6, P = 0.001) were significant independent risk factors for progression to CP. Kaplan-Meier testing showed that the progression rate to CP was approximately 10% at 3 years and 30% at 10 years in total AIP patients and 30% at 3 years and 60% at 10 years in subjects with both risk factors. AIP with pancreatic head swelling and a history of relapse may cause pancreatic juice stagnation and nonnarrowing of the main pancreatic duct in the pancreatic body, which can progress to advanced stage chronic pancreatitis.

Autoimmune pancreatitis can develop into chronic pancreatitis

Autoimmune pancreatitis (AIP) has been recognized as a distinct type of pancreatitis that is possibly caused by autoimmune mechanisms. AIP is characterized by high serum IgG4 and IgG4-positive plasma cell infiltration in affected pancreatic tissue. Acute phase AIP responds favorably to corticosteroid therapy and results in the amelioration of clinical findings. However, the long-term prognosis and outcome of AIP remain unclear. We have proposed a working hypothesis that AIP can develop into ordinary chronic pancreatitis resembling alcoholic pancreatitis over a long-term course based on several clinical findings, most notably frequent pancreatic stone formation. In this review article, we describe a series of study results to confirm our hypothesis and clarify that: 1) pancreatic calcification in AIP is closely associated with disease recurrence; 2) advanced stage AIP might have earlier been included in ordinary chronic pancreatitis; 3) approximately 40% of AIP patients experience pancreatic stone formation over a long-term course, for which a primary risk factor is narrowing of both Wirsung’s and Santorini’s ducts; and 4) nearly 20% of AIP patients progress to confirmed chronic pancreatitis according to the revised Japanese Clinical Diagnostic Criteria, with independent risk factors being pancreatic head swelling and non-narrowing of the pancreatic body duct.

Lymphoproliferative disease of granular lymphocytes with T-cell receptor gamma delta-positive phenotype : restricted usage of T-cell receptor gamma and delta subunit genes

Abstract: Lymphoproliferative disease of granular lymphocytes (LDGL) is characterized by more than 0.5 × 109/L of proliferating granular lymphocytes in the peripheral blood. Because of its rarity, the characteristics of LDGL with T‐cell receptor (TCR) γδ phenotype (γδT‐LDGL) have not yet been identified. This report describes the clinical, hematological, and immunological findings of four patients with this disease. In two cases, the clinical course was indolent and the other two patients required various therapies. The cells had a common immunophenotype: CD3+, CD4–, CD16+, CD56–, CD57–, CD122–, TCR‐γδ+, and three were CD8‐positive. The immunopurified TCR‐γδ cells from the patients expressed only Vγ9 and Vδ1. Spectratyping and sequencing showed mono‐ or oligoclonality for TCRγ and TCRδ subunit genes. Soluble Fas ligand in sera was significantly elevated in all patients. These findings suggest that γδT‐LDGL qualifies as a distinct disease entity.

Microsatellite Scan Identifies New Candidate Genes for Susceptibility to Alcoholic Chronic Pancreatitis in Japanese Patients

Alcohol abuse is one of the most common risk factor for chronic pancreatitis, but the underlying pathophysiological mechanisms remain unclear. The aim of this study was to identify genes that contribute to susceptibility or resistance for alcoholic chronic pancreatitis by screening the whole genome. Sixty-five patients with alcoholic chronic pancreatitis (63 men and 2 women, mean age 55.2 years) and 99 healthy Japanese controls were enrolled in this study. This was an association study using 400 polymorphic microsatellite markers with an average spacing of 10.8 cM distributed throughout the whole genome. This search revealed 10 candidate susceptibility regions and 5 candidate resistant regions throughout the genome. No specific microsatellite markers were detected in association with previously reported susceptibility genes for chronic pancreatitis, such as PRSS1, PRSS2, CTRC, SPINK1, CFTR, ALDH2, and CYP2E1. Among the statistically significant markers, D15S1007 on chromosome 15q14 showed strong evidence for disease susceptibility (70.8% vs. 35.1%, Pc = 0.0001). Within 500 kb of D15S1007, several genes were candidate genes for susceptibility, including FMN1, DKFZP686C2281, LOC440268, RYR3, and AVEN, This study identified 10 candidate susceptibility and 5 candidate resistant regions that may contain genes involved in ACP pathogenesis.