IgG4-related sclerosing disease incorporating sclerosing pancreatitis, cholangitis, sialadenitis and retroperitoneal fibrosis with lymphadenopathy

Lymphoplasmacytic sclerosing pancreatitis and retroperitoneal fibrosis

Although cases of lymphoplasmacytic sclerosing pancreatitis (LSP) associated with idiopathic retroperitoneal fibrosis have been reported, the association is rare. We describe a 74-year-old man who presented with obstructive jaundice and weight loss. Nineteen months earlier, he had been diagnosed with idiopathic retroperitoneal fibrosis and treated with bilateral ureteric stents. Initial investigations were suggestive of a diagnosis of LSP, however, a malignant cause could not be ruled out. He underwent an exploratory laparotomy and frozen sections confirmed the diagnosis of LSP. An internal biliary bypass was performed using a Roux loop of jejunum, and the patient made an uneventful recovery. This case illustrates the difficulty in distinguishing LSP from pancreatic carcinoma preoperatively.

Update on the diagnosis and treatment of autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is the pancreatic manifestation of a systemic fibroinflammatory disease (IgG4-related systemic disease) in which affected organs demonstrate dense lymphoplasmacytic infiltration with abundant IgG4-positive cells. The diagnosis of AIP and its differentiation from pancreatic cancer, its main differential diagnosis, remains a clinical challenge. The five cardinal features of AIP are characteristic histology, imaging, and serology; other organ involvement; and response to steroid therapy. Recent advances in our understanding of these features have resulted in enhanced recognition and diagnosis of this benign disease. This in turn has resulted in the avoidance of unnecessary surgical procedures for suspected malignancy. This article reviews recent updates in the diagnosis and treatment of autoimmune pancreatitis.

Diagnostic criteria for autoimmune pancreatitis

Autoimmune pancreatitis (AIP), a particular type of pancreatitis, is thought to have an autoimmune etiology; it is recognized as a distinct entity worldwide. AIP has many characteristic clinical, serologic, morphologic, and histopathologic features. In the absence of a diagnostic serologic marker for AIP, AIP should be diagnosed on the basis of combination of characteristic findings. AIP responds dramatically to steroid therapy; thus, accurate diagnosis of AIP can avoid unnecessary laparotomy or resection. It is important not to misdiagnose pancreatic cancer as AIP, and not to misdiagnose AIP as pancreatic cancer. Currently, 3 sets of major diagnostic criteria for AIP have been proposed in Japan, Korea, and the United States. The Japanese criteria are based on the minimum consensus features of AIP and aim to avoid misdiagnosis of malignancy. When response to steroid therapy is added to the criteria, the diagnostic sensitivity is increased. However, the use of a steroid trial in cases where differentiation from malignancy is an issue may result in delaying pancreatic cancer surgery, which could lead to cancer progression in several cases. Thus, given that AIP is an IgG4-related systemic disease, an additional criterion can be recommended to the Japanese diagnostic criteria: IgG4-immunostaining of biopsied extrapancreatic lesions such as the major duodenal papilla, the bile duct, or the minor salivary gland. It is also time for an international consensus on AIP.

IgG4-related sclerosing lymphoplasmacytic pancreatitis and cholangitis mimicking carcinoma of pancreas and Klatskin tumour

BACKGROUND

Autoimmune sclerosing pancreatitis is a well-known disease entity for years, particularly recognizing the difficulty in distinguishing it from malignancy. Immunohistochemical study showed that immunoglobulin IgG4 staining was positive in plasma cells of some autoimmune pancreatitis or cholangitis. The term 'autoimmune sclerosing pancreatocholangitis' was used as it was believed that they belonged to a range of disease involving both pancreas and biliary tree. It may also be part of a systemic fibro-inflammatory disease.

PATIENTS AND METHODS

All the patients suffering from immunoglobulin G4 (IgG4)-related pancreatitis and cholangitis from May 2003 to September 2006 in Queen Elizabeth Hospital, Hong Kong were retrospectively studied.

RESULTS

A total of five patients with clinical diagnosis of IgG4-related autoimmune pancreatitis or cholangitis were analysed. All presented with jaundice or abdominal pain, mimicking carcinoma. Two patients had major resection, two patients were diagnosed by intraoperative biopsy and one was based on serum IgG4 level.

CONCLUSION

With the growing awareness of this relatively recently characterized clinical entity and its similar presentation to pancreatic carcinoma or bile duct cholangiocarcinoma, it is important for autoimmune sclerosing pancreatocholangitis to be included in the differential diagnosis of pancreaticobiliary disease. The management strategy has shown to be modified--from major resection to intraoperative biopsy and to the assay of serum IgG4 level without the necessity of histology confirmation.

Immunoglobulin G4-associated cholangitis: clinical profile and response to therapy

BACKGROUND & AIMS

Immunoglobulin (Ig)G4-associated cholangitis (IAC) is the biliary manifestation of a steroid-responsive multisystem fibroinflammatory disorder in which affected organs have a characteristic lymphoplasmacytic infiltrate rich in IgG4-positive cells. We describe clinical features, treatment response, and predictors of relapse in IAC and compare relapse rates in IAC with intrapancreatic vs proximal bile duct strictures.

METHODS

We reviewed clinical, serologic, and imaging characteristics and treatment response in 53 IAC patients.

RESULTS

IAC patients generally were older (mean age, 62 y) men (85%), presenting with obstructive jaundice (77%) associated with autoimmune pancreatitis (92%), increased serum IgG4 levels (74%), and abundant IgG4-positive cells in bile duct biopsy specimens (88%). At presentation, biliary strictures were confined to the intrapancreatic bile duct in 51%; the proximal extrahepatic/intrahepatic ducts were involved in 49%. Initial presentation was treated with steroids (n = 30; median follow-up period, 29.5 months), surgical resection (n = 18; median follow-up period, 58 months), or was conservative (n = 5; median follow-up period, 35 months). Relapses occurred in 53% after steroid withdrawal; 44% relapsed after surgery and were treated with steroids. The presence of proximal extrahepatic/intrahepatic strictures was predictive of relapse. Steroid therapy normalized liver enzyme levels in 61%; biliary stents could be removed in 17 of 18 patients. Fifteen patients treated with steroids for relapse after steroid withdrawal responded; 7 patients on additional immunomodulatory drugs remain in steroid-free remission (median follow-up period, 6 months).

CONCLUSIONS

IAC should be suspected in unexplained biliary strictures associated with increased serum IgG4 and unexplained pancreatic disease. Relapses are common after steroid withdrawal, especially with proximal strictures. The role of immunomodulatory drugs for relapses needs further study.

Lessons from diseases mimicking Sjögren's syndrome

Sjögren's syndrome (SS) is a systemic autoimmune disease that mainly affects the exocrine glands and usually presents as persistent dryness of the mouth and eyes because of functional impairment of the salivary and lacrimal glands. The histological hallmark is a focal lymphocytic infiltration of the exocrine glands, and the spectrum of the disease extends from an organ-specific autoimmune disease (autoimmune exocrinopathy) to a systemic process with diverse extraglandular manifestations. In the absence of an associated systemic autoimmune disease, patients with this condition are classified as having primary SS. The differential diagnosis includes processes that specifically involve the exocrine glands. On the one hand, some chronic viral infections may induce lymphocytic infiltration of the exocrine glands, in some cases indistinguishable from that observed in primary SS. On the other hand, some processes may mimic the clinical picture of SS through nonlymphocytic infiltration of the exocrine glands. This review focuses on these two groups of diseases that mimic SS (infections and infiltrating processes).

Autoimmune pancreatitis

Autoimmune pancreatitis is a form of chronic pancreatitis of presumed autoimmune aetiology. The disease is characterised with clinical, serological, histomorphological and imaging features. Autoimmune pancreatitis is recognised as a T-cell-mediated specific disease with lymphoplasmatic infiltration of pancreatic tissue and pancreatic parenchyma fibrosis. Serum immunoglobulin IgG or IgG4 and antibodies (rheumatoid factor, lactoferrin antibodies, carbonic anhydrase II, etc) are usually increased. But the lack of specific biochemical markers is a major drawback in the diagnosis of autoimmune pancreatitis. The Japan Pancreas Society proposed diagnostic criteria for autoimmune pancreatitis as the presence antibodies, pancreas enlargement and pancreatic duct narrowing, lymphoplasmatic infiltration, response to corticosteroid therapy, and association with other autoimmune diseases such as autoimmune hepatitis, sclerosing cholangitis, primary biliary cirrhosis, sialoadenitis, inflammatory bowel disease and Sjögren syndrome. New criteria (HISORt Criteria) incorporate imaging changes, organ involvement, specific elevation of IgG4 subclass and histopathological markers. Autoimmune pancreatitis could be associated with diabetes mellitus and exocrine pancreatic dysfunction. Clinically, autoimmune pancreatitis is a disease with mild symptoms; severe attacks of abdominal pain are not typical. Typically, pancreatic calcifications and pseudocyst are absent; on the other hand jaundice and/or pancreatic mass are frequent signs, and both make differential diagnosis with pancreatic cancer difficult. From a practical point of view, in an elderly male presenting with obstructive jaundice and pancreatic mass, autoimmune pancreatitis is one of the differential diagnoses to avoid unnecessary surgical therapy.

Serum Immunoglobulin G Fraction 4 Levels in Pancreatic Cancer: Elevations Not Associated With Autoimmune Pancreatitis

Context.—Autoimmune pancreatitis is an uncommon, inflammatory disease of the pancreas that presents with clinical features, such as painless jaundice and a pancreatic mass, similar to those caused by pancreatic cancer. Patients with autoimmune pancreatitis frequently have elevated serum immunoglobulin G fraction 4 (IgG4) levels, and their pancreatic tissue may show IgG4-positive plasma cell infiltration. It is imperative to differentiate autoimmune pancreatitis from pancreatic cancer because autoimmune pancreatitis typically responds to corticosteroid treatment. A previous Japanese study reported that serum IgG4 greater than 135 mg/dL was 97% specific and 95% sensitive in predicting autoimmune pancreatitis.

Objective.—To prospectively measure serum IgG4 levels in pancreatic cancer patients to ascertain whether increased levels might be present in this North American population.

Design.—We collected blood samples and phenotypic information on 71 consecutive pancreatic cancer patients and 103 healthy controls who visited our clinics between October 2004 and April 2006. IgG4 levels were determined using a single radial immunodiffusion assay. A serum IgG4 level greater than 135 mg/dL was considered elevated.

Results.—Five cancer patients had IgG4 elevation, with a mean serum IgG4 level of 160.8 mg/dL. None of our cancer patients with plasma IgG4 elevation demonstrated evidence of autoimmune pancreatitis. One control subject demonstrated elevated serum IgG4 unrelated to identified etiology.

Conclusions.—As many as 7% of patients with pancreatic cancer have serum IgG4 levels above 135 mg/dL. In patients with pancreatic mass lesions and suspicion of cancer, an IgG4 level measuring between 135 and 200 mg/dL should be interpreted cautiously and not accepted as diagnostic of autoimmune pancreatitis without further evaluation.

Is pancreatic core biopsy sufficient to diagnose autoimmune chronic pancreatitis?

OBJECTIVES

This study aimed to evaluate the adequacy of pancreatic core biopsy in histological diagnosis of autoimmune chronic pancreatitis (AIP).

METHODS

Histopathologic study as well as immunohistochemical staining using anti-IgG4 antibody was done with pancreatic tissue specimens of 26 AIP patients (19 transabdominal ultrasound (US)-guided core biopsies, 3 intraoperative wedge biopsies, and 4 surgical resections). Eight patients with alcoholic chronic pancreatitis and 10 patients with pancreatic cancer served as controls.

RESULTS

Lymphoplasmacytic sclerosing pancreatitis (LPSP) histology was observed in 26% (5/19) of US-guided core biopsy specimens, 33% (1/3) of open biopsy specimens, and all 4 resection specimens in AIP patients. None of the patients in the control group showed the full spectrum of changes of LPSP. Abundant IgG4-positive cells (>10 cells/high-power field) in the pancreas were observed in 21% (4/19) of AIP patients with US-guided core biopsy specimen. Abundant IgG4-positive cells in the pancreas were also observed in 2 of 8 patients with chronic alcoholic pancreatitis and 1 of 10 patients with pancreatic cancer.

CONCLUSIONS

Transabdominal US-guided pancreatic core biopsy may not provide enough tissue to evaluate characteristic histopathologic features of AIP that include LPSP or abundant IgG4-positive cell infiltration. The LPSP histology may be specific to AIP, but abundant IgG4-positive cells in the pancreas may not.

Pancréatite auto-immune

Chronic autoimmune pancreatitis is an entity distinct from all other forms of chronic pancreatitis. It is expressed by signs of acute or chronic pancreatitis, sometimes associated with cholestatic jaundice. In imaging, it may appear as diffuse (duct destructive) or pseudotumoral lesions. These 2 aspects are probably different clinical forms of chronic autoimmune pancreatitis. Some autoimmune diseases are associated with chronic autoimmune pancreatitis, but not consistently. One such disease involves a bile disorder very similar to primary sclerosing cholangitis but responsive to corticosteroid treatment. Pancreatitis may be a sign of intestinal inflammatory diseases (and vice versa): testing for Crohn's disease and ulcerative rectocolitis is justified in patients with idiopathic pancreatitis. Chronic autoimmune pancreatitis must be routinely considered in patients with a pancreatic tumor that is for a clinical, epidemiologic, serologic or imaging reason not completely consistent with pancreatic adenocarcinoma. A short corticosteroid therapy (< 4 weeks) is probably less harmful in a patient with pancreatic adenocarcinoma than pancreatectomy (or chemotherapy) in patients with chronic autoimmune pancreatitis. Diagnosis depends on a body of clinical and radiologic evidence. The diagnostic value of serologic markers and especially of autoantibodies must be clarified in the future.

Pathology and immunopathology of immunoglobulin G4-related sclerosing cholangitis: The latest addition to the sclerosing cholangitis family

Sclerosing cholangitis is heterogeneous in its etiopathogenesis. Recently, sclerosing cholangitis showing abundant immunoglobulin (Ig)G4+ plasma cell infiltration was added to the sclerosing cholangitis group. This form was frequently associated with sclerosing pancreatitis (autoimmune pancreatitis) and also occasionally with other diseases such as chronic sclerosing sialadenitis, all of which falls within IgG4-related sclerosing disease. Herein, this new member, called IgG4-related sclerosing cholangitis (IgG4-SC), is reviewed. IgG4-SC shows grossly medullary and fleshy lesions along the biliary tree, and histologically marked lymphoplasmacytic infiltration with extensive fibrosis, and obliterative phlebitis, sharing histopathological features with sclerosing pancreatitis. Peribiliary glands are also severely affected. Interestingly, hepatic inflammatory pseudotumor (HIP) is not infrequently associated with IgG4-SC, and is thought as a local exaggeration of IgG4-SC. Immunohistochemically, many IgG4+ plasma cells and CD4+/CD25+ regulatory T cells are found around the affected bile ducts and portal tracts. Incontrast, these cells are scarce in the affected bile ducts of primary sclerosing cholangitis (PSC), a prototype of sclerosing cholangitis. Biliary lining epithelia are relatively spared in IgG4-SC in comparison with those of PSC showing degeneration and ulceration. In some cases of IgG4-SC, IgG4+ plasma cells are also found considerably in small portal tracts, so needle liver biopsy is useful for the diagnosis of IgG4-SC. Therapeutically, IgG4-SC responds well to steroid therapy, while such character is not reported in PSC. Taken together, IgG4-SC may be etiologically different from PSC, and immunopathological processes relating to IgG4 and regulatory T cells may be involved in the pathogenesis of IgG4-SC. Further studies are needed to clarify the etiopathogenesis of IgG4-SC and its related disorders.

The use of immunoglobulin g4 immunostaining in diagnosing pancreatic and extrapancreatic involvement in autoimmune pancreatitis

BACKGROUND & AIMS

Autoimmune pancreatitis (AIP) is recognized increasingly as a multisystem disorder. We evaluated the use of immunoglobulin (Ig)G4 immunostaining of pancreatic and extrapancreatic biopsy specimens to make a definitive diagnosis of AIP.

METHODS

Seventeen biopsy specimens and 3 gallbladder resections were assessed from 11 patients with clinical and radiologic features of AIP. Biopsy specimens from pancreas, liver, colon, stomach, duodenum, bone marrow, salivary gland, and kidney were analyzed morphologically, immunostained for IgG4-positive plasma cells, and compared with controls.

RESULTS

Positive IgG4 immunostaining enabled a definitive diagnosis in 10 of 11 (91%) AIP patients. In both pancreatic and extrapancreatic tissues, high levels of IgG4 immunostaining (>10 IgG4-positive plasma cells/high-power field) were found in 17 of 20 (85%) specimens from AIP patients compared with 1 of 175 (0.6%) specimens from controls (P < .05). Positive extrapancreatic IgG4 immunostaining was found in 8 of 11 (73%) patients, including all those with diagnostic features in the pancreas. Increased tissue IgG4 was found irrespective of serum IgG4 level.

CONCLUSIONS

The finding of IgG4 immunostaining within a range of clinically involved tissues supports the hypothesis that AIP is a multisystem disease. Positive IgG4 immunostaining in extrapancreatic tissues may allow a definitive diagnosis of AIP to be made in those with evidence of pancreatic disease, without the necessity of pancreatic biopsy or surgical exploration. Immunostaining of involved tissue for IgG4 may be particularly useful when AIP is suspected clinically but the serum IgG4 level is normal.

[Inflammatory pancreatic disease due to enzyme autodigestion: an exceptional model of glandular crinophagy]

The exocrine pancreas is a functionally dangerous structure since it is exposed to digestion by its most aggressive enzymes (proteases, etc) despite self-protective measures such as the synthesis of some of these enzymes in the form of inactive zymogens (trypsinogen, etc.). We review inflammatory pancreatic disease by separately analyzing its classical forms of onset: acute and chronic pancreatitis (AP and CP). There is general consensus that the initial pathogenic event in AP is intraacinar activation of trypsinogen into trypsin, followed by that of the remaining proenzymes, giving rise to an unusual model of autophagic inflammation. In contrast, consensus is lacking on the initial pathogenic event in CP (toxic-metabolic lesion, oxidative stress, ductal hypertension, etc.?), although in some cases a <<necrosis-fibrosis>> sequence due to recurrent episodes of AP seems evident. The pathogenic features shared by both forms of the disease and which justify some recent attempts to formulate an overall explanation of the pathogenesis of pancreatitis are discussed. Such an explanation would place both forms of pancreatitis within the conceptual framework of an <<inflammatory pancreatic disease due to enzyme autodigestion>>.

Manifestations salivaires dans la Maladie Fibrosclérosante Multiple à IgG4

OBJECTIVES

To report a case of IgG4-related multifocal fibrosclerosis, revealed by a multifocal salivary involvement.

MATERIAL AND METHODS

A 59-year-old man, with chronic pancreatitis, was managed for fibrotic involvement of the 2 submaxillary glands and the 2 parotids. Clinical, radiological, and histologic features were retrospectively studied.

RESULTS

Pathological features of submandibular gland revealed a chronic sclerosing sialadenitis. Retroperitoneal fibrosis in computed tomography and high rate of IgG4 are objectived. The diagnosis of IgG4-related multifocal fibrosclerosis is evoked. The patient's state improved with corticosteroid therapy.

CONCLUSION

Salivary involvement in IgG4-related multifocal fibrosclerosis must be recognized in salivary medical pathology.

Autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is a benign, IgG4-related, fibroinflammatory form of chronic pancreatitis that can mimic pancreatic ductal adenocarcinoma both clinically and radiographically. Laboratory studies typically demonstrate elevated serum IgG4 levels and imaging studies reveal a diffusely or focally enlarged pancreas with associated diffuse or focal narrowing of the pancreatic duct. The pathologic features include periductal lymphoplasmacytic inflammation, obliterative phlebitis, and abundant IgG4-positive plasma cells. The treatment of choice for AIP is steroid therapy. Diagnostic criteria for AIP have been proposed that incorporate histologic, radiographic, serologic, and clinical information.

Sclerosing mesenteritis: clinical features, treatment, and outcome in ninety-two patients

BACKGROUND & AIMS

Sclerosing mesenteritis is a rare non-neoplastic disease that affects the small bowel mesentery with chronic fibrosing inflammation. There are few data on the natural history and therapeutic options for this condition.

METHODS

We performed a retrospective and prospective study to describe the clinical characteristics, therapy, and outcome of all cases of sclerosing mesenteritis diagnosed at the Mayo Clinic, Rochester, from 1982-2005.

RESULTS

Ninety-two cases were identified; 70% were male, with a median age of 65 years (interquartile range, 55-72). Common presenting symptoms included abdominal pain in 70%, diarrhea in 25%, and weight loss in 23%. Treatment included medical therapy alone in 26%, surgery alone in 13%, surgery followed by medical therapy in 9%, and 52% received no treatment. Ten percent responded to surgery alone, 20% responded to additional medical treatment after surgery, and 38% responded to medical therapy alone. Tamoxifen in combination with prednisone was used in 20 patients, and 60% improved. Non-tamoxifen-based regimens were used in 12 patients, and 8% improved. Eighteen deaths were noted during the study period, and 17% were attributed to complications of sclerosing mesenteritis or its treatment.

CONCLUSIONS

Although a relatively benign condition, sclerosing mesenteritis can have a prolonged debilitating course with a fatal outcome. Our results suggest that symptomatic patients might benefit from medical therapy, particularly tamoxifen and prednisone combination treatment. Long-term follow-up is needed to substantiate these results.

Prognosis of autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is responsive to steroid therapy, but some AIP patients improve spontaneously, or only improve after biliary drainage. Pancreatic enlargement and irregular narrowing of the main pancreatic duct usually improves in almost all patients, but marked atrophy of the pancreas develops in some patients. Biliary stenosis improves to various degrees, and a biliary drainage tube can be withdrawn. Other extrapancreatic lesions, including swelling of the salivary or lacrimal glands, lymphadenopathy, and retroperitoneal fibrosis also improve with steroid therapy. Pancreatic endocrine and exocrine function is frequently impaired in AIP patients, and steroid therapy is occasionally effective for these dysfunction. Deterioration of pancreatic exocrine function is rarely detected after steroid therapy. In the literature, the recurrence rate of AIP was reported to be about 17% (range 6% to 26%). AIP patients who relapse during maintenance steroid therapy or after stopping steroid medication should be re-treated with a high-dose steroid. Although AIP is rarely associated with pancreatic stones, stones are formed in some relapsing AIP patients. The long-term prognosis for AIP is unknown. As the pancreatic exocrine and endocrine functions as well as the morphological findings are reversible after steroid therapy, the prognosis for AIP seems better than that of chronic pancreatitis, which is usually followed by exocrine and endocrine pancreatic insufficiency with disease progression. Although carcinogenesis of AIP is unknown, some AIP patients developed a malignancy during follow-up. Since AIP occurs predominantly in the elderly, clinicians should pay attention to any complicating diseases in follow-up of AIP patients. Further studies are necessary to clarify the pathogenesis as well as the long-term prognosis of AIP.

Inflammatory pseudotumors of the pancreas and liver with infiltration of IgG4-positive plasma cells

Recently, it has been reported that autoimmune pancreatitis (AIP) can be complicated with various extrapancreatic lesions. Here, we report a very rare case of pancreatic and hepatic inflammatory pseudotumor (IPT) with the infiltration of IgG4-positive plasmacytes. The patient showed pancreatic and hepatic masses with elevated levels of serum IgG4. Endoscopic retrograde cholangiopancreatography revealed narrowing of the intrapancreatic bile duct. Fluorine-18fluorodeoxyglucose positron emission tomography suggested pancreatic cancer with hepatic metastasis. Histopathologic findings showed fibrosis and infiltration of IgG4-positive plasmacytes, suggesting IPT. The present case suggests a possible common mechanism in the development of AIP and IPT of the liver.

The relationship of salivary gland function to elevated serum IgG4 in autoimmune pancreatitis

OBJECTIVE

To compare salivary gland function in autoimmune pancreatitis (AIP) patients with and without an elevated serum IgG4 concentration.

PATIENTS AND METHODS

We allocated 14 AIP patients into 2 groups: one group had high (>135 mg/dL) serum IgG4 and the other low serum IgG4. Sialochemistry and submandibular and parotid gland scintigraphy were done in these patients.

RESULTS

Serum IgG4 levels were elevated in 10 patients. Bilateral submandibular gland swelling was present in 5 patients with a high serum IgG4; there was no swelling in patients with a low serum IgG4. The salivary Na+ concentration was increased significantly in both patient groups (p<0.01) compared to controls. The beta2-microglobulin concentration was significantly higher in patients with a high serum IgG4 than in those with a low serum IgG4 (p<0.05) and controls (p<0.01). On submandibular and parotid gland scintigraphy, both the ratio of the cumulative peak count to the injected radionuclide (PCR) and the washout ratio (WR) were significantly lower in the high serum IgG4 group than in controls (p<0.01). In the low serum IgG4 group, the PCR on submandibular gland scintigraphy, and the PCR and WR on parotid gland scintigraphy were significantly lower than in controls (p<0.05, p<0.01 and p<0.05, respectively). On submandibular gland scintigraphy, the PCR was significantly lower in the high serum IgG4 group than in the low serum IgG4 group (p<0.05).

CONCLUSIONS

Salivary gland function was impaired in all AIP patients, but it was more impaired in patients with a high serum IgG4 than in those with a low serum IgG4.

Prevalence and distribution of extrapancreatic lesions complicating autoimmune pancreatitis

BACKGROUND

Autoimmune 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.

METHODS

The frequency, distribution, clinical characteristics, and pathology of five extrapancreatic lesions were determined in 64 patients with autoimmune pancreatitis by examining clinical and laboratory findings.

RESULTS

The 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.

CONCLUSIONS

Autoimmune pancreatitis was recognized as a systemic inflammatory disease. Furthermore, recognition of these characteristic findings will aid in the correct diagnosis of this disease.

Nephropathy in IgG4-related Systemic Disease

Lymphoplasmacytic sclerosing pancreatitis ("autoimmune" pancreatitis) is the best-known manifestation of an unusual corticosteroid-sensitive systemic fibrosclerotic disease that is associated with high plasma immunoglobulin G4 (IgG4) and tissue infiltration with IgG4-secreting plasma cells. Pancreatic and biliary manifestations of this condition are well-reported, but reports of other systemic involvement are few. We report here a case of initially unrecognized autoimmune pancreatitis followed 5 years later by a focal sclerosing lymphoplasmacytic tubulointerstitial nephritis and concurrent membranous nephropathy. The patient presented with hypertension, a raised serum creatinine, proteinuria, elevated serum IgG4, and eosinophilia. Immunolabeling of renal tissue showed numerous IgG4 positive plasma cells with peritubular and glomerular subepithelial IgG4 deposition. On steroid therapy serum IgG4 levels normalized, the eosinophilia resolved, and there was improvement in symptomatic wheeze, dry eyes, serum creatinine, and liver function tests. This case highlights a distinctive and potentially treatable form of interstitial nephritis manifesting from a systemic immune disorder, and provides circumstantial evidence to support the notion that dysregulated IgG4 can precipitate the development of a form of membranous nephropathy.

Pancreatic cancer with a high serum IgG4 concentration

Differentiation between autoimmune pancreatitis and pancreatic cancer is sometimes difficult. It has been reported that serum IgG4 concentrations are significantly elevated and particularly high (>135 mg/dL) in autoimmune pancreatitis. Measurement of serum IgG4 has become a useful tool for differentiating between autoimmune pancreatitis and pancreatic cancer. However, we present a 74-year-old female with a markedly elevated serum IgG4 (433 mg/dL) who underwent pancreaticoduodenectomy for pancreatic cancer. Elevated serum IgG4 levels continued after the resection. On histology, adenocarcinoma of the pancreas accompanied with moderate lymphoplasmacytic infiltration infiltrated the lower bile duct and duodenum, but there were no findings of autoimmune pancreatitis. Although a small metastasis was detected in one parapancreatic lymph node, regional lymph nodes were swollen. Abundant IgG4-positive plasma cells infiltrated the cancerous areas of the pancreas, but only a few IgG4-positive plasma cells were detected in the noncancerous areas. Pancreatic cancer cells were not immunoreactive for IgG4. An abundant infiltration of IgG4-positive plasma cells was detected in the swollen regional lymph nodes and in the duodenal mucosa. We believe that the serum IgG4 level was elevated in this patient with pancreatic cancer as the result of an IgG4-related systemic disease that had no clinical manifestations other than lymphadenopathy.

Hyper-IgG4 disease: report and characterisation of a new disease

BACKGROUND

We highlight a chronic inflammatory disease we call 'hyper-IgG4 disease', which has many synonyms depending on the organ involved, the country of origin and the year of the report. It is characterized histologically by a lymphoplasmacytic inflammation with IgG4-positive cells and exuberant fibrosis, which leaves dense fibrosis on resolution. A typical example is idiopathic retroperitoneal fibrosis, but the initial report in 2001 was of sclerosing pancreatitis.

METHODS

We report an index case with fever and severe systemic disease. We have also reviewed the histology of 11 further patients with idiopathic retroperitoneal fibrosis for evidence of IgG4-expressing plasma cells, and examined a wide range of other inflammatory conditions and fibrotic diseases as organ-specific controls. We have reviewed the published literature for disease associations with idiopathic, systemic fibrosing conditions and the synonyms: pseudotumour, myofibroblastic tumour, plasma cell granuloma, systemic fibrosis, xanthofibrogranulomatosis, and multifocal fibrosclerosis.

RESULTS

Histology from all 12 patients showed, to varying degrees, fibrosis, intense inflammatory cell infiltration with lymphocytes, plasma cells, scattered neutrophils, and sometimes eosinophilic aggregates, with venulitis and obliterative arteritis. The majority of lymphocytes were T cells that expressed CD8 and CD4, with scattered B-cell-rich small lymphoid follicles. In all cases, there was a significant increase in IgG4-positive plasma cells compared with controls. In two cases, biopsies before and after steroid treatment were available, and only scattered plasma cells were seen after treatment, none of them expressing IgG4. Review of the literature shows that although pathology commonly appears confined to one organ, patients can have systemic symptoms and fever. In the active period, there is an acute phase response with a high serum concentration of IgG, and during this phase, there is a rapid clinical response to glucocorticoid steroid treatment.

CONCLUSION

We believe that hyper-IgG4 disease is an important condition to recognise, as the diagnosis can be readily verified and the outcome with treatment is very good.

Chronic pancreatitis

PURPOSE OF REVIEW

As in our previous reviews, we endeavor to review important new observations in chronic pancreatitis made in the past year. Topics recently reviewed were truncated to accommodate a surge in publications on clinical aspects of chronic pancreatitis, which contained new observations or insights into new or old concepts.

RECENT FINDINGS

Cystic fibrosis carriers have been found to be at increased risk of pancreatitis. Autoimmune pancreatitis may belong to a multiorgan immunoglobulin G4-related autoimmune disease, and the natural history of chronic pancreatitis differs among the etiologies. Diffusion-weighted magnetic resonance imaging improves upon previous methodologies for diagnosing reduced pancreatic exocrine secretion, and fecal elastase-1 has been found to be a poor test for diagnosing pancreatic malabsorption. Visceral hyperalgesia or heightened central pain perception may contribute to pain in chronic pancreatitis. Instruments are evolving to assess quality of life in chronic pancreatitis, and fibrolytic agents have been found to have therapeutic promise.

SUMMARY

Researchers this past year have further characterized genetic, molecular and clinical aspects of chronic pancreatitis. Advancing the understanding of fibrogenesis, mechanisms of exocrine insufficiency, calcification, and pain and continuing development/modification of diagnostic tests should lead to improved prevention, detection and treatment of the condition. More accurate quantification of outcomes is critical for translating potential therapies from bench to bedside.

Autoimmune pancreatitis: proposal of IgG4-related sclerosing disease

Autoimmune pancreatitis (AIP) is a peculiar type of pancreatitis of presumed autoimmune etiology. Many new clinical aspects of AIP have been clarified during the past 10 years, and AIP has become a distinct entity recognized worldwide. However, its precise pathogenesis or pathophysiology remains unclear. As AIP dramatically responds to steroid therapy, accurate diagnosis of AIP is necessary to avoid unnecessary surgery. Characteristic dense lymphoplasmacytic infiltration and fibrosis in the pancreas may prove to be the gold standard for diagnosis of AIP. However, since it is difficult to obtain sufficient pancreatic tissue, AIP should be diagnosed currently based on the characteristic radiological findings (irregular narrowing of the main pancreatic duct and enlargement of the pancreas) in combination with serological findings (elevation of serum gamma-globulin, IgG, or IgG4, along with the presence of autoantibodies), clinical findings (elderly male preponderance, fluctuating obstructive jaundice without pain, occasional extrapancreatic lesions, and favorable response to steroid therapy), and histopathological findings (dense infiltration of IgG4-positive plasma cells and T lymphocytes with fibrosis and obliterative phlebitis in various organs). It is apparent that elevation of serum IgG4 levels and infiltration of abundant IgG4-positive plasma cells into various organs are rather specific to AIP patients. We propose a new clinicopathological entity, "IgG4-related sclerosing disease", and suggest that AIP is a pancreatic lesion reflecting this systemic disease.