Current status of type 1 (IgG4-related) autoimmune pancreatitis

In 1995, Yoshida et al. proposed first the concept of "autoimmune pancreatitis" (AIP). Since then, AIP has been accepted as a new pancreatic inflammatory disease and is now divided two subtypes. Type 1 AIP affected immunoglobulin G4 (IgG4) and implicates the pancreatic manifestation of IgG4-related disease, while type 2 is characterized by neutrophil infiltration and granulocytic epithelial lesions (GEL). Recent research has clarified the clinical and pathophysiological aspects of type 1 AIP, which is more than type 2 among the Japanese population. However, many details remain unclear about the pathogenesis and progression of this disease. In this review, we discuss the current knowledge and recent advances relating to type 1 AIP.

Clinicopathological differential diagnosis of IgG4-related disease: A historical overview and a proposal of the criteria for excluding mimickers of IgG4-related disease

IgG4-related disease (RD) is a relatively new entity, which was first proposed in 2001. Since then, clinical and pathological characteristics of the disease have been investigated. As IgG4-RD has been studied extensively, the diagnostic criteria for IgG4-RD of each organ and the comprehensive diagnostic criteria for IgG4-RD have also been developed. However, one of the biggest challenges in the field is distinguishing between IgG4-RD and mimickers, which show overlapping features with IgG4-RD. It is now known that some non-IgG4-RDs may meet the diagnostic criteria of IgG4-RD and can be misdiagnosed as IgG4-RD. However, accurate diagnosis is crucial, as the treatments for IgG4-RD and those for other diseases that may be misdiagnosed as IgG4-RD are different. This prompted us to create and propose comprehensive exclusion criteria for IgG4-RD. In this review, we have described the comprehensive exclusion criteria for IgG4-RD, with a historical overview of the disease. These exclusion criteria were recently created by the Research Program for Intractable Disease of the Ministry of Health, Labor, and Welfare of Japan, All Japan IgG4 team, to support correct and accurate diagnosis of IgG4-RD.

Clinical and pathophysiological aspects of type 1 autoimmune pancreatitis

In 1995, Yoshida and colleagues proposed the concept of "autoimmune pancreatitis" (AIP), which has recently been recognized as a new pancreatic inflammatory disease. Recent studies have suggested the existence of two subtypes of AIP: type 1, which involves immunoglobulin G4 (IgG4) and is the pancreatic manifestation of IgG4-related disease (IgG4-RD); and type 2, which is characterized by granulocytic epithelial lesions. Type 2 AIP is thought to be rare in Japan. Type 1 AIP is characterized by increased serum IgG4 concentrations, lymphoplasmacytic infiltrations, storiform fibrosis, and obliterative phlebitis. However, although type 1 AIP has become increasingly recognized, many clinical and basic issues remain to be solved. This review provides an overview of the recent clinical and basic knowledge of type 1 AIP.

Current approach to the diagnosis of IgG4-related disease - Combination of comprehensive diagnostic and organ-specific criteria

IgG4-related disease (IgG4-RD) is a fascinating clinical entity proposed by Japanese investigators, and includes a wide variety of diseases, formerly diagnosed as Mikulicz's disease (MD), autoimmune pancreatitis (AIP), interstitial nephritis, prostatitis, retroperitoneal fibrosis, etc. Although all clinicians in every field of medicine may encounter this new disease, a unifying diagnostic criterion has not been established. In 2011, the Japanese IgG4 team, organized by the Ministry of Health, Labor and Welfare (MHLW) of Japan, published comprehensive diagnostic criteria for IgG4-RD. Several problems with these criteria have arisen in clinical practice, however, including the difficulty obtaining biopsy samples from some patients, and the sensitivity and the specificity of techniques used to measure serum IgG4 concentrations. Although serum IgG4 concentration is an important clinical marker for IgG4-RD, its diagnostic utility in differentiating IgG4-RD from other diseases, called IgG4-RD mimickers, remains unclear. This review describes the current optimal approach for the diagnosis of IgG4-RD, based on both comprehensive and organ-specific diagnostic criteria, in patients with diseases such as IgG4-related pancreatitis (AIP), sclerosing cholangitis, and renal, lung and orbital diseases.

Imaging of IgG4-related disease of the head and neck

IgG4-related disease is a systemic, inflammatory disorder typically involving multiple organ systems. Several eponymous conditions described previously in the clinical and radiology literature are now recognised to be part of the IgG4-related disease spectrum. This includes multiple manifestations in the head and neck region, which are the subject of this review. Imaging can occasionally suggest the specific diagnosis of IgG4 disease. More commonly, it will be included in a limited differential diagnosis that requires clarification with the aid of image-guided biopsy. There are strict histopathological criteria for the diagnosis of IgG4-related disease.

Overlap of IgG4-related Disease and Primary Biliary Cirrhosis Complicated with Autoimmune Thrombocytopenia

A 63-year-old woman was referred to Fukushima Red Cross Hospital with an enlargement of the left submandibular gland and subcutaneous bleeding in the chest and legs. A diffuse enlargement of the pancreas was also detected by abdominal computed tomography, and laboratory data showed severe thrombocytopenia. She was diagnosed with IgG4-related disease (IgG4-RD) complicated with autoimmune thrombocytopenia and was treated with methylprednisolone, after which the number of platelets favorably increased. Further investigation for liver dysfunction revealed underlying primary biliary cirrhosis (PBC). We herein report a rare case of IgG4-RD overlapping PBC complicated with autoimmune thrombocytopenia.

The changing faces of IgG4-related disease: Clinical manifestations and pathogenesis

Since the earliest reports in 2001, immunoglobulin G4 (IgG4)-related disease has been defined as an autoimmune systemic disease characterized by the lymphoplasmacytic infiltration of affected tissues leading to fibrosis and obliterative phlebitis along with elevated serum IgG4 levels. Prior to this unifying hypothesis, a plethora of clinical manifestations were considered as separate entities despite the similar laboratory profile. The pathology can be observed in virtually all organs and may thus be a challenging diagnosis, especially when the adequate clinical suspicion is not present or when obtaining a tissue biopsy is not feasible. Nonetheless, the most frequently involved organs are the pancreas and exocrine glands but these may be spared. Immunosuppressants lead to a prompt clinical response in virtually all cases and prevent histological sequelae and, as a consequence, an early differential diagnosis from other conditions, particularly infections and cancer, as well as an early treatment should be pursued. We describe herein two cases in which atypical disease manifestations were observed, i.e., one with recurrent neck lymph node enlargement and proptosis, and one with jaundice. Our understanding of the pathogenesis of IgG4-related disease is largely incomplete but data support a significant role for Th2 cytokines with the contribution of innate immunity factors such as Toll-like receptors, macrophages and basophils. Further, macrophages activated by IL4 overexpress B cell activating factors and contribute to chronic inflammation and the development of fibrosis. We cannot rule out the possibility that the largely variable disease phenotypes reflect different pathogenetic mechanisms and the tissue microenvironment may then contribute to the organ involvement.

IgG4-related disease initially presented as an orbital mass lesion mimicking optic nerve sheath meningioma

We report a case of an optic nerve mass lesion associated with IgG4-related disease. A 39-year-old man presented with right blurred vision and proptosis 8 years before admission. Magnetic resonance imaging showed a mass lesion in the center of the right orbit, which was diagnosed as optic nerve sheath meningioma by neuroradiologists and neurosurgeons. Irradiation was selected for treatment of the lesion on the basis of the radiological diagnosis; subsequently, the lesion gradually reduced in size. However, regrowth of an optic nerve mass lesion observed during the previous 2 years caused remarkable exophthalmos, and removal of the orbital mass lesion was performed via a transcranial orbital approach. Pathological examinations resulted in a diagnosis of IgG4-related disease, and hematological tests revealed an elevated level of serum IgG4. Additional radiological examinations showed mass lesions in the left maxillary nerve, bilateral inferior alveolar nerves, paravertebral tissue, and left kidney. Treatment with oral steroids has produced a reduction in the size of these lesions.

T helper subsets in Sjögren's syndrome and IgG4-related dacryoadenitis and sialoadenitis: a critical review

IgG4-related disease (IgG4-RD) is a systemic disease characterized by the elevation of serum IgG4 and infiltration of IgG4-positive plasma cells in multiple target organs, including the pancreas, kidney, biliary tract and salivary glands. In contrast, Mikulicz's disease (MD) has been considered a subtype of Sjögren's syndrome (SS) based on histopathological similarities. However, it is now recognized that MD is an IgG4-RD distinguishable from SS and called as IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS). Regarding immunological aspects, it is generally accepted that CD4+ T helper (Th) cells play a crucial role in the pathogenesis of SS. Since it is well known that IgG4 is induced by Th2 cytokines such as interleukin (IL)-4 and IL-13, IgG4-DS is speculated to be a unique inflammatory disorder characterized by Th2 immune reactions. However, the involvement of Th cells in the pathogenesis of IgG4-DS remains to be clarified. Exploring the role of Th cell subsets in IgG4-DS is a highly promising field of investigation. In this review, we focus on the selective localization and respective functions of Th cell subsets and discuss the differences between SS and IgG4-DS to clarify the pathogenic mechanisms of these diseases.

A survey of the histopathology of lacrimal gland lesions in a tertiary referral centre

PURPOSE

To describe the histopathological distribution of biopsied lacrimal gland lesions in a tertiary referral centre in Singapore.

METHODS

This was a retrospective chart review. Clinical records of patients who underwent lacrimal gland biopsy at a tertiary referral centre in Singapore between 2000 to 2010, were reviewed. Data collated included patient demographics, clinical presentation, association with systemic disease and histopathological diagnosis.

RESULTS

Sixty-nine patients were studied. Median age of presentation was 50 years. Forty patients (58%) were female and the majority (84%, n = 29) were Chinese. The mean follow-up duration was 35.0 ± 34.5 months. 30.4% (n = 21) of the patients had bilateral disease. Chronic dacryoadenitis (46%, n = 32) was the most common histopathological diagnosis, followed by lymphoproliferative disorders (38%, n = 26) and pleomorphic adenoma (10%, n = 7). The diagnoses in four other patients included adenoid cystic carcinoma, lacrimal gland hypertrophy, lacrimal duct cyst and orbital vascular malformation.

CONCLUSION

Chronic dacryoadenitis and lymphoproliferative disorders are the two commonest causes of lacrimal gland lesions in our series. Although many cases remain non-specific, about 60% have a specific inflammation that may be associated with a systemic disease. As one third of our patients with lymphoproliferative disease of the lacrimal gland had an associated systemic lymphoma, patients with such lesions should be referred for investigation of possible systemic lymphoma. The results of our study can aid in providing a more targeted approach to patient management.

Clinical characteristics of Mikulicz's disease as an IgG4-related disease

OBJECTIVES

Mikulicz's disease (MD) was considered to be a subtype of Sjögren's syndrome (SS), based on histopathological similarities. However, recent studies have indicated that patients with MD show high serum IgG4 concentration, and suggested that MD is one of "IgG4-related disease" and distinguishable from SS. Therefore, we clinically and histopathologically examined the disease states of MD and SS in detail.

MATERIALS AND METHODS

Twenty patients with Mikulicz's disease and 18 with SS were comparatively studied to determine clinical characteristics in MD patients.

RESULTS

Sialography in MD patients did not show the "apple-tree sign" typically seen in SS. Serologically, high serum IgG4 levels but not anti-SS-A or anti-SS-B antibodies were observed in MD. SS showed lymphocytic infiltration of various subsets with atrophy or severe destruction of the acini, while MD showed selective infiltration of IgG4+ plasma cells with hyperplastic germinal centers and mild acini destruction. Corticosteroid treatment of MD reduced IgG and IgG4 levels and improved salivary function. A negative correlation between disease duration and increasing rate of salivary flow was observed in MD.

CONCLUSIONS

These results suggested that the pathogenesis of MD might be different from those of SS.

CLINICAL RELEVANCE

early diagnosis and treatment of MD is important for the improvement of salivary function.

Th2 and regulatory immune reactions contribute to IgG4 production and the initiation of Mikulicz disease

OBJECTIVE

Mikulicz disease has been considered to be a subtype of Sjögren's syndrome (SS). However, recent studies have suggested that Mikulicz disease is an IgG4-related disease and is distinguishable from SS. In addition, it has been reported that both interleukin-4 (IL-4) and IL-10 induce IgG4 production and inhibit IgE. This study was undertaken to examine the expression of these cytokines in patients with Mikulicz disease and patients with SS.

METHODS

Labial salivary gland (LSG) sections from 15 patients with Mikulicz disease and 18 patients with SS were examined for subsets of the infiltrating lymphocytes, expression patterns of messenger RNA (mRNA) for cytokines/chemokines, and relationships between the IgG4:IgG ratio and the expression of mRNA for IL-4 or IL-10.

RESULTS

Immunohistochemical analysis showed lymphocyte infiltration of various subsets in the LSGs of SS patients, and the selective infiltration of IgG4-positive plasma cells and Treg cells in the LSGs of Mikulicz disease patients. The levels of mRNA for both Th1 and Th2 cytokines and chemokines in LSGs from patients with SS were significantly higher than in controls, while the expression of both Th2 and Treg cells was significantly higher in the patients with Mikulicz disease than in controls. Furthermore, the expression of IL-4 or IL-10 in the LSGs was correlated with the IgG4:IgG ratio.

CONCLUSION

These results suggest that the pathogenesis of Mikulicz disease is different from that of SS. Mikulicz disease is a unique inflammatory disorder characterized by Th2 and regulatory immune reactions that might play key roles in IgG4 production.

Comprehensive diagnostic criteria for IgG4-related disease (IgG4-RD), 2011

BACKGROUND

IgG4-related disease (IgG4-RD) is a novel clinical disease entity characterized by elevated serum IgG4 concentration and tumefaction or tissue infiltration by IgG4+ plasma cells. Although IgG4-RD is not rare and is clinically important, its clinical diagnostic criteria have not been established. Comprehensive diagnostic criteria for IgG4-RD, including the involvement of various organs, are intended for the practical use of general physicians and nonspecialists.

METHODS

Two IgG4-RD study groups, the Umehara and Okazaki teams, were organized by the Ministry of Health, Labor and Welfare Japan. As IgG4-RD comprises a wide variety of diseases, these groups consist of physicians and researchers in various disciplines, including rheumatology, hematology, gastroenterology, nephrology, pulmonology, ophthalmology, odontology, pathology, statistics, and basic and molecular immunology throughout Japan, with 66 and 56 members of the Umehara and Okazaki teams, respectively. Collaborations of the two study groups involved detailed analyses of clinical symptoms, laboratory results, and biopsy specimens of patients with IgG4-RD, resulting in the establishment of comprehensive diagnostic criteria for IgG4-RD.

RESULTS

Although many patients with IgG4-RD have lesions in several organs, either synchronously or metachronously, and the pathological features of each organ differ, consensus has been reached on two diagnostic criteria for IgG4RD: (1) serum IgG4 concentration >135 mg/dl, and (2) >40% of IgG+ plasma cells being IgG4+ and >10 cells/high powered field of biopsy sample. Although the comprehensive diagnostic criteria are not sufficiently sensitive for the diagnosis of type 1 IgG4-related autoimmune pancreatitis (IgG4-related AIP), they are adequately sensitive for IgG4-related Mikulicz's disease (MD) and kidney disease (KD). In addition, the comprehensive diagnostic criteria, combined with organ-specific diagnostic criteria, have increased the sensitivity of diagnosis to 100% for IgG4-related MD, KD, and AIP.

CONCLUSION

Our comprehensive diagnostic criteria for IgG4-RD are practically useful for general physicians and nonspecialists.

Comprehensive diagnostic criteria for IgG4-related disease (IgG4-RD), 2011

BACKGROUND

IgG4-related disease (IgG4-RD) is a novel clinical disease entity characterized by elevated serum IgG4 concentration and tumefaction or tissue infiltration by IgG4+ plasma cells. Although IgG4-RD is not rare and is clinically important, its clinical diagnostic criteria have not been established. Comprehensive diagnostic criteria for IgG4-RD, including the involvement of various organs, are intended for the practical use of general physicians and nonspecialists.

METHODS

Two IgG4-RD study groups, the Umehara and Okazaki teams, were organized by the Ministry of Health, Labor and Welfare Japan. As IgG4-RD comprises a wide variety of diseases, these groups consist of physicians and researchers in various disciplines, including rheumatology, hematology, gastroenterology, nephrology, pulmonology, ophthalmology, odontology, pathology, statistics, and basic and molecular immunology throughout Japan, with 66 and 56 members of the Umehara and Okazaki teams, respectively. Collaborations of the two study groups involved detailed analyses of clinical symptoms, laboratory results, and biopsy specimens of patients with IgG4-RD, resulting in the establishment of comprehensive diagnostic criteria for IgG4-RD.

RESULTS

Although many patients with IgG4-RD have lesions in several organs, either synchronously or metachronously, and the pathological features of each organ differ, consensus has been reached on two diagnostic criteria for IgG4RD: (1) serum IgG4 concentration >135 mg/dl, and (2) >40% of IgG+ plasma cells being IgG4+ and >10 cells/high powered field of biopsy sample. Although the comprehensive diagnostic criteria are not sufficiently sensitive for the diagnosis of type 1 IgG4-related autoimmune pancreatitis (IgG4-related AIP), they are adequately sensitive for IgG4-related Mikulicz's disease (MD) and kidney disease (KD). In addition, the comprehensive diagnostic criteria, combined with organ-specific diagnostic criteria, have increased the sensitivity of diagnosis to 100% for IgG4-related MD, KD, and AIP.

CONCLUSION

Our comprehensive diagnostic criteria for IgG4-RD are practically useful for general physicians and nonspecialists.

[IgG4-related systemic disease: emergence of a new systemic disease? Literature review]

Hyper-IgG4 syndrome, or IgG4-related systemic disease (IgG4-RSD), has been recently characterized by the association of a focal or diffuse enlargement in one or more organs, elevated levels of serum IgG4 and histopathological findings including "storiform" fibrosis and prominent infiltration of lymphocytes and IgG4-positive plasma cells. Pancreas was the first organ involved with sclerosing pancreatitis (or autoimmune pancreatitis). Since this first description, many extrapancreatic lesions have been described, even in the absence of pancreatitis and include sialadenitis, lacrimal gland inflammation, lymphadenopathy, aortitis, sclerosing cholangitis, tubulointerstitial nephritis, retroperitoneal fibrosis or inflammatory pseudotumors. Multiorgan lesions can occur synchronously or metachronously in a same patient, usually after 50 years of age. They all share common histopathological findings. The disease often responds well to corticosteroid therapy. In this literature review on IgG4-RSD, we present historical, epidemiological and clinical characteristics, and we review the biological and histological diagnostic criteria. To date there is no international validated diagnostic criteria. Pathophysiological hypothesis and therapeutic approaches are also discussed.

Immune Complex-Mediated Complement Activation in a Patient with IgG4-Related Tubulointerstitial Nephritis

A 59-year-old man was diagnosed with IgG4-related tubulointerstitial nephritis. His symptoms as well as laboratory and imaging findings were improved after initiation of steroid therapy. Serologically, he showed hypocomplementemia (C3 23 mg/dl, C4 <2 mg/dl, CH50 <7 U/ml) with high levels of IgG (IgG4 1,970 mg/dl) and immune complexes (C1q assay 8.1 μg/ml) and a low level of C1q (<2.0 mg/dl). Histologically, he also showed linear depositions of IgG, IgM, C3, C4d, C1q, membrane attack complex and all IgG subclasses (IgG1, IgG2, IgG3 and IgG4) along the tubular basement membrane, as well as granular depositions of these components in the renal interstitium. However, mannose-binding lectin and L-ficolin were not detected in these tissues. Homogeneous electron-dense deposits were observed by electron microscopy in the tubular basement membrane. It appears that the immune complexes might activate the classical pathway of the complement in both blood and local tissues in a patient with IgG4-related tubulointerstitial nephritis.

Infraorbital nerve swelling associated with autoimmune pancreatitis

PURPOSE

The aim of our study was to examine the relation between autoimmune pancreatitis (AIP) and infraorbital nerve swelling.

MATERIALS AND METHODS

A total of 11 AIP patients underwent magnetic resonance imaging (MRI) examination of the head and neck region. The infraorbital nerve thicknesses were measured on coronal images and compared with those of a control group. We also examined whether the infraorbital nerve thicknesses were altered from before to after steroid therapy in nine patients who underwent MRI examination after such therapy.

RESULTS

The mean thicknesses were 3.8 ± 2.0 mm in the AIP group and 2.6 ± 0.5 mm in the control group (P < 0.05). The nerve thicknesses were >5 mm in 5 of 11 patients (45%) in the AIP group, and <5 mm in all of the control group. Among the nine patients who underwent MRI examination after steroid therapy, three had shown nerve swelling before steroid therapy; the therapy diminished the swelling in all three patients.

CONCLUSION

Infraorbital nerve swelling was observed more frequently in AIP patients than in patients without a history of AIP. Therefore, such swelling seems to be an extrapancreatic lesion of AIP.

Orbital necrobiotic xanthogranuloma associated with systemic IgG4 disease

PURPOSE

The authors describe 2 cases of orbital xanthogranulomatous disease associated with an increase in IgG4-positive plasma cells, and also examine IgG4 in other types of orbital inflammation.

METHODS

Immunohistochemistry for total IgG and IgG4 was performed in 18 cases of orbital inflammation, including chronic dacryoadenitis (n=10), necrobiotic xanthogranuloma (n=2), xanthogranuloma (n=1), idiopathic orbital inflammation/pseudotumor (n=4), and fungal infection (n=1).

RESULTS

One patient presenting with necrobiotic xanthogranuloma had signs of systemic IgG4 disease. His orbital lesion showed an elevated number of IgG4 positive plasma cells (55%). An orbital xanthogranulomatous lesion in a second patient lacking systemic symptoms also contained a high percentage of IgG4-positive plasma cells (80%). Only 1 case of chronic dacryoadenitis contained prominent IgG4-positive plasma cells (mean 17/hpf).

CONCLUSIONS

IgG4-positive plasma cells are relatively rare in nonsclerosing orbital inflammatory lesions. However, systemic disease IgG4 can be associated with necrobiotic xanthogranuloma of the orbit.

[IgG4-related Mikulicz's disease: a report of 3 cases]

INTRODUCTION

We report three cases of hyper-IgG4 disease with synchronous or asynchronous lymphocytic infiltration onset, IgG4 positive plasma cell infiltration, and fibril formation in multiple exocrine glands and extranodal organs. IgG4-related sialadenitis attracting recent attention has yet to be clarified as a clinical entity.

CASE REPORT

Case 1, a 61-year-old man, had a submandibular gland sample showing IgG4-positive plasma cell infiltration. Case 2, a 61-year-old man, was diagnosed with IgG4-related Mikulicz's disease confirmed by a sublingual gland sample. Case 3, a 57-year-old woman, had a diagnosis of IgG4-related Mikulicz's disease confirmed based on labial and sublingual gland samples. All reported oral dryness and bilateral submandibular swelling. Cases 1 and 2 recovered following Predonine administration tapered from 30 or 20 mg.

DISCUSSION

IgG4-related Mikulicz's disease must be recognized as a clinical entity, together with its diagnostic criteria and treatment. Sublingual gland biopsy should be done to confirm its diagnosis following sublingual gland swelling.

Eosinophilia and allergic disorders in autoimmune pancreatitis

OBJECTIVES

In autoimmune pancreatitis (AIP), the prevalence, interrelationships, and significance of peripheral eosinophilia, allergic disorders, and eosinophil infiltration in the pancreas remain unclear.

METHODS

From medical records, we obtained data on peripheral eosinophil counts at presentation and follow-up, and clinical diagnoses of allergic disorders in 97 AIP patients (78 type 1 and 19 type 2), which were compared with matched healthy controls. Available pancreatic histologic specimens were graded for eosinophils. Peripheral eosinophilia was defined as counts >0.5×10(9) per liter. We examined nature of and association between these parameters in AIP.

RESULTS

Among 78 type 1 AIP patients (mean age 62±14 years, 77% men), peripheral eosinophilia at presentation was diagnosed in 12% and allergic disorders in 15% (vs. 0 and 4% in controls, P=0.0004 and 0.006, respectively). Allergic disorders were observed in 27 and 11% of type 1 AIP with and without eosinophilia, respectively (P=0.08). Patients with and without peripheral eosinophilia were similar in clinical profile. Moderate-to-severe eosinophil infiltration was present in 67% of pancreas resection specimens and did not correlate with peripheral eosinophilia. Type 2 AIP did not differ from type 1 AIP in any of these parameters.

CONCLUSIONS

Peripheral eosinophilia, allergic disorders, and pancreatic eosinophil infiltration are associated with AIP. Eosinophilia in AIP may not reflect an allergic phenomenon, but appears to be consistent with autoimmune mechanism.

Hypophysitis presenting with atypical rapid deterioration: with special reference to immunoglobulin G4-related disease-case report-

Primary hypophysitis is believed to be a chronic inflammation of the pituitary tissue caused by the autoimmune mechanism. The disease can be classified based on morphology and histology simultaneously, but the relationships between these subtypes remain unclarified. Moreover, hypophysitis may occur as a part of systemic immunoglobulin G4 (IgG4)-related plasmacytic disease. A 74-year-old woman was initially diagnosed with infundibulo-hypophysitis. After a long period of stability, she suffered rapid deterioration with evolving endocrinopathies and visual symptoms. Biopsy specimen established the diagnosis as granulomatous hypophysitis with positive reaction for IgG4 in infiltrating plasma cells. Postoperative glucocorticoid administration improved her condition dramatically. This case illustrates two interesting points: The rapid deterioration after a long stable clinical course, and the presence of IgG4-positive tissue in the pituitary gland, which can be considered as "primary" hypophysitis with no systemic IgG4-related disease in other organs.

Mikulicz's disease with severe thrombocytopenia following autologous stem cell transplantation in a multiple myeloma patient

We report the first case of Mikulicz's disease (MD) occurring 2 years after autologous peripheral blood stem cell transplantation (PBSCT) for multiple myeloma (MM). A 70-year-old man developed bilateral enlargement of parotid and submandibular glands. The patient had previously received 2 courses of autologous PBSCT for IgG-kappa type MM, and had been stable for 2 years. This salivary gland enlargement was initially felt to represent a recurrence of MM, since along with gland swelling, IgG was also elevated. However, repeated biopsy of the left submandibular gland revealed chronic sclerosing sialadenitis rather than plasmacytoma. Results of salivary gland scintigraphy, serological testing, and absence of sicca symptoms also supported the diagnosis of MD. Concurrently, the patient developed severe thrombocytopenia (0.8 x 10(4)/microl). Bone marrow biopsy showed abundant megakaryocytes, suggesting enhanced platelet destruction. After high-dose steroid and immunoglobulin therapy, the platelet count gradually returned to normal with complete resolution of the salivary gland enlargement. No apparent signs of MM recurrence were documented during these clinical events.

Autoimmune pancreatitis

PURPOSE OF REVIEW

Autoimmune pancreatitis (AIP) is an increasingly recognized clinical condition. Our objective is to provide a concise review of the advances in the past year in our understanding of AIP.

RECENT FINDINGS

In a hospital survey from Japan, the prevalence of AIP was estimated at 0.82 per 100,000 individuals. The pathogenesis of AIP remains unclear but a recent report noted that T helper type 2 and T regulatory cells predominantly mediate the immune reaction in AIP. Genetic associations that may predispose to relapse of AIP were reported. Multiple case series further described the clinical profile of AIP and its extrapancreatic manifestations. A large series on immunoglobulin G4 (IgG4)-associated cholangitis noted that patients with IgG4-associated cholangitis presented with obstructive jaundice and had increased serum IgG4 levels and IgG4-positive cells in bile duct biopsy specimens. Tissue IgG4 staining is likely to be a useful adjunct to serological diagnosis. AIP is steroid-responsive but maintaining remission continues to remain challenging. Presently low-dose steroids or immunomodulators are being used but efficacy of these medications remains to be determined.

SUMMARY

There has been significant progress in understanding the clinical profile of AIP but knowledge of pathogenesis remains limited. Treatment practices vary widely and management of refractory disease continues to be challenging.

A sudden onset of diabetic ketoacidosis and acute pancreatitis after introduction of mizoribine therapy in a patient with rheumatoid arthritis

Mizoribine has been recognized to have an acceptable toxicity profile compared with other immunosuppressants. In this study, however, we report a case of diabetic ketoacidosis and acute pancreatitis that suddenly occurred in a rheumatoid arthritis patient 2 weeks after introduction of mizoribine therapy. To the best of our knowledge, this is the first case in the literature to show mizoribine-induced diabetic ketoacidosis. Through prompt diagnosis and treatment, the patient recovered from these extremely rare but potentially lethal complications.