A new conceptualization for Mikulicz's disease as an IgG4-related plasmacytic disease

IgG4-related disease with massive pericardial effusion diagnosed clinically using FDG-PETCT: a case report

Background

IgG4-related disease (IgG4-RD) is a systemic inflammatory disease which involves various organs such as the pancreas, lacrimal gland, salivary gland, retroperitoneum, and so on. These organs can be affected concomitantly. 18-Fluorodeoxyglucose positron emission tomography computed tomography (FDG-PETCT) is a systemic examination which can identify active inflammation and detect multiple organ involvement simultaneously. Pericardial involvement is rare in IgG4-RD, early detection and treatment can greatly improve the prognosis of patients.

Case summary

We reported a 82-year-old female patient referred to our department complaining of chest tightness and abdominal fullness for 8 months and massive pericardial effusion for 2 months. A large amount of pericardial effusion was found during the hospitalization of Gastroenterology. Then she was transferred to cardiology. Although infectious, tuberculous, and neoplastic pericardial effusions were excluded, there was still no diagnosis. The patients were examined by FDG-PETCT which considered IgG4-RD. After coming to our department, the results of the patient's laboratory tests showed that immunoglobulin subgroup IgG4 was 14.0 g/L. Then we performed a biopsy of the right submandibular gland. Pathological morphology and immunohistochemistry suggested IgG4-RD. Combined with level of IgG4, clinical, pathological and immunohistochemical results, we determined the final diagnosis of IgG4 related diseases. Then we gave glucocorticoid and immunosuppressant treatment. At the end, pericardial effusion was completely absorbed. As prednisone acetate was gradually reduced, no recurrence of the disease has been observed.

Conclusion

Pericardial effusion can be the initial presentation in IgG4-RD. For patients with massive pericardial effusion of unknown cause, early detection of IgG4 is recommended, and PETCT may be helpful for obtaining the diagnosis.

[The clinical case of IgG4-related thyroid disease in a 6-year-old child]

IgG4-related disease is a rare chronic pathology manifested by lymphoplasmacytic infiltration of one or more organs, the formation of storiform fibrosis, tissue edema, and an increase of IgG4 in the blood. This disease was singled out as an independent nosological unit only in 2001. The incidence is less than 1 in 100,000 people per year. Almost any organ can be affected in IgG4-related disease. The association of Riedel's thyroiditis with IgG4 was established in 2010. Riedel's thyroiditis is an extremely rare inflammatory disease of the thyroid gland, which diagnosis is complicated by an atypical course and the absence of characteristic symptoms. Less than 300 clinical cases of the disease have been described in the world, only two from them were in children. This article presents a clinical case of a 6-year-old boy with Riedel's thyroiditis.

Missing link between tissue specific expressing pattern of ERβ and the clinical manifestations in LGBLEL

Purpose

Lacrimal gland benign lymphoepithelial lesion (LGBLEL) is an IgG4-related disease of unknown etiology with a risk for malignant transformation. Estrogen is considered to be related to LGBLEL onset.

Methods

Seventy-eight LGBLEL and 13 control clinical samples were collected and studied to determine the relationship between estrogen and its receptors and LGBLEL development.

Results

The serological analysis revealed no significant differences in the levels of three estrogens be-tween the LGBLEL and control groups. However, immunohistochemical analyses indicated that the expression levels of ERβ and its downstream receptor RERG were relatively lower in LGBLEL samples than in control samples, with higher expression in the lacrimal gland and lower expression in the lymphocyte infiltration region. However, low expression of ERα was detected. The transcriptome sequence analysis revealed upregulated genes associated with LGBLEL enriched in lymphocyte proliferation and activation function; downregulated genes were enriched in epithelial and vascular proliferation functions. The key genes and gene networks were further analyzed. Interactions between B cells and epithelial cells were analyzed due to the identified involvement of leukocyte subsets and epithelial cells. B cell proliferation was found to potentially contribute to lacrimal gland apoptosis.

Conclusion

Therefore, the tissue-heterogeneous expression pattern of ERβ is potentially related to the clinical manifestations and progression of LGBLEL, although further investigations are required to confirm this finding.

IgG4-RD in a Unilateral Parotid Mass: A Rare Manifestation and Review of the Literature

IgG4 related disease (IgG4-RD) is a rare, immune-mediated inflammatory disease that varies widely in its presentation because it can affect nearly any organ. We present a case of a 73-year-old male who presented with an ill-defined mass of the parotid gland, found to be IgG4-RD, after several months of work up and tissue sampling. Most cases of salivary gland involvement in IgG4-RD present as bilateral swelling of the submandibular glands. We present this case as a unique manifestation of salivary gland disease in IgG4-RD as a persistent, non-discrete unilateral mass in the parotid gland. It is critical that clinicians who regularly treat salivary gland pathologies are familiar with this rare disease and its potential manifestations in the oral cavity.

Immunoglobulin G4-Related Thyroid Disease: A Single-Center Experience and Literature Review

BACKGROUND

Immunoglobulin G4 (IgG4)-related disease is an entity that can involve the thyroid gland. The spectrum of IgG4-related thyroid disease (IgG4-RTD) includes Hashimoto thyroiditis (HT) and its fibrotic variant, Riedel thyroiditis, as well as Graves' disease. The early diagnosis of IgG4-RTD is important because it is a medically treatable disease, and a delay in the diagnosis might result in unnecessary surgery. We present a case series of IgG4-RTD with a review of the literature.

METHODS

We retrospectively reviewed the clinical presentation and the radiological and pathological findings of patients diagnosed with IgG4-RTD between 2017 and 2021 at a tertiary medical center in Korea. We also conducted a literature review of IgG4-RTD.

RESULTS

Five patients were diagnosed with IgG4-RTD during the study period. The patients' age ranged from 31 to 76 years, and three patients were men. Most patients visited the clinic for a neck mass, and hypoechogenic nodular lesions were observed on neck ultrasonography. Three patients had IgG4 HT, and two patients had IgG4 Riedel thyroiditis. All patients developed hypothyroidism that necessitated L-thyroxine replacement. The diagnosis of IgG4-RTD was confirmed after a pathological examination of the surgical specimen in the first two cases. However, the early diagnosis was possible after a core needle biopsy in three clinically suspected patients.

CONCLUSION

The diagnosis of IgG4-RTD requires clinical suspicion combined with serology and histological analyses using IgG4 immunostaining. The early diagnosis of IgG4-RTD is difficult; thus, biopsy with IgG4 immunostaining and serum IgG4 measurements will help diagnose patients suspected of having IgG4-RTD.

Immunoglobulin G4-related Disease: A New Systemic Disease Emerging in Japan

Immunoglobulin G4-related disease (IgG4-RD) is a fibro-inflammatory disease characterized by organ enlargement and elevated serum IgG4 levels. In 2003, IgG4-RD was proposed as a distinct form of IgG4-related systemic disease based on a histopathological study involving patients with autoimmune pancreatitis. IgG4-RD occurs mainly in older men and can affect almost any organ simultaneously or metachronously. Pathophysiologically, IgG4-RD occurs when an autoantigen triggers an immune response characterized by Th2 predominance with increased production of cytokines, such as interleukin 4 (IL-4), IL-5, IL-10, IL-13, and tumor growth factor-β (TGF-β), in the affected organ. IL-10 and TGF-β produced by the increased number of regulatory T cells induce a switch from B cells to IgG4-producing plasma cells and fibrosis, respectively. The characteristic histological features consist of dense infiltration of lymphocytes and IgG4-positive plasma cells, storiform fibrosis, and obliterative phlebitis. IgG4-RD is diagnosed based on a combination of clinical, serological, radiological, and histopathological findings. Differentiating IgG4-RD from malignant tumors or similar inflammatory diseases in the affected organs is important. The 2019 America College of Rheumatology/European League against Rheumatism classification criteria for IgG4-RD have high diagnostic sensitivity and specificity. IgG4-RD generally responds well to treatment with steroids, and a swift response is reassuring and provides further diagnostic confirmation. However, relapses are common during tapering or after cessation of steroids. In Japan, low-dose steroid maintenance therapy is usually given to prevent a relapse. B-cell depletion with rituximab is effective in patients resistant to or dependent on steroids. Most patients with IgG4-RD who receive steroid therapy show good short-term clinical, morphological, and functional outcomes. However, long-term outcomes, such as relapse, fibrosis development, and associated malignancies, have not been clearly defined. Therefore, novel treatment strategies, including rituximab, need to be tested in international randomized controlled clinical trials.

Amendment of the Japanese consensus guidelines for autoimmune pancreatitis, 2020

In response to the latest knowledge and the amendment of the Japanese diagnostic criteria for autoimmune pancreatitis (AIP) in 2018, the Japanese consensus guidelines for managing AIP in 2013 were required to be revised. Three committees [the professional committee for developing clinical questions (CQs) and statements by Japanese specialists; the expert panelist committee for rating statements by the modified Delphi method; and the evaluating committee of moderators] were organized. Twenty specialists in AIP extracted the specific clinical statements from a total of 5218 articles (1963-2019) from a search in PubMed and the Cochrane Library. The professional committee made 14, 9, 5, and 11 CQs and statements for the current concept and diagnosis, extra-pancreatic lesions, differential diagnosis, and treatment, respectively. The expert panelists regarded the statements as valid after a two-round modified Delphi approach with individually rating these clinical statements, in which a clinical statement receiving a median score greater than 7 on a 9-point scale from the panel was regarded as valid. After evaluation by the moderators, the amendment of the Japanese consensus guidelines for AIP has been proposed in 2020.

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.

The FcεRI signaling pathway is involved in the pathogenesis of lacrimal gland benign lymphoepithelial lesions as shown by transcriptomic analysis

This study aimed to analyze the role of the FcepsilonRI (FcεRI) signaling pathway in the pathogenesis of benign lymphoepithelial lesion of lacrimal gland (LGBLEL). Transcriptomic analysis was performed on LGBLEL and orbital cavernous hemangioma (CH) patients diagnosed via histopathology in Beijing Tongren Hospital, Capital Medical University, between July 2010 and October 2013. Four LGBLEL and three orbital CH patients, diagnosed between October 2018 and August 2019, were randomly selected as experimental and control groups, respectively. RT-PCR, immunohistochemical staining, and western blotting were used to verify genes and proteins related to the FcεRI signaling pathway. Transcriptomic analysis showed that the FcεRI signaling pathway was upregulated in the LGBLEL compared with the CH group. The mRNA expression levels of important genes including SYK, p38, JNK, PI3K, and ERK were significantly increased in the LGBLEL group (P = 0.0066, P = 0.0002, P = 0.0003, P < 0.0001, P < 0.0001, respectively). Immunohistochemical staining results showed that SYK, p38, and ERK were positively expressed in LGBLEL, while JNK and PI3K were not. The protein contents of P-SYK, P-p38, P-JNK, P-PI3K, and P-ERK were significantly higher in the LGBLEL than in the CH group (P = 0.0169, P = 0.0074, P = 0.0046, P = 0.0157, P = 0.0156, respectively). The FcεRI signaling pathway participates in the pathogenesis of LGBLEL.

IgG4 as a Biomarker in Graves' Orbitopathy

Immunoglobulin G4-related disease (IgG4-RD) is a chronic inflammatory disorder associated with fibrosis and abundant tissue lymphoplasmacytic infiltrations. It typically affects the pancreas, the salivary glands, and the retroperitoneal space. However, it might also involve multiple other organs, including the orbit and the thyroid. Recent studies have suggested that IgG4 plays a role in the pathophysiology of autoimmune thyroid diseases. This ultimately led to the establishment of new clinical entities called IgG4-related thyroid disease and thyroid disease with an elevation of IgG4. The aim of this paper is to describe the pathophysiological, histopathological, and clinical features of Graves' Disease (GD) and Graves' Orbitopathy (GO) with elevated IgG4 levels. Multiple studies have demonstrated higher IgG4 serum concentrations in GD patients than in healthy euthyroid controls. Depending on the studied population, elevated serum IgG4 levels occur in 6.4-23% (average: 10.3%) of all patients with GD, 8.3-37.5% (average: 17.6%) of patients with GO, and 0-9.8% (average: 5.4%) of patients with GD without GO, while GO patients comprise 37.5-100% (average: 65.8%) of all GD patients with elevated IgG4 levels. Characteristic features of GD with elevated IgG4 levels include lower echogenicity of the thyroid gland on ultrasound examination, peripheral blood eosinophilia, higher prevalence of orbitopathy, and better response to antithyroid drugs with a tendency to develop hypothyroidism when compared to patients with GD and normal levels of IgG4. Typical signs of GO accompanied by increased concentration of IgG4 include younger age at diagnosis, and more severe course of the disease with a higher Clinical Activity Score (CAS).. We strongly recommend considering the diagnosis of GO with elevated IgG4 in patients with an established diagnosis of GD, elevated serum IgG4 levels, and clinical features of ophthalmic disease overlapping with those of IgG4-related orbital disease.

IgG4-related disease: an atypical presentation of steroid-responsive renal mass

IgG₄-related disease (IgG₄-RD) is a systemic fibroinflammatory disease characterised by dense lymphoplasmacytic infiltration rich in IgG₄-positive plasma cells, storiform fibrosis and obliterative phlebitis. Serum IgG₄ levels are typically elevated but half of the patients had normal serum IgG₄ levels. IgG₄-RD represents a spectrum of diseases that involve various organs such as the pancreas, liver, kidneys, and salivary glands often manifesting as diffuse organ enlargement or a mass-like lesion mimicking cancer. An increased incidence of malignancy among patients with IgG₄-RD has been reported. Thus, differentiating malignancy from IgG₄-RD manifestation is important as the treatment differs. Glucocorticoids are considered first-line therapy and should be started early to prevent fibrosis. Patients usually have an excellent clinical response to steroids, and poor steroid response is indicative of an alternative diagnoses such as malignancy. This case report describes a case of IgG₄-RD with renal mass in a young man that resolved with glucocorticoid therapy alone.

Review of Diagnostic Biomarkers in Autoimmune Pancreatitis: Where Are We Now?

Autoimmune pancreatitis (AIP) is a pancreatic manifestation of an IgG4-related disease (IgG4-RD). AIP lacks disease-specific biomarkers, and therefore, it is difficult to distinguish AIP from malignancies, especially pancreatic cancer. In this review, we have summarized the latest findings on potential diagnostic biomarkers for AIP. Many investigations have been conducted, but no specific biomarkers for AIP are identified. Therefore, further studies are required to identify accurate diagnostic biomarkers for AIP.

Rare Diseases of the Salivary Glands and of Facial Nerve

Salivary gland diseases are rare. In the European Union (EU) a disease is considered to be rare if not more than 5 of 10,000 people are affected by it. According to estimates in Germany are about 4 million people with a rare disease. In the EU are about 30 million people with rare diseases [1]. In the present work most of the described diseases of salivary glands and of the facial nerve fall in this category. They form a very heterogeneous group whose treatment takes place mainly in specialized centers. Still, it is essential for the otolaryngologist to identify and to diagnose these diseases in order to initiate the right therapeutic steps. The work is a compilation of innate andacquired rare salivary gland disorders and of rare facial nerve disorders. The etiologies of inflammatory diseases, autoimmune disorders and tumors are taken into account. For the individual topics, the current literature, if available, was evaluated and turned into summarized facts. In this context the development of new processes, diagnostics, imaging and therapy are considered. Genetic backgrounds of salivary gland tumors and the trends in the treatment of tumorous lesions of the facial nerve are picked up. Furthermore, also rare diseases of the salivary glands in childhood are described. Some of them can occur in adults as well, but differ in frequency and symptoms. Due to the rarity of these diseases, it is recommended to tread these in centers with special expertise for it. Finally, the difficulties of initiation of studies and the problems of establishing disease registries concerning salivary gland disorders are discussed. This is very relevant because these pathologies are comparatively seldom.

IgG4-related disease: Changing epidemiology and new thoughts on a multisystem disease

IgG4-related disease (IgG4-RD) represents an immune-mediated fibroinflammatory condition with peculiar histopathologic changes that can affect various organs. In 2012 its unified nomenclature was published, which allows to abandon other synonymous names. Up to now, only little is known about its epidemiology around the world. However, although it is generally considered a rare condition, the number of patients with IgG4-RD is increasing enormously. Likewise, the annual number of publications on this subject has increased progressively. The spectrum of clinical manifestations in IgG4-RD is highly variable, depending on the severity of the disease as well as the presence of organ(s) involvement. This review gives an overview on changing epidemiology of IgG4-RD focusing the attention on the large cohorts of patients published in the literature.

IgG4-related disease with multiple organs involvement was effectively controlled by glucocorticoids: a case report

Immunoglobulin G4 (IgG4) related disease is a rare autoimmune disease involving multiple organs and tissues. A diagnosis of IgG4-related disease (IgG4-RD) is mainly based on serum IgG4 concentration, imaging, pathology, and effective glucocorticoids therapy. In this paper, we report a 53-year-old male with typical signs and symptoms of IgG4-RD successfully treated with glucocorticoids. This patient had experienced bilateral mumps for more than 8 months and intermittent abdominal pain spreading to his lower back for 2 months before his admission. During his hospitalization, based on the characteristic appearance of magnetic resonance imaging (MRI), magnetic resonance cholangiopancreatography (MRCP), and computed tomography with positron emission tomography, a diagnosis of autoimmune pancreatitis (AIP), cholangitis with biliary obstruction, lachrymal adenitis, and submandibular adenitis was made. A high serum IgG4 concentration further supported a diagnosis of IgG4-RD. Then, the treatment was promptly initiated with corticosteroids. MRI, MRCP, and IgG4 concentration were re-examined during his follow up, suggesting that glucocorticoid treatment resulted in a resolution of his disease. The dosage of glucocorticoid had been gradually decreased. Now, he is stable with oral low-dose glucocorticoids. Certainly, long-term follow up of this patient with such a rare disease is very essential to observe the possibility of disease recurrence and glucocorticoids related complications.

Analysis of Innate and Adaptive Immunological Characteristics in Patients with IgG4-Related Disease

BACKGROUND

Immunoglobulin G4-related disease (IgG4-RD) is a systemic immunological disorder characterized by fibro-inflammatory conditions; however, the pathobiology of IgG4-RD has not been fully identified.

OBJECTIVE

This study aimed to analyze systemic differences of innate and adaptive immune cells from healthy controls and patients with IgG4-RD.

METHODS

Healthy controls (n = 9) and IgG4-RD patients (n = 7) were recruited with informed consent. Peripheral blood was collected from healthy controls and IgG4-RD patients, and three blood samples from IgG4-RD patients were re-collected two months after the last rituximab (RTX) treatment. The various immune cells and cytokine productions were measured by flow cytometry.

RESULTS

Blood CD14+ monocytes and steady-state follicular helper T cells were increased in patients with IgG4-RD. However, there were no changes in other immune cell populations, including B cells, CD4 T cells, CD8 T cells, and innate lymphoid cells. Also, the TGF-β-producing CD14+ monocytes were significantly augmented in patients with IgG4-RD. Two months after RTX treatment, total B cells (CD19+) were depleted; however, the expressions of TGF-β from CD14+ monocytes remained unchanged.

CONCLUSION

These findings showed that IgG4-RD is related to the increment of CD14+ monocytes. Besides, controlling increased TGF-β-producing CD14+ monocytes with RTX treatment might be a conducive way to regulate IgG4-RD.

Immunoglobulin G4-related chronic sclerosing sialadenitis: An emerging entity

Chronic sclerosing sialadenitis is associated with the immunoglobulin G4 (IgG4)-related disease (RD) spectrum. IgG4-RD is a newly recognized immunomediated fibroinflammatory condition characterized by several features: a tendency to form tumefactive lesions at multiple sites, lymphoplasmacytic infiltrate, fibrosis and obliterative phlebitis. Often but not always, the serum IgG4 concentrations are also elevated. Immunohistochemistry for IgG4 is helpful to clinch the diagnosis. Here, we describe a case of 65-year-old male with IgG4-related chronic sclerosing sialadenitis of the s ubmandibular gland. We have discussed the histopathological criteria to diagnose this entity.

Autoimmune Pancreatitis and IgG4-Related Disease: The Storiform Discovery to Treatment

Autoimmune pancreatitis (AIP) is an entity that has been recognized since 1961. Prior to the discovery of elevated serum IgG4 as a useful biomarker for its diagnosis, Dr. Yoshida in 1995 first described the entity of AIP, which in retrospect closely resembles the current concept of type 1 AIP. Since the discovery of IgG4 as a biomarker (the IgG4-era), a novel concept of IgG4-related disease (IgG4-RD) has been accepted as being comprised of two subtypes of AIP: type 1 defined as the pancreatic manifestation of IgG4-RD, and type 2 characterized by granulocytic epithelial lesions. The characteristic features of type 1 AIP are increased serum IgG4 levels, lymphoplasmacytic sclerosing pancreatitis (abundant infiltration of IgG4+ plasmocytes and lymphocytes, storiform fibrosis, and obliterative phlebitis), extrapancreatic manifestations of IgG4-RD (e.g., sclerosing cholangitis, sclerosing sialadenitis, retroperitoneal fibrosis), and steroid responsiveness. These entities can be differentiated from mimickers by a combination of serum IgG4 level, imaging features, and histopathological findings. The current first-line therapy is corticosteroids, or rituximab in high-risk patients with steroid intolerance. Although relapse rates are high, treatment of relapsed disease remains experimental.

Magnetic resonance imaging indicator of the causes of optic neuropathy in IgG4-related ophthalmic disease

Background

The following study investigates the involvement of optic neuropathy in IgG4-related ophthalmic diseases (IgG4-ROD) based on the magnetic resonance imaging (MRI) data, and different imaging features of IgG4-ROD related optic neuropathy related to other orbital diseases.

Methods

This retrospective study included 225 patients with IgG4-RD admitted at two ophthalmology centers between January 2014 and December 2017. Twenty-six patients had both pre-therapeutic orbital MRI and optic never injury. The causes of optic neuropathy were analyzed, and the special sign in MRI to diagnose IgG4-ROD was also evaluated.

Results

Twelve cases had inflammation of the optic nerve sheath, while 14 cases had compression due to extraocular muscles and pseudo tumor masses. Two cases had hypertrophic cranial pachymeningitis, while one case had hypophysis involving optic chiasma.

Conclusion

The most common causes of optic nerve injury in IgG-4 ROD are inflammation of optic nerve sheath, compression of extraocular muscles, pseudo tumor mass and hypertrophic cranial pachymeningitis, and hypophysis involving optic chiasma.

Clinicopathologic features of biopsied lacrimal gland masses in 95 Korean patients

PURPOSE

To investigate the clinicopathologic features of lacrimal gland masses biopsied in a tertiary referral hospital in Korea.

METHODS

Records from 95 Korean patients who underwent lacrimal gland mass biopsy were retrospectively reviewed. Data included demographics, clinical presentation, imaging findings, histopathologic diagnosis, and associated systemic disease.

RESULTS

The median age was 52.0 years (range, 16-76 years), and 51 patients (53.7%) were female. Thirty-three patients (34.7%) had bilateral disease. The histopathologic diagnoses were as follows: chronic dacryoadenitis (52.6%, n = 50;29 non-specific and 21 immunoglobulin G4-related disease (IgG4-RD)), lymphoproliferative disease (25.5%, n = 24; 18 lymphoma and six lymphoid hyperplasia), benign epithelial tumour (13.7%, 13 pleomorphic adenoma), malignant epithelial tumour (3.2%, three adenoid cystic carcinoma), dacryops (3.2%, n = 3), solitary fibrous tumour (1.1%, n = 1), and xanthogranulomatous inflammation (1.1%, n = 1). Patients with chronic dacryoadenitis were significantly more likely to be younger (mean 47.5 years), have bilateral involvement (52.0%), and have a longer symptom period (mean 15.6 months) than those with lymphoproliferative disease (60.0 years, 25.0%, and 6.7 months, respectively; p < 0.05, each comparison). Patients with IgG4-related dacryoadenitis were significantly more likely to have bilateral involvement (85.7%) and have associated systemic involvement (52.4%) than those with non-specific dacryoadenitis (37.9 and 0%, respectively; p < 0.05, each comparison). Sixteen patients (16.8%) had associated systemic involvement: 11 with IgG4-RD and 5 with lymphoma.

CONCLUSIONS

Chronic dacryoadenitis and lymphoproliferative disease were the most common causes of lacrimal gland masses in our cohort. Younger patients with bilateral involvement and a longer symptom period were more likely to have chronic dacryoadenitis than lymphoproliferative disease. Associated systemic involvement was not rare in patients with IgG4-RD or lymphoma. Our results suggest that biopsy of chronic lacrimal gland masses should be performed for proper evaluation and management.

IgG4-related Pericarditis in which Oral Corticosteroid Therapy Was Effective

IgG4-related diseases (IgG4-RDs) have recently been reported in many organs other than the salivary, pancreatic and hepatobiliary systems. A 64-year-old woman was referred to our department for her abdominal fullness and cardiomegaly on chest X-ray. After draining the pericardial fluid, her symptom promptly diminished, and pericardial friction rubbing became clearly audible. Elevated serum levels of IgG and IgG4 and ureteral wall thickening on computed tomography suggested IgG4-RD. After the initiation of oral corticosteroid therapy, the pericardial effusion was resolved, and she has been in a steady-state condition for the past two years.

Immunoglobulin G4-related Disease: An Overview

Immunoglobulin G4-related disease (IgG4-RD) is a recently established systemic disease that is characteristically associated with elevated serum immunoglobulin G4 (IgG4) levels and believed to be caused by autoimmune mechanisms. The clinical features of IgG4-RD include (i) systemic distribution, (ii) imaging findings of swelling, nodules, and/or wall thickening, (iii) high serum IgG4 levels, (iv) abundant IgG4-bearing plasma cell infiltration and fibrosis in affected organs, (v) a favorable response to corticosteroid therapy, and (vi) coexistence with other IgG4-RD manifestations simultaneously or in a metachronous fashion. The concept of IgG4-RD was established based on the culmination of specific discoveries. Specifically, a close association between autoimmune pancreatitis (AIP) and high serum IgG4 levels, massive IgG4-bearing plasma cell infiltration in pancreatic tissues affected by AIP, and systemic other organ involvements in AIP with similar IgG4-bearing plasma cell features opened the gateway from AIP to IgG4-RD. The systemic distribution of IgG4-RD seems to be capable of affecting every organ, causing well-established members including AIP, lacrimal and salivary gland lesions such as Mikulicz’s disease, respiratory diseases, sclerosing cholangitis, kidney diseases, and retroperitoneal fibrosis. IgG4-RD has been diagnosed worldwide, and international collaboration efforts on the disease have led to consensus publications on its nomenclature, pathology findings, and management approach. The algorithms developed for the comprehensive diagnostic criteria for IgG4-RD have remarkably increased detection sensitivity. Oral glucocorticoids are the first-line agents for remission induction, and certain patients with high disease activity may benefit from maintenance therapy afterwards. Originally, IgG4-RD had been considered reversible and to have a good prognosis; however, long-term afflictions sometimes result in transition to advanced-stage conditions with dysfunction and/or complicating malignancy. The immunological abnormalities in IgG4-RD have been reported in both innate and adaptive immune systems; however, it remains unclear whether IgG4 has a pathogenic role or a protective one in disease onset and progression.

Differences and similarities between IgG4-related disease with and without dacryoadenitis and sialoadenitis: clinical manifestations and treatment efficacy

Background

This study aimed to compare the differences and similarities in the clinical manifestations and treatment efficacy of IgG4-related disease (IgG4-RD) in patients with and without dacryoadenitis and sialoadenitis (DS).

Methods

A total of 121 untreated IgG4-RD patients in Peking Union Medical College Hospital were enrolled in this study. The patients were divided into three groups: DS-predominant (group A), non-DS (group B), and DS with other internal organs affected (group C). The patients were followed up for at least 15 months. Baseline and follow-up data were collected. The disease activity was evaluated according to the IgG4-RD responder index.

Results

The mean ± SD age at disease onset was 53.2 ± 14.1 years, and 71.9% of the patients were male. The prevalence of allergies was higher in groups A (21, 61.8%) and C (32, 69.6%) than group B (14, 34.1%). More patients with DS (17, 50.0%, and 17, 37.0%) had sinonasal lesions than those without DS (5, 12.2%). Moreover, an increased number of eosinophils were more common in patients with DS than in those without, as were increased serum IgG, IgG4, and IgE levels. More patients in group B and group C (28, 68.3%, and 31, 67.4%) received a combination therapy of corticosteroid and immunosuppressant. During the 15-month follow-up, 28 (23.1%) patients had disease relapse.

Conclusion

Results demonstrated that IgG4-RD patients with DS had distinctive clinical features compared with non-DS. Allergy and sinonasal involvement were more common in patients with DS. Patients with DS showed higher serum IgG4 levels than those without DS.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1828-8) contains supplementary material, which is available to authorized users.

A case of recurrent Mikulicz's disease with mononeuritis multiplex

We report an 82-year-old man with recurrence of Mikulicz’s disease accompanied with mononeuritis multiplex. On admission, both upper eyelids, the salivary gland, the dorsum of the left hand and both legs were swollen. Neurological examination showed motor weakness of distal limbs (manual muscle testing 3/5) and decreased touch, pain and vibration sensation of the dorsum of the left hand and both legs. Deep tendon reflex in both legs was also decreased. We diagnosed Mikulicz’s disease based on high serum immunoglobulin (Ig)G4 (630 mg/dl, 26.1% of total IgG) and lacrimal gland biopsy findings. Clinical symptoms and motor conduction study findings improved after steroid therapy. However, tapering of the steroid dose resulted in recurrence two years later. Steroid therapy is usually effective for IgG4-related neuropathy, and we found that an increase of steroid dose was effective to treat the recurrence. But, in general, a suitable maintenance dose of steroid in combination with an immunosuppressant may be necessary to prevent relapse.

Macrophage migration inhibitory factor contributes to the pathogenesis of benign lymphoepithelial lesion of the lacrimal gland

Background

Benign Lymphoepithelial Lesion (BLEL) is a rare disease observed in the adult population. Despite the growing numbers of people suffering from BLEL, the etiology and mechanisms underlying its pathogenesis remain unknown.

Methods

In the present study, we used gene and cytokines expression profiling, western blot and immunohistochemistry to get further insight into the cellular and molecular mechanisms involved in the pathogenesis of BLEL of the lacrimal gland.

Results

The results showed that Macrophage Migration Inhibitory Factor (MIF) was the most highly expressed cytokine in BLEL, and its expression positively correlated with the expression of Th2 and Th17 cells cytokines. MIF was found to regulate biological functions and pathways involved in BLEL pathogenesis, such as proliferation, resistance to apoptosis, MAPK and PI3K/Akt pathways. We also found that MIF promotes fibrosis in BLEL by inducing BLEL fibroblast differentiation into myofibroblasts as well as the synthesis and the deposit of extracellular matrix in BLEL tissues.

Conclusions

Our findings demonstrate the contribution of MIF to the pathogenesis of BLEL of the lacrimal gland and suggested MIF as a promising therapeutic target for its treatment.

Electronic supplementary material

The online version of this article (10.1186/s12964-018-0284-4) contains supplementary material, which is available to authorized users.

Sialendoscopic management of autoimmune sialadenitis: a review of literature

Autoimmune diseases of major salivary glands include Sjögren's syndrome and a complex of disorders classified as immunoglobulin G4-related diseases. These pathologies are characterised by an autoimmune reaction mediated by T-helper lymphocytes that targets the ducts of exocrine glands in Sjögren's syndrome and glandular parenchyma in immunoglobulin G4-related diseases. Immunoglobulin G4-related diseases represent recently introduced multi-organ diseases that also involve the salivary glands. However, the morbid conditions once known as Mikulicz's disease and Kuttner's tumour were recently considered as two variants of immunoglobulin G4-related diseases affecting the major salivary glands ( immunoglobulin G4-related sialadenitis). This review briefly summarises the pathogenesis and clinical features of autoimmune diseases of the major salivary glands, focusing on the diagnostic and therapeutic role of sialendoscopy.

Immunoglobulin G4-Related Disease: An Update

Immunoglobulin G4-related disease (IgG4-RD) is an increasingly recognized immune-mediated condition comprised of a collection of disorders that share specific pathological, serological, and clinical features. IgG4-RD is a fibroinflammatory condition with a tendency to form tumors with inflammatory infiltrate with IgG4 rich plasma cells and elevation of serum IgG4, which may affect virtually every organ and tissue. IgG4-related ophthalmic disease may present as dacryoadenitis, myositis, or involvement of other orbital tissue. Hypophysitis or pachymeningitis may manifest as cranial neuropathies. The diagnosis of IgG4-RD is based on a typical clinical scenario, supportive laboratory test, expected radiological characteristics, and distinct histopathological and immunohistochemical features. Corticosteroids and immunosuppressives form the mainline treatment.

Clinicoserological factors associated with response to steroid treatment and recurrence in patients with IgG4-related ophthalmic disease

Purpose

To investigate the factors associated with response to steroid treatment and recurrence in patients with IgG4-related ophthalmic disease (ROD).

Methods

Twenty-eight patients with biopsy-proven IgG4-ROD treated between March 2010 and January 2017 were included in this retrospective study. Clinical features, serum IgG4 levels, systemic involvement, treatments and treatment outcome, factors associated with response to treatment and recurrence were assessed.

Result

Thirteen men and 15 women (mean age 50.8 years) were evaluated over mean follow-up period of 27.3 months. Elevated serum IgG4 levels (>1.35 g/L) and systemic disease were noted in 9 (32%) and 18 patients (64%), respectively. The lacrimal gland was involved in all patients, and 22 patients (78.6%) had bilateral involvement. Most patients (82%) responded well to systemic steroids, but 12 (43%) relapsed after the initial steroid treatment, requiring additional therapies to achieve remission. Complete response to initial steroid treatment was associated with elevated serum IgG4 levels before treatment (P=0.001) and bilateral orbital involvement (P=0.050). Recurrence was associated with elevated serum IgG4 levels before treatment (P=0.007), lower dose (P=0.057) and shorter duration of initial steroids (P=0.042). Patients with recurrence eventually required significantly more steroids than those without recurrence (P=0.011).

Conclusions

Patients with IgG4-ROD responded well to systemic steroid treatment, but recurrence was common, particularly among those with elevated serum IgG4 levels and shorter duration of initial steroid treatment. Low-dose maintenance treatment with systemic steroids should be considered to avoid recurrence in patients with elevated serum IgG4 levels.

Immunoglobulin G4-related dacyroadenitis presenting as bilateral chorioretinal folds from severely enlarged lacrimal glands

Purpose

To describe a case of immunoglobulin G4 (IgG4)-related dacyroadenitis presenting as bilateral chorioretinal folds from eyeball compression by massively enlarged lacrimal glands.

Observations

A 51-year-old woman with severely enlarged bilateral lacrimal glands was diagnosed as having IgG4-related dacryoadenitis. The glands strongly compressed the globes, forming chorioretinal folds resembling those found in orbital malignancy. Eventual treatment with oral prednisolone dramatically reduced the volume of the lacrimal glands and released globe compression on magnetic resonance imaging. However, the chorioretinal folds remained in the right fundus and symptoms of blurred vision improved but persisted.

Conclusions and importance

This is the first account of chorioretinal fold formation by severely enlarged lacrimal glands appearing in IgG4-related dacryoadenitis. Chorioretinal fold formation by an enlarged lacrimal gland occurring bilaterally may represent a basis for suspecting IgG4-related dacryoadenitis. Prompt treatment is recommended for patients presenting with very large lacrimal glands to avoid visual impairment.

Case report: IgG4-related mass-forming thyroiditis accompanied by regional lymphadenopathy

Background

It has been recently accepted that IgG4-related thyroiditis is comparable to the Hashimoto and Riedel thyroiditis and Graves disease which are rich in IgG4-secreting plasma cells. Many physicians believe that in IgG4-related thyroiditis, the thyroid is entirely enlarged and diffusely affected, which is similar to conventional thyroiditis, but rarely ever accompanied by pseudoneoplastic mass formation as in IgG4-related disease in the other organs. This report introduces another pattern of IgG4-related thyroiditis as mass-forming thyroiditis and presents the occurrence of IgG4-related regional lymphadenopathy as an unusual accompanying symptom.

Case presentation

A 66-year-old woman presented with an approximately 2.5-cm mass in the right thyroidal lobe and regional lymph node swelling, which were preoperatively misinterpreted as thyroidal carcinoma. After lobectomy, histological examination was performed, revealing that the mass showed dense stromal fibrosis, lymphoplasmacytic infiltration, and effacement of thyroid follicles, while the background thyroidal tissue seemed to mimic lymphocytic thyroiditis without fibrosis. Immunohistochemistry revealed predominance of IgG4-secreting plasma cells among infiltrating lymphocytes independent of mass lesion or background tissue. In addition, the regional Delphian and paratracheal lymph nodes were swollen, histologically showing numerous IgG4-secreting plasma cell infiltrations in the interfollicular zone.

Conclusions

IgG4-related mass-forming thyroiditis, which may be an extremely rare but recognizable pattern of IgG4-related thyroiditis, may be distinguishable from Hashimoto and Riedel thyroiditis, Graves disease, and thyroidal carcinoma. In addition, the regional IgG4-related lymphadenopathy, also possibly misdiagnosed as metastatic thyroidal carcinoma, may be a newly recognized manifestation of IgG4-related thyroiditis.

Current perspectives on autoimmune pancreatitis and IgG4-related disease

IgG4-related disease (IgG4-RD) is a fibroinflammatory disorder recognized as a novel clinical entity with either synchronous or metachronous multi-organ involvement. Patients with IgG4-RD show diffuse or focal organ enlargement and mass-forming or nodular/thickened lesions with abundant infiltration of IgG4-positive plasmacytes and fibrosis, and such patients respond well to steroid treatment. It should be differentiated from mimics by a combination of serum IgG4 level, imaging features, and histopathological findings. The current first-line drug is corticosteroids, or rituximab in high-risk patients for steroid intolerance. Although relapse rates are high, standardized protocols for relapsed cases have not been approved yet. Based on genetic factors, disease-specific or -related antigens, abnormal innate and adaptive immunity may be involved, although the precise pathogenic mechanism and long-term outcome still remain unclear.

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.

Genes and pathways associated with the occurrence of malignancy in benign lymphoepithelial lesions

There is increasing evidence concerning the occurrence of malignant lymphoma among people suffering from Mikulicz disease, also termed benign lymphoepithelial lesion (BLEL) and immunoglobulin G4-associated disease. However, the underlying molecular mechanism of the malignant transformation remains unclear. The present study aimed to investigate the gene expression profile between BLEL and malignant lymphoepithelial lesion (MLEL) conditions using tissue microarray analysis, to identify genes and pathways which may be associated with the risk of malignant transformation. Comparing gene expression profiles between BLEL tissues (n=13) and MLEL (n=14), a total of 1,002 differentially expressed genes (DEGs) were identified including 364 downregulated and 638 upregulated DEGs in BLEL. The downregulated DEGs in BLEL were frequently associated with immune-based functions, immune cell differentiation, proliferation and survival, and metabolic functions, whereas the upregulated DEGs were primarily associated with organ, gland and tissue developmental processes. The B cell receptor signaling pathway, the transcription factor p65 signaling pathway, low affinity immunoglobulin γ Fc region receptor II-mediated phagocytosis, the high affinity immunoglobulin ε receptor subunit γ signaling pathway and Epstein-Barr virus infection, and pathways in cancer, were the pathways associated with the downregulated DEGs. The upregulated DEGs were associated with three pathways, including glutathione metabolism, salivary secretion and mineral absorption pathways. These results suggested that the identified signaling pathways and their associated genes may be crucial for understanding the molecular mechanisms underlying malignant transformation from BLEL, and they may be considered to be markers for predicting malignancy among the BLEL group.

Clinical features of IgG4-related periaortitis/periarteritis based on the analysis of 179 patients with IgG4-related disease: a case-control study

BACKGROUND

Immunoglobulin G4-related disease (IgG4-RD) is a newly recognized systemic condition characterized by high serum immunoglobulin G4 (IgG4) concentration and IgG4-bearing plasma cell infiltration in affected organs. Although it has become evident that IgG4-RD also involves the systemic aortic/arterial system, the precise details of this condition remain unclear. The present study sought to clarify the clinical features of IgG4-related periaortitis/periarteritis.

METHODS

Among 223 patients with IgG4-RD, 179 (131 male, median onset age 67 years) were recruited for this study. Periaortitis/periarteritis was defined as vessel wall thickness with circumferential enhancement on contrast-enhanced computed tomography.

RESULTS

Periaortitis/periarteritis was identified in 65 (36.3%; 53 male) of 179 IgG-RD patients. The distribution of IgG4-related periaortitis/periarteritis could be broadly classified into five types, with the most prevalent Type 2 (44.6%) being localized at the infra-renal artery portion of the abdominal aorta and continuing to the iliac arteries. The infra-renal artery region of the abdominal aorta was most frequently involved (>80%) among IgG4-related periaortitis/periarteritis cases. Comparisons of clinical parameters between IgG4-RD patients with and without periaortitis/periarteritis revealed significantly higher propensities for older IgG4-RD onset age and highly active disease state featuring elevated serum IgG, IgG4, circulating immune complex, and soluble interleukin-2 receptor. All patients showed improvement of wall thickening after steroid therapy, although nine patients (20.9%) exhibited worsening of luminal dilatation. The main risk factor for this manifestation was prior luminal dilatation according to multivariate analysis.

CONCLUSION

IgG4-related periaortitis/periarteritis predominantly occurred at the infra-renal artery portion of the abdominal aorta, affected older IgG4-RD onset patients, and was prevalent in highly active disease states. As reported previously, the main risk factor for worsening luminal dilation after corticosteroid therapy was the existence of luminal dilation beforehand.

Immunoglobulin G4-Related Thyroid Diseases

Immunoglobulin G4-related disease (IgG4-RD) is a new disease category involving many organ systems, including the endocrine system in general and the thyroid in particular. Since an initial association was made between hypothyroidism and autoimmune (IgG4-related) pancreatitis, more forms of IgG4-related thyroid disease (IgG4-RTD) have been recognized. Four subcategories of IgG4-RTD have so far been identified: Riedel thyroiditis (RT), fibrosing variant of Hashimoto thyroiditis (FVHT), IgG4-related Hashimoto thyroiditis, and Graves disease with elevated IgG4 levels. Although a male predominance is seen for IgG4-RD in general, RT and FVHT have a female preponderance. The pathogenesis of IgG4-RD is not completely understood; however, genetic factors, antigen-antibody reactions, and an allergic phenomenon have been described. Diagnosis of IgG4-RD requires a combination of clinical features, serological evidence, and histological features. Histology is the mainstay of diagnosis, with IgG4 immunostaining. Although serum IgG4 levels are usually elevated in IgG4-RD, raised serum IgG4 is neither necessary nor adequate for diagnosis. Imaging supports the diagnosis and is a useful tool in disease monitoring. Management of IgG4-RTD is both medical and surgical. Steroids are the first-line treatment and may produce a swift response. Tamoxifen and rituximab are second-line agents used in steroid-resistant patients. Surgical debulking is carried out in RT solely as a procedure to relieve obstruction. Other endocrine associations described with IgG4-RD are hypophysitis and Hashimoto encephalopathy. IgG4-RTD is an uncommon disease entity, and prompt diagnosis and treatment can improve outcomes.

IgG4-Related Lung Disease Associated with Usual Interstitial Pneumonia

We report a case of immunoglobulin(Ig)G4-related disease with the radiologic and histopathological manifestations resembling usual interstitial pneumonia (UIP). The patient was a 62-year-old man who presented with progressive dyspnea of insidious onset. High resolution computed tomography of the chest showed lower-lobe predominant peripheral reticulation and traction bronchiectasis but no honeycomb change. Microscopic examination of the surgical lung biopsy showed characteristic features of UIP including architectural distortion by fibrosis with peripheral and paraseptal accentuation, scattered fibroblast foci and microscopic honeycomb change. In addition there were prominent multifocal lymphoplasmacytic infiltrates with a marked increase of IgG4-positive plasma cells (79 per high power field in hot spots) and high IgG4/IgG ratio (up to 67%). The serum IgG4 level was elevated at 760 mg/dl (reference range 9-89), with normal levels for the other IgG subclasses and negative serologic markers for autoimmune diseases. The patient’s symptoms improved significantly with oral corticosteroid treatment.

Association Between Immunoglobulin G4-related Disease and Malignancy within 12 Years after Diagnosis: An Analysis after Longterm Followup

OBJECTIVE

Because it is uncertain whether immunoglobulin G4-related disease (IgG4-RD) is associated with malignancy, we evaluated the incidence of cancer development in a large cohort of patients with IgG4-RD.

METHODS

The study enrolled 158 patients diagnosed as having IgG4-RD between 1992 and 2012. We calculated the standardized incidence ratio (SIR) and cumulative rate of malignancies in this group and searched for risk factors associated with the occurrence of tumors.

RESULTS

A total of 34 malignancies were observed in the patients with IgG4-RD over a mean followup period of 5.95 ± 4.48 years. The overall SIR of malignancies was 2.01 (95% CI 1.34-2.69). The SIR of patients who exhibited a tumor within 1 year after IgG4-RD diagnosis was 3.53 (95% CI 1.23-5.83), while that of subjects forming a malignancy in subsequent years was 1.48 (95% CI 0.99-1.98). The cumulative rate of malignancy development was significantly higher in patients with IgG4-RD within 12 years after diagnosis than in the Japanese general population. Comparable results were obtained for an autoimmune pancreatitis subgroup. The serum concentrations of several disease activity markers at diagnosis were significantly higher in patients with malignancies than in those without.

CONCLUSION

We identified a close association between IgG4-RD and malignancy formation within 12 years after diagnosis, particularly during the first year. An active IgG4-RD state is presumed to be a strong risk factor for malignancy development.

Effectiveness of imaging modalities for screening IgG4-related dacryoadenitis and sialadenitis (Mikulicz's disease) and for differentiating it from Sjögren's syndrome (SS), with an emphasis on sonography

INTRODUCTION

The aim of this study was to clarify the effectiveness of various imaging modalities and characteristic imaging features in the screening of IgG4-related dacryoadenitis and sialadenitis (IgG4-DS), and to show the differences in the imaging features between IgG4-DS and Sjögren's syndrome (SS).

METHODS

Thirty-nine patients with IgG4-DS, 51 with SS and 36 with normal salivary glands were enrolled. Images of the parotid and submandibular glands obtained using sonography, 2-[(18)F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT), computed tomography (CT) and magnetic resonance imaging (MRI) were retrospectively analyzed. Six oral and maxillofacial radiologists randomly reviewed the arranged image sets under blinded conditions. Each observer scored the confidence rating regarding the presence of the characteristic imaging findings using a 5-grade rating system. After scoring various findings, diagnosis was made as normal, IgG4-DS or SS, considering all findings for each case.

RESULTS

On sonography, multiple hypoechoic areas and hyperechoic lines and/or spots in the parotid glands and obscuration of submandibular gland configuration were detected mainly in patients with SS (median scores 4, 4 and 3, respectively). Reticular and nodal patterns were observed primarily in patients with IgG4-DS (median score 5). FDG-PET/CT revealed a tendency for abnormal (18)F-FDG accumulation and swelling of both the parotid and submandibular glands in patients with IgG4-DS, particularly in the submandibular glands. On MRI, SS had a high score regarding the findings of a salt-and-pepper appearance and/or multiple cystic areas in the parotid glands (median score 4.5). Sonography showed the highest values among the four imaging modalities for sensitivity, specificity and accuracy. There were significant differences between sonography and CT (p = 0.0001) and between sonography and FDG-PET/CT (p = 0.0058) concerning accuracy.

CONCLUSIONS

Changes in the submandibular glands affected by IgG4-DS could be easily detected using sonography (characteristic bilateral nodal/reticular change) and FDG-PET/CT (abnormal (18)F-FDG accumulation). Even inexperienced observers could detect these findings. In addition, sonography could also differentiate SS. Consequently, we recommend sonography as a modality for the screening of IgG4-DS, because it is easy to use, involves no radiation exposure and is an effective imaging modality.

Clinicopathological characteristics of immunoglobulin G4-related sialadenitis

Introduction

Immunoglobulin G4-related disease (IgG4-RD) is a newly recognized fibro-inflammatory condition. Forty-two cases with immunoglobulin G4-related sialadenitis (IgG4-RS) confirmed by histopathological and immunohistochemical assessment were studied to clarify the clinicopathologic characteristics of the salivary glands involved in IgG4-RS, especially the relationship between the histopathologic features and function of salivary glands or serum levels of IgG4.

Methods

Clinical, serologic, imaging and histopathological data of these cases were analyzed. CT volumes of submandibular, parotid, and lacrimal glands were calculated. The saliva flow rate was measured. Scintigraphy with 99mTc-pertechnetate was undertaken in 31 cases, and the concentration index (CI) and secretion index (SI) was calculated. Relationships between fibrosis severity and salivary gland function or serum IgG4 levels were analyzed.

Results

The first symptom was swelling of bilateral submandibular or lacrimal glands. Physical examination showed multiple bilateral major salivary glands (including sublingual and accessory parotid glands) and lacrimal glands were enlarged in IgG4 RS. Multiple enlarged cervical lymph nodes were noted in 30 patients. Saliva flow at rest was lower than normal in 34 cases; stimulated saliva flow was lower than normal in 15 cases. Secretory function was reduced more severely in the submandibular glands than in the parotid glands. Serum levels of IgG4 were elevated in 95.2% of cases and 78.6% patients had increased IgE levels. Serum IgG4 level was higher and saliva secretion lower as glandular fibrosis increased.

Conclusions

Prominent changes in the morphology, histology, immunohistochemistry and secretion of the major salivary glands of IgG4-RS patients were accompanied by involvement of the lacrimal glands and cervical lymph nodes. Elevated IgE, allergic history, eosinophil infiltration suggest allergic reactions as a potential pathogenesis of IgG4-RS. Severity of glandular fibrosis correlated with salivary function and serum levels of IgG4.

Organ Correlation in IgG4-Related Diseases

IgG4-related disease (IgG4-RD) is a potentially multiorgan disorder. In this study, clinical and serological features from 132 IgG4-RD patients were compared about organ correlations. Underlying pathologies comprised autoimmune pancreatitis (AIP) in 85 cases, IgG4-related sclerosing cholangitis (IgG4-SC) in 12, IgG4-related sialadenitis (IgG4-SIA) in 56, IgG4-related dacryoadenitis (IgG4-DAC) in 38, IgG4-related lymphadenopathy (IgG4-LYM) in 20, IgG4-related retroperitoneal fibrosis (IgG4-RF) in 19, IgG4-related kidney disease (IgG4-KD) in 6, IgG4-related pseudotumor (IgG4-PT) in 3. Sixty-five patients (49%) had multiple IgG4-RD (two affected organs in 36 patients, three in 19, four in 8, five in 1, and six in 1). Serum IgG4 levels were significantly higher with multiple lesions than with a single lesion (P<0.001). The proportion of association with other IgG4-RD was 42% in AIP, the lowest of all IgG4-RDs. Serum IgG4 level was lower in AIP than in other IgG4-RDs. Frequently associated IgG4-RDs were SIA (25%) and DAC (12%) for AIP; AIP (75%) for IgG4-SC; DAC (57%), AIP (38%) and LYM (27%) for IgG4-SIA; AIP (26%) and LYM (26%) for IgG4-DAC; SIA (75%), DAC (50%) and AIP (45%) for IgG4-LYM; SIA (58%), AIP (42%) and LYM (32%) for IgG4-RF; AIP (100%) and SIA (67%) for IgG4-KID; and DAC (67%) and SIA (67%) for IgG4-PT. Most associated IgG4-RD lesions were diagnosed simultaneously, but IgG4-SIA and IgG4-DAC were sometimes identified before other lesions. About half of IgG4-RD patients had multiple IgG4-RD lesions, and some associations were seen between specific organs.

IgG4 related disease of the head and neck

IgG4 related disease of the head and neck region represents one of the more common manifestations of IgG4 related disease. Involvement of the submandibular and parotid glands, the orbit and thyroid represent some of the more common sites involved by IgG4 related disease. Eosinophilic angiocentric fibrosis, Mikulicz disease and Riedel thyroiditis are also members of the family of IgG4 related disease. Clinically, the disease is characterized by tumefactive lesions, often multicentric, that show a swift response to immunosuppressive therapy. An elevated serum IgG4 represents the only validated blood based biomarker. However, elevated serum IgG4 is detected in only half the patients with this disease. Histology continues to represent the gold standard for the diagnosis of IgG4 related disease: storiform-type fibrosis and obliterative phlebitis constitute characteristic features of this disease. A definitive diagnosis of IgG4 related disease also requires the presence of elevated numbers of IgG4 positive plasma cells as well as an IgG4 to IgG ratio of greater than 40 %. In isolation, elevated numbers of IgG4 positive plasma cells represents a non-specific feature, detected in a variety of other inflammatory as well as neoplastic diseases. Attention to the clinical context, histological features, as well as an elevated IgG4 to IgG ratio is critical to avoiding overdiagnosis of IgG4 related disease.

IgG4-related systemic disease mimicking renal pelvic cancer: a rare case

Background

Immunoglobulin G4–related disease (IgG4-RD) is a new clinical entity. Characteristic features of IgG4-RD are elevated serum IgG4 levels, infiltration of IgG4-positive cells, mass-forming lesions with fibrosis and good response to corticosteroids. The variable imaging features of IgG4-RD and the overlap with other differential diagnoses often pose a diagnostic challenge, as they frequently mimic malignant tumors or other inflammatory diseases in the abdomen.

Case presentation

A 54-year-old woman visited our hospital with left flank discomfort and palpebral edema. Computed tomography, magnetic resonance imaging, retrograde pyelography and positron emission tomography/computed tomography indicated renal pelvic cancer. However, after a left-sided nephroureteral cystectomy was performed, the mass was pathologically confirmed as an IgG4-related lesion. Her elevated serum IgG4 level and a past history of sicca complex supported the diagnosis of IgG4-RD.

Conclusions

It is critical to recognize the importance of laboratory examinations such as serum IgG4 level if a patient has a past history of rheumatic disease.

B-cell depletion attenuates serological biomarkers of fibrosis and myofibroblast activation in IgG4-related disease

OBJECTIVES

Fibrosis is a predominant feature of IgG4-related disease (IgG4-RD). B-cell depletion induces a prompt clinical and immunological response in patients with IgG4-RD, but the effects of this intervention on fibrosis in IgG4-RD are unknown. We used the enhanced liver fibrosis (ELF) score to address the impact of rituximab on fibroblast activation. The ELF score is an algorithm based on serum concentrations of procollagen-III aminoterminal propeptide, tissue inhibitor of matrix metalloproteinase-1 and hyaluronic acid.

METHODS

Ten patients with active, untreated IgG4-RD were enrolled. ELF scores were measured and correlated with the IgG4-RD Responder Index, serum IgG4, circulating plasmablasts and imaging studies. Through immunohistochemical stains for CD3, CD20, IgG4 and α-smooth muscle actin, we assessed the extent of the lymphoplasmacytic infiltration and the degree of fibroblast activation in one patient with tissue biopsies before and after rituximab.

RESULTS

The ELF score was increased in patients with IgG4-RD compared with healthy controls (8.3±1.4 vs 6.2±0.9; p=0.002) and correlated with the number of organs involved (R(2)=0.41; p=0.04). Rituximab induced significant reductions in the ELF score, the number of circulating plasmablasts and the IgG4-RD Responder Index (p<0.05 for all three parameters). Rituximab reduced both the lymphoplasmacytic infiltrate and myofibroblast activation. IgG4-RD relapse coincided with recurrent increases in the ELF score, indicating reactivation of collagen deposition.

CONCLUSIONS

The ELF score may be a clinically useful indicator of active fibrosis and the extent of disease in IgG4-RD. B-cell depletion has the potential to halt continued collagen deposition by attenuating the secretory phenotype of myofibroblasts in IgG4-RD lesions.

Recent advances in the concept and pathogenesis of IgG4-related disease in the hepato-bilio-pancreatic system

Recent studies have proposed nomenclatures of type 1 autoimmune pancreatitis (AIP) (IgG4-related pancreatitis), IgG4-related sclerosing cholangitis (IgG4-SC), IgG4-related cholecystitis, and IgG4-related hepatopathy as IgG4-related disease (IgG4-RD) in the hepato-bilio-pancreatic system. In IgG4-related hepatopathy, a novel concept of IgG4-related autoimmune hepatitis (AIH) with the same histopathological features as AIH has been proposed. Among organs involved in IgG4-RD, associations with pancreatic and biliary lesions are most frequently observed, supporting the novel concept of “biliary diseases with pancreatic counterparts.” Targets of type 1 AIP and IgG4-SC may be periductal glands around the bile and pancreatic ducts. Based on genetic backgrounds, innate and acquired immunity, Th2-dominant immune status, regulatory T (Treg) or B cells, and complement activation via a classical pathway may be involved in the development of IgG4-RD. Although the role of IgG4 remains unclear in IgG4-RD, IgG4-production is upregulated by interleukin 10 from Treg cells and by B cell activating factor from monocytes/basophils with stimulation of toll-like receptors/nucleotide-binding oligomerization domain-like receptors. Based on these findings, we have proposed a hypothesis for the development of IgG4-RD in the hepato-bilio-pancreatic system. Further studies are necessary to clarify the pathogenic mechanism of IgG4-RD.

IgG4- related disease: an orphan disease with many faces

Immunoglobulin G4- related disease (IgG4-RD) is a rare systemic fibro-inflammatory disorder (ORPHA284264). Although patients have been described more than 100 years ago, the systemic nature of this disease has been recognized in the 21^st century only. Type 1 autoimmune pancreatitis is the most frequent manifestation of IgG4-RD. However, IgG4-RD can affect any organ such as salivary glands, orbits, retroperitoneum and many others. Recent research enabled a clear clinical and histopathological description of IgG4-RD. Typically, lymphoplasmacellular inflammation, storiform fibrosis and obliterative phlebitis are found in IgG4-RD biopsies and the tissue invading plasma cells largely produce IgG4. Elevated serum IgG4 levels are found in many but not all patients. Consequently, diagnostic criteria for IgG4-RD have been proposed recently. Treatment is largely based on clinical experience and retrospective case series. Glucocorticoids are the mainstay of therapy, although adjunctive immunosuppressive agents are used in relapsing patients. This review summarizes current knowledge on clinical manifestations, pathophysiology and treatment of IgG4-RD.

Clinical relevance of Küttner tumour and IgG4-related dacryoadenitis and sialoadenitis

Objectives

Küttner tumour (KT), so-called chronic sclerosing sialoadenitis, is characterised by concomitant swelling of the submandibular glands secondary to strong lymphocytic infiltration and fibrosis independent of sialolith formation. However, recent studies have indicated that some patients with KT develop high serum levels of IgG4 and infiltration of IgG4-positive plasma cells, namely IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS), so-called Mikulicz's disease. The aim of this study was to clarify the clinical and pathological associations between KT and IgG4-DS.

Materials and Methods

Fifty-four patients pathologically diagnosed with KT or chronic sialoadenitis were divided into two groups according to the presence or absence of sialolith (KT-S (+) or KT-S (−), respectively).

Results

There were no significant differences in the clinical findings, including the mean age, sex and disease duration, between the two groups. All patients in the KT-S (+) group showed unilateral swelling without infiltration of IgG4-positive plasma cells or a history of other IgG4-related diseases (IgG4-RD), while those in the KT-S (−) group showed bilateral swelling (37.5%), strong infiltration of IgG4-positive plasma cells (87.5%) and a history of other IgG4-RD (12.5%).

Conclusions

These results suggest an association between the pathogeneses of KT-S (−) and IgG4-DS, but not KT-S (+).

Autoimmune pancreatitis: pathogenesis, latest developments and clinical guidance

Recently, autoimmune pancreatitis has been classified into two subtypes. Type 1 is related to immunoglobulin G4 and type 2 is related to granulocytic epithelial lesions, but pathogenetic mechanisms in both still remain unclear. Apart from type 2 autoimmune pancreatitis, the pathological features of type 1 autoimmune pancreatitis with increased serum immunoglobulin G4/immunoglobulin E levels, abundant infiltration of immunoglobulin G4+plasmacytes and lymphocytes, fibrosis, and steroid responsiveness are suggestive of abnormal immunity such as allergy or autoimmunity. Although pathophysiological conditions seem to be different in each, both respond well to steroid drugs. After remission, the patients with type 1 autoimmune pancreatitis show high relapse rates (30-50% within 6-12 months), whereas those with type 2 autoimmune pancreatitis seldom relapse. After remission, the steroid maintenance therapy and therapeutic strategy for relapsing patients with type 1 is different among local expertise. In this paper, recent advances in pathogenesis and clinical guidance for therapy are discussed.

The first case of IgG4-related disease in Italy

BACKGROUND

Recently, Mikulicz's disease has been defined as an IgG-4 related disease, a systemic condition, where the hallmark pathology findings are lymphoplasmacytic infiltrates, immunoglobulin (Ig)G4-positive plasma cells, modest tissue eosinophilia, and intense fibrosis.

CASE

We present a case of 63-year-old man who showed epigastralgia and elevated serum lipase levels. Computed tomography of the abdomen revealed a bulky mass of the pancreas, so he underwent bilious-digestive anastomosis, and biopsy of the pancreas revealed massive infiltration of lymphocytes and plasma cells. The patient was therefore diagnosed with sclerosing chronic pancreatitis (Kuttner's tumour). After one year, the patient began to exhibit signs of "sicca syndrome", and at the same time, he demonstrated progressive renal failure. Immunological tests showed hypocomplementemia, and the renal biopsy specimen demonstrated interstitial inflammation, in which infiltrate was composed of lymphocytes, while infiltrating plasma cells showed immunoreactivity to IgG4. Sialography revealed severe involvement of the salivary glands, and Schirmer's test resulted positive.

CONCLUSIONS

Here, we report successful treatment of the first case in Italy of a patient with hypocomplementemic tubulointerstitial nephritis in IgG4-related disease.

Orbital Manifestations of Immunoglobulin G4-Related Disease in Bilateral Lacrimal Glands, Optic Nerves, Trigeminal Nerves, and Maxillary Sinuses

Immunoglobulin G4 (IgG4)-related disease is characterised by numerous aggregates of IgG4-positive plasma cells in multiple organs. We report two patients who had bilateral proptosis associated with extensive inflammation bilaterally in lacrimal glands, optic nerves, trigeminal nerves, and maxillary sinuses. The patients were treated as idiopathic orbital inflammation syndrome with corticosteroid pulse therapy. As symptoms relapsed upon tapering, a reassessment of immunohistochemical stains of the lacrimal glands confirmed the diagnosis of IgG4-related disease. During 2 years of follow-up, the inflammation regressed spontaneously without any medical treatment in the first patient; however, inflammation in the other patient progressed, and he lost his vision. The extensive orbital involvement, characteristic pathological findings, and slowly progressive clinical course might help practitioners differentiate orbital IgG4-related disease from presumed idiopathic orbital inflammation syndrome.

Concomitant occurrence of IgG4-related pleuritis and periaortitis: a case report with review of the literature

IgG4-related sclerosing disease is an established disease entity with characteristic clinicopathological features. Some recent reports have demonstrated that this disease can occur in the respiratory system including the pleura. Herein, we describe the first documented case of concomitant occurrence of IgG4-related pleuritis and periaortitis. A 71-year-old Japanese female with a history of essential thrombocythemia presented with persistent cough and difficulty in breathing. Computed tomography demonstrated thickening of the right parietal pleura, pericardium, and periaortic tissue and pleural and cardiac effusions. Histopathological study of the surgical biopsy specimen of the parietal pleura revealed marked fibrous thickening with lymphoplasmacytic infiltration. Phlebitis was noted, however, only a few eosinophils had infiltrated. Immunohistochemical study revealed abundant IgG4-positive plasma cell infiltration and high ratio of IgG4-/IgG-positive plasma cells (84%). Therefore, a diagnosis of IgG4-related pleuritis was made with consideration of the elevated serum IgG4 level (684 mg/dL). Recently, the spectrum of IgG4-related sclerosing disease has expanded, and this disease can occur in the pleura, pericardium, and periaortic tissue. Although histopathological analysis of the pericardium and periaortic tissue was not performed in the present case, it was suspected that thickening of the pericardium and periaortic tissue was clinically due to IgG4-related sclerosing disease. Our clinicopathological analyses of IgG4-related pleuritis and pericarditis reveal that this disease can present as dyspnea and pleural and pericardial effusion as seen in the present case, therefore, it is important to recognize that IgG4-related sclerosing disease can occur in these organs for accurate diagnosis and treatment.