[Clinical and laboratory characteristics of IgG4-realated disease and its diagnostic algorithm]

AIM

to propose diagnostic algorithm of IgG4-related disease (IgG4-RD).

MATERIALS AND METHODS

One center retrospective research. 52 pts with IgG4-RD were included. The diagnosis was proved histologically and immunohistochemically. 48 out of 52 pts received treatment. Treatment included one of the following schemes (along with low oral glucocorticoids): rituximab monotherapy, cyclophosphamide monotherapy or their combination.

RESULTS

The mean age was 47.4±5.9 years, the mean age of the disease onset was 43.9±16.0 years. Median time before the diagnosis was 24 months. The most often sites of IgG4-RD were lacrimal (63.5%), salivary (46.2%) glands, lungs (48%), lymph nodes (34.6%) and retroperitoneum (17.3%). In clinical picture the leading complain was organ enlargement, but not its dysfunction. Pain was characteristic for retroperitoneum localization. In 56.8% of pts with IgG4-related syalo - and/or dacryoadenitis there was association with ear - nose - throat organs affection. In 4 pts (7.7%) IgG4-RD was combined with some malignant disease, including MALT-lymphoma of lacrimal glands. Irreversible organ damage as an IgG4-RD outcome had 15.4% of pts. The main laboratory markers of IgG4-RD were ESR elevation (38.5%), blood eosinophilia (9.6%), immunological disturbances (serum total IgG and IgG4 elevation, IgE elevation, antinuclear antibodies, rheumatoid factor detection, hypocomplementemia). Serum IgG4 level >1.35 g/l was elevated in 88% of pts and correlated with the number of affected organs (Spearman correlation coefficient 0.39, Student's test, р=0.0056). Monoclonal serum secretion and B-cell clonality in the tissue was detected in 4 (23.5%) out of 17 pts, but not all of them had both signs.

CONCLUSION

Based on the analysis of clinical and laboratory characteristics of IgG4-RD a diagnostic algorithm was proposed that enhances the detection and examination of the patients with suspected IgG4-RD.

Immunoglobulin G4-related hypertrophic pachymeningitis: A case-oriented review

Objective

Meningeal involvement in Immunoglobulin G (IgG)-4-related disease is rare and only described in case reports and series. Because a review into the disease is lacking, we present 2 cases followed by a literature review of IgG4-related hypertrophic pachymeningitis (IgG4-HP).

Methods

Two IgG4-HP cases were reported, one involving the spinal cord and responding to surgical management and a second involving the brain and responding to Rituximab therapy. We then review clinical cases and case-series of histologically proven IgG4-HP that were published in the PubMed-NCBI database.

Results

Forty-two case reports and 5 case-series were studied (60 patients, 20 women). The median age was 53. Eighteen patients had systemic involvement and 24 had single-organ IgG4-HP. Fifty-five percent of patients had an elevated serum IgG4. Treatment was surgical in 20/53 cases. Steroid therapy and immunosuppressors were effective in 85% and more than 90% of the cases, respectively. The rate of disease relapse was 42.1% after steroid therapy was discontinued.

Discussion/conclusion

IgG4-HP is characterized by the lack of extra-neurologic organ-involvement and systemic signs. Histopathologic studies should be performed as it is crucial for diagnosis because serum markers are rarely informative. 18F-FDG positon tomography can be useful to characterize systemic forms. There is no specific CSF marker for IgG4-HP and the diagnostic value of CSF IgG4 levels needs to be studied with larger samples. We provide a treatment algorithm for IgG4-HP. Such treatment strategies rely on early surgery, steroids, and early immunosuppressive therapy to prevent neurologic complications.

Hypophysitis in the era of immune checkpoint inhibitors and immunoglobulin G4-related disease

INTRODUCTION

Hypophysitis is a rare disorder, defined as inflammation of the pituitary gland that may result in pituitary enlargement and varying anterior and posterior pituitary hormonal deficits. It involves different histopathological subtypes and variable etiologies, with considerable overlap between classification systems. Histopathology is the gold standard diagnostic approach.

AREAS COVERED

In this article, we will review the major histopathological subtypes of hypophysitis with a special focus on immunoglobulin G4 (IgG4)-related hypophysitis and immune checkpoint inhibitor-induced hypophysitis, given their recent appearance and increasing incidence. We will summarize the similarities and differences between the different subtypes as it relates to epidemiology, pathogenesis, presentation, diagnosis, and management.

EXPERT OPINION

Hypophysitis is a heterogeneous and wide term used to describe different, possibly distinct diseases often with poorly understood pathogenesis. It involves a wide range of subtypes with certain differences in incidence rates, pathogenesis, and management. Management usually focuses on relieving the mass effect symptoms and replacing the deficient pituitary hormones. Spontaneous recovery is possible but recurrence is not uncommon.

New causes of hypophysitis

Hypophysitis is a rare entity characterized by inflammation of the pituitary gland and its stalk that can cause hypopituitarism and/or mass effect. Etiology can be categorized as primary or secondary to systemic disease, but may also be classified according to anatomical and hispathological criteria. Newly recognized causes of hypophysits have been described, mainly secondary to immunomodulatory medications and IgG4-related disease. Diagnosis is based on clinical, laboratory and imaging data, whereas pituitary biopsy, though rarely indicated, may provide a definitive histological diagnosis. For the clinician, obtaining a broad clinical and drug history, and performing a thorough physical examination is essential. Management of hypophysitis includes hormone replacement therapy if hypopituitarism is present and control of the consequences of the inflammatory pituitary mass (e.g. compression of the optic chiasm) using high-dose glucocorticoids, whereas pituitary surgery is reserved for those unresponsive to medical therapy and/or have progressive disease. However, there remains an unmet need for controlled studies to inform clinical practice.

IgG4-related disease can present as recurrent spontaneous hemothorax: a case report

Background

Immunoglobulin G4-related disease (IgG4-RD) encompasses a group of immune-mediated disorders that are gaining increasing recognition. Pulmonary presentations are common, with four types of patterns been described on radiography, including solid nodular, bronchovascular, ground glass opacities, and alveolar interstitial. Pleural thickening and pleural effusion have also been reported. However, there have been no reports of IgG4-RD that presents as spontaneous hemothorax.

Case presentation

A 61-year-old Chinese woman experienced recurrent right-sided chest pain and transient syncope. A significant decrease in her hemoglobin level and thick bloody pleural fluid demonstrated spontaneous hemothorax. The elevated serum IgG4 and histopathological analysis of the right pleura and intercostal lymph node specimens all supported the diagnosis of IgG4-RD in this patient. Further diagnostic evaluation did not reveal other causes for spontaneous hemothorax. She received steroids and no recurrent bleeding event occurred during a follow-up period of more than 1 year.

Conclusion

Recurrent spontaneous hemothorax can be a rare manifestation of IgG4-RD, with pleural involvement as the most probable mechanism.

IgG4-related hypophysitis in patients with autoimmune pancreatitis

PURPOSE

IgG4-related disease involves various organs including the pituitary and pancreas. The prevalence of IgG4-related hypophysitis is relatively rare compared with IgG4-related pancreatitis (autoimmune pancreatitis). Although several cases demonstrating both autoimmune pancreatitis and hypophysitis have been reported, the prevalence of IgG4-related hypophysitis in patients with autoimmune pancreatitis remains unknown. This study aimed at screening for IgG4-related hypophysitis to accurately determine its prevalence in patients with autoimmune pancreatitis.

METHODS

In this cohort study, we screened IgG4-related hypophysitis via pituitary magnetic resonance imaging (MRI) and endocrinological examination in 27 patients who were undergoing follow-up for autoimmune pancreatitis at Kobe University Hospital between 2014 and 2018.

RESULTS

Among 27 patients with autoimmune pancreatitis, 5 patients exhibited morphological abnormalities in the pituitary (18.5%). Among them, one patient (3.7%) met the criteria for hypophysitis with an enlarged pituitary and stalk concomitant with hypopituitarism. After glucocorticoid treatment, the enlarged pituitary shrank and became empty sella during the clinical course. Four patients (14.8%) revealed empty sella without obvious pituitary dysfunction. Four of 5 patients with morphological pituitary abnormalities showed multiple organ involvement in addition to pancreatic and pituitary involvement. Accordingly, multiple organ involvement was more prevalent in patients with morphological pituitary abnormalities (80%) compared to those without (48%).

CONCLUSIONS

Although a large-scale study is necessary to validate these results, these data suggest that the prevalence of hypophysitis in patients with autoimmune pancreatitis may be underestimated. Based on our findings, we recommend screening for hypophysitis, especially in patients with multiple organ involvement.

Retroperitoneal fibrosis associated with orbital pseudotumor without evidence of IgG4: A case report with review of literature

Retroperitoneal fibrosis (RPF) is a rare disease characterized by chronic inflammation and periaortic fibrosis that affects retroperitoneal structures and often entraps the ureters. The idiopathic form has an incidence of 0.1-1.3/100,000 person-years. A substantial percentage of patients with idiopathic retroperitoneal fibrosis (IRF), as well as patients with orbital pseudotumor, is associated with IgG4-related disease (IgG4-RD). It is not clear what percentage of IRF is related to the spectrum of the IgG4-RD or if both represent different stages of the same disease (especially in those cases with extra-retroperitoneal involvement). Histopathological features such as storiform fibrosis, obliterative phlebitis and tissue infiltration of IgG4-positive plasma cells (ratio IgG4+/IgG higher than 0.4) are essential to identify this association. Extra-retroperitoneal manifestations are often presented among patients with IgG4-related RPF. About 90% of cases of IRF have a good prognosis, with adequate response to treatment. We report a case of a 59-year-old woman with history of past occupational asbestos exposure and smoking habit. She was diagnosed with RPF, periaortitis and orbital pseudotumor, without histopathologic or serologic features of IgG4- related disease. This could be related to the fact that the biopsy was done in a place with scarce inflammatory activity but high fibrosis. We want to emphasize the usual need to perform several biopsies or to be guided by positron emission tomography (PET-CT) in order to achieve a histopathological confirmation. Our case differs from the main IgG4 international cohorts in the involvement of the retroperitoneum, aorta and eye, whereas the usual involvement includes liver, pancreas, lymph nodes and salivary glands. Our patient had lower IgG4 serum levels than those described in the international cohorts. However, they were similar to those of the Spanish population.

A Series of Biopsy-proven Patients with Immunoglobulin G4-related Neurological Disease

Aim:

To study the clinical presentation, radiological findings, and therapy responsiveness of patients with biopsy-proven immunoglobulin G4 (IgG4)-related neurological disease.

Methods:

The study was conducted between January 2016 and March 2018 from the Department of Neurology and Pathology of Nizam's Institute of Medical Sciences. Patients with neurological symptoms and biopsy suggestive of IgG4-related disease (IgG4-RD) were included. These patients were studied for their demographic pattern and clinical presentation. The presence of serological markers such as vasculitic profile and IgG4 levels was analyzed. Radiological findings were studied in detail. Therapeutic agents used and the response to therapy were assessed.

Results:

There were six cases with IgG4-related neurological disease which were all hypertrophic pachymeningitis. The age ranged from 35 to 64 (mean = 46) years. The clinical presentation was acute in one, subacute in two, and chronic in three patients. The most common presenting symptom was headache (4), followed by gait and/or urinary disturbances (2), paraparesis (1), and diplopia (1). IgG4 levels were elevated in 50% of them. Pseudotumor-like mass and sinovenous thrombosis, not described previously, were seen in one patient. All the patients were treated with oral or intravenous steroid. Rituximab was given in three patients; azathioprine was the steroid-sparing agent in one patient. Those with acute/subacute onset of presentation had an excellent response to steroids. All the patients with a chronic duration of their symptoms received empirical anti-tuberculous therapy before a definitive diagnosis of Ig G4-RD was made.

Conclusions:

The characterization of patients with IgG4-related neurological disease based on the understanding of the clinical spectrum increases the confidence in the clinician to resort to early immunosuppression, thereby having prognostic implications.

Clinical Manifestations and Long-term Outcomes of IgG4-Related Kidney and Retroperitoneal Involvement in a United Kingdom IgG4-Related Disease Cohort

INTRODUCTION

IgG4-related disease (IgG4-RD) is a relapsing multisystem fibro-inflammatory disease, which may involve the kidney (IgG4-related kidney disease [IgG4-RKD]) and retroperitoneum (IgG4-related retroperitoneal fibrosis [IgG4-RPF]). The aim of this study was to describe IgG4-RKD and IgG4-RPF in the United Kingdom.

METHODS

We conducted a retrospective observational study of patients with IgG4-RKD and IgG4-RPF in a multicenter IgG4-RD cohort. Data were collected through review of medical records. We describe clinical parameters at baseline, histological and radiological findings, treatment, and patient outcomes.

RESULTS

Of 154 patients with IgG4-RD, 14 (9.1%) had IgG4-RKD, 10 (6.5%) had IgG4-RPF, and 4 (2.6%) had both. Patients were aged 58.2 ± 14.2 years, and 26 (92.9%) were male. Creatinine at presentation was worse in those with intrinsic renal disease (229 μmol/l vs. 110 μmol/l; P = 0.0076). Serum IgG4 was elevated in the majority of patients (87.5%), and hypocomplementemia was present in half of those with IgG4-RKD. Fifteen patients underwent renal biopsy; tubulointerstitial nephritis with abundant IgG4+ plasma cells was the most common finding (n = 14; 93.3%), and 4 (26.7%) patients had membranous nephropathy. Most patients (89.3%) were treated with corticosteroids, and 4 (16.0%) with additional azathioprine as initial management. Thirteen patients (46.4%) relapsed over 60 ± 48 months of follow-up, at median 18 (12-36) months after renal/RPF diagnosis; 61.5% of relapses were in the kidney. Renal function deteriorated in 5 patients (20.8%), including 2 (8.3%) who reached end-stage renal disease (ESRD).

CONCLUSION

IgG4-RKD and IgG4-RPF represent major organ manifestations of IgG4-RD, and should be identified early with prompt treatment to prevent progression to ESRD.

Head and neck immunoglobulin G4 related disease: systematic review

BACKGROUND

Immunoglobulin G4 related disease is a recently described systemic syndrome. The head and neck region is the second most common site for presentation after the pancreas.

METHODS

PubMed and the Cochrane Library were searched from 1995 to July 2017 for all the studies on immunoglobulin G4 related disease diagnosed in the head and neck compartment. Patient-specific data were extracted and basic statistical analysis was performed.

RESULTS

Ninety-one patients were identified. Treatment was specified in 76 patients. Twenty patients received surgical treatment, eight of them in association with medical therapy. Fifty-six patients received medical treatment. The disease recurred in 25 per cent of patients treated with surgical treatment alone, in 3.6 per cent of patients treated with medical treatment alone and in 12.5 per cent of patients treated with both. All medical treatment protocols contained high-dose corticosteroids.

CONCLUSION

Early and correct diagnosis can avoid unnecessary surgical treatment, and glucocorticoid therapy can improve the long-term prognosis.

New insights into the pathophysiology of IgG4-related disease and markers of disease activity

INTRODUCTION

Recently, IgG4-related disease (IgG4-RD) has become a well-recognized clinical entity, although its causes are still not well understood. The pathophysiology of IgG4-RD has been reported from a variety of aspects. Areas covered: In this review, we outline a number of recent advances in our understanding of the pathogenesis of IgG4-RD, divided according to acquired immunology and innate immunology and other topics. Furthermore, we also focus on some proposed markers of disease activity of IgG4-RD. Expert commentary: One striking advance made recently is the identification of novel autoantigens of IgG4-RD. At the onset of IgG4-RD, various T cell side factors such as Tfh, Th2 cells are at work, in addition to B cell side factors like plasmablasts and plasma cells, and innate immunology via TLR and M2 macrophages. The efficacy of B cell depletion therapy using rituximab has been reported, with the establishment of steroid-sparing therapies targeting other molecules also anticipated.

IgG4-Related Disease, the Malignancy Mimicker: Case Series from Bahrain

IgG4-related disease is an evolving immune-mediated condition. The hallmark of this condition is IgG4(+) plasma cells infiltration of the affected organs accompanied by a variable degree of fibrosis and occasionally elevated serum IgG4 level. It links many conditions that were once recognized as isolated unrelated idiopathic single organ disorders (e.g., autoimmune pancreatitis, Mikulicz syndrome, and retroperitoneal fibrosis) under one umbrella. It usually presents clinically as tumor-like swelling of the involved organs that can be misdiagnosed as neoplasia. In this case series, we present four cases that were considered as neoplasia but turned out to be IgG4-related disease, we demonstrate the protean manifestations of this condition and variable organs involvement, and we share our experience in using rituximab as the steroid sparing immunosuppressant agent to control this disease.

Primary hypophysitis and other autoimmune disorders of the sellar and suprasellar regions

The pituitary gland and the hypothalamus can be affected by autoimmune-mediated structural and functional disruption. These autoimmune-mediated diseases occur more commonly in females and are often found during pregnancy or in the post-partum period. Autoimmune diseases can either affect parts of the pituitary or hypothalamus, or can involve both sellar and suprasellar structures. Most of these cases comprise primary hypophysitis (PRH). Over the years, there has been a tremendous increase in the number of reported PRH cases and related disorders, including hypophysitis induced by immune checkpoint inhibitors. With this increasing data, more light is being shed on the spectrum of clinical presentations, biochemical and imaging abnormalities of these disorders. Regardless, these disorders are still relatively rare. The clinical presentation can vary vastly, based on the type of pituitary cell or the area of the suprasellar region affected. The severity can range from clinically silent disease to progressive and rapid deterioration and death, likely due to unrecognized central adrenal insufficiency. Although biopsy remains a gold standard for diagnosing these disorders, the current standard of practice is biochemical assessment for hormonal deficiencies and imaging studies. In several instances, these disorders spontaneously resolve, but medical or surgical intervention might be necessary to treat symptomatic disease. Due to the subtlety and a vast spectrum of clinical manifestations which could often be asymptomatic, and the rarity of the occurrence of these diseases in clinical practice, the diagnosis can be easily missed which could potentially lead to substantial morbidity or mortality. Therefore, it is crucial to have a strong clinical suspicion and pursue timely biochemical and imaging studies to initiate prompt treatment. In this article, we review the various autoimmune conditions that affect the sellar and suprasellar structures, their diagnostic approach and management of these disorders.

Thymic inflammatory pseudotumor with multilocular thymic cyst caused by immunoglobulin G4-related disease

A 44-year-old man was referred to our hospital after an anterior mediastinal tumor was noted on computed tomography during follow-up observation after left testicular seminoma resection. Chest computed tomography revealed an enhanced mass measuring 33 x 16 x 15 mm at the anterior mediastinum. Chest magnetic resonance imaging revealed high signal intensity on T2-weighted imaging, and F¹⁸  fluorodeoxyglucose-positron emission tomography showed a maximum standardized uptake of 12.45. Laboratory tests revealed no elevated tumor markers, except for mildly elevated interleukin-2. Based on these results, complete resection was performed under suspicion of a malignant tumor, mediastinal metastasis of seminoma, or malignant lymphoma. An extended thymectomy with partial merger pericardial resection was performed using a subxiphoid approach. Small nodules and multiple thymic cysts were observed the thymus in addition to the main mass. Microscopic examination of the tumor revealed fibrosis, lymphocyte infiltration with lymphoid follicular hyperplasia, and hyperplasia of the thymus. Numerous immunoglobulin G4 (IgG4)-positive plasma cells were found on immunohistochemical staining. The ratio of IgG4 to total IgG was approximately 60%. We ultimately diagnosed the patient with a thymic inflammatory pseudotumor with multilocular cyst caused by IgG4-related disease.

Immunoglobulin G4-Related Disease Mimicking an Anterior Mediastinal Tumor

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated collection of disorders that were once thought to be unrelated but are increasingly being recognized as a single entity. The tumor-like swelling of the involved organ, a storiform pattern of fibrosis, and a serologic elevation of IgG4 can lead to the diagnosis of IgG4-RD. The usual organs affected are the pancreas, biliary tract, and salivary and lacrimal glands. There have been few reports of intrathoracic cases, which usually have pulmonary lesions. We here report a case of IgG4-RD of the anterior mediastinum in the form of a mass, a rare entity, the second such patient described in the literature to date.

Neuro-surgical considerations for treating IgG4-related disease with rare spinal epidural compression

Background:

Immunoglobulin G4-related disease (IgG4-RD) is a group of distinct autoimmune disorders affecting nearly every organ system in the body. Although central nervous system involvement is quite rare, it may present as hypertrophic pachymeningitis more frequently affecting the brain than the spine. In this study, we provide a case of spinal IgG4-RD pseudotumor resulting in cord compression, and a comprehensive review of the literature.

Case Description:

A patient presented with an extradural mass causing spinal cord compression at the L2-L3 level. Pathologically this proved to be an IgG4-RD pseudotumor. The patient was treated with thecal sac decompression and post-operative steroids that resulted in complete resolution of his symptoms.

Conclusion:

IgG4-RD is typically under-recognized and under-reported in the spinal literature. The clinical spinal presentation and non-surgical vs. surgical treatment are relatively straightforward. Although most cases can be managed with a course of steroids, surgical decompression may be required in patients presenting with spinal cord and/or nerve root compression. The differential diagnoses for these spinal tumors or pseudotumors should include IgG4-RD. Early detection and appropriate treatment can lead to satisfactory outcomes.

Gastrointestinal and Extra-Intestinal Manifestations of IgG4-Related Disease

IgG4-related disease (IgG4-RD) is a chronic relapsing multi-organ fibro-inflammatory syndrome of presumed autoimmune etiology. It is characterized by increased serum levels of IgG4 and tissue infiltration by IgG4⁺ cells. Increased titers of autoantibodies against a spectrum of self-antigens and response to steroids have led to its characterization as an autoimmune disease. However, the pathognomonic antigens probably differ among manifestations, and different antigens or autoantibodies produce similar immune reactions in different organs. Little is known about the pathogenic effects, if any, of serum IgG4 or IgG4⁺ plasma cells in tissues. Despite several animal models of the disease, none truly recapitulates human IgG4-RD. Histologic analyses of tissues from patients with IgG4-RD reveal a dense lymphoplasmacytic infiltrate rich in IgG4⁺ plasma cells, storiform fibrosis, and obliterative phlebitis, although these features vary among organs. Typical presentation and imaging findings include mass-forming synchronous or metachronous lesions in almost any organ, but most commonly in the pancreas, bile duct, retroperitoneum, kidneys, lungs, salivary and lacrimal glands, orbit, and lymph nodes. In all organs, inflammation can be reduced by corticosteroids and drugs that deplete B cells, such as rituximab. Patients with IgG4-RD have relapses that respond to primary therapy. Intense fibrosis accompanies the inflammatory response, leading to permanent organ damage and insufficiency. Death from IgG4-RD is rare. IgG4-RD is a multi-organ disease with predominant pancreatico-biliary involvement. Despite its relapsing-remitting course, patients have an excellent prognosis.

Factors in glucocorticoid regimens associated with treatment response and relapses of IgG4-related disease: a multicentre study

Glucocorticoids (GC) are effective for treating IgG4-related disease (IgG4-RD); however, relapse is often observed. We conducted a retrospective multicentre study to investigate risk factors in GC regimens associated with relapses of IgG4-RD. Data on 166 patients with definitive IgG4-RD diagnosis were collected from 12 institutions. Comprehensive surveillance of clinical backgrounds and GC regimens as well as multivariate analysis of factors associated with treatment responses and relapses was performed. To determine the initial maximal GC dose, the patients were stratified into three groups depending on the initial prednisolone (PSL) dosage: <0.39, 0.4–0.69 and >0.7 mg/kg/day. The multivariate analysis extracted the disease duration and reduction speed of initial GC dose. Patients treated with initial GC <0.39 or >0.7 mg/kg/day of PSL showed higher relapse rates than those treated with 0.4–0.69 mg/kg/day. The relapse rates were significantly higher in patients with fast reduction of the initial dose (>0.4 mg/day) than in patients with slow reduction (<0.4 mg/day). To avoid relapse, 0.4–0.69 mg/kg/day of initial PSL with slow reduction speed (<0.4 mg/day) is needed in the early treatment of IgG4-RD.

Identification and preliminary study of immunogens involved in autoimmune prostatitis in human males

BACKGROUND

Experimental models have confirmed that autoimmunity is an important factor in the onset of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS); however, there is no conclusive evidence on whether autoimmune prostatitis exists in human males.

METHODS

Rabbits were immunized with either human prostate tissue homogenates or normal saline and the antiserum was collected. Two-dimensional electrophoresis (2-DE) was performed on the homogenates and Western blotting was conducted on the sera. The identified human prostate tissue immunodominant antigens (HPTIAs) were detected by mass spectrometry. The serum immunoglobulin (Ig)G from the immunized rabbits was purified with protein A-agarose, and the purified IgG was linked with Sepharose to purify HPTIAs by affinity chromatography. Non-obese diabetic (NOD) mice were immunized with the purified HPTIAs, and the levels of serum antibodies, INF-γ, and histopathological changes in their prostate tissues were detected. The purified HPTIAs were coated into polystyrene pores and serum autoantibodies in CP/CPPS patients were detected by enzyme-linked immunosorbent assay (ELISA). Meanwhile, serum interleukin 2 (IL-2), interferon gamma (IFNγ), and tumor necrosis factor alpha (TNFα) levels in CP/CPPS patients were also determined by ELISA.

RESULTS

Sixteen HPTIAs were identified. Among them, three types were reported to be associated with prostatic diseases. Prostatitis was induced in mice immunized with the 16-HPTIA complex, with positive serum autoantibody and increased prostatic IFN-γ levels. The positive rate of serum autoantibodies against HPTIAs was significantly higher in CP/CPPS patients (23.1%, 18/78) than in the control (2.7%, 2/75). But there was no significant difference in serum TNFα, IFNγ, and IL-2 levels between the CPPS patients with positive and negative autoantibodies against HPTIAs.

CONCLUSIONS

Autoantibodies against HPTIAs exist in part in CP/CPPS patients, which implies that autoimmunity and the 16 HPTIAs are important factors in the onset of CP/CPPS. The detection of serum autoantibodies could be applied in clinical diagnoses of autoimmune prostatitis; treatment protocols might change. Additional studies are needed to determine which of the 16 HPTIAs is the most important.

IgG4-related retroperitoneal fibrosis overlapping with primary biliary cirrhosis and primary Sjögren's syndrome: A case report

RATIONALE

IgG4-related disease (IgG4-RD) is a chronic fibro-inflammatory disorder which is characterized by elevated levels of serum IgG4 and infiltration of IgG4-bearing plasma cells in the involved organs. Primary biliary cirrhosis (PBC) and Primary Sjögren's syndrome (pSS) are both distinct from IgG4-related disease. We herein describe a Chinese patient with IgG4-related RPF overlapping with PBC and pSS.

PATIENT CONCERNS

We report a case of 69-year-old male with recurrent lower abdominal pain for 10 months. Laboratory data showed elevated erythrocyte sedimentation rate and hepatobiliary enzymes, renal dysfunction, high titers of antinuclear antibody, anti-SS-A antibody and anti-mitochondrial type 2, high immunoglobulin (Ig) G levels and elevated serum IgG4 (9 g/L). Contrast-enhanced computed tomography and magnetic resonance imaging were suggestive of retroperitoneal fibrosis and unilateral ureteral occlusion. Immunohistochemical staining for IgG4 did not demonstrate infiltration of IgG4-positive plasma cells in the retroperitoneal mass, but revealed significant infiltration of lymphocytoplasma cells as well as fibrosis and fibrin accumulation.

DIAGNOSES

The patient was diagnosed with IgG4-related retroperitoneal fibrosis based on the International Consensus Diagnostic Criteria. He was also diagnosed with primary biliary cirrhosis and primary Sjögren's syndrome.

INTERVENTIONS

250 mg ursodeoxycholic acid was administered twice daily, and prednisolone was initiated at a dose of 40 mg/day and then tapered to 25 mg after 45 days.

OUTCOMES

The size of the retroperitoneal soft tissue mass gradually reduced and the abnormal laboratory parameters were restored to normal.

LESSONS

This rare clinical condition has seldom been reported in the literature, which suggests that common immunogenetic factors may be involved in the development of IgG-related RPF, PBC and pSS.

Failure of remission induction by glucocorticoids alone or in combination with immunosuppressive agents in IgG4-related disease: a prospective study of 215 patients

Background

The aim of this study was to assess the outcomes of remission induction in patients with IgG4-related disease (IgG4-RD) in our cohort, and to investigate the characteristics, prognosis, and risk factors in the patients failed of remission induction.

Methods

We prospectively enrolled 215 newly diagnosed patients with IgG4-RD, who were initially treated with glucocorticoid (GC) alone or in combination with immunosuppressive agents (IM), and had at least 6 months of follow up. The therapeutic goals of remission induction were defined as fulfilling each of the following after the 6-month remission induction stage: (1) ≥ 50% decline in the IgG4-RD responder index (RI); (2) GC tapered to maintenance dose; and (3) no relapse during GC tapering. The patients not achieving the therapeutic goals were considered to have failed of remission induction.

Results

There were 26 patients in our cohort who failed of remission induction, including 16 (20.8%) on GC monotherapy, and 10 (7.2%) on combination therapy comprising GC and IM. The lacrimal gland and lung were most common sites of remission induction failure. Among the patients who relapsed during remission induction stage, 52.9% had secondary relapse during follow-up. Eosinophilia, higher baseline RI, more than five organs involved and dacryoadenitis were risk factors for remission induction failure with GC monotherapy, and the incidence of remission induction failure was 71.4% in the patients with more than three risk factors. After 6-month treatment, the patients who failed of remission induction had significantly higher erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and IgG4.

Conclusion

In our cohort, 20.8% of patients failed of remission induction with GC monotherapy, while 7.2% of patients failed of remission induction with combination therapy comprising GC and IM.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1567-2) contains supplementary material, which is available to authorized users.

Treatment of immunoglobulin G4-related sialadenitis: outcomes of glucocorticoid therapy combined with steroid-sparing agents

Background

Immunoglobulin G4-related sialadenitis (IgG4-RS) is a newly recognized immune-mediated systemic disease. Despite its good response to steroid therapy, its treatment protocol is not standardized and the long-term outcome is controversial. The study was conducted to determine the short-term and long-term outcomes of IgG4-RS patients treated with glucocorticoids and steroid-sparing immunosuppressive agents, to analyze secretory function, serological and radiological changes in salivary glands and to assess the usefulness of serum IgG4 level as an indicator of disease activity.

Methods

IgG4-RS patients who were treated for more than 3 months were enrolled. Serological tests, salivary gland function assessment and computed tomography (CT) were performed before treatment and during follow up. The treatment outcomes in the short and the long term were evaluated, and the relationship between serum IgG4 level and salivary gland volume was analyzed.

Results

Glucocorticoids were used in all 43 patients and steroid-sparing immunosuppressive agents in 38 patients (88.4%). The follow-up period was 24.6 ± 14.9 months. Clinical remission was achieved in all patients after induction therapy. During short-term observation, salivary gland secretion significantly increased, and the serum IgG4 levels, the volumes and CT values of submandibular and parotid gland decreased significantly (P < 0.001). For long term, relapse occurred in 32.5% patients within 55 months in the regularly treated group, while all seven irregularly treated patients relapsed. However, the relapse-free survival curves were not significantly different between the steroid monotherapy and the combination therapy groups (P = 0.566). Submandibular glands, lacrimal glands, sublingual glands, nasal and paranasal cavity were commonly relapsing organs. In clinically stable patients, a serologically unstable condition occurred in 54.9% patients within 55 months and medication adjustment was performed accordingly. Volume changes in the submandibular and parotid glands were associated with serum IgG4 levels and time of follow up (R²_adjusted = 0.905, P < 0.0001 and R²_adjusted = 0.9334, P < 0.0001, respectively).

Conclusions

The combination of glucocorticoid and steroid-sparing agents could be effective for treating IgG4-RS, and restoring salivary gland function. Serum IgG4 levels could predict disease activity.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1507-6) contains supplementary material, which is available to authorized users.

Hypophyseal Involvement in Immunoglobulin G4-Related Disease: A Retrospective Study from a Single Tertiary Center

This study aims to outline the clinical features and outcomes of IgG4-related hypophysitis (IgG4-RH) patients in a tertiary medical center. We reviewed clinical manifestations and imaging and pituitary function tests at baseline, as well as during follow-up. Ten patients were included. The mean age at diagnosis of IgG4-RH was 48.4 (16.0-64.0) years. An average of 3 (0-9) extrapituitary organs were involved. Five patients had panhypopituitarism, three had only posterior hypopituitarism, one had only anterior hypopituitarism, and one had a normal pituitary function. One patient in our study had pituitary mass biopsy, lacking IgG4-positive cells despite lymphocyte infiltration forming an inflammatory pseudotumor. Five patients with a clinical course of IgG4-RH less than nine months and a whole course of IgG4-RD less than two years were managed with glucocorticoids, while three patients with a longer history were administered glucocorticoids plus immunosuppressive agents. One patient went through surgical excision, and one patient was lost to follow-up. All patients showed a prompt response clinically, but only three patients had normalized serum IgG4 levels. Two patients who took medications for less than six months relapsed. Conclusions. IgG4-RD is a broad disease, and all physicians involved have to be aware of the possibility of pituitary dysfunction. Younger patients should be expected. The histopathological feature of pituitary gland biopsy could be atypical. For patients with a longer history, the combination of GC and immunosuppressive agents is favorable. Early and adequate courses of treatment are crucial for the management of IgG4-RH. With GC and/or immunosuppressant treatment, however, pituitary function or diabetes insipidus did not improve considerably.

New clues to the nature of immunoglobulin G4-related disease: a retrospective Japanese multicenter study of baseline clinical features of 334 cases

Background

The aim was to further characterize immunoglobulin G4-related disease (IgG4-RD) by a large-scale multicenter study of its clinical and laboratory features conducted by multidisciplinary physicians of IgG4-RD in Japan.

Methods

Various specialists retrospectively evaluated IgG4-RD patients diagnosed between 1996 and 2015 in five hospitals by analyzing their baseline clinical features, laboratory, imaging, and pathological test findings, and treatment.

Results

Of the 334 patients listed, 205 were male and median age at diagnosis was 65 years. The mean number of organs involved was 3.2 at diagnosis. The most frequently affected organs were the salivary glands, followed by the lacrimal glands, lymph nodes, pancreas, retroperitoneum/periaorta, kidneys, and lungs. The mean serum level of IgG4 was 755 mg/dl, and more than 95% of patients had elevated serum IgG4 levels. The median serum level of C-reactive protein (CRP) was 0.1 mg/dl and the level was less than 1 mg/dl in 90% of patients. A total of 34.7% of patients had low serum levels of C3. Serum levels of C3 and non-IgG4 IgG, calculated as the total IgG minus IgG4, showed an inverse correlation in patients with kidney lesions, while serum IgG4 levels were not correlated with serum C3 levels. Corticosteroid was administered in 78.0% of patients, and was effective in all.

Conclusions

The serum CRP level is generally low and the serum IgG4 level is elevated in most Japanese IgG4-RD patients, in contrast to western patients. These original findings suggest that these two parameters in IgG4-RD differ in some interesting ways from those hitherto reported in western populations. Additional studies, especially international comparative ones, are needed to elucidate the extent and significance of these differences between populations. Attention will also have to be paid to whether the existence of such differences requires consideration when devising international classification criteria.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1467-x) contains supplementary material, which is available to authorized users.

Long-term efficacy and safety of rituximab in IgG4-related disease: Data from a French nationwide study of thirty-three patients

OBJECTIVES

To assess efficacy and safety of rituximab (RTX) as induction therapy, maintenance of remission and treatment of relapses in a cohort of IgG4-related disease (IgG4-RD) patients.

METHODS

Nationwide retrospective multicenter study of IgG4-RD patients treated with at least one course of RTX. Clinical, biological and radiological response, relapse rate and drug tolerance were analyzed. Kaplan-Meier curves were plotted and risk factors for relapse studied with a Cox regression model.

RESULTS

Among 156 IgG4-RD patients included in the French database, 33 received rituximab. Clinical response was noted in 29/31 (93.5%) symptomatic patients. Glucocorticoids withdrawal was achieved in 17 (51.5%) patients. During a mean follow-up of 24.8 ±21 months, 13/31 (41.9%) responder patients relapsed after a mean delay of 19 ±11 months after RTX. Active disease, as defined by an IgG4-RD Responder Index >9 before RTX, was significantly associated with relapse (HR = 3.68, 95% CI: 1.1, 12.6) (P = 0.04), whereas maintenance therapy with systematic (i.e. before occurrence of a relapse) RTX retreatment was associated with longer relapse-free survival (41 versus 21 months; P = 0.02). Eight severe infections occurred in 4 patients during follow-up (severe infections rate of 12.1/100 patient-years) and hypogammaglobulinemia ≤5 g/l in 3 patients.

CONCLUSION

RTX is effective for both induction therapy and treatment of relapses in IgG4-RD, but relapses are frequent after B-cell reconstitution. Maintenance therapy with systematic RTX infusions is associated with longer relapse-free survival and might represent a novel treatment strategy. Yet, the high rate of infections and the temporary effect of RTX might be hindrances to such strategy.

The Lung in Dysregulated States of Humoral Immunity

In common variable immunodeficiency, lung manifestations are related to different mechanisms: recurrent pneumonias due to encapsulated bacteria responsible for diffuse bronchiectasis, diffuse infiltrative pneumonia with various patterns, and lymphomas, mostly B cell extranodal non-Hodgkin type. The diagnosis relies on significant serum Ig deficiency and the exclusion of any primary or secondary cause. Histopathology may be needed. Immunoglobulin (IgG) replacement is crucial to prevent infections and bronchiectasis. IgG4-related respiratory disease, often associated with extrapulmonary localizations, presents with solitary nodules or masses, diffuse interstitial lung diseases, bronchiolitis, lymphadenopathy, and pleural or pericardial involvement. Diagnosis relies on international criteria including serum IgG4 dosage and significantly increased IgG4/IgG plasma cells ratio in pathologically suggestive biopsy. Respiratory amyloidosis presents with tracheobronchial, nodular, and cystic or diffuse interstitial lung infiltration. Usually of AL (amyloid light chain) subtype, it may be localized or systemic, primary or secondary to a lymphoproliferative process. Very rare other diseases due to nonamyloid IgG deposits are described. Among the various lung manifestations of dysregulated states of humoral immunity, this article covers only those associated with the common variable immunodeficiency, IgG4-related disease, amyloidosis, and pulmonary light-chain deposition disease. Autoimmune connective-vascular tissue diseases or lymphoproliferative disorders are addressed in other chapters of this issue.

Utility of Serum IgG4 Levels in a Multiethnic Population

BACKGROUND

IgG4-related disease (IgG4-RD) is a recently recognized condition defined by characteristic histopathologic findings in affected organs. Serum IgG4 concentration is often but not always elevated. The sensitivity and specificity of serum IgG4 vary greatly across studies and has been anecdotally associated to ethnicity. Our study was conducted to investigate the difference in serum IgG4 levels between Asian and non-Asian patients with IgG4-RD.

METHODS

This is a single-center retrospective study of 26 Asian and 10 non-Asian patients with histologically confirmed IgG4-RD. Serum IgG4 levels, clinical features and other laboratory findings were compared between the 2 groups, 31 Asian and 11 non-Asian patients with non-IgG4-RD rheumatic diseases were randomly identified to evaluate test characteristics of serum IgG4 measurement.

RESULTS

Median serum IgG4 at time of diagnosis was significantly higher in Asian (median = 11.2g/L, interquartile range: 4.6-19.7) than non-Asian patients (median = 2.9g/L, interquartile range: 0.7-5.4, P = 0.0094), as well as the median serum IgG and total protein. Asian patients had more eosinophilia and polyclonal hypergammaglobulinemia than non-Asian patients (P = 0.016 and 0.001, respectively). Test sensitivity was higher in Asian (96%) than non-Asian patients (67%), whereas test specificity was higher in non-Asian patients (91% versus 71%).

CONCLUSION

Asian patients with IgG4-RD have more exuberant serum IgG4, IgG and polyclonal hypergammaglobulinemia than non-Asian patients; the mechanism of this difference requires further study. These findings have significant clinical importance and must be accounted for in the diagnostic workup of patients in multiethnic settings.

Efficacy of Cyclophosphamide treatment for immunoglobulin G4-related disease with addition of glucocorticoids

Aim to evaluate the efficacy and safety of glucocorticoid monotherapy vs combination therapy of cyclophosphamide (CYC) for IgG4 related disease (IgG4-RD). 102 newly diagnosed IgG4-RD patients were enrolled and assigned to 2 groups: Group I was prednisone monotherapy (0.5-1.0 mg/kg.d, tapered gradually) and Group II was glucocorticoid and CYC (50-100 mg per day). Patients were assessed at different periods. Primary end point was relapse rate; secondary end points included response, remission rate and adverse effects. 52 patients were in Group I and 50 in Group II. At 1 month, both groups achieved obvious improvement. Accumulated relapse rate during 1 year was 38.5% in Group 1, including 12 cases with clinical relapse and 8 patients manifesting only serological relapse; whereas there was 12.0% of relapse in Group 2, only 1 with clinical relapse and other 5 patients got serological relapse. The mean flare time in Group II was significantly longer than that in Group I. All relapsing patients in Group I were sensitive to immunosuppressants. Most patients involving more than 6 organs in Group I relapsed during 1 year. IgG4 levels of relapse cases were significantly higher than non-relapsing patients at baseline. Bile duct, lacrimal glands and lymph nodes were commonly relapsed organs in Group I.

Immunoglobulin G4-related kidney disease: Pathogenesis, diagnosis, and treatment

Immunoglobulin G4-related disease (IgG4-RD) is a recently recognized clinical entity that often involves multiple organs; it is characterized by high levels of serum immunoglobulin G4 (IgG4), dense infiltration of IgG4+ cells, and storiform fibrosis. Cellular immunity, particularly T cell-mediated immunity, has been implicated in the pathogenesis of IgG4-RD. The most frequent renal manifestations of IgG4-RD are IgG4-related tubulointerstitial nephritis, membranous glomerulonephropathy (MGN), and obstructive nephropathy secondary to urinary tract obstruction due to IgG4-related retroperitoneal fibrosis, prostatitis, or ureter inflammation. Kidney function impairment can be acute or chronic. In IgG4-MGN, proteinuria can be in the nephrotic range. The diagnosis of IgG4-related kidney disease should not be based solely on serum IgG4 levels or the number of tissue-infiltrating IgG4+ plasma cells. Diagnosis should be based on specific histopathological findings, confirmed by tissue immunostaining and an appropriate clinical context. Steroid treatment is the first-line therapy. For relapsing or refractory cases, immunosuppressants could be combined with steroids. In hydronephrosis patients, appropriate immunosuppressive therapy could preclude the implantation of a double J ureteral catheter.

IgG4-related skin disease may have distinct systemic manifestations: a systematic review

IgG4-related disease (IgG4-RD) is an increasingly prevalent protean multisystem disorder characterized by single or multi-organ infiltration of IgG4-bearing plasma cells. Skin involvement has been recognized and is relevant to proper diagnosis. A systematic literature review of 50 cases involving the skin reveals that patients with IgG4-related skin disease show predominant involvement of the head and neck and have a distinct pattern of systemic involvement, also favoring the head and neck - lymphatics, orbit, salivary, and lacrimal glands - but generally lacking pancreaticobiliary involvement (16% of cases), which by contrast is a predominant manifestation in systemic IgG4-RD (60% with pancreaticobiliary involvement). We summarize clinical and pathologic descriptive data from this systematic review. We review differential diagnosis and propose a diagnostic scheme for stratifying probability of disease based upon comprehensive integration of clinical, histopathologic, and laboratory data. Plasmacyte infiltration and storiform fibrosis are prominent in IgG4-related skin disease, but obliterative venulitis is less common than in the prototypical IgG4-related disease manifestation of autoimmune pancreatitis. IgG4 tissue and serum values, with a mean (±95% CI) in the reviewed cases of 132.8 ± 32.6 IgG4-positive plasma cells per high-power field and 580 ± 183.8 mg/dl, respectively, are incorporated into the suggested criteria. The distinct set of manifestations identified by this systematic review and the proposed diagnostic considerations, while requiring further validation in prospective studies, highlight the need to consider that IgG4-related skin disease defines a unique systemic disease complex along the spectrum of IgG4-RD.

IgG4-related Disease and the Liver

Pathologists are likely to encounter IgG4-related disease in several organ systems. This article focuses on helping pathologists diagnose IgG4-related disease in the hepatobiliary system. Missing the diagnosis can result in unnecessary organ damage and/or unnecessary surgical and cancer therapy. In the liver, tumefactive lesion(s) involving the bile ducts with storiform fibrosis and an IgG4-enriched lymphoplasmacytic infiltrate are highly concerning for IgG4-related disease. The recent identification of oligoclonal populations of T cells and B cells in IgG4-related disease may lead to molecular tests, new therapeutics, and a greater mechanistic understanding of the disease.

Neurological Manifestations of IgG4-Related Disease

OPINION STATEMENT

IgG4-related disease (IgG4-RD) is a multisystem inflammatory disorder. Early recognition of IgG4-RD is important to avoid permanent organ dysfunction and disability. Neurological involvement by IgG4-RD is relatively uncommon, but well recognised-hypertrophic pachymeningitis and hypophysitis are the most frequent manifestations. Although the nervous system may be involved in isolation, this more frequently occurs in conjunction with involvement of other systems. Elevated circulating levels of IgG4 are suggestive of the condition, but these are not pathognomonic and exclusion of other inflammatory disorders including vasculitis is required. Wherever possible, a tissue diagnosis should be established. The characteristic histopathological changes include a lymphoplasmacytoid infiltrate, storiform fibrosis and obliterative phlebitis. IgG4-RD typically responds well to treatment with glucocorticoids, although relapse is relatively common and treatment with a steroid-sparing agent or rituximab may be required. Improved understanding of the pathogenesis of IgG4-RD is likely to lead to the development of more specific disease treatments in the future.

Types of Organ Involvement in Patients with Immunoglobulin G4-related Disease

Background:

Immunoglobulin G4-related disease (IgG4-RD) is a newly recognized systemic disease that can involve multiple organs and various clinical phenotypes. The purpose of this study was to analyze different types of organ involvement in IgG4-RD patients in China.

Methods:

We conducted a prospective cohort study on IgG4-RD patients to analyze the clinical manifestations and rare features of IgG4-RD. Patients were grouped into different types according to organ involvement regarding organ number and organ site. The constituent ratio in different types was also analyzed.

Results:

A total of 200 IgG4-RD patients, with a male:female ratio of 2.08:1, were grouped into different types. Cases having involvement of two or three organs were the most common whereas the fewest number of patients had multi-organ (≥4) involvement. Serum IgG4 and IgE levels, IgG4/IgG ratio, and percentage of eosinophils increased as the number of involved organs increased. In addition, constituent ratio analysis revealed that patients with salivary gland/lacrimal gland swelling, who also constituted the largest number of IgG4-RD patients, had higher serum IgG4 concentrations and IgG4/IgG values, had higher percentage of Eos, and were more likely to have had a history of allergies relative to patients with internal organ involvement.

Conclusions:

The characteristic feature of IgG4-RD is multiple organ involvement with various clinical manifestations and different types. Although serum IgG4 levels increased with the number of involved organs, serum IgG4 levels were higher for those patients with salivary gland/lacrimal gland swelling compared with those with internal organ involvement. Thus, valuable clues to the differential diagnosis of IgG4-RD could be obtained by examining the clinical patterns of organ involvement.

Pulmonary function tests findings and their diagnostic value in patients with IgG4-related disease

BACKGROUND

IgG4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory disorder that can affect most organs. To date, there have been no detailed assessments of pulmonary function in patients with IgG4-RD. In this study, we investigated pulmonary function in IgG4-RD patients and evaluated the value of pulmonary function tests (PFTs) in diagnosing IgG4-related respiratory disease (IgG4-RRD).

METHODS

This was a retrospective study of 17 patients with IgG4-RD. The patients were divided into two groups: IgG4-RRD group and IgG4-related disease extrapulmonary involvement (IgG4-RDEI) group. The PFT results were compared between the two groups.

RESULTS

All patients in the IgG4-RRD group had pulmonary dysfunction. Five of 8 (62.5%) patients in the IgG4-RDEI group had pulmonary dysfunction, despite having normal thoracic computed tomography scans and no respiratory symptoms. Patients in both groups showed restrictive ventilatory dysfunction and abnormal diffusing capacity, and two patients in the IgG4-RRD group had obstructive ventilatory dysfunction. The incidence of diffusing capacity of the lung for carbon monoxide per liter of alveolar volume (D_LCO/V_A) decrease were significantly higher in the IgG4-RRD group than in the IgG4-RDEI group (P=0.029). D_LCO/V_A were significantly higher in the IgG4-RDEI than in the IgG4-RRD group (P=0.044), but otherwise, there were no significant differences. We report the first finding of a negative correlation between pulmonary diffusing capacity and total serum concentrations of IgG and IgG subclasses (IgG4, IgG3 and IgG2).

CONCLUSIONS

D_LCO/V_A plays an important role for detecting lung involvement in IgG4-RD patients. The patient with high serum IgG may be more prone to respiratory involvement.

Ophthalmic manifestations in IgG4-related disease: Clinical presentation and response to treatment in a French case-series

IgG4-related disease (IgG4-RD) is characterized by variable tissue or organ involvements sharing common pathological findings. Orbital or orbital adnexa involvement of the disease has been reported in a few case series. The aim of our study was to characterize and analyze ophthalmic manifestations from a nationwide French case-series.Patients with IgG4-RD and orbital or orbital adnexa involvement included in the French multicentric IgG4-RD case-registry were identified. Only patients fulfilling "modified" comprehensive diagnostic criteria with pathological documentation were retained for the study. Clinical, biological, pathological, radiological findings and data regarding the response to treatment were retrospectively analyzed.According to our data registry, the frequency of IgG4-related ophthalmic disease (IgG4-ROD) was 17%. Mean age at diagnosis was 55.1 ± 7.1 years with a male/female ratio of 2.2. The 19 cases of IgG4-ROD consisted of lacrimal gland (68.4%), soft tissue (57.9%), extra-ocular muscles (36.8%), palpebral (21.1%), optical nerve (10.5%), orbital bone (10.5%), and mononeuritis (V1 and/or V2, 10.5%) involvements. IgG4-ROD was bilateral in 57.9% of cases. Extra-ophthalmic manifestations were reported in 78.9% of cases. All patients responded to prednisone but two-thirds of patients relapsed within a mean (SD) of 9.8 (3.5) months and 72.2% required long-term glucocorticoids and/or immunosuppressive agents. Eight patients were treated by rituximab with a favorable response in 87.5% of cases.Lacrimal involvement is the most frequent ophthalmic manifestation of IgG4-RD and is frequently associated with extra-orbital manifestations. Despite initial favorable response to steroids, the long-term management of relapsing patients needs to be improved.

IgG4-related disease in an adolescent with radiologic-pathologic correlation

Immunoglobulin G4–related disease (IgG4RD) is an immune-mediated condition characterized by lymphoplasmacytic infiltrates and fibrosis of affected organs. IgG4RD may affect many different organs either individually or together in a multiorgan condition and, thus, incorporates a wide range of fibroinflammatory phenotypes with shared pathologic features. Although IgG4RD most commonly occurs in late adulthood, it may affect children and adolescents. Only one case of IgG4RD presenting as isolated submandibular gland involvement has been reported in the pediatric population. Radiographic features of IgG4RD are often nonspecific making diagnosis challenging, but it is important for radiologists to be familiar with this diseased as its inclusion the differential for diffuse salivary enlargement may be the first step in making an accurate diagnosis. Here, we report a case of a child presenting with bilateral submandibular gland swelling to increase awareness of this condition in the pediatric population.

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Circulating plasmablasts/plasma cells: a potential biomarker for IgG4-related disease

BACKGROUND

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a multisystem fibroinflammatory disease. We previously reported that a circulating cell population expressing CD19⁺CD24^-CD38^hi was increased in patients with IgG4-RD. In this study, we aimed to document that this cell population represented circulating plasmablasts/plasma cells, to identify the detailed phenotype and gene expression profile of these IgG4-secreting plasmablasts/plasma cells, and to determine whether this B-cell lineage subset could be a biomarker in IgG4-related disease (IgG4-RD).

METHODS

A total of 42 untreated patients with IgG4-RD were evaluated. Peripheral B-cell subsets, including CD19⁺CD24^-CD38^hi plasmablasts/plasma cells, CD19⁺CD24⁺CD38^- memory B cells, CD19⁺CD24^intCD38^int naïve B cells, and CD19⁺CD24^hiCD38^hi regulatory B cells, were assessed and sorted by flow cytometry. Microarray analysis was used to measure gene expression of circulating B-cell lineage subsets. Further characterization of CD19⁺CD24^-CD38^hi plasmablasts/plasma cells was carried out by evaluating additional surface markers, including CD27, CD95, and human leukocyte antigen (HLA)-DR, by flow cytometric assay. In addition, various B-cell lineage subsets were cultured in vitro and IgG4 concentrations were measured by cytometric bead array.

RESULTS

In untreated patients with IgG4-RD, the peripheral CD19⁺CD24^-CD38^hi plasmablast/plasma cell subset was increased and positively correlated with serum IgG4 levels, the number of involved organs, and the IgG4-related Disease Responder Index. It decreased after treatment with glucocorticoids. Characterization of the plasmablast/plasma cell population by gene expression profiling documented a typical plasmablast/plasma cell signature with higher expression of X-box binding protein 1 and IFN regulatory factor 4, but lower expression of paired box gene 5 and B-cell lymphoma 6 protein. In addition, CD27, CD95, and HLA-DR were highly expressed on CD19⁺CD24^-CD38^hi plasmablasts/plasma cells from patients with IgG4-RD. Furthermore, CD19⁺CD24^-CD38^hi plasmablasts/plasma cells secreted more IgG4 than other B-cell populations.

CONCLUSIONS

Circulating CD19⁺CD24^-CD38^hi plasmablasts/plasma cells are elevated in active IgG4-RD and decreased after glucocorticoid treatment. This IgG4-secreting plasmablast/plasma cell population might be a potentially useful biomarker for diagnosis and assessing response to treatment.

IgG4-related hypophysitis is highly prevalent among cases of histologically confirmed hypophysitis

IgG4-related disease is an immune-mediated disease with manifestations in most organ systems among them the pituitary gland. To date, few cases of histologically confirmed cases of IgG-related hypophysitis have been reported. The aim of this study was to retrospectively determine the prevalence of IgG4-related hypophysitis among cases previously diagnosed as primary hypophysitis (lymphocytic hypophysitis, granulomatous hypophysitis and hypophysitis not otherwise specified). Histological and immunohistochemical analysis revealed that 12 of 29 cases (41.4%) previously diagnosed as primary hypophysitis fulfilled the criteria for IgG4-related disease and, thus, IgG4-related hypophysitis should always be considered in the differential diagnosis of primary hypophysitis. All cases of IgG4-related hypophysitis showed a dense lymphoplasmacytic infiltrate with more than 10 IgG4-positive cells per high power field and a ratio of IgG4/IgG-positive cells of more than 40%, whereas storiform fibrosis was an inconsistent histological feature and was also seen in few cases of non-IgG-related hypophysitis, thus lacking sensitivity and specificity. Obliterative phlebitis was not seen in any case. Thus, histological criteria defined for IgG4-related disease in other organs should be modified for IgG4-related hypophysitis, accordingly.

Revisitation of autoimmune hypophysitis: knowledge and uncertainties on pathophysiological and clinical aspects

PURPOSE

This publication reviews the accepted knowledges and the findings still discussed on several features of autoimmune hypophysitis, including the most recently described forms, such as IgG4 and cancer immunotherapy- related hypophysitis.

METHODS

The most characteristic findings and the pending controversies were derived from a literature review and previous personal experiences. A single paragraph focused on some atypical examples of the disease presenting under confounding pretences.

RESULTS

Headache, visual field alterations and impaired pituitary secretion are the most frequent clinical findings of the disease. Pituitary biopsy, still considered the gold diagnostic standard, does not always receive consent from the patients. The role of magnetic resonance imaging is limited, as this disease may generate images similar to those of other diseases. The role of antipituitary and antihypothalamus antibodies is still discussed owing to methodological difficulties and also because the findings on the true pituitary antigen(s) are still debated. However, the low sensitivity and specificity of immunofluorescence, one of the more widely employed methods to detect these antibodies, may be improved, considering a predetermined cut-off titre and a particular kind of immunostaining.

CONCLUSION

Autoimmune hypophysitis is a multifaceted disease, which may certainly be diagnosed by pituitary biopsy. However, the possible different clinical, laboratory and imaging features must be considered by the physician to avoid a misdiagnosis when examining a possibly affected patient. Therapeutic choice has to be made taking into account the clinical conditions and the degree of hypothalamic-pituitary involvement, but also considering that spontaneous remissions can occur.

Retroperitoneal fibrosis - the state-of-the-art

Retroperitoneal fibrosis (RPF) is a rare disease, hallmarked by inflammation and deposition of fibrous tissue around the abdominal aorta. This process may spread contiguously and involve adjacent structures, leading to many complications, among which the most frequent and most severe is ureteral obstruction. The condition usually has idiopathic origin (idiopathic retroperitoneal fibrosis – IRF), but can also develop secondarily to a number of factors. The etiology of the disease remains unclear. Current research suggests that about half of the cases of IRF may be a symptom of a recently discovered, clinically heterogeneous immunoglobulin G4-related disease (IgG4-RD). Corticosteroids are the first-line treatment for IRF, but effective attempts to use immunosuppressants are also made. This paper presents the current state of knowledge on the etiopathogenesis, clinical presentation, diagnosis and therapeutic possibilities in different forms of RPF. Based on the latest research, an analysis of the relationship between IRF and IgG4-RD was performed.