Withdrawal of immunosuppressants and low-dose steroids in patients with stable IgG4-RD (WInS IgG4-RD): an investigator-initiated, multicentre, open-label, randomised controlled trial

OBJECTIVES

IgG4-related disease (IgG4-RD) is an immune-mediated, fibroinflammatory disease. Induction treatment with glucocorticoid (GC) is usually effective, but its tendency of relapse makes the strategy for maintenance treatment a challenge. The WInS IgG4-RD (withdraw immunosuppressants (IMs) and steroid in stable IgG4-RD) trial tested whether discontinuation of GC and IM was feasible in stable IgG4-RD.

METHODS

The WInS IgG4-RD trial was a multicentre, open-label, randomised controlled trial. Patients with IgG4-RD receiving GC+IM as maintenance treatment with clinically quiescent disease for at least 12 months were randomised (1:1:1) into three groups: group 1: withdraw GC+IM; group 2: withdraw GC but maintain IM; group 3: maintain GC+IM. The primary outcome was the relapse rate of disease within 18 months. The secondary outcomes included the changes of IgG4-RD Responder Index (RI), Physician's Global Assessment (PGA), serum IgG4 and IgG, as well as adverse events.

RESULTS

One hundred and forty-six patients were randomised, with 48 patients in group 1, 49 patients in group 2 and group 3, respectively. Within the 18-month follow-up period, disease relapse occurred in 25 out of 48 (52.1%) patients in group 1 vs 7 out of 49 (14.2%) in group 2 and 6 out of 49 (12.2%) in group 3 (p<0.001). The changes in RI and PGA were significantly higher in group 1 than in group 2 (p<0.001) or group 3 (p<0.001).

CONCLUSIONS

The maintenance of IMs, with or without low-dose GC, was found to be superior to withdraw GC+IM in preventing relapse for long-time stable IgG4-RD.

TRIAL REGISTRATION NUMBER

NCT04124861.

Current and future advances in practice: IgG4-related disease

IgG4-related disease (IgG4-RD) is an increasingly recognized cause of fibroinflammatory lesions in patients of diverse racial and ethnic backgrounds and is associated with an increased risk of death. The aetiology of IgG4-RD is incompletely understood, but evidence to date suggests that B and T cells are important players in pathogenesis, both of which are key targets of ongoing drug development programmes. The diagnosis of IgG4-RD requires clinicopathological correlation because there is no highly specific or sensitive test. Glucocorticoids are highly effective, but their use is limited by toxicity, highlighting the need for studies investigating the efficacy of glucocorticoid-sparing agents. B cell-targeted therapies, particularly rituximab, have demonstrated benefit, but no randomized clinical trials have evaluated their efficacy. If untreated or under-treated, IgG4-RD can cause irreversible organ damage, hence close monitoring and consideration for long-term immunosuppression is warranted in certain cases.

IgG4-related autoimmune liver disease

The term IgG4-related autoimmune liver disease (AILD) refers to hepato-biliary manifestations of Immunoglobin G4-related disease (IgG4-RD) including IgG4-related sclerosing cholangitis and IgG4-related pseudotumor. The association of some forms of autoimmune hepatitis to IgG4-RD remains controversial. Although autoimmune phenomena have not been clearly observed in IgG4-AILD, perturbation of the adaptive immune system and activation of the humoral response represent established pathophysiological hallmarks and potential therapeutic targets. Clinical manifestations of IgG4-AILD are virtually indistinguishable from bile duct cancer or primary sclerosing cholangitis and are due to mass forming lesions and thickening of the biliary tract that progressively lead to biliary ducts obstruction. There are no current reliable biomarkers for IgG4-AILD and diagnosis should rely on the integration of clinical, serological, radiological, and histological findings. In analogy to most IgG4-RD manifestations, and in contrast to its major mimickers, IgG4-AILD promptly responds to glucocorticoids but frequently relapses, thus requiring long-term maintenance therapy to avoid progressive fibrosclerotic disease and liver cirrhosis. Accumulating evidence on the efficacy of B-cell depletion therapy in patients with systemic IgG4-RD is gradually changing the treatment paradigm of IgG4-AILD and biologics will be increasingly used also for gastroenterological manifestations of IgG4-RD to spare glucocorticoids and traditional immunosuppressive agents. Looking ahead, identification of reliable biomarkers and of mini-invasive strategies to obtain informative biopsies from the biliary tree represent unavoidable priorities to optimize diagnosis and management of IgG4-AILD.

Comparison of the efficacy and safety of leflunomide versus mycophenolate mofetil in treating IgG4-related disease: a retrospective cohort study

OBJECTIVE

Combination therapy of glucocorticoids (GCs) plus leflunomide (LEF) and GCs plus mycophenolate mofetil (MMF) was reported to have good efficacy and safety in the management of IgG4-RD. However, studies comparing the efficacy and safety of these two combination therapies were unavailable. Herein, this study aimed to compare the efficacy and safety of GCs plus LEF and GCs plus MMF in treating IgG4-RD.

METHODS

This study included 130 newly diagnosed IgG4-RD patients who received the therapy of GCs plus LEF (group I) and GCs plus MMF (group II). Clinical data at baseline and after treatment, treatment response, relapse rate, and adverse effects were recorded and analyzed.

RESULTS

Patients in both groups responded well to the treatment in the 1st-month follow-up, and 100% of patients achieved treatment response. However, at the 6th and 12th-month follow-up, the total response rate of group II was higher than that in group I (75.6 vs. 53.7%, p = 0.038 and 85.4% vs. 61.0%, p = 0.013, respectively). In addition, the duration of disease remission in group II was longer than that in group I (9 (6-9) vs. 6 (6-6) months, p = 0.014). Moreover, more patients in group I had adverse effects compared with group II (36.6 vs. 7.3%, p < 0.01); and the most common adverse events of LEF were rash (12.2%) and elevation of liver enzymes (9.8%).

CONCLUSION

The combination therapy of GCs plus low-dose MMF had better efficacy and safety in the management of IgG4-RD compared with the therapy of GCs plus LEF.

IgG4 related disease and aortitis: an up-to-date review

Aortic involvement in immunoglobulin G4-related disease (IgG4-RD) is extremely rare and is often overlooked during the aortitis work-up. IgG4-related aortitis differs from non-IgG4-related aortitis in its histopathological features, site of involvement, laboratory markers, and treatment options. The histopathological examination of the vessel walls characteristically reveals adventitial thickening with intimal sparing, typically affecting the infrarenal abdominal aorta. In addition, inadequate knowledge about the disease often leads to delayed or missed diagnosis and undermanagement of a potentially treatable condition. Hence, in this paper, we review the unique clinical manifestations, laboratory markers, diagnostic features, current treatment strategies, and novel experimental therapeutic options in the management of IgG4-related aortitis.

Advantages of an alternate-day glucocorticoid treatment strategy for the treatment of IgG4-related disease: A preliminary retrospective cohort study

Alternate-day glucocorticoid (GC) therapy is a treatment option that can reduce GC-associated adverse events. We investigated the safety and efficacy of alternate-day GC therapy in patients with immunoglobulin G4-related disease (IgG4-RD). Medical records of patients with IgG4-RD who were followed for at least one year at St. Luke's International Hospital, Tokyo, Japan, from 2004 to 2020 were reviewed. Patients who fulfilled comprehensive IgG4-RD diagnostic criteria were divided into alternate-day or daily GC treatment groups based on their treatment protocol. The effect of alternate-day GC therapy on glucocorticoid toxicity index (GTI) score was evaluated using multilinear analysis with adjustments for cumulative GC doses until each assessment point and propensity scores (PS) for alternate-day GC therapy. Kaplan-Meier curves and Cox proportional hazard models were used to assess the efficacy of alternate-day GC therapy for disease control. Among the 67 patients with IgG4-RD, patients with alternate-day (n = 13) and daily (n = 31) GC treatments were analyzed after excluding 23 ineligible patients. The median (interquartile range) age was 64 (60-70) years, 29 (65.9%) were male patients, 26 (59.1%) patients had positive biopsy results, and the median follow-up period was 1643 days. Significantly more patients with alternate-day GC treatment used concomitant immunosuppressants (11 [84.6%] vs 11 [35.5%]; P = .007). The alternate-day strategy significantly lowered the GTI score after adjusting for cumulative GC dose until the assessment and PS (adjusted coefficient: -29.5 [-54.3, -4.8], P = .021 at 12 months; -20.0 [-39.8, -0.1], P = .049 at 24 months). Serious infections were numerically less frequent in the alternate-day group (incidence ratio [95% confidence interval [CI]: 0.45 [0.05, 3.63], P = .45). Most patients (92.3%) in the alternate-day GC treatment group and all patients in the daily GC treatment group showed treatment responses in the remission induction therapy. The PS-adjusted hazard ratio of alternate-day GC treatment for disease flares was not significant (1.55 [0.53, 4.51]; P = .43). The alternate-day treatment strategy significantly reduced GC-related adverse events regardless of the cumulative GC dose. Alternate-day GC treatment is a feasible option for patients with IgG4-RD, without a significant increase in disease flares particularly when combined with immunosuppressants.

Concomitant presentation of eosinophilic or oncocytic mucoepidermoid carcinoma, immunoglobulin G4-related disease, and adult-onset asthma and periocular xanthogranuloma: Case report of 3 uncommon clinical entities

RATIONALE

Immunoglobulin (Ig) G4-related disease (IgG4-RD) reportedly has a strong relationship with adult-onset asthma and periocular xanthogranuloma (AAPOX) and may be linked to sclerosing mucoepidermoid carcinoma (MEC). We present a rare case of IgG4-RD and AAPOX occurring in a patient with resected eosinophilic or oncocytic MEC.

PATIENT CONCERNS

A 52-year-old woman was referred to our rheumatology clinic in 2020 to be evaluated for suspected IgG4-RD.

DIAGNOSES

The patient had diagnoses of periorbital xanthelasmas, worsening glucocorticoid-dependent chronic rhinosinusitis and adult-onset asthma, and cervical lymphadenopathy persisting 2 years after resection of a low-grade MEC of a minor salivary gland.

INTERVENTIONS

Because the patient's symptomatic relief was glucocorticoid dependent, IgG4-RD was suspected, and she was referred to our medical center. Her amylase and lipase levels were elevated. Serum IgG4 levels were initially within normal limits, but IgG4-RD was diagnosed because of the presence of lymphadenopathy and evidence of pancreatitis, which was shown on positron emission tomography/computed tomography. Furthermore, the IgG4 levels later increased without explanation. After the patient began combination therapy with a glucocorticoid (prednisone) and methotrexate, her symptoms improved but recurred when the daily oral glucocorticoid dosage decreased below 10 mg. An excisional biopsy of her right submandibular gland in 2021 yielded results consistent with IgG4-RD. In addition, AAPOX was diagnosed, given the presence of periocular edema and plaques, adult-onset asthma, and rhinosinusitis.

OUTCOME

The patient was carcinoma free at last follow-up and was receiving medication to treat the other conditions.

LESSONS

The diagnosis of these 3 concomitant, uncommon entities required approximately 7 years of medical investigations. Clinicians should know that IgG4-RD, AAPOX, and MEC may occur together.

IgG4-related disease in patients with idiopathic orbital inflammation

Background

To identify the prevalence of positive IgG4 immunostaining in orbital tissue among patients previously diagnosed with nongranulomatous idiopathic orbital inflammation (IOI) and to compare the clinical characteristics of patients with and without IgG4-positive cells.

Methods

A retrospective review of all patients with a histopathologic diagnosis of IOI was performed. Immunohistochemical staining was performed to identify IgG-positive cells and IgG4-positive cells. Multivariate analysis was performed using likelihood ratio-test logistic regression on the differences between IgG4-related disease (IgG4-RD) and non-IgG4-RD.

Results

Of the 45 patients included, 21 patients (46.7%) had IgG4-positive cells, with 52.4% being male and a mean age of 55.9 ± 13.4 years. Bilateral ocular adnexal involvement (adjusted odds ratio [aOR] = 9.45; P = 0.016) and infraorbital nerve enlargement (aOR = 12.11; P = 0.008) were frequently found in IgG4-RD patients. Complete remission occurred in 23.8% of IgG4-RD patients and 41.7% of non-IgG4-RD patients. IgG4-RD patients had more frequent recurrent disease than non-IgG4-RD patients.

Conclusions

Nearly 50% of IgG4-RD patients were previously diagnosed with biopsy-proven IOI. IgG4-RD was more frequent in patients with bilateral disease and infraorbital nerve enlargement, showing the importance of tissue biopsy in these patients. Immunohistochemistry studies of all histopathology slides showing nongranulomatous IOI are highly recommended to evaluate for IgG4-RD.

Renal Involvement in Retroperitoneal Fibrosis: Prevalence, Impact and Management Challenges

Retroperitoneal fibrosis (RPF) is a rare disorder consisting of idiopathic and various secondary forms and characterized by chronic inflammatory infiltrates and marked fibrosis in the retroperitoneal space. In idiopathic RPF (IRPF), 35–60% of cases have been reported to be IgG4-related RPF, the retroperitoneal lesions of IgG4-related disease (IgG4-RD). IRPF can frequently lead to renal insufficiency mediated by urinary tract obstruction and hydronephrosis irrespective of being IgG4-related or not. Clinical pictures, laboratory and imaging findings, and location of the urinary tract obstruction are generally similar in IgG4-related and non-IgG4-related IRPF although multiple organ involvement and serum IgG4 elevation may be characteristic of the IgG4-related forms. Periaortic/periarterial lesions are the most frequent cause of renal insufficiency. Although the response to glucocorticoids is generally good, relapse does occur in a considerable proportion of patients, and may require an additional immunosuppressive agent and/or urological intervention in cases with multiple relapses or refractory obstructive uropathy. In general, the prognosis of patients with IRPF is good, but careful attention needs to be paid to chronic kidney disease as a major complication and rupture of the affected aorta/artery as a life-threatening one. Further studies are necessary to better understand the pathogenesis of the disease and to establish the optimal diagnostic and therapeutic strategies for it.

Emerging therapy options for IgG4-related disease

INTRODUCTION

Awareness of IgG4-related disease (IgG4-RD) is increasing worldwide and specialists are now familiar with most of its clinical manifestations and mimickers. IgG4-RD promptly responds to glucocorticoids and repeated courses are typically used to induce and maintain remission because the disease relapses in most patients. If left untreated, it can lead to organ dysfunction, organ failure and death. Advancement in our understanding of IgG4-RD pathogenesis is leading to the identification of novel therapeutic targets and emerging treatments are now setting the stage for personalized therapies for the future.

AREAS COVERED

This review focuses on emerging treatment options for IgG4-RD based on our advancing understanding of disease pathophysiology. Research was performed in the English literature on Pubmed and clinicaltrials.gov databases.

EXPERT OPINION

Glucocorticoids remain the first-line induction treatment for the multi-organ manifestations of IgG4-RD. Alternative immunosuppressive agents for maintaining remission are warranted in order to avoid long-term steroid toxicity, and to offer a more mechanistic and personalized therapeutic strategy. Targeting B and T-lymphocyte activation represents the most promising approach, but randomized controlled trials are eagerly awaited to confirm positive preliminary experiences reported in case series and small cohort studies.

Effectiveness and safety of Mizoribine for the treatment of IgG4-related Disease: A Retrospective Cohort Study

OBJECTIVE

Patients with IgG4-Related Disease (IgG4RD) usually require steroid-sparing agents due to relapse with tapering glucocorticoids (GC). The aim of this study was to determine the efficacy and safety of Mizoribine (MZR) among IgG4RD, which inhibits inosine monophosphate dehydrogenase, a rate-limiting enzyme in the de novo pathway of purine synthesis.

METHODS

We retrospectively reviewed records of IgG4RD patients at the Immuno-Rheumatology Center in St. Luke's International Hospital, Tokyo, Japan. Patients were classified into the MZR combination group, and those treated with GCs alone or with other immunosuppressants were included in the control group. Disease exacerbation, GC dose, IgG-IgG4 titre, and adverse events were evaluated using univariate analyses, including the Kaplan-Meier method. The Cox proportional hazard model was used to evaluate risk factors for exacerbation.

RESULTS

A total of 14 and 29 cases were included in the MZR combination and control groups, respectively. Multiple organ involvement (≥3 organs) was significantly more frequent in the MZR combination treatment group (10 [71.4%] vs 9 [31.0%], p= 0.021). Kaplan-Meier analysis revealed a significant reduction in exacerbation in patients with multiple organ involvement (p< 0.001), but not in total (p= 0.42). The adjusted hazard ratios of MZR use and multiple organ involvement for exacerbation were 0.34[0.12-1.01] (p= 0.052), and 3.51[1.29-9.51] (p= 0.014). The cumulative GC dose tended to be lower in the MZR combination group (1448[1003, 1642] vs 2179[1264, 3425]; p= 0.09).

CONCLUSION

MZR showed a significant steroid-sparing effect and decrease in exacerbation among IgG4RD patients with multi-organ involvement. MZR could be a treatment option for IgG4RD.

The enigmatic immunoglobulin G4-related disease and its varied cardiovascular manifestations

Immunoglobulin G4-related disease (IgG4-RD) is a systemic fibroinflammatory disease characterised by multiorgan lymphoplasmacytic infiltration, obliterative phlebitis and storiform fibrosis. It can be associated with cardiovascular pathology. The objective of this narrative review is to summarise the published literature on cardiovascular manifestations of IgG4-RD and to provide a basis for diagnosis and management of the condition by the practising cardiologist.We propose the following categorisations of cardiovascular IgG4-RD: aortitis, medium-vessel arteritis, pulmonary vascular disease, phlebitis, valvulopathy, pericarditis, myocardial disease and antineutrophilic cytoplasmic antibody-associated vasculitis. We also review herein developments in radiological diagnosis and reported medical and surgical therapies. Cardiovascular lesions frequently require procedural and/or surgical interventions, such as aortic aneurysm repair and valve replacement. IgG4-RD of the cardiovascular system results in serious complications that can be missed if not evaluated aggressively. These are likely underdiagnosed, as clinical presentations frequently mimic cardiovascular disease due to more common aetiologies (myocardial infarction, abdominal aortic aneurysm and so on). While systemic corticosteroids are the mainstay of IgG4-RD treatment, biological and disease-modifying agents are becoming more widely used. Cardiologists should be aware of cardiovascular IgG4-RD as a differential diagnosis, and understand the roles of corticosteroids, disease-modifying agents and biologicals, as well as their integration with surgical approaches. There are several knowledge gaps, including diagnosis, risk factors, pathogenesis and appropriate management in Ig4-RD of the cardiovascular system. Areas lacking well-conducted randomized trials include safety of steroids in the setting of vascular aneurysms and the role of disease-modifying drugs and biological agents in patients with established cardiovascular complications of this multifaceted enigmatic disease.

The eosinophilic esophagitis and IgG4-related disease involving the esophagus

The study of eosinophilic esophagitis has become a dynamic field with an evolving understanding of the pathogenesis, diagnosis, and treatment. Immunoglobulin G4 (IgG4)-related disease exhibits systemic involvement but very rarely involves the esophagus. The article presents a clinical case: the history of ulcer and stricture of the esophagus in a young man of 17 years. The patient was finally diagnosed with IgG4-related and eosinophilic esophagitis and showed a good response to corticosteroid therapy. We herein report a rare case of dysphagia associated with IgG4-related disease and eosinophilic. We presented a review of modern data on the relationship of eosinophilic esophagitis and pathological IgG4-response.

European Guideline on IgG4-related digestive disease - UEG and SGF evidence-based recommendations

The overall objective of these guidelines is to provide evidence-based recommendations for the diagnosis and management of immunoglobulin G4 (IgG4)-related digestive disease in adults and children. IgG4-related digestive disease can be diagnosed only with a comprehensive work-up that includes histology, organ morphology at imaging, serology, search for other organ involvement, and response to glucocorticoid treatment. Indications for treatment are symptomatic patients with obstructive jaundice, abdominal pain, posterior pancreatic pain, and involvement of extra-pancreatic digestive organs, including IgG4-related cholangitis. Treatment with glucocorticoids should be weight-based and initiated at a dose of 0.6-0.8 mg/kg body weight/day orally (typical starting dose 30-40 mg/day prednisone equivalent) for 1 month to induce remission and then be tapered within two additional months. Response to initial treatment should be assessed at week 2-4 with clinical, biochemical and morphological markers. Maintenance treatment with glucocorticoids should be considered in multi-organ disease or history of relapse. If there is no change in disease activity and burden within 3 months, the diagnosis should be reconsidered. If the disease relapsed during the 3 months of treatment, immunosuppressive drugs should be added.

Advances in the diagnosis and management of IgG4 related disease

IgG4 related disease was recognized as a unified disease entity only 15 years ago. Awareness of IgG4 related disease has increased worldwide since then, and specialists are now familiar with most of its clinical manifestations. Involvement of the pancreato-biliary tract, retroperitoneum/aorta, head and neck, and salivary glands are the most frequently observed disease phenotypes, differing in epidemiological features, serological findings, and prognostic outcomes. In view of this multifaceted presentation, IgG4 related disease represents a great mimicker of many neoplastic, inflammatory, and infectious conditions. Histopathology remains key to diagnosis because reliable biomarkers are lacking. Recently released classification criteria will be invaluable in improving early recognition of the disease. IgG4 related disease is highly treatable and responds promptly to glucocorticoids, but it can lead to end stage organ failure and even death if unrecognized. Prolonged courses of corticosteroids are often needed to maintain remission because the disease relapses in most patients. Rapid advancement in our understanding of the pathophysiology of IgG4 related disease is leading to the identification of novel therapeutic targets and possible personalized approaches to treatment.

IgG4-related disease: a clinical perspective

IgG4-related disease (IgG4-RD) is a recently recognized fibro-inflammatory disorder that can affect almost any organ. Common presentations include major salivary and lacrimal gland enlargement, orbital disease, autoimmune pancreatitis, retroperitoneal fibrosis and tubulointerstitial nephritis. The main histopathological features are a dense, polyclonal, lymphoplasmacytic infiltrate rich in IgG4+ plasma cells, storiform fibrosis and obliterative phlebitis. The precise pathogenic mechanisms of IgG4-RD are still unclear. CD4+ T and B cells, including IgG4-expressing plasmablasts, constitute the major inflammatory cell populations and are believed to cause organ damage and tissue fibrosis. The diagnosis of the disease may be challenging and should be based on specific histopathological findings, typical laboratory and radiological aspects and an appropriate clinical context. The first-line treatment of IgG4-RD is based on glucocorticoids, which are usually efficacious. However, B cell depletion induced by rituximab has also been found to induce remission in steroid-resistant disease or has been used as steroid-sparing agent for relapsing disease. This review provides an update on clinical and therapeutic aspects of IgG4-RD.

Identifying clinical subgroups in IgG4-related disease patients using cluster analysis and IgG4-RD composite score

Background

To explore the clinical patterns of patients with IgG4-related disease (IgG4-RD) based on laboratory tests and the number of organs involved.

Methods

Twenty-two baseline variables were obtained from 154 patients with IgG4-RD. Based on principal component analysis (PCA), patients with IgG4-RD were classified into different subgroups using cluster analysis. Additionally, IgG4-RD composite score (IgG4-RD CS) as a comprehensive score was calculated for each patient by principal component evaluation. Multiple linear regression was used to establish the “IgG4-RD CS” prediction model for the comprehensive assessment of IgG4-RD. To evaluate the value of the IgG4-RD CS in the assessment of disease severity, patients in different IgG4-RD CS groups and in different IgG4-RD responder index (RI) groups were compared.

Results

PCA indicated that the 22 baseline variables of IgG4-RD patients mainly consisted of inflammation, high serum IgG4, multi-organ involvement, and allergy-related phenotypes. Cluster analysis classified patients into three groups: cluster 1, inflammation and immunoglobulin-dominant group; cluster 2, internal organs-dominant group; and cluster 3, inflammation and immunoglobulin-low with superficial organs-dominant group. Moreover, there were significant differences in serum and clinical characteristics among subgroups based on the CS and RI scores. IgG4-RD CS had a similar ability to assess disease severity as RI. The “IgG4-RD CS” prediction model was established using four independent variables including lymphocyte count, eosinophil count, IgG levels, and the total number of involved organs.

Conclusion

Our study indicated that newly diagnosed IgG4-RD patients could be divided into three subgroups. We also showed that the IgG4-RD CS had the potential to be complementary to the RI score, which can help assess disease severity.

Glucocorticoids and steroid sparing medications monotherapies or in combination for IgG4-RD: a systematic review and network meta-analysis

Objective

To assess the safety and efficacy of glucocorticoids (GCs), immunosuppressive agents (IM) and rituximab (RTX), alone or in combination, for the treatment of IgG4-RD.

Methods

Relevant articles published were searched in the databases with relevant key words. Network meta-analysis was conducted, with various outcomes including relapse rate, remission rate and adverse events. Data were calculated with odds ratio (ORs) and 95% CI. P-score was used to rank the treatments.

Results

A total of 15 studies involving 1169 patients were included. Network meta-analysis indicated that RTX maintenance therapy had the lowest relapse rate of all treatments (OR = 0.10, 95% CI [0.01, 1.63]), whereas GCs + IM was associated with a lower relapse rate compared with GCs alone (OR = 0.39, 95% CI [0.20, 0.80]). Further, patients treated with GCs + IM had a higher remission rate than those given GCs (OR= 3.36, 95% CI [1.44, 7.83]), IM (OR= 55.31, 95% CI [13.73, 222.73]) monotherapies or RTX induction therapy only (OR= 7.38, 95% CI [1.56, 34.94]). The rate of adverse events was comparable among the different treatment groups.

Conclusion

Treatment of IgG4-RD patients with GCs and IM was associated with higher remission rates and lower relapse rates, as well as comparable safety profiles compared with GC, IM and RTX induction therapy. RTX maintenance therapy had a larger reduction in the relapse rate compared with GC and IM. The current evidence should be carefully scrutinized as the included studies were observational in design. Larger randomized controlled trials are needed to confirm.

The treatment outcomes in IgG4-related orbital disease: a systematic review of the literature

IgG4-related disease (IgG4-RD) is an immune-mediated systemic fibro inflammatory disease. Treatment of IgG4-related orbital disease (IgG4-ROD) is often indicated to relieve the symptoms and to prevent complications. For IgG4-ROD, no international formal treatment guidelines are available and the optimal treatment strategy is uncertain. In this systematic review, we describe the efficacy of conventional and biologic disease-modifying antirheumatic drugs (DMARDs) in IgG4-ROD. A systematic search of Embase, Medline, Web-of-Science, PubMed publisher, Cochrane and Google Scholar was performed for treatment outcomes in IgG4-ROD. Relevant articles on treatment of IgG4-ROD were retrieved to last date of inclusion 3 January 2018. The following inclusion criteria were used: articles in English or English translation, studies evaluating the use of DMARDs (conventional and biologic) in the treatment of IgG4-ROD. Meta-analysis and review articles were excluded. A final selection after full-text evaluation was made by independent reviewers, based on treatment of IgG4-ROD with DMARDs and the availability of treatment outcomes. With this systematic review, we identified 35 studies and case reports/series on IgG4-ROD, describing 95 patients, treated with conventional and/or biologic DMARDs. The success of conventional DMARDs varies between 36% and 75% in patients with IgG4-ROD, while rituximab is successful in the majority (93%) of the patients. Based on this systematic review, rituximab is the most effective DMARD in IgG4-ROD, while the efficacy of conventional DMARDs is limited. We propose early initiation of rituximab in case of refractory and organ- or life-threatening disease.

IgG4-Related Disease: Beyond Glucocorticoids

IgG4-related disease is a heterogeneous immune-mediated fibroinflammatory condition that can affect every single organ. This disease is more prevalent in the elderly (the mean age of patients is above 60 years) and the prevalence rate is estimated to be over 4.6 per 100,000 population. Before making a diagnosis, the exclusion of malignancies, lymphoma, anti-neutrophil cytoplasmic antibody-associated vasculitis, multicentric Castleman disease, and other mimickers is crucial for appropriate treatment. Broad management guidelines have been published emphasizing the need for prompt treatment and the use of glucocorticoids as first-line drug therapy for induction of remission. However, the toxic effects of glucocorticoids are problematic because IgG4-related disease is more prevalent in patients above 60 years of age, a population with frequent comorbid conditions and polypharmacy. Immunosuppressants (cyclophosphamide, methotrexate, leflunomide, and tacrolimus) and targeted immunomodulators (rituximab, XmAb5871, and abatacept) are appealing to overcome potential toxic effects of glucocorticoids and as emerging glucocorticoid-sparing and/or maintenance treatments. In this review, we provide an overview of our understanding of the pathophysiology of the disease (T follicular helper cells, CD4⁺ cytotoxic T cells, plasmablasts, and alternatively activated M2 macrophages) and clinical characteristics, and highlight the potential targets for treatment intervention.

IgG4-related disease: review of the histopathologic features, differential diagnosis, and therapeutic approach

Immunoglobulin G4-related disease (IgG4-RD) is an uncommon disorder that demonstrates characteristic clinicopathologic features including sclerosing lesions with storiform fibrosis, increased IgG4+ plasma cells with an increased IgG4+/IgG+ plasma cell ratio, obliterative phlebitis, and often an increased serum IgG4 level. This review summarizes the characteristic histopathologic and clinical features of IgG4-RD with detailed discussion of the histopathologic characteristics of the most commonly involved anatomic sites. We also present recent advances in our understanding of the pathophysiologic mechanisms of IgG4-RD and discuss updates on the treatment, prognosis, and outcomes of this rare disease, including discussion of the possible association between IgG4-RD and malignancy.

IgG4-Related Pleuritis With No Other Organ Involvement

A 65-year-old man was admitted for productive cough and dyspnea. Bilateral pleural effusions were observed on chest X-ray. Although the bilateral pleural effusions were exudative with an increased number of lymphocytes, bacterial culture and polymerase chain reaction analysis for Mycobacterium tuberculosis were negative. Immunological examinations showed high levels of immunoglobulin G4 (IgG4) in both serum and pleural effusion fluid. Pathologic evaluation of a left pleural biopsy specimen using hematoxylin and eosin staining and immunohistochemical staining showed fibrosis-associated lymphoplasmacytic infiltration, 50 IgG4-positive plasma cells per high-power field, and an IgG4/IgG ratio of 40%. Thus, a diagnosis of IgG4-related pleuritis without other systemic manifestations was established. The bilateral pleural effusion improved following corticosteroid therapy. This is a rare case of IgG4-related pleuritis with no other organ involvement.

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.

IgG4-related disease involving the esophagus: a clinicopathological study

Immunoglobulin G4 (IgG4)-related disease is a recently coined systemic disease characterized by specific histopathologic findings of an intense lymphoplasmacytic infiltrate, storiform fibrosis, and obliterative phlebitis in the presence of predominant IgG4-positive plasma cells. Although IgG4-related disease has been described in many organs, involvement of the esophagus is very rare. In this study, we describe the clinicopathologic characteristics of eight patients with IgG4-related esophagitis. We evaluated chronic esophagitis specimens with lymphoplasmacytic infiltrate obtained over the past 6 years (from January 2011 to February 2017) using a chart review, pathologic examination, and IgG4 immunohistochemical staining. The diagnoses of the specimens were either confirmed as IgG4-related esophagitis (IgG4-RE) or chronic esophagitis, not otherwise specified (CENOS), and the clinicopathologic data from each group were compared. Eight patients were diagnosed with IgG4-RE and 10 controls were identified and diagnosed with CENOS. In the IgG4-RE group, esophageal strictures were identified in three patients, two patients had postmyotomy treated achalasia, one patient had erosive esophagitis and another presented with an esophageal nodule. Only one patient had an unremarkable mucosa on endoscopy. In the CENOS group, four patients had esophageal strictures, six had erosive esophagitis, one patient had mild esophagitis. The IgG4-RE group had significantly higher numbers of IgG4-positive plasma cells (66.9 ± 21.9 vs. 4.7 ± 2.4 per high power field; P< 0.001) and a greater IgG4: IgG ratio 0.76 ± 0.13 vs. 0.06 ± 0.05; P< 0.001) when compared to CENOS patients. Two of the patients with recurrent esophageal strictures in the IgG4-RE group showed initial response to steroid therapy and are currently on immunosuppressive therapy which has significantly reduced the need for multiple esophageal dilatations. The presentation of IgG4-related esophageal disease can vary and the key to diagnosis is dependent on histopathology. These observations highlight the need for IgG4 immunohistochemical staining of esophageal biopsies especially in patients with mucosal ulceration, chronic inflammation, and plasmacytosis on biopsy. This will prevent unwarranted esophagectomies and failed medical treatment due to lack of recognition of this entity.

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.

IgG4-related disease of the biliary tract and pancreas: clinical and experimental advances

PURPOSE OF REVIEW

IgG4-related disease (IgG4-RD) is an immune-mediated disease of unknown cause. It predominantly affects the biliary tract [IgG4-associated cholangitis (IAC)] and pancreas [autoimmune pancreatitis (AIP)] of mostly elderly men. Accurate diagnostic tests are lacking. Patients benefit from predniso(lo)ne treatment. However, disease relapse is often seen. This review will address pathophysiological aspects and advances in diagnostic and therapeutic strategies.

RECENT FINDINGS

The role of IgG1 and IgG4 in the pathophysiology of IgG4-RD was studied in mice which showed more intense organ damage of pancreas and salivary glands when IgG1 rather than IgG4 of patients with IgG4-RD was injected. Coadministration of IgG1+IgG4 led to dampening of IgG1-mediated injury supporting the view that IgG4 exerts immune-dampening effects. IgG4+ B-cell receptor clones identified by next-generation sequencing and the IgG4/IgG RNA ratio in human blood assessed by quantitative PCR were able to accurately distinguish IAC/AIP from primary sclerosing cholangitis or pancreatobiliary malignancies. Long-term treatment with low-dose prednisolone was safe and reduced the number of flare-ups in patients with AIP.

SUMMARY

Early diagnosis by a novel accurate and easy-to-use qPCR test may prevent life-threatening complications, unnecessary interventions and fatal course because of misdiagnosis. Prednisolone treatment remains the standard of care in patients with IgG4-RD.

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.

New strategies for the treatment of IgG4-related disease

IgG4-related disease is a chronic and fibroinflammatory disorder, which is characterized with elevated levels of serum IgG4, and prominent infiltration of IgG4-bearing plasma cells in the involved organs. It often affects with lacrimal glands, salivary glands, pancreas, kidneys, lungs, and retroperitoneal cavity. Now, the first line of the induction therapy for IgG4-related disease is glucocorticoid, but almost patients need the maintenance treatment and experience the relapse. It is recently reported that biologic agents, including rituximab and abatacept, are effective for the relapse of IgG4-related disease. It is clear that the tapering effect of glucocorticoid is better than conventional oral immunosuppressants. We can use it in safely if we choose the appropriate cases. The investigator-initiated trial of rituximab for IgG4-related disease is scheduled in Japan. This article reviews the new strategies for the treatment of IgG4-related disease with our data of SMART registry, and discuss the problems of each biologic agents for IgG4-related disease.

Sporadic occurrence of non-diagnosed IgG4-related disease in lymphoma patients with a previous Sjögren's syndrome diagnosis

BACKGROUND

IgG4-related disease (IgG4-RD) is a recently recognized fibro-inflammatory disorder, which may affect many organs, and often comes to clinical attention due to tumor-like organ swelling or is identified incidentally by specific biopsy findings. Typical histopathology of IgG4-RD is lymphoplasmacytic infiltration rich in IgG4 + plasma cells (PCs), storiform fibrosis, and obliterative phlebitis. Patients with sicca symptoms can be misdiagnosed as primary Sjögren's syndrome (pSS) instead of IgG4-RD because of clinical and histopathological similarities. Moreover, an association with lymphoma development is described in both diseases. This study investigated signs of IgG4-RD in a population-based cohort of patients diagnosed with pSS complicated by lymphoma.

METHODS

Patients with pSS and lymphoma diagnoses and available lymphoma specimens were identified by linkage with the Swedish Patient Register 1964-2007 and the Cancer Register 1990-2007 (n = 79). Clinical data and lymphomas were reviewed and the diagnoses evaluated. All lymphoma tissues and available minor salivary gland biopsies (n = 11) were immunostained for IgG4 + PCs and evaluated for other histopathological signs of IgG4-RD. In a case with specific findings of IgG4-RD, other available tissue specimens of the same patient were investigated for IgG4-RD.

RESULTS

Only one patient of 79 (1.3%) had >10 IgG4 + PCs/high power field (HPF) in the lymphoma tissue, an unspecified low-grade B-cell lymphoma localized in the submandibular gland. This patient also had other histopathological features of IgG4-RD in the lymphoma and a surgical lung biopsy taken five years before lymphoma diagnosis and, therefore, fulfilled the criteria for IgG4-RD. Occasional IgG4 + PCs (<10/HPF) without signs of IgG4-RD were observed in another six lymphomas. No IgG4 + PCs were identified in the minor salivary gland biopsies.

CONCLUSION

Histopathological findings of IgG4-RD may co-exist with low malignant B-cell lymphoma in patients with initially suspected pSS and may be associated with an underlying IgG4-RD.

Immunoglobulin G4-related pleuritis - A case report

Immunoglobulin G4-related disease (IgG4-RD) is a chronic disease that presents with inflammation and fibrosis of involved tissue. It encompasses several disorders previously described using different terms, but all disorders are characterised by IgG4-positive plasma cells and lymphocytes infiltration of tissues. We report a rare case of a 58-year-old man with IgG4-related pleural disease without other systemic manifestations. The diagnosis was based on characteristic changes on PET-CT and typical histopathology in a pleural specimen. The patient’s condition improved following immunosuppressive therapy.

IgG4-related disease in Italy: clinical features and outcomes of a large cohort of patients

OBJECTIVES

To describe the clinical features, treatment response, and follow-up of a large cohort of Italian patients with immunoglobulin (Ig)G4-related disease (IgG4-RD) referred to a single tertiary care centre.

METHOD

Clinical, laboratory, histological, and imaging features were retrospectively reviewed. IgG4-RD was classified as 'definite' or 'possible' according to international consensus guidelines and comprehensive diagnostic criteria for IgG4-RD. Disease activity was assessed by means of the IgG4-RD Responder Index (IgG4-RD RI).

RESULTS

Forty-one patients (15 females, 26 males) were included in this study: 26 with 'definite' IgG4-RD and 15 with 'possible' IgG4-RD. The median age at diagnosis was 62 years. The median follow-up was 36 months (IQR 24-51). A history of atopy was present in 30% of patients. The pancreas, retroperitoneum, and major salivary glands were the most frequently involved organs. Serum IgG4 levels were elevated in 68% of cases. Thirty-six patients were initially treated with glucocorticoids (GCs) to induce remission. IgG4-RD RI decreased from a median of 7.8 at baseline to 2.9 after 1 month of therapy. Relapse occurred in 19/41 patients (46%) and required additional immunosuppressive drugs to maintain long-term remission. Multiple flares occurred in a minority of patients. A single case of orbital pseudotumour did not respond to medical therapy and underwent surgical debulking.

CONCLUSIONS

IgG4-RD is an elusive inflammatory disease to be considered in the differential diagnosis of isolated or multiple tumefactive lesions. Long-term disease control can be achieved with corticosteroids and immunosuppressive drugs in the majority of cases.

Immunology of IgG4-related disease

Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition that derives its name from the characteristic finding of abundant IgG4(+) plasma cells in affected tissues, as well as the presence of elevated serum IgG4 concentrations in many patients. In contrast to fibrotic disorders, such as systemic sclerosis or idiopathic pulmonary fibrosis in which the tissues fibrosis has remained largely intractable to treatment, many IgG4-RD patients appear to have a condition in which the collagen deposition is reversible. The mechanisms underlying this peculiar feature remain unknown, but the remarkable efficacy of B cell depletion in these patients supports an important pathogenic role of B cell/T cell collaboration. In particular, aberrant T helper type 2 (Th2)/regulatory T cells sustained by putative autoreactive B cells have been proposed to drive collagen deposition through the production of profibrotic cytokines, but definitive demonstrations of this hypothesis are lacking. Indeed, a number of unsolved questions need to be addressed in order to fully understand the pathogenesis of IgG4-RD. These include the identification of an antigenic trigger(s), the implications (if any) of IgG4 antibodies for pathophysiology and the precise immunological mechanisms leading to fibrosis. Recent investigations have also raised the possibility that innate immunity might precede adaptive immunity, thus further complicating the pathological scenario. Here, we aim to review the most recent insights on the immunology of IgG4-RD, focusing on the relative contribution of innate and adaptive immune responses to the full pathological phenotype of this fibrotic condition. Clinical, histological and therapeutic features are also addressed.