The Role of Symptom Duration and Serologic Factors in the Relapse of IgG4-Related Ophthalmic Disease following Surgery: A Retrospective Cohort Study.

IgG4-related disease (IgG4-RD) affects multiple organs and is characterized by immune-mediated inflammation and fibrosis; IgG-RD affecting orbital tissue is known as IgG4-related ophthalmic disease (IgG4-ROD). This research is aimed at exploring whether symptom duration and common serologic factors, such as IgG, IgE, and eosinophils, are potential risk factors for IgG4-ROD patient relapse after surgery and identifying possible causes of the positive correlation between symptom duration and relapse. This retrospective cohort study included 40 IgG4-ROD patients after surgery. Auxiliary inspection results were obtained before surgery and during follow-up, and relapse risk factors were identified based on previous studies. We used the Spearman rank correlation test to reveal the relationship between symptom duration and relapse time and identified the optimal cutoff value for symptom duration by X-tile. Then, we divided the patients into the long-duration and short-duration groups. Kaplan-Meier survival analyses and log-rank tests were performed to identify the relationship between symptom duration and relapse using X-tile software. Finally, we studied the relationship between previously studied relapse risk factors and symptom duration. The survival curves of the long-duration and short-duration groups were obviously different, and the baseline serum IgG, IgE, and eosinophil levels and asthma concomitant rate were significantly different between the long-duration and short-duration groups. Furthermore, the baseline serum IgG (r = 0.485, P = 0.002), IgE (r = 0.350, P = 0.037), and eosinophil (r = 0.6535, P < 0.0001) levels were positively correlated with symptom duration. Our study shows that IgG4-ROD symptom duration is significantly positively correlated with relapse rate and negatively correlated with relapse time. Symptom duration was positively correlated with serum baseline IgG4, IgE, and eosinophil levels and asthma history, which were potential risk factors for disease relapse. We recommended that IgG4-ROD patients with symptom durations greater than 96 months continue to receive maintenance steroid therapy longer than 1 year postsurgery to reduce the relapse rate.

The role of PD-1/PD-Ls in the pathogenesis of IgG4-related disease.

OBJECTIVE: To investigate the role of programmed cell death protein 1 (PD-1) and its two ligands, PD-L1 and PD-L2, in the pathogenesis of IgG4-related disease (IgG4-RD). METHODS: Patients with IgG4-RD (n = 43) and healthy controls (n = 34) were recruited. Expression levels of PD-1, PD-L1 and PD-L2 in plasma, submandibular gland and T cell subsets were determined by ELISA, immunohistochemistry and flow cytometry. Naïve T cells were stimulated with or without PD-L1/PD-L2 or anti-PD-L1/anti-PD-L2 for 7 days and the proportion of CD4+CD25+ Treg cells was detected by flow cytometry. RESULTS: The expression of PD-1, PD-L1 and PD-L2 in the plasma, submandibular gland and on the surface of Treg cells was increased in IgG4-RD patients. Plasma soluble (s)PD-1 was positively correlated with serum IgG, IgG1, IgG3, IgG4, IgG4-RD responder index and numbers of organs involved, and negatively correlated with serum IgM, IgA, C3 and C4. Plasma sPD-L2 was positively correlated with serum IgG1, and plasma sPD-L1 was positively correlated with sPD-L2 and negatively correlated with C3. Stimulation of PD-L1 but not PD-L2 promoted the differentiation of naïve T cells from IgG4-RD patients into CD4+CD25+ Treg cells. CONCLUSION: Plasma concentrations of sPD-1, sPD-L1 and sPD-L2 were significantly increased in patients with IgG4-RD, and the expression of PD-1 and PD-L2 on Treg cells was upregulated. PD-1-PD-L1 can promote the differentiation of naïve T cells into Treg cells and thus participate in the pathogenesis of IgG4-RD.

Enfermedad relacionada con IgG4, según criterios ACR/EULAR 2019 sin evidencia de IgG4 en sangre / IgG4-related disease according to ACR/EULAR 2019 criteria without evidence of IgG4 in blood

INTRODUCCIÓN. La enfermedad relacionada con IgG4 es una patología fibroinflamatoria multiorgánica, de origen desconocido, que simula trastornos malignos, infecciosos e inflamatorios. Los criterios del American College of Rheumatology y la European League against Rheumatism 2019, son útiles para el diagnóstico diferencial de ésta enfermedad cuando se no se cuenta con evidencia de inmunoglobulina G4 en sangre. CASO CLÍNICO. Paciente hombre de 45 años de edad, nacido en Ambato-Ecuador, con ingreso en noviembre del 2017, en emergencias del Hospital de Especialidades Carlos Andrade Marín, con presencia de tos con hemoptisis leve, febrícula, astenia, pérdida de peso e hiporexia de dos semanas de evolución. Se realizó múltiples exámenes, tras observar infiltrados pulmonares intersticiales, con elevación de inmunoglobulina G en suero, negativas para malignidad; se sospechó de enfermedad relacionada a inmunoglobulina G4. Se ampliaron los estudios para descartar otras patologías más prevalentes y cuyo diferencial es primordial. Se inició tratamiento con prednisona y micofenolato con buena respuesta clínica; durante dos años. DISCUSIÓN. La evidencia científica registró que el hallazgo más importante en la enfermedad relacionada con inmunoglobulina G4 fue un aumento de sus niveles séricos. La recurrencia de la enfermedad en un órgano afectado o la aparición de un nuevo órgano involucrado pudo conducir al diagnóstico en el caso presentado. CONCLUSIÓN. La enfermedad relacionada con inmunoglobulina G4 al ser una patología heterogénea, inmunomediada, al simular otras afecciones puede retrasar el diagnóstico; se debe tener una alta sospecha clínica, si al excluir otros procesos infecciosos, autoinmunes y/o eoplásicos, hay evidencia de patología fibroesclerosante multiorgánica sin causa establecida.

INTRODUCTION. IgG4-related disease is a multiorgan fibroinflammatory pathology of unknown origin that mimics malignant, infectious, and inflammatory disorders. The criteria of the American College of Rheumatology and the European League against Rheumatism 2019 are useful for the differential diagnosis of this disease when there is no evidence of immunoglobulin G4 in blood. CLINICAL CASE. 45-year-old male patient, born in Ambato-Ecuador, with admission in November 2017, in the emergency room of the Hospital de Especialidades Carlos Andrade Marín, with the presence of cough with mild hemoptysis, fever, asthenia, weight loss and hyporexia of two weeks of evolution. Multiple tests were performed, after observing interstitial pulmonary infiltrates, with elevated serum immunoglobulin G, negative for malignancy; immunoglobulin G4-related disease was suspected. Studies were extended to rule out other more prevalent pathologies whose differential is paramount. Treatment with prednisone and mycophenolate was started with good clinical response; for two years. DISCUSSION. The scientific evidence recorded that the most important finding in immunoglobulin G4-related disease was an increase in its serum levels. Recurrence of the disease in an affected organ or the appearance of a new involved organ could have led to the diagnosis in the presented case. CONCLUSION. Immunoglobulin G4-related disease, being a heterogeneous, immune-mediated pathology, by simulating other conditions may delay diagnosis; a high clinical suspicion should be maintained if, when other infectious, autoimmune and/or neoplastic processes are excluded, there is evidence of multiorgan fibrosclerosing pathology without established cause.

IgG4-related pachymeningitis and mastoiditis, associated with cerebral venous thrombosis: A case report.

IgG4-related disease (IgG4-RD) is a multisystem fibroinflammatory condition; this can be a challenging diagnosis that requires clinico-pathologic correlation. We report a young woman, presenting with cranial nerve palsy. The work-up revealed pachymeningitis, cerebral venous thrombosis (CVT), and a destructive lesion in the mastoid. We diagnosed IgG4-RD through mastoidectomy. Thus, a biopsy of asymptomatic, infrequently affected organs, like the mastoid, can meet all histopathological criteria. In neuro-meningeal presentations, CVT may be secondary to the local inflammatory environment of pachymeningitis. Since our patient had a deep vein thrombosis one year prior, we discuss a possible higher risk of thrombosis in IgG4-RD patients.

IgG4 producing POEMS syndrome: A rarely recognized subtype.

Serum IgG4 is typically measured for Immunoglobulin G4-related Disease (IgG4-RD), a fibroinflammatory condition associated with polyclonal increase in serum IgG4. Yet, increased IgG4 may still be monoclonal, and little is known about IgG4 POEMS syndrome. We present a case of 40-year-old male with a mass lesion in the left sacral ala. The mass was composed of non-neoplastic fibrous tissue and dense infiltrate of mature plasmacytes with dense eosinophilic cytoplasm and eccentrically placed nuclei that express monoclonal Lambda free light chains and show diffuse positivity for IgG and IgG4. We discuss clinical manifestations and challenges encountered in the diagnosis and treatment of this rare coexistence.

Coronary (peri)-arteritis in patients with IgG4-related disease: A case series from the Central Anatolia Region of Turkey.

OBJECTIVE: Immunoglobulin G4-related disease (IgG4-RD) is a newly recognized fibro-inflammatory disease which affects many systems, as well as the cardiovascular system. Identifying the coronary involvement like periaortitis, coronary periarteritis and pericarditis is important, as they often cause unfavorable outcomes. METHODS: Eighty-one patients with IgG4-RD were retrospectively evaluated for symptomatic coronary artery involvement from Hacettepe University Vasculitis Research Center (HUVAC) database. The demographic, laboratory, radiologic and clinical characteristics of the patients were assessed. RESULTS: Among 81 patients with IgG4-RD, 6 patients (M/F:5/1) had coronary artery involvement. The patients' median age was 57 and serum IgG4 levels were above normal except for one case. All patients with coronary arteritis revealed an increased coronary vessel wall thickening and stenotic lesions. The coronary aneurysm and pericarditis were observed in half of the patients. Immunosuppressive treatments were given to all the patients and most of them followed in stable condition. CONCLUSION: Coronary arteritis is a rare but notable manifestation of IgG4-RD. Although coronary periarteritis can cause significant morbidity and mortality, it seems better results can be achieved with early diagnosis and treatment.

Serum IgG4 levels at diagnosis can predict unfavorable outcomes of untreated patients with IgG4-related disease.

The outcomes of patients with immunoglobulin G4 (IgG4)-related disease (IgG4-RD) who are not treated are unclear. This study aimed to clarify these outcomes and identify the factors related to them. We retrospectively evaluated various clinical features including laboratory data and involved organs at diagnosis in 107 patients with IgG4-RD, who were followed up for more than 6 months, at a single center in Japan. We compared the clinical features of the 27 untreated patients with those of the 80 patients treated with glucocorticoid. The patient outcomes were investigated, and logistic regression analysis was performed to identify factors related to them. The patients comprised 73 men and 34 women (median age 67 years). The untreated patients had significantly lower IgG4-RD responder index (9 vs. 12) and fewer affected organs (1 vs. 3) than did those treated with glucocorticoid. Of these 27 patients, 8 experienced deterioration of IgG4-RD after the diagnosis. In the age- and sex-adjusted logistic regression analysis, serum IgG4 elevation (per 100 mg/dL, odds ratio 1.194, 95% confidence interval 1.017-1.402) was the only significant factor related to disease deterioration in untreated patients with IgG4-RD, whereas not serum IgG4 levels (per 100 mg/dL, odds ratio 0.995, 95% confidence interval 0.921-1.075) but history of allergy (OR 3.134, 95% confidence interval 1.094-8.977, P = 0.033) related to deterioration in patients who underwent treatment. Serum IgG4 levels may be a useful predictor of unfavorable outcomes in untreated patients with IgG4-RD, who tend to have fewer affected organs and lower IgG4-RD responder index.

Proteomic analyses of plasma-derived exosomes in immunoglobulin (Ig) G4-related disease and their potential roles in B cell differentiation and tissue damage.

OBJECTIVE: To investigate the proteomic profiles of plasma exosomes isolated from patients with immunoglobulin (Ig) G4-related disease (IgG4-RD) and to determine their potential roles in B cell differentiation and tissue damage. METHODS: One hundred untreated IgG4-RD patients and 135 sex- and age-matched healthy controls (HCs) were enrolled in this study. A combination of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and tandem mass tag (TMT)-label quantitation was used for proteomic profiling. Differentially expressed proteins were validated by Western blot, enzyme-linked immunosorbent assay (ELISA) and real-time quantitative PCR (RT-qPCR) analyses. B cell activation, apoptosis, differentiation and reactive oxygen species (ROS) production were analyzed by flow cytometry. We also analyzed the correlations between differentially expressed complement proteins and laboratory parameters. RESULTS: A total of 178 differentially expressed proteins were identified in plasma exosomes in IgG4-RD patients compared with HCs, and these proteins were enriched predominantly in the complement cascade pathway. Furthermore, reduced expression levels of complement components C3 and C5 in IgG4-RD were correlated with clinical parameters. Following stimulation with IgG4-RD plasma exosomes, the percentages of naïve B cells decreased, while those of memory B cells and plasmablasts increased; the levels of cytochrome c, somatic (CYCS) and downstream complement system activation also increased. Moreover, ROS production was greater in B cells of IgG4-RD patients than in those of HCs. In affected submandibular glands, the BCR signalling pathway was activated, and exosomes were enriched. CONCLUSION: Proteomic profiling revealed that plasma exosome proteins may participate in the pathogenesis of IgG4-RD through complement activation and may be involved in B cell differentiation and activation of the B cell auto-oxidative damage pathway.

Disparities between IgG4-related kidney disease and extrarenal IgG4-related disease in a case-control study based on 450 patients.

We aimed to compare the demographic, clinical and laboratory characteristics between IgG4-related kidney disease (IgG4-RKD+) and extrarenal IgG4-related disease (IgG4-RKD-) in a large Chinese cohort, as well as describing the radiological and pathological features of IgG4-RKD+. We retrospectively analyzed the medical records of 470 IgG4-related disease (IgG4-RD) patients at Peking University People's Hospital from January 2004 to January 2020. The demographic, clinical, laboratory, radiological and pathological characteristics between IgG4-RKD+ and IgG4-RKD- were compared. Twenty IgG4-RD patients who had definite etiology of renal impairment including diabetes, hypertension and etc. were excluded. Among the remained 450 IgG4-RD patients, 53 were diagnosed with IgG4-RKD+ . IgG4-RKD+ patients had older age at onset and at diagnosis. Male to female ratio of IgG4-RKD+ patients is significantly higher. In the IgG4-RKD+ group, the most commonly involved organs were salivary gland, lymph nodes and pancreas. It was found that renal function was impaired in approximately 40% of IgG4-RKD+ patients. The most common imaging finding is multiple, often bilateral, hypodense lesions. Male sex, more than three organs involved, and low serum C3 level were risk factors for IgG4-RKD+ in IgG4-RD patients. These findings indicate potential differences in pathogenesis of these two phenotypes.

Cut-off values of serum IgG4 among three reagents, including a novel IgG4 reagent: a multicenter study.

Elevated serum IgG4 is a useful marker of IgG4-related disease (IgG4-RD) activity. However, there is no uniformity in the cut-off values of IgG4 among the various reagents. The aim of this study was to compare the measured and cut-off values of IgG4 assessed using three different reagents. This study enrolled 466 IgG4-RD and non-IgG4-RD patients who required measurement of serum IgG4 levels to diagnose or treat IgG4-RD. Serum IgG4 was measured using three reagents: N-assay LA IgG4 Nittobo (Nittobo), BS-NIA IgG4 (TBS), and N Latex IgG4 (Siemens). The values obtained using the three reagents were compared, and cut-off values were calculated for each. Although there was good correlation among the results with the three reagents, the measured and cut-off values were all different. The Nittobo values were 1.4 times the TBS values and the TBS values were almost half those of the Siemens values. ROC curve analysis showed cut-off values for the Nittobo, TBS, and Siemens reagents of 1.42, 1.31, and 2.38 g/L, respectively. The measured and cut-off values of serum IgG4 vary depending on the reagents used for the assay, although there is good correlation among the values measured by the three reagents.

IgG4-Related Disease: A Retrospective Chinese Study of Features and Treatment Response of 98 Patients Including 4 Rare Cases.

The features and treatment of 98 Chinese patients with immunoglobulin G4 (IgG4)-related disease (IgG4-RD) referred to a single tertiary referring centre were reviewed. Patients diagnosed with IgG4-RD according to the comprehensive diagnostic criteria (CDC) were included in the retrospective study from May 2012 to March 2019. We collected data on clinical, laboratory, imaging, histological features and treatment. Totally, 98 patients with IgG4-RD were enrolled. The common clinical manifestations included abdominal pain, salivary gland swelling and lymphadenopathy. 51% of the patients had multiple organs involvement. Lymph nodes, pancreas and salivary glands were most commonly involved. Four rare sites including ulna, cerebellum, scalp, and mammary gland were found. The serum IgG4 level was increased by 85.7%. The serum IgG4 level was positively correlated with the number of involved organs, IgG and IgG4/IgG. Low C3 and C4 levels were observed in 37.5% and 12.2% patients respectively, and all patients with kidney involvement had hypocomplementemia. A total of 54 patients underwent tissue biopsies, and 55.6%, 31.5% and 11.1% cases were diagnosed as definite, probable and possible IgG4-RD, respectively. Eighty-eight patients received glucocorticoids (GCs) therapy. Five patients underwent radical surgery to remove the lesion. 73% of them presented a complete or partial remission. IgG4-RD is a systemic fibroinflammatory disease with involvement of multiple organs throughout the body including some rare sites. Most IgG4-RD patients had increased serum IgG4 levels and patients with kidney involvement showed hypocomplementemia. GCs therapy is effective. More research is needed to provide a more reliable basis for the diagnosis and treatment of patients.

Serum free light chain assessment in type 1 autoimmune pancreatitis.

BACKGROUND: /Object: Some patients with type 1 autoimmune pancreatitis (AIP), the pancreatic manifestation of IgG4-related disease, have normal serum IgG4. The aim of this study is to investigate the diagnostic value of measuring serum free light chains (FLCs) in type 1 AIP. MATERIALS AND METHODS: Thirty-seven patients with type 1 AIP, and 21 healthy, 17 alcoholic chronic pancreatitis (ACP), 21 idiopathic chronic pancreatitis (ICP) and 20 pancreatic cancer (PC) patients were enrolled. Serum IgG4 and FLC concentrations were measured using sFLC Freelite assays on a nephelometric analyzer. RESULTS: Active AIP patients have significantly higher serum levels of κ (median 30.97 (12.3-227.0) mg/L) and λFLC (median 20.53 (12.36-102.7) mg/L)) than healthy controls (κFLC; median 12.5 (3.1-52.1) mg/L), λFLC: median 12.45 (5.4-39.5) mg/L) (p < 0.05) correlating with raised serum IgG4, and significantly higher summated FLCs (∑) (median 53.09 (25.0-218.0) mg/L) than ICP patients (median 26.77 (15.0-89.2) mg/L) and healthy controls (median 24.43 (8.5-91.6) mg/L) (p < 0.05). AIP patients (median 1.43 (0.84-3.24)) showed significantly higher κ/λ ratios than ACP (median 0.83 (0.42-1.18)), ICP (median 0.87 (0.47-2.16)), PC patients (median 0.90 (0.48-1.27)) and healthy controls (median 0.963 (0.51-1.32)). There was a correlation between increased κ and λ FLCs levels and the number of affected organs involved in IgG4 related disease. CONCLUSION: Patients with type 1 AIP have increased serum k and λ FLC concentrations, Σ FLC, and κ/λ ratios. These novel biomarkers may be useful in the diagnosis of type 1 AIP and in monitoring disease activity.

Follow-up with serum IgG4-monitoring in 8 patients with IgG4-related disease diagnosed by a lacrimal gland mass.

The diagnostic criteria for IgG4-related disease were previously published and serum IgG4 measurement has been reimbursed by national health insurance in Japan since 2012. Eight patients diagnosed with IgG4-related disease based on lacrimal gland masses were retrospectively reviewed. The 8 patients were 3 men and 5 women ranging in age from 52 to 77 (median, 63) years at the initial visit and their follow-up period ranged from 0.25 to 11 (median, 7) years. Bilateral and unilateral involvement were noted in 4 patients each; 2 on the right side and 2 on the left side in those with unilateral involvement. Serum IgG4 was high in 5 of 8 patients at the initial visit. Five patients with no systemic signs were followed without treatment, whereas oral steroids were administered and tapered in the other 3 patients who exhibited systemic signs. One patient with a history of radiation for MALT lymphoma in bilateral lacrimal glands developed IgG4-related disease in the left lacrimal gland 10 years later and was followed without treatment. Nine years later, her serum IgG4 level increased to 1500 mg/dL and paracardiac lesions, found on positron emission tomography, were confirmed to be MALT lymphoma by needle biopsy, leading to systemic chemotherapy. The other 7 patients had neither local recurrence nor additional systemic signs. Serum IgG4 monitoring may be useful to detect systemic complications in IgG4-related ophthalmic disease and markedly high serum IgG4 levels may indicate new lymphoma at other sites.

IgG4-related pleural effusion with high adenosine deaminase levels: A case report and literature review.

RATIONALE: Levels of pleural fluid adenosine deaminase (ADA), a useful marker for the diagnosis of tuberculous pleurisy, are elevated in some reports of immunoglobulin G4 (IgG4)-related pleural effusion. We describe a patient with IgG4-related pleural effusion who exhibited a high concentration of ADA. Furthermore, we reviewed the literature to compare patients with IgG4-related pleural effusion and tuberculous pleurisy. PATIENT CONCERNS: A 75-year-old male patient had dyspnea for 1 month with a left pleural effusion that was exudative, lymphocyte dominant. The pleural fluid test results revealed a total protein (TP) concentration of 6.60 g/dl, a lactate dehydrogenase (LDH) level of 383 IU/dl, and an ADA concentration of 54.5 U/L. An interferon gamma release assay showed a negative result. DIAGNOSES: Histological analysis of the thoracoscopic pleural biopsy revealed lymphoplasmacytic infiltration, with 80 IgG4-positive plasma cells/high-power field, and an IgG4/IgG ratio of approximately 40% to 50%. Other diseases were ruled out based on symptoms, negative autoimmune antigen results, and histopathologic findings. Thus, he was diagnosed with IgG4-related pleural effusion. INTERVENTIONS: He received 15 mg of prednisolone as therapy. OUTCOMES: His pleural effusion and symptoms improved gradually within several months, and prednisolone was tapered to 6 mg daily. LESSONS: It is important to distinguish between IgG4-related pleural effusion and tuberculous pleurisy. Therefore, we compared 22 patients with IgG4-related pleural effusion from PubMed and the Japan Medical Abstracts Society to 40 patients with tuberculous pleurisy at Fukujuji Hospital from January 2017 to May 2019. According to thoracentesis findings, 14 of 18 patients with IgG4-related pleural effusion had high ADA more than 40 U/L. The pleural effusion of patients with IgG4-related pleural effusion showed higher TP levels (P < .001) and lower LDH (P < .001) and ADA levels (P = .002) than those with tuberculous pleurisy. Moreover, the pleural fluid ADA/TP ratio was a good predictor for differentiating IgG4-related pleural effusion and tuberculous pleurisy (area under the receiver operating characteristic curve of 0.909; 95% confidence level: 0.824-0.994).

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). We aimed to determine the efficacy and safety of mizoribine (MZR) among IgG4RD patients. METHODS: We retrospectively reviewed records of IgG4RD patients at Immuno-Rheumatology Center in St. Luke's International Hospital, Tokyo, Japan. Patients treated with MZR were classified into the MZR group, and those treated with GC 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 disease exacerbation. RESULTS: A total of 14 and 29 cases were included in the MZR and control group. Multiple organ involvement (three or more organs) was significantly more frequent in the MZR group [10 (71.4%) vs 9 (31.0%), P= 0.021]. Kaplan-Meier analysis revealed a significant reduction inexacerbation 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 (95%CI 0.12-1.01; P = 0.052) and 3.51 (95%CI 1.29-9.51; P= 0.014). The cumulative GC dose (mg per year, interquartile range) tended to be lower in the MZR group [1448 (1003-1642) vs 2179 (1264-3425); P= 0.09]. CONCLUSION: MZR decreased disease exacerbation among IgG4RD patients with multi-organ involvement and showed a steroid-sparing effect. MZR could be a treatment option for IgG4RD.

Serum immunoglobulin free light chains and their association with clinical phenotypes, serology and activity in patients with IgG4-related disease.

The clinical utility of serum immunoglobulin free light chains (sFLC) in IgG4-related disease (IgG4-RD) is unknown. Herein we evaluated their association with clinical phenotypes, serology and activity in patients with IgG4-RD. Cross-sectional study that included 45 patients with IgG4-RD, and as controls 25 with Sjögren's syndrome (SS) and 15 with sarcoidosis. IgG4-RD patients were classified in clinical phenotypes: pancreato-hepato-biliary, retroperitoneum/aorta, head/neck-limited and Mikulicz/systemic; as well as proliferative vs. fibrotic phenotypes. We assessed the IgG4-RD Responder Index (IgG4-RD RI) at recruitment and measured IgG1, IgG4, κ and λ sFLC serum levels by turbidometry. sFLC levels were similar among IgG4-RD, SS and sarcoidosis groups. Regarding the IgG4-RD patients, the mean age was 49 years, 24 (53.3%) were men and 55.5% had activity. Eight (17.7%) belonged to pancreato-hepato-biliary, 6 (13.3%) to retroperitoneum/aorta, 14 (31.1%) to head/neck-limited, 16 (35.5%) to Mikulicz/systemic phenotypes, whereas 36 (80%) to proliferative and 9 (20%) to fibrotic phenotypes. High κ sFLC, λ sFLC and κ/λ ratio were present in 29 (64.4%), 13 (28.9%) and 13 (28.9%) of IgG4-RD patients, respectively. There were no differences in sFLC among IgG4-RD phenotypes. κ sFLC and κ/λ ratio correlated positively with the number of involved organs and IgG4-RD RI. Patients with renal involvement had higher κ sFLC and λ sFLC. The AUC for κ sFLC and λ sFLC, for renal involvement was 0.78 and 0.72, respectively. Active IgG4-RD had higher levels of κ sFLC and more frequently a high κ/λ ratio. The AUC for κ sFLC and κ/λ ratio for predicting active IgG4-RD was 0.67 and 0.70, respectively. sFLC correlated positively with IgG1 and IgG4 levels. sFLC may be useful as a biomarker of disease activity as well as multiorgan and renal involvement. In particular, a high κ/λ ratio may identify patients with active disease.

Hypocomplementemia is related to elevated serum levels of IgG subclasses other than IgG4 in IgG4-related kidney disease.

OBJECTIVES: This study investigated the clinical features of IgG4-RKD patients with hypocomplementemia compared with those without it, so as to clarify the factors related to hypocomplementemia. METHODS: In this single-center retrospective study, we analyzed the clinical features of 25 patients with IgG4-RKD according to the presence/absence of hypocomplementemia. Additionally, we validated the results of a single-center study in a separate large multicenter cohort of 328 patients with IgG4-RD, and searched for factors related to hypocomplementemia. RESULTS: Serum IgG levels (p < .001), non-IgG4 IgG levels, calculated as the total IgG minus IgG4 (p < .001), serum IgG1 levels (p = .017), and the number of involved organs (p = .018) were significantly higher in the hypocomplementemia group. At relapse of renal lesions in four patients, all had serum IgG4 re-elevation, with the three with hypocomplementemia presenting worsening of hypocomplementemia and re-elevation of non-IgG4 IgG levels. In a validation cohort of 328 patients with IgG4-RD, multivariate logistic regression analysis indicated elevation of non-IgG4 IgG levels to be an independent factor related to hypocomplementemia in the patients with IgG4-RKD. CONCLUSION: The present study suggests that hypocomplementemia is associated with elevation of IgG subclasses other than IgG4 including IgG1 in IgG4-RKD.

Urgent manifestations of immunoglobulin G4-related disease.

Objective: Immunoglobulin G4-related disease (IgG4-RD) is considered a chronic condition with insidious presentation, but clinical experience suggests that disease onset prompts admission to the emergency department (ED) in a sizeable proportion of patients. We assessed the prevalence of acute manifestations associated with IgG4-RD onset requiring referral to the ED. Method: We revised our database and identified patients admitted to the ED because of symptoms latterly attributed to IgG4-RD onset (Group 1) and those who were referred to our outpatient clinic without previous urgent manifestations (Group 2). Acute manifestations were clustered based on the anatomical region affected by IgG4-RD. Epidemiological, clinical, and serological features of Groups 1 and 2 were compared. Results: The study included 141 patients with IgG4-RD. Of these, 76 (54%) presented to the ED at disease onset. The most common clinical manifestations requiring admission to the ED were jaundice (53%), abdominal pain (41%), and fever (10%). Gastrointestinal involvement was the most frequent cause of referral to the ED (71% of cases), followed by involvement of the retroperitoneum (14.5%) and the nervous system (6.6%). Pancreatobiliary involvement was significantly more frequent in Group 1 than in Group 2. Head and neck, and salivary and lacrimal gland involvement was more frequent in Group 2 than in Group 1. The diagnostic delay was significantly shorter in Group 1 than in Group 2. Conclusion: Clinical manifestations associated with IgG4-RD onset require referral to the ED in most cases. This finding contrasts with the general view of IgG4-RD as a condition with non-acute presentation.

Lymphadenopathy in IgG4-related disease: a phenotype of severe activity and poor prognosis, with eotaxin-3 as a new biomarker.

OBJECTIVE: To clarify relevant proteins and clinical characteristics of a phenotype of IgG4-related disease (IgG4-RD) with lymphadenopathy. METHODS: We enrolled patients newly diagnosed with IgG4-RD in our department between January 2000 and June 2018 and performed proteomic analysis to measure serum concentrations of 1305 proteins. We extracted proteins overexpressed in patients with IgG4-RD with lymphadenopathy by comparing between those with lymphadenopathy, those without lymphadenopathy and healthy controls. We further reviewed all the patients with IgG4-RD in our institution and investigated the characteristics and prognosis of the patients with IgG4-RD with lymphadenopathy. RESULTS: Eighty-five patients with IgG4-RD were enrolled, of which, 55% had lymphadenopathy. Proteomic analysis in 31 patients with IgG4-RD and 6 healthy controls revealed that eotaxin-3 was a potential serum biomarker in the patients with lymphadenopathy versus those without lymphadenopathy and healthy controls. A cohort of 85 patients with IgG4-RD demonstrated that patients with lymphadenopathy showed a significantly higher serum IgG4, IgG4:IgG ratio, IgG4-RD responder index and eosinophilia (P < 0.001 for all), irrelevant of the extent to which organ involvement developed. Patients with lymphadenopathy treated with glucocorticoid alone relapsed with significantly higher rates than those without lymphadenopathy (P = 0.03). CONCLUSION: Lymphadenopathy in IgG4-RD represents a phenotype associated with high disease activities, eosinophilia and relapsing disease. Eotaxin-3 is a novel biomarker related to IgG4-RD with lymphadenopathy.