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

Diagnostic value of a novel salivary gland ultrasound scoring system in IgG4-related sialadenitis

OBJECTIVES

To develop a novel ultrasound scoring system for the major salivary glands in patients with immunoglobulin G4-related sialadenitis (IgG4-RS) and assess its diagnostic value in a multicentre cohort of Chinese patients.

METHODS

Twenty clinicians (rheumatologists, stomatologists and radiologists) participated. The study was conducted in four steps: (i) defining the ultrasonography (US) elements, (ii) developing a novel ultrasound scoring system for US of the salivary glands, (iii) evaluation of inter- and intra-reader reliabilities using the new ultrasound scoring system, and (iv) assessing the diagnostic value of this novel ultrasound scoring system in IgG4-RS patients in a Chinese multicentre cohort.

RESULTS

A novel ultrasound scoring system for the salivary glands was developed, with total scores ranging from 0 to 34. The inter- and intra-reader reliabilities of the ultrasound scoring system were excellent (0.972 and 0.940, respectively). A total of 470 people were recruited in this study; 187 patients were diagnosed with IgG4-RS, and the remaining 283 people were diagnosed with non-IgG4-RS. Patients with IgG4-RS group had significantly higher US scores than the non-IgG4-RS group (mean US score = 16 vs 4, P < 0.001). The calculated area under the curve for the total US score was 0.852 (95% CI: 0.814, 0.891). The total US scores ≥9 showed a sensitivity of 75.4% and a specificity of 91.9%. Association analysis showed a positive correlation between total US scores and serum IgG4 levels and hypocomplementaemia (r = 0.221 and r = 0.349, respectively; P = 0.002 and P < 0.001, respectively) and a negative correlation between total US scores and serum C3 and C4 levels (r = -0.210 and r = -0.303, respectively; P = 0.005 and P < 0.001, respectively).

CONCLUSION

A novel semiquantitative ultrasound scoring system for patients with IgG4-RS was developed, with good diagnostic performance. The inter- and intra-reader reliabilities were excellent. US scores were correlated with IgG4, C3 and C4 levels and hypocomplementaemia.

The Differential Complement, Fc and Chemokine Receptor Expression of B Cells in IgG4-Related Pancreatobiliary Disease and Primary Sclerosing Cholangitis and Its Relevance for Targeting B Cell Pathways in Disease

Background: Immune-mediated liver and biliary conditions, such as IgG4-related pancreatobiliary disease (IgG4-PB) and a subset of primary sclerosing cholangitis (PSC- high(h)IgG4), exhibit increased IgG4 levels in the blood. The relative expression of IgG4+ and IgG1+ B cells in the blood and the expression of complement and Fc receptors on these IgG1+ and IgG4+ B cells in IgG4-PB and PSC have not been previously described. We hypothesised that the patterns of expression of these cells and their receptors would differ, are relevant to disease pathogenesis and may represent therapeutic targets. Methods: CD19+ B cells were sorted from blood collected from patients with IgG4-PB, PSC-high(h)IgG4 and healthy volunteers. Cells were stained with fluorescent labelled antibodies specific to IgG1, IgG4, complement receptors (CR1 and CR2), Fc receptors (FcεRII and FcγRIIb) and chemokine receptors (CXCR3, CXCR4, CXCR5) and were analysed by flow cytometry. Findings: IgG4-PB, compared to healthy volunteers, showed decreased CR2 expression on IgG1+ B cells (MFI 416 (275-552) vs. 865 (515-3631), p = 0.04) and IgG4+ B cells (MFI 337 (231-353) vs. 571 (398-2521), p = 0.03). IgG4-PB, compared to healthy volunteers, showed increased FcεRII expression on IgG4+ B cells (MFI 296 (225-617) vs. 100 (92-138), p = 0.0145) and decreased FcγRIIb expression on IgG1+ B cells (134 (72-161) vs. 234 (175-291), p = 0.0262). FcγRIIb expression was also decreased in IgG1+ B cells in patients with PSC-hIgG4 compared to healthy volunteers. Conclusions: This exploratory study indicates that in IgG4-PB, B cells have decreased CR2 and FcγRIIb expression and increased FcεRII expression, suggesting altered sensitivity to complement, IgG-mediated inhibition and sensitisation by IgE, which may promote the relative expansion of IgG4+ B cells in this disease.

Clinical phenotypes and prognosis of IgG4-related diseases accompanied by deteriorated kidney function: a retrospective study

INTRODUCTION

IgG4-related disease (IgG4-RD) is a multiorgan autoimmune disorder that causes irreversible injury. Deteriorated kidney functions are common but easily ignored complications associated with IgG4-RD. Yet the clinical manifestations and prognosis of this specific entity have not been fully illustrated.

METHOD

Three hundred fifty patients with IgG4-RD were retrospectively enrolled and divided into 119 IgG4-RD with chronic kidney disease (IgG4-RD CKD+) and 231 IgG4-RD without CKD (IgG4-RD CKD-). Demographic clinical and laboratory characteristics and survival of two cohorts were compared using restricted cubic splines, logistic and Cox regression, and Kaplan-Meier analysis. A nomogram was generated for calculating the probability of CKD in IgG4-RD.

RESULTS

The spectrum of organ involvement was different between IgG4-RD CKD+ and CKD- cohorts (p<0.001). Lung (26.89%) and retroperitoneum (18.49%) involvement were more common in the IgG4-RD CKD+ cohort. Increased serum potassium and phosphorus, reduced calcium levels, and hypocomplementemia (all p<0.05) were observed in IgG4-RD CKD+. Restricted cubic splines revealed a U-shaped plot regarding associations between serum potassium and CKD. Kaplan-Meier analysis demonstrated significantly lower long-term survival rates in IgG4-RD patients with kidney function at CKD stages 4-5. Cox regression revealed declined kidney functions (G4 HR 6.537 (95% CI: 1.134-37.675)) associated with increased all-cause mortality in IgG4-RD patients. A nomogram was constructed to predict CKD in IgG4-RD promptly with a discrimination (C-index) of 0.846.

CONCLUSIONS

CKD in IgG4-RD was associated with poor outcomes and electrolyte disturbances. Patients with IgG4-RD should be aware of possible deterioration in kidney function. The nomogram proposed would help to identify the subtle possibility of CKD in IgG4-RD. Key points • IgG4-related diseases with deteriorated kidney function have specific clinical and laboratory characteristics. • It is crucial to recognize and address the negative impact of deteriorating kidney function in IgG4-related diseases to prevent further harm. • The nomogram proposed would help to identify subtle kidney involvement by evaluating the possibility of CKD in IgG4-related diseases.

Clinical features and relapse risks factors of IgG4 related disease: a single-center retrospective study

OBJECTIVE

The aim of this study was to observe the demographic and clinical characteristics of immunoglobulin (Ig) G4-related disease (IgG4-RD). We aimed to compare different treatment methods and to identify the risk factors for non-response and relapse after treatment.

METHODS

We performed a retrospective study of 201 IgG4-RD patients initially diagnosed and treated at the First Affiliated Hospital of China Medical University from January 2016 to December 2020. Patients' sex, age, clinical manifestations, baseline biochemical values, the number of organs involved, and the type of organ involvement were recorded. All patients received glucocorticoid (GC) monotherapy or GC + immunosuppressant combination therapy. The serum IgG4 concentration as well as the details of clinical response, relapse, and side effects were recorded at 1, 3, 6, and 12 months after treatment.

RESULTS

The incidence of IgG4-RD was primarily centered in the age group of 50-70 years old, and the proportion of affected male patients increased with age. The most common clinical symptom was swollen glands or eyes (42.79%). The rates of single- and double-organ involvement were 34.83% and 46.27%, respectively. The pancreas (45.77%) was the most frequently involved organ in cases of single-organ involvement, and the pancreas and biliary tract (45.12%) was the most common organ combination in cases of double-organ involvement. Correlation analysis showed that the number of organs involved was positively related to the serum IgG4 concentration (r = 0.161). The effective rate of GC monotherapy was 91.82%, the recurrence rate was 31.46%, and the incidence of adverse reactions was 36.77%. Meanwhile, the effective rate of GC + immunosuppressant combination therapy was 88.52%, the recurrence rate was 19.61%, and the adverse reaction rate was 41.00%. There were no statistically significant differences in response, recurrence, and adverse reactions. The overall response rate within 12 months was 90.64%. Age (< 50 years old) and aorta involvement were significantly associated with non-response. The overall recurrence rate within 12 months was 26.90%. Age (< 50 years old), low serum C4 concentration, a high number of involved organs, and lymph node involvement were significantly associated with recurrence.

CONCLUSION

The clinical features vary among different age groups and according to gender. The number of organs involved in IgG4-RD is related to the serum IgG4 concentration. Age (< 50 years old), low serum C4 concentration, a high number of involved organs, and lymph node involvement are risk factors for recurrence.

Gastroenterological Manifestations of Immunoglobulin G Subclass 4-Related Disease-Epidemiology, Clinical Manifestations, Diagnosis and Treatment

Despite causing high morbidity, IgG4-related disease (IgG4-RD) and its gastroenterological manifestations lack better and greater theoretical contributions. Therefore, the objective of this work was to evaluate the clinical-epidemiological, diagnostic and treatment aspects of the gastrointestinal manifestations of this disease. A systematic review was carried out using the PubMed, Scopus and Embase databases between January 2012 and March 2023 with the following descriptors: "Immunoglobulin G4-Related Disease" (MeSH) AND #2 "Gastrointestinal Tract" (MeSH). Our data collection grouped a total of 3607 patients from mostly epidemiological cohort studies and cross-sectional follow-ups. In the subgroup analysis, IgG4-RD was associated with male gender, with an estimated prevalence between 54% and 80%. In our findings, the prevalence by topography was presented in the following ranges: lacrimal glands (17-57%); salivary glands (28-72%); pancreas (19-60%); biliary tract (5-40%); retroperitoneal cavity (9-43%). Longitudinal studies are needed to better map the natural history of the gastrointestinal manifestations of IgG4-RD and enable the formulation of individualized treatments.

IgG4-related disease as a variable-vessel vasculitis: A case series of 13 patients with medium-sized coronary artery involvement

INTRODUCTION

IgG4-related disease (IgG4-RD) is a systemic autoimmune fibroinflammatory disease that can affect multiple organ systems. Although large-vessel vasculitis is a well-recognized manifestation of IgG4-RD, this condition is generally not regarded as a vasculitis. We aimed to describe coronary artery involvement (CAI), a vascular distribution about which little is known in IgG4-RD.

MATERIAL AND METHODS

Patients with IgG4-related CAI were identified from a large, prospective IgG4-RD cohort. CAI was confirmed by imaging evidence of arterial or periarterial inflammation in any coronary artery. We extracted details regarding demographics, features of IgG4-RD, and manifestations of CAI.

RESULTS

Of 361 cases in the cohort, 13 (4%) patients had IgG4-related CAI. All were male and all had highly-elevated serum IgG4 concentrations, with a median value of 955 mg/dL (interquartile range [IQR]: 510-1568 mg/dL; reference: 4-86 mg/dL). Median disease duration at the time of CAI diagnosis was 11 years (IQR: 8.23-15.5 years). Extensive disease in the coronary arteries was the rule: all three major coronary arteries were involved in 11 patients (85%). The coronary artery manifestations included wall thickening or periarterial soft tissue encasement (85%), stenosis (69%), calcification (69%), and aneurysms or ectasia (62%). Five patients (38%) had myocardial infarctions, 2 (15%) required coronary artery bypass grafting, and 2 (15%) developed ischemic cardiomyopathy.

DISCUSSION

Coronary arteritis and periarteritis are important manifestations of IgG4-RD, which should be regarded as a variable-vessel vasculitis that is among the most diverse forms of vasculitis known. Potential complications of CAI include coronary artery aneurysms, myocardial infarction, and ischemic cardiomyopathy.

Recent advances in IgG4-related kidney disease

Recent advances in the management and understanding of immunoglobulin (Ig)G4-related kidney disease (RKD) have emphasized the importance of urgent treatment in IgG4-related tubulointerstitial nephritis. On the other hand, to avoid long-term glucocorticoid toxicity, strategies for early withdrawal of steroids or combination of immunosuppressants, such as rituximab, and the minimum dose of steroids have been pursued. However, disease recurrence after reducing or stopping steroid therapy hampers early withdrawal of glucocorticoid maintenance therapy. In addition, knowledge has accumulated in diagnostic approaches including differential diagnosis of anti-neutrophil cytoplasmic antibodies-associated vasculitis, idiopathic multicentric Castleman's disease, and Rosai-Dorfman disease with kidney lesion, which leads to earlier and precise diagnosis of IgG4-RKD. This review summarizes recent progress in the differential diagnosis of IgG4-RKD and related treatment strategies and recent topics of hypocomplementaemia, membranous glomerulonephritis, and IgG4-related pyelitis and periureteral lesion.

Characteristics of IgG4-related disease complicated with allergic rhinitis or chronic rhinosinusitis: a large cross-sectional cohort study

In clinical practice, we found that IgG4-related disease (IgG4-RD) patients complicated with allergic rhinitis (AR)/chronic rhinosinusitis (CRS) seemed to have unique characteristics different from patients with IgG4-RD alone. In this study, demographic, clinical and laboratory characteristics of IgG4-RD patients complicated with AR/CRS were investigated. We retrospectively analyzed 756 IgG4-RD patients who were recruited in four medical centers from 2009 to 2021. We divided 756 IgG4-RD patients into 2 groups: the case group included IgG4-RD patients complicated with AR/CRS, and the control group included IgG4-RD patients without AR/CRS. 411 patients were complicated with AR/CRS among 756 IgG4-RD patients. Multiple organs involvement (≥ 3, p < 0.0001, OR 3.585 (95% CI 2.655–4.839)) and other types of allergic disease (p < 0.0001, OR 2.007 (95% CI 1.490–2.693)) were more common in the case group. Patients in the case group had a higher level of serum IgG4 (650 mg/dL vs 385 mg/dL, p < 0.0001), IgE (347 mg/dL vs 98 mg/dL, p < 0.0001) and ESR (14 mm/h vs 12 mm/h, p < 0.05). High IgE level (p < 0.01, OR 1.003 (95% CI 1.001–1.005)) and other types of allergic disease (p < 0.05, OR 3.196 (95% CI 1.146–8.908)) were risk factors for patients in the case group, in which most patients had nasal manifestations before the diagnosis of IgG4-RD. The median time interval from nasal symptoms appearance to IgG4-RD diagnosis was − 120 and − 90 months for patients complicated with AR and CRS, respectively. IgG4-RD patients are often complicated with AR/CRS and have distinct characteristics, which appear to be a subgroup of IgG4-RD. The data suggests a pathogenic association of IgG4-RD and AR/CRS.