Biomaterial Database

Hypocomplementemia is related to elevated serum levels of IgG subclasses other than IgG4 in IgG4-related kidney disease. 2021

Yuhei Fujisawa, and Ichiro Mizushima, and Kazunori Yamada, and Motohisa Yamamoto, and Takako Saeki, and Shoko Matsui, and Syunsuke Tsuge, and Satoshi Hara, and Kiyoaki Ito, and Hiroshi Fujii, and Hiroki Takahashi, and Hideki Nomura, and Shigeyuki Kawa, and Mitsuhiro Kawano

Department of Cardiovascular and Internal Medicine, Division of Rheumatology, Kanazawa University Graduates School of Medicine, Kanazawa, Japan.

OBJECTIVE 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. CONCLUSIONS The present study suggests that hypocomplementemia is associated with elevation of IgG subclasses other than IgG4 including IgG1 in IgG4-RKD.

UI	MeSH Term	Description	Entries
D007074	Immunoglobulin G	The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.	Gamma Globulin, 7S,IgG,IgG Antibody,Allerglobuline,IgG(T),IgG1,IgG2,IgG2A,IgG2B,IgG3,IgG4,Immunoglobulin GT,Polyglobin,7S Gamma Globulin,Antibody, IgG,GT, Immunoglobulin
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D007674	Kidney Diseases	Pathological processes of the KIDNEY or its component tissues.	Disease, Kidney,Diseases, Kidney,Kidney Disease
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000077733	Immunoglobulin G4-Related Disease	A spectrum of systemic autoimmune diseases in which IMMUNOGLOBULIN G4 plays a pathophysiologic role. It can affect multiple organs in highly variable presentations, characterized by inflammatory lesions composed of IgG4-positive PLASMA CELLS, further infiltrated by T helper cells (T-LYMPHOCYTES, HELPER-INDUCER) when linked to progressive FIBROSIS and eventual organ damage.	IgG4-Related Kidney Disease,IgG4-Related Sclerosing Disease,Immunoglobulin G4-Related Kidney Disease,Immunoglobulin G4-Related Sclerosing Disease,IgG4 Related Systemic Disease,IgG4-Associated Autoimmune Disease,IgG4-RD,IgG4-Related Disease,Autoimmune Disease, IgG4-Associated,IgG4 Associated Autoimmune Disease,IgG4 Related Disease,IgG4 Related Kidney Disease,IgG4 Related Sclerosing Disease,IgG4-Associated Autoimmune Diseases,IgG4-Related Diseases,IgG4-Related Kidney Diseases,IgG4-Related Sclerosing Diseases,Immunoglobulin G4 Related Disease,Immunoglobulin G4 Related Kidney Disease,Immunoglobulin G4 Related Sclerosing Disease,Immunoglobulin G4-Related Diseases,Kidney Disease, IgG4-Related,Sclerosing Disease, IgG4-Related