Disparities between IgG4-related kidney disease and extrarenal IgG4-related disease in a case\u2013control study based on 450 patients

Qiaozhu Zeng,Yanying Liu,Jingyuan Gao,Xiying Chi,Ziqiao Wang,Zhenfan Wang,Qianyu Shi,Aichun Liu,Fei Yang,Zhan-Guo Li,Yi Wang,Xinyu Zhang

doi:10.1038/s41598-021-89844-7

Abstract

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.

Highlights

IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory immune-mediated disorder, which is characterized by high levels of serum IgG4, dense lymphoplasmacytic infiltration with IgG4-positive plasma cells in multiple organs, featured storiform fibrosis, and obliterative phlebitis[1,2,3,4]
In 2001, IgG4-RD was first described in pancreas, which was called type 1 autoimmune pancreatitis (AIP)[5]
Subsequent studies have revealed that IgG4-RD can affect any organ system

Summary

Introduction

IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory immune-mediated disorder, which is characterized by high levels of serum IgG4, dense lymphoplasmacytic infiltration with IgG4-positive plasma cells in multiple organs, featured storiform fibrosis, and obliterative phlebitis[1,2,3,4]. Subsequent studies have revealed that IgG4-RD can affect any organ system. IgG4-related kidney disease (IgG4RKD+) refers to the renal lesions in association with IgG4-RD. Previous studies have reported the kidney involvement in approximately 12–23% of total IgG4-RD p atients[4,6,7,8]. IgG4-RKD+ could be manifested by a variety of clinical and histological characteristics, such as tubulointerstitial nephritis (TIN), membranous glomerulonephropathy (MGN) and other infrequent glomerular lesions, pyelitis, hydronephrosis and acute renal failure[9,10]. Demographic, clinical, and laboratory disparities in the 53 IgG4-RKD+ and 397 IgG4RKD− patients were investigated. This is the largest study to compare the two phenotypes of patients with or without IgG4-RKD+. Determining the characteristics of these two phenotypes may help identify risk factors and their potential differences in pathogenesis

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Discussion

Conclusion