Abstract:

Objective: To analyze the clinical and pathological features of IgG4 related kidney disease (IgG4-RKD), and to provide reference for clinicians to recognize the disease in early stage, diagnose and treat the disease rationally. Methods The general information, laboratory examination index, pathological examination result, treatment, and follow-up in the patients with IgG4-RKD who firstly visited our department from April 2017 to March 2020 were collected and retrospectively analyzed. Results The age of 9 patients with IgG4-RKD ranged from 50 to 71 years old, including 7 males and 2 females. The reasons of the first visit were elevated serum creatinine (6 cases) or pancreatic mass (2 cases) and lacrimal gland enlargement (1 case). One case only had kidney damage; 6, 2 and 2 cases were found 2, 3 or 4 organ damages, respectively (including kidney). The serological characteristics were as follows: the indexes including IgG4(8/8), IgG (8/9), serum creatinine (8/9), erythrocyte sedimentation rate (ESR) (7/8), and IgE (5/9) all increased, while complement C3 (8/9) and complement C4 (3/9) decreased. Abnormal urine tests showed low urinary calcium (5/9), and increased urinary protein (8/9) and α-microglobulin (8/8). Seven patients underwent renal puncture, the results showed all cases had IgG4 deposition, and 6 cases had fine pattern alterations. There were 2 cases treated with glucocorticoid alone, 3 cases with glucocorticoid plus cyclophosphamide, 3 cases with glucocorticoid plus rituximab; and 1 case received plasma exchange combined with glucocorticoid. Conclusions The clinical manifestations of IgG4-RKD are diverse, usually involving multiple systems and organs, and the rate of misdiagnosis is high. Clinicians need to recognize and diagnose the disease as early as possible and conduct effective treatment to delay progression of the disease.

Key words: IgG4 related kidney disease, Autoimmune disease, Urinary protein