IgG4-related membranous nephropathy: a case report

Abstract

IgG4-related kidney disease （IgG4-RKD） is a newly recognized immune-related disease, which is involved with renal tubules and glomerulus. IgG4-RKD is sensitive to glucocorticoid （hormone） therapy. The exact pathogenesis of IgG4-RKD is still unclear. This article reported a middle-aged female patient who presented with skin pruritus and exophthalmos for over nine years and foamy urine for three months as chief complaints. This patient was diagnosed with thyroid nodules. The serum level of IgG4 was elevated up to 19 700 mg/L. Renal biopsy revealed typical pathological features （immunohistochemical staining detected dense plasmacytic infiltration in the renal stroma with infiltrating IgG4+ plasma cells > 10/high-power field）. The diagnosis of IgG4-RKD （mainly the membranous nephropathy） was considered. After hormone treatment, clinical symptoms were significantly relieved. This case suggests that during clinical diagnosis and treatment, the possibility of IgG4-RKD should be excluded for patients presenting with repeated allergy, abnormal renal function and fibrosis of related organs. Extensive attention should be paid to differential diagnosis. It is necessary to deliver routine screening of allergens for patients with allergy. Detection of IgE, IgG4, imaging and histopathological examination should be comprehensively conducted. The risk of multiple system injuries should be evaluated to deliver prompt intervention and treatment.

Keywords

• |igg4-related disease|membranous nephropathy|allergy|diagnosis|treatment