Clinicopathological features of IgG4-related kidney disease
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ABSTRACT

AIMS: To explore the clinicopathological features of IgG4-related kidney disease (IgG4-RKD) in Chinese patients. MATERIALS AND METHODS: We retrospectively analyzed the clinicopathological features of 7 patients with IgG4-RKD and reviewed relevant literature. RESULTS: There were 7 patients (4 males and 3 females) aged 41 - 78 years (median age 57.1 years), with a mean affliction of 2.6 organs per patient. All 7 patients had elevated serum IgG4 levels, and most of them had acute or chronic renal insufficiency. Two patients had positive myeloperoxidase-antineutrophil cytoplasmic antibodies (MPO-ANCA), and another 2 patients had positive serum antinuclear antibodies (ANA). All 7 patients had tubulointerstitial nephritis (TIN) with IgG4+ plasma cell infiltration, 3 patients also had glomerular lesions, 2 patients had ANCA-associated glomerulonephritis (ANCA-GN), and the remaining patient had membranous nephropathy (MN). All these patients were treated with glucocorticoids, and 3 of them were given cyclophosphamide simultaneously. Six patients achieved remission and had improved renal function, while 1 patient was on maintenance dialysis. CONCLUSION: IgG4-RKD should be diagnosed by combining the clinical data and renal pathological changes, and it should be differentiated from a variety of diseases. Although ANCA-associated vasculitis (AAV) and IgG4-related disease are distinguishable in most cases, coexistence of ANCA-GN and IgG4-RKD should be considered in some special cases.