Long-term outcome of IgA nephropathy with minimal change disease: a comparison between patients with and without minimal change disease.

BACKGROUND: The clinicopathological characteristics, treatment response and long-term outcome of immunoglobulin (Ig)A nephropathy with minimal change disease (MCD-IgAN) are not well defined.

METHODS: Patients with biopsy-proven MCD-IgAN from the Jinling Hospital IgA nephropathy Registry were systematically reviewed and compared with those with IgA nephropathy without minimal change disease (Non-MCD-IgAN).

RESULTS: We compared data of 247 MCD-IgAN patients and 1,121 Non-MCD-IgAN patients. Compared to Non-MCD-IgAN, MCD-IgAN patients were younger,with male predominance, had higher levels of proteinuria, total cholesterol and estimated glomerular filtration rate (eGFR), lower incidence of hypertension and microhematuria, lower level of serum creatinine, and had less severe glomerular, tubulointerstitial and vascular lesions in renal pathology. In the Non-MCD-IgAN group, 157 patients (14.0 %) reached the renal endpoint and 103 patients (9.2 %) entered end-stage renal disease (ESRD). The 5-,10-, 15- and 20-year cumulative renal survival rates from ESRD, calculated by Kaplan-Meier method, were 95.0, 83.0, 72.9 and 65.4 %, respectively. In the MCD-IgAN group, no patients entered ESRD and only 4 (1.6 %) reached the renal endpoint. Patients with MCD-IgAN had a significantly better renal outcome than Non-MCD-IgAN (p < 0.01). At multivariate Cox analysis, proteinuria >1.0 g/day, hypertension, eGFR <60 ml/min/1.73 m(2), hypoproteinemia and hyperuricemia were independent risk factors of renal survival for Non-MCD-IgAN patients [hazard ratio (HR) 3.43, p < 0.001; HR 1.65, p < 0.05; HR 2.61, p < 0.001; HR 2.40, p < 0.001; HR 2.27, p < 0.001, respectively), but not for patients with MCD-IgAN.

CONCLUSIONS: The long-term outcome of patients with MCD-IgAN is significantly better than that of patients with Non-MCD-IgAN.