Clinical and pathological features of idiopathic membranous nephropathy with focal segmental sclerosis

Background: The goal of this study was to investigate the clinical and pathological features and prognosis of idiopathic membranous nephropathy (IMN) with focal segmental lesions.

Methods: In our hospital, 305 patients with nephrotic syndrome confirmed as IMN by renal biopsy were divided into a non-focal segmental lesion group (FSGS- group) and a focal segmental glomerulosclerosis (FSGS) group (FSGS+ group) and retrospectively analyzed. In all, 180 patients were followed for periods ranging from 6 months to 2 years. The general clinicopathological data of both groups were compared, and the effects of different treatment schemes on the prognosis of both groups were observed.

Results: The FSGS+ group had a longer disease course, higher blood pressure levels, and higher serum creatinine and β₂-microglobulin levels than did the FSGS- group (all P < 0.05). Pathologically, the FSGS+ group had increased glomerular sclerosis, glomerular mesangial hyperplasia, and acute and chronic tubular lesion rates (all P < 0.05). The remission rate was lower in the FSGS+ group than in the FSGS- group (64.7% vs 82.2%) and, among patients in the FSGS+ group, was lower in patients treated with calmodulin inhibitors than in those treated with cyclophosphamide (P < 0.01). Survival analysis showed that the FSGS+ group had a poor prognosis (χ² = 4.377, P = 0.036), and risk factor analysis suggested that age at renal biopsy (P = 0.006), 24-h urinary protein quantity (P = 0.01), chronic tubulointerstitial lesions (P = 0.055), and FSGS lesions (P = 0.062) were risk factors for worsening renal condition; furthermore, 24-h urinary protein quantity was an independent risk factor for worsening renal condition.

Conclusions: Membranous nephropathy with FSGS is a risk factor, but not an independent risk factor, for IMN. Patients with membranous nephropathy with FSGS often present hypertension and tubule injury. The nonselective drug cyclophosphamide is preferred, and calcineurin inhibitors should be used with caution.