Focal segmental glomerulosclerosis associated with nephrotic syndrome in cholesterol atheroembolism: clinicopathological correlations

Abstract

To better characterize the heavy proteinuria occasionally described in cholesterol atheroembolic renal disease (CAE), we reviewed the clinical features and histological findings of 24 patients found at renal biopsy to have CAE. Twelve (50%) had a typical clinical presentation soon after an invasive vascular procedure. Eight (33%) underwent biopsies to evaluate proteinuria and four (17%) with insidiously developing renal failure to exclude rapidly progressive glomerulonephritis. All had usual and similar risk factors for CAE; 71% were male, 96% had peripheral vascular disease, 79% had recently undergone an invasive vascular procedure, 74% were hypercholesterolemic, and all were hypertensive. Proteinuria was higher and serum creatinine lower in the proteinuria group. In the nine (38%) nephrotic patients, serum creatinine measurements were lower (2.7 +/- 1.2 v 5.6 +/- 2.4 mg/dL), duration of renal disease to biopsy longer, and time from biopsy to dialysis greater (23.5 +/- 14.8 v 0.03 +/- 0.098 mo, P < 0.05 for all). Focal segmental glomerulosclerosis (FSGS) was observed in 15 (63%) of the biopsy specimens. Although FSGS itself did not occur more commonly in nephrotic patients, these patients did have a higher fraction of segmentally sclerosed glomeruli (0.158 +/- 0.097 v 0.026 +/- 0.050, P < 0.01). A variant of FSGS, the cellular lesion with epithelial cell prominence and capillary loop collapse, was observed in 7 of 9 (78%) patients with nephrotic-range proteinuria, but in only 3 of 12 (25%) patients with lesser degrees of protein excretion (P < 0.05). The cellular lesion was accompanied by higher mean proteinuria, 7.6 +/- 4.3 versus 2.1 +/- 2.4 g/24 hr (P < 0.01). In a larger group of patients with a similar age range as the CAE group who were identified by search of a computerized biopsy database, membranous nephropathy was the only other form of idiopathic glomerulonephritis that occurred with CAE. One of 82 (1.2%) patients with membranous nephropathy also had CAE, compared with 20 of 102 (19.6%) with FSGS (P < 0.0002, chi2). Thus, the finding of FSGS with CAE was not coincidence. Mean follow-up was 20 +/- 26 months (range, 0 to 103 months). Six patients (25%) were followed-up at least 3 years after renal biopsy. These findings indicate that extended survival in CAE is not rare and that heavy proteinuria occurs as part of a chronic disorder with distinctive histological features. Cholesterol atheroembolism with FSGS should be considered in the differential diagnosis of nephrotic syndrome in elderly patients with advanced atherosclerosis.