A Case of Familial Kidney Disease

Abstract

L.N. was born in 1981 in the Los Angeles area, where she continues to live. As a child, she had a history of seizures but was otherwise healthy. Proteinuria was noted at 15 yr of age. Quantification of urine protein and blood chemistries from that time are not known. She underwent kidney biopsy at age 16. Light microscopic examination of the biopsy revealed global or segmental glomerulosclerosis involving 10 of 12 glomeruli (Figure 1). Moderate atrophy involving 60% of the tubulointerstitial compartment was also apparent, and the arteries and arterioles exhibited mild subintimal sclerosis. Immunofluorescence microscopy showed segmentally prominent IgM and C3 deposition in the glomerular tufts but no IgA or IgG. Electron microscopy showed extensive effacement of glomerular visceral epithelial cell (podocyte) foot processes, along with other podocyte degenerative changes, including microvillous degeneration and cell swelling (Figure 1). There were no significant abnormalities of the glomerular basement membranes, and electron-dense deposits were not observed in the mesangium or along the peripheral capillary loops. Figure 1. (A) Photomicrograph of periodic acid-Schiff–stained biopsy from patient L.N. showing global and segmental glomerulosclerosis, moderate tubular atrophy, and arteries and arterioles with mild subintimal sclerosis. (B) Higher power photomicrograph showing segmental glomerulosclerosis. (C) Electron micrograph showing extensive effacement of podocyte foot processes, along with podocyte degenerative changes including microvillous degeneration and cell swelling. L.N.'s kidney disease did not respond to glucocorticoid therapy. Kidney disease progressed to stage 5 chronic kidney disease, and hemodialysis was initiated at age 18. Bilateral nephrectomy was performed at the time of dialysis initiation because of “malignant hypertension.” Histologic examination of the nephrectomy specimen revealed end-stage histopathology, including widespread tubular atrophy and interstitial fibrosis, severe vascular sclerosis, and extensive global glomerulosclerosis involving >80% of the glomeruli (Figure 2). Figure 2. Photomicrographs of end-stage kidney specimen from patient L.N. showing widespread tubular atrophy, interstitial …