Glomerular morphology in nephrotic heroin addicts

Renal biopsies of 23 heroin addicts who presented with the nephrotic syndrome were examined by light and electron microscopy. The majority of patients (14) showed focal segmental glomerular sclerosis on light microscopy, 4 patients showed 'minimal change', and 2 were classified as 'focal global sclerosis'. In 1 case focal mesangial proliferation was the outstanding feature; 1 patient had diabetic glomerulosclerosis; and 1 had mesangiocapillary glomerulonephritis and dysproteinemia. Visceral epithelial swelling and proliferation were present in 14 patients on light microscopy. Electron microscopy showed distinct podocyte changes consisting of loss of foot processes, vacuolization, and cytoplasmic degeneration; focal separation of podocytes from basement membranes was found in 11 of 18 cases. In some instances a few electron dense deposits were present in the mesangium. Membranous nephropathy was not encountered, although it occurs in 30 to 40% of unselected adult nephrotic individuals. Of 15 patients followed up for 2 mth to 5 yr, 1 died of heroin overdose, 8 went into renal failure, 2 improved, and 4 continued to have proteinuria. It is concluded that nephrotic syndrome of heroin addicts is most often associated with focal segmental glomerular sclerosis and occasionally with minimal change disease or focal global sclerosis. Conceivably these 3 conditions represent different phases of 1 disease process, although different reactions to heroin or its various vehicles and contaminants cannot be excluded. The morphologic resemblance to experimental aminonucleoside and N,N' diacetylbenzidine induced nephrosis suggests a possible toxic origin.