Different clinicopathological types of segmental sclerosing glomerular lesions in adults.

Renal biopsies and kidneys from 111 adult patients with segmental sclerosing glomerular lesions were put into different morphological groups by pathologists unaware of clinical findings. 'Overload changes' (n = 11) were large glomeruli with hilar lesions. Ten of these patients had reduced renal mass. In the 'glomerular tip lesion' (n = 10) there were changes at the tubular origin in otherwise normal glomeruli. All patients in this group had the nephrotic syndrome, completely responsive to steroids. 'Mesangial hypercellularity with diffuse segmental changes at the glomerular tip', corresponding to 'early classical focal segmental glomerulosclerosis' (n = 18), differed from the glomerular tip lesion in that glomeruli were larger and hypercellular. Most patients with this classification had the nephrotic syndrome, several were given additional immunosuppression, and less than half had complete remission. 'Diffuse multiple segmental lesions', corresponding to 'late classical focal segmental glomerulosclerosis' (n = 16), presented usually with the nephrotic syndrome, and most of these patients had no response to immunosuppression. Unlike most other groups, in 'focal segmental sclerosing lesions' (n = 56) there were genuinely focal lesions, not in every glomerulus. Most patients had asymptomatic proteinuria. Pathological study is able to classify segmental lesions that would often be grouped as 'focal segmental glomerulosclerosis' into types with different pathogenesis, clinical findings, appropriate treatment, response to treatment, and prognosis.

Assessment of glomerular size in renal biopsies including minimal change nephropathy and single kidneys.

A method of assessing glomerular size on sections of post-mortem kidney was adapted for use on needle biopsies of kidney. A semi-automatic image analyser was used to measure the cross-sectional area of the outline of Bowman's capsule on all glomeruli in renal biopsies. The mean of approximately the largest 25 per cent of areas was calculated. The method was used to compare glomeruli in 13 control patients without obvious structural abnormalities with those in 10 patients with a single kidney, 22 with minimal change nephropathy, and 20 with membranous nephropathy. Patients were at least 14 years old. Glomeruli in minimal change nephropathy were significantly smaller than those in all other groups. Glomeruli in single kidneys were significantly larger than those in all other groups. Glomeruli in membranous nephropathy were the same size as controls. Any differences between groups could not be explained by differences in body build. It is possible that in adults glomeruli in minimal change nephropathy are abnormally small. The method of assessing glomerular size can be used on renal biopsies as well as on sections of whole kidney.