Analysis of the position of segmental lesions in glomeruli in vasculitic-type glomerulonephritis and other disorders.

A method was developed of plotting the position of segmental lesions in glomeruli on histological sections of kidney. Using a Leitz Imagan semi-automatic image analyser, the outline of lesions was traced, as was the outline of Bowman's capsule. The centre of gravity of a lesion, computed by the image analyser, was plotted with reference to the line through the hilum and the centre of gravity of the glomerulus, by taking its angle to that line and its proportional distance between that line and Bowman's capsule. Points representing all lesions were transferred onto a circle graphically representing a glomerulus. Lesions in 11 renal biopsies with the glomerular tip lesion were clustered at the tubular origin. Lesions in four necropsy kidneys from patients with one kidney were clustered at both the vascular pole and the tubular origin. Lesions in 13 renal biopsies with acute vasculitic-type glomerulonephritis were shown to be randomly scattered by nearest-neighbour analysis, after allowance had been made for an edge effect due to the method of plotting lesions and for an area where the arterioles passed through Bowman's capsule. Scientific analysis of the position of segmental lesions is possible and has confirmed previous suggestions that there are at least three general sites in which these lesions can be distributed in glomeruli: at the tip, at the vascular pole, and randomly.