SEGMENTAL GLOMERULAR NECROSIS AS AN ACTIVE INDEX OF IGA NEPHROPATHY -A STUDY WITH 100 SERIAL SECTIONS OF 128 CASES

One hundred serial sections from each of 128 cases with immunoglobulin A (IgA) nephropathy were examined by light microscopy to clarify the relationship between segmental glomerular necrosis (SGN) and progressi on of glomerular injury. The cases were divided into five groups accor ding to the percentage of glomeruli with cellular-fibrocellular (CIF) crescents, fibrous adhesion and/or sclerosis: grade I, 0%; grade II, < 20%; grade III, 20-50%; grade IV, 50-80%; and grade V, 80% or more. T he serial sections revealed unequivocally focal occurrence of SGN in 3 9 cases (30%). Segmental glomerular necrosis was never found in the ca ses of grade I (0%, 0/28), while it appeared in those of grade II (33% , 12/36), grade III (46%, 13/28), grade IV (48%, 13/27) and grade V (1 1%, 1/9). The incidence of the cases with C/F crescents showed a simil ar tendency among the groups. In addition, focal C/F crescents were mo re frequent in cases with SGN (82%) than in those without SGN (24%). I n particular, cellular crescents in 26 cases were formed in close prox imity to SGN. These results suggested that SGN in IgA nephropathy was a more common finding than formerly evaluated and that it potentially participated in the progression of glomerular injuries closely associa ted with crescent formation. Unequivocally, focal occurrence of SGN co rresponded well with the slowly progressive course of the glomerular d isease.