Zamami R, Kohagura K, Kinjyo K, Nakamura T, Kinjo T, Yamazato M, Ishida A, Ohya Y: The Association between Glomerular Diameter and Secondary Focal Segmental Glomerulosclerosis in Chronic Kidney Disease. Kidney and Blood Pressure Research DOI 10.1159/000515528
Disease-related loss of nephrons (but not normal aging-related loss of nephrons) is commonly associated with the enlargement (hypertrophy) of residual, less-damaged glomeruli. Comorbid conditions such as obesity or diabetes can also result in glomerular hypertrophy. However, the relationships between such hypertrophy and specific glomerular lesions (such as FSGS) have not been systematically evaluated.
Zamami and coworkers investigated the association between glomerular diameter (as a measure of glomerular hypertrophy) in 77 patients undergoing kidney biopsy with “non-primary” FSGS lesions on kidney biopsy, also excluding those with active proliferative or crescentic glomerulonephritis. The presence of glomerular hypertrophy correlated with FSGS lesions. The optimal threshold for predicting the presence of FSGS lesions was a glomerular diameter of >224 μm, independent of other confounding features.
Of course, a study of this design does not prove causality of the glomerular enlargement and the development of FSGS lesions; however, such a connection is plausible. Glomerular density (the number of glomeruli per centimeter of section) does not correlate with glomerular diameter, but the total nephron number per kidney was not quantified in this study. A high glomerular diameter is linked to progressive CKD. This study indicates that glomerulomegaly is a feature of secondary FGSS lesions and, when present, indicates an unfavorable prognosis.