GLOMERULAR HYPERTROPHY AS A PROGNOSTIC MARKER IN CHILDHOOD IGA NEPHROPATHY

A clinicopathological and morphometric analysis of glomerular hypertro phy (GH) was conducted using biopsies obtained from 52 selected pediat ric patients with IgA nephropathy (IgAN). Of the 52 patients, consisti ng of 12 with chronic renal failure (CRF) and 40 without CRF, various clinical and morphometric parameters were compared to 10 controls with benign hematuria. The mean glomerular tuft size, mesangial area, and interstitial area all significantly increased in patients with poor pr ognosis when compared to the non-CRF-IgAN cases and the control cases. The glomerular capillary loop size was also significantly greater in CRF-IgAN than in non-CRF-IgAn patients (1.37 times) and the controls ( 1.55 times). The 10-year renal survival rates of patients with 'large' loop size (>1.55-fold) were significantly lower (p < 0.001) than thos e of patients with a smaller capillary loop size. The size of the capi llary loops was directly related to the relative interstitial area (A( int)) (r(2) = 0.43, p < 0.001), to the degree of glomerulosclerosis (G S; r(2) = 0.348, p < 0.001) and the mesangial area (r(2) = 0.326, p < 0.001). Proteinuria tightly correlated with the capillary loop size (r (2) = 0.374, p < 0.001). It was not unexpected that a strong relations hip was detected between the serum creatinine level and A(int) (r(2) = 0.452, p < 0.001) and the percentage of GS (r(2) = 0.342, p < 0.001). In IgAN the percentage of GS correlated significantly with A(int) (r( 2) = 0.484, p < 0.001). GH, which was manifested by glomerular capilla ry loop dilatation, shows a close correlation with the interstitial ex pansion, degree of GS and mesangial enlargement. These data suggest th at both extra- and intraglomerular hemodynamic changes followed by pri mary glomerular damage thus lead to capillary dilatation of the intact glomeruli as a morphological manifestation of GH and therefore such c hanges play a key role in the progression of IgAN.