Histological grading of IgA nephropathy predicting renal outcome: revisiting H. S. Lee's glomerular grading system.
BACKGROUND
The glomerular grading system is useful to compare biopsy specimens and to predict the natural course of disease in IgA nephropathy (IgAN), although no grading system can be perfect.


METHODS
H. S. Lee's grading system for IgAN was refined as follows: grade I, normal or focal mesangial cell proliferation; grade II, diffuse mesangial cell proliferation, or <25% of glomeruli with crescent (Cr)/segmental sclerosis (SS)/global sclerosis (GS); grade III, 25-49% of glomeruli with Cr/SS/GS; grade IV, 50-75% of glomeruli with Cr/SS/GS; grade V, >75% of glomeruli with Cr/SS/GS. This refined H. S. Lee grading system was then tested for clinical relevance on 187 patients with IgAN followed up for an average of 6.5 years (minimum, 3 years). In the survival analysis, a modified primary end-point (progressive renal disease) was used.


RESULTS
The glomerular grades were significantly related to hypertension, serum creatinine levels and the amounts of proteinuria at time of biopsy. By univariate analysis, glomerular grades, hypertension, renal insufficiency and significant proteinuria (> or =1 g/day) were significantly associated with progressive renal disease. By multivariate analysis using the Cox regression model, glomerular grades, renal insufficiency and significant proteinuria were independent prognostic factors for progressive renal disease. At the end of follow-up, glomerular grades were significantly related to serum creatinine levels, amounts of proteinuria, hypertension and progressive renal disease.


CONCLUSIONS
These findings indicate that the refined H. S. Lee grading system for IgAN is useful in assessing the patients' clinical outcome and is sufficiently simple and easy to reproduce as to be universally applicable in prognostic work.
Lee
Hyun Soon
HS
Department of Pathology, Seoul National University College of Medicine, Chongno-gu, Yongon-dong 28, Seoul 110-799, Korea. hyunsoon@plaza.snu.ac.kr
Lee
Myung Suk
MS
Lee
Sa Min
SM
Lee
Sang Yun
SY
Lee
Eun Sun
ES
Lee
Eun Young
EY
Park
So Yeon
SY
Han
Jin Suk
JS
Kim
Sungkwon
S
Lee
Jung Sang
JS
D000328:Adult; D001706:Biopsy; D003404:Creatinine / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D005922:Glomerulonephritis, IGA / Q000145:classification* / Q000401:mortality / Q000473:pathology; D006417:Hematuria; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007676:Kidney Failure, Chronic / Q000453:epidemiology / Q000401:mortality; D007678:Kidney Glomerulus / Q000473:pathology*; D008297:Male; D011507:Proteinuria; D012044:Regression Analysis; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
D003404:Creatinine