IgA nephropathy: prognostic classification of end-stage renal failure. L'Association des Néphrologues de l'Est.

The validity of Lee’s prognostic classification was confirmed using an independent sample. Background. As yet, no clinical or morphological prognostic classification of IgA nephropathy (IgAN ) has Conclusions. These classifications identify groups at high risk of ESRF. Therapeutic studies should focus been generally accepted. The objective of our study was to quantify the risk of developing end-stage renal on these groups. failure (ESRF ) in IgAN. Methods. We report a prospective longitudinal study of 210 patients with IgAN confirmed by biopsy Key words: end-stage renal failure; IgA nephropathy; between 1987 and 1991. Thirty-two (15.2%) patients prognostic classification were lost to follow-up. Mean follow-up after renal biopsy was 5.6 (SD=2.6) years. The variables included age, gender, illnesses prior to discovery of IgAN, clinical features at IgAN discovery, 24-h proteinuria, serum creatinine, IgA level, and antihypertensive drugs taken at the time of renal biopsy. Sixty-six renal Introduction biopsies were classified by light-microscopy according to Lee’s morphological classification. The end-point IgA nephropathy (IgAN ) is the most frequent primitwas ESRF. Survival was analysed by a backward and ive glomerulonephritis [1,2]. Despite 25 years of forward stepwise procedure using the Cox model. The research into this condition much remains unknown most accurate determination of relative risk was about its pathogenesis and therapy [3,4]. One major obtained by assessing collinearity of the variables. problem is that the prognostic evaluation of IgAN is Results. Thirty-three patients (15.7%) (31 men) unreliable. Five studies [5‐9] have examined prodeveloped ESRF. The five univariately significant vari- gnostic factors using multivariate analysis, but the ables: gender, gross haematuria, 24-h proteinuria candidate factors and their prognostic value varied (24-P), serum creatinine (SC ), and antihypertensive from one study to another [10]. These diVerences treatment, were candidates for multivariate analysis. are undoubtedly due to diVering epidemiological The final model used SC (100, 100‐150, approaches. All the studies were retrospective, with >150 mmol/l ), 24-P ( 150 mmol/l and 24-P 150 mmol/l and 24-P 1g /day). The ESRF-free if it cannot predict the outcome for individual patients, survival was estimated with Kaplan‐Meier analysis. It because it may help evaluate the disease progression was 98.5% for stage 1, 86.6% for stage 2, 21.3% for and outcome for a group of patients. It may thus assist stage 3 (P<0.001), 7 years after histological diagnosis. clinicians to formulate appropriate management plans