Early prediction of IgA nephropathy progression: proteinuria and AOPP are strong prognostic markers.
BACKGROUND
Inflammation and oxidative stress have been incriminated in the pathogenesis of IgA nephropathy (IgAN). The aim of the present study was to assess whether markers reflecting these pathophysiologic processes, namely C-reactive protein (CRP) and advanced oxidation protein products (AOPP), would allow-in conjunction with clinical and histopathologic parameters-to predict disease progression.


METHODS
Between 1994 and 1997, 120 adult patients with biopsy-proven IgAN were included in a prospective cohort study, and followed until the end of 2002 or start of dialysis. In every patient, we determined plasma levels of CRP and AOPP. These parameters were included, together with clinical data, in a multivariate Cox proportional hazard regression analysis, with halving of baseline creatinine clearance as the primary renal end point.


RESULTS
A total of 51 patients reached the renal end point, including 30 who had to start dialysis. With multivariate analysis, the most potent independent risk factors of poor renal outcome were proteinuria > or =1 g/day [proportional hazard risk (HR) = 23.7, P= 0.0001], hypertension (HR = 8.13, P= 0.008), and AOPP plasma level (HR = 1.09 per 10 micromol/L, P= 0.042), whereas angiotensin II inhibitors were protective (HR = 0.19, P= 0.001).


CONCLUSIONS
Our data support the role of oxidative stress in the pathogenesis of IgAN and suggest that patients with proteinuria > or =1 g/day should be eligible for early implemented antioxidant and/or anti-inflammatory therapeutic strategies, with AOPP plasma level as a surrogate marker to evaluate their effects.
INSERM U507 and Department of Nephrology, Necker Hospital, Paris, France. b.descamps@necker.fr
Béatrice
B
Descamps-Latscha
Véronique
V
Witko-Sarsat
Thao
T
Nguyen-Khoa
Anh Thu
AT
Nguyen
Valérie
V
Gausson
Nadya
N
Mothu
Camila
C
Cardoso
Laure-Hélène
LH
Noël
Alain P
AP
Guérin
Gérard M
GM
London
Paul
P
Jungers
D000328:Adult; D001798:Blood Proteins / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D005922:Glomerulonephritis, IGA / Q000175:diagnosis* / Q000401:mortality*; D006801:Humans; D006977:Hypertension, Renal / Q000175:diagnosis / Q000401:mortality; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011507:Proteinuria / Q000175:diagnosis* / Q000401:mortality*
D001798:Blood Proteins; D002097:C-Reactive Protein