Alexandra Cambier1, Marion Rabant2, Khalil El Karoui3, Michel Peuchmaur4, Aude Servais5, Alexandre Hertig6,7, Georges Deschenes8, Remi Salomon9, Julien Hogan8, Thomas Robert10. 1. Service de néphrologie pédiatrique, APHP, Hôpital Universitaire Robert-Debré, 48 Boulevard Serrurier, 75019, Paris, France. alexandra.cambier@aphp.fr. 2. Service de Pathologie, Hôpital Universitaire Hôpital Necker, APHP, Paris, France. 3. Service de néphrologie et transplantation rénale, Hôpital Universitaire Henri-Mondor, Paris, France. 4. Service de Pathologie, Hôpital Universitaire Robert Debré APHP, Paris et Université Diderot, Paris, France. 5. Service de néphrologie et transplantation rénale, Hôpital Necker, APHP, Paris, France. 6. Service des urgences néphrologiques et transplantation rénales, APHP, Hôpital Universitaire Tenon, Paris, France. 7. Université Pierre et Marie Curie Paris 6, Paris, France. 8. Service de néphrologie pédiatrique, APHP, Hôpital Universitaire Robert-Debré, 48 Boulevard Serrurier, 75019, Paris, France. 9. Service de néphrologie pédiatrique, APHP, Hôpital Universitaire Necker, Paris, France. 10. Centre de néphrologie et transplantation rénale, APHM, Hôpital Universitaire de la Conception, 147 Bd Baille, 13385, Marseille, France. t.robert13@hotmail.fr.
Abstract
BACKGROUND: Previous reports suggest initial presentation of IgA nephropathy (IgAN) in children is different from adults. No systematic comparison of clinical, biological, and histological childhood- and adult-onset IgAN is currently available. METHODS: We compared pediatric and adult clinical and histological characteristics at IgAN diagnosis. Data on 211 consecutive patients from two different centers in Paris (82 children, 129 adults) were reviewed. Kidney biopsies were scored for Oxford classification and podocytopathic (P1) features. RESULTS: We report higher eGFR at diagnosis in children compared to adults (89.5 vs. 64 ml/min/1.73 m2; p = 0.0001) but no difference in proteinuria. Histological analysis of kidney biopsy found higher proportions of mesangial (M1) and endocapillary (E1) hypercellularity in children compared with adults (M1 [80.7% vs. 27.9%, p = 0.0001]; E1 [71.3% vs. 30%, p = 0.0001]). Focal glomerulosclerosis (S1), tubular atrophy/interstitial fibrosis ≥ 25% (T1), and P1 were more frequent in adults (S1 [81.5% vs. 61.3%, p = 0.0012], T1 [49.5% vs. 1.35%, p = 0.0001], P1 [33.8% vs. 16.4%, p = 0.008). Proteinuria associated with M1, E1, and C1 in children (M1, p = 0.0001; E1, p = 0.0005; C1, p = 0.0014) but S1, P1, and T1 in adults (S1, p = 0.0001; P1, p = 0.0001; T1, p = 0.001). After steroid treatment (41 children and 28 adults), proteinuria decreased in children (p < 0.001, follow-up 38 months) and adults (p < 0.001, follow-up 76.9 months), whereas eGFR remained stable in adults but increased significantly in children (90.6 to 110 ml/min/1.73m2). CONCLUSION: Proteinuria in children with IgAN is a marker of glomerular proliferative lesions whereas its presence in adults often reflects the presence of chronic lesions. This suggests the need for histological assessment.
BACKGROUND: Previous reports suggest initial presentation of IgA nephropathy (IgAN) in children is different from adults. No systematic comparison of clinical, biological, and histological childhood- and adult-onset IgAN is currently available. METHODS: We compared pediatric and adult clinical and histological characteristics at IgAN diagnosis. Data on 211 consecutive patients from two different centers in Paris (82 children, 129 adults) were reviewed. Kidney biopsies were scored for Oxford classification and podocytopathic (P1) features. RESULTS: We report higher eGFR at diagnosis in children compared to adults (89.5 vs. 64 ml/min/1.73 m2; p = 0.0001) but no difference in proteinuria. Histological analysis of kidney biopsy found higher proportions of mesangial (M1) and endocapillary (E1) hypercellularity in children compared with adults (M1 [80.7% vs. 27.9%, p = 0.0001]; E1 [71.3% vs. 30%, p = 0.0001]). Focal glomerulosclerosis (S1), tubular atrophy/interstitial fibrosis ≥ 25% (T1), and P1 were more frequent in adults (S1 [81.5% vs. 61.3%, p = 0.0012], T1 [49.5% vs. 1.35%, p = 0.0001], P1 [33.8% vs. 16.4%, p = 0.008). Proteinuria associated with M1, E1, and C1 in children (M1, p = 0.0001; E1, p = 0.0005; C1, p = 0.0014) but S1, P1, and T1 in adults (S1, p = 0.0001; P1, p = 0.0001; T1, p = 0.001). After steroid treatment (41 children and 28 adults), proteinuria decreased in children (p < 0.001, follow-up 38 months) and adults (p < 0.001, follow-up 76.9 months), whereas eGFR remained stable in adults but increased significantly in children (90.6 to 110 ml/min/1.73m2). CONCLUSION:Proteinuria in children with IgAN is a marker of glomerular proliferative lesions whereas its presence in adults often reflects the presence of chronic lesions. This suggests the need for histological assessment.
Authors: Alexandra Cambier; Thomas Robert; Julien Hogan; Marion Rabant; Michel Peuchmaur; Olivia Boyer; Tim Ulinski; Renato C Monteiro; Laurent Mesnard Journal: Kidney Int Rep Date: 2021-03-03