ESPN 54th Annual Meeting

ESPN 2022


 
IgA nephropathy in children with minimal proteinuria : to biopsy or not to biopsy ?
CAMBIER ALEXANDRA 1 JEAN-PHILLIPE ROY 1 CLAIRE DOSSIER 2 NATACHA PATEY 1 OLIVIA BOYER 3 MARION RABANT 3 JEAN DANIEL DELBET 4 ANNE-LAURE LAPEYRAQUE 1 JULIEN HOGAN 2

1- SAINTE JUSTINE HOSPITAL
2- ROBERT DEBRé HOSPITAL
3- NECKER HOSPITAL
4- TROUSSEAU HOSPITAL
 
Introduction:

 Glomerular inflammation severity and tubulointerstitial lesions have been shown to correlate with the amount of proteinuria in childhood IgA nephropathy (cIgAN). However, data are lacking regarding the severity of histopathologic findings in cIgAN with minimal to absent proteinuria since kidney biopsy indications are not well defined in such cases.

Material and methods:

 Data on 140 consecutive cIgAN patients with a kidney biopsy from 4 different centers in Paris (France) and Montreal (Canada) were reviewed in order to select patients with urine protein/creatinine ratio (UP/Cr) < 0.03 g/mmol and normal renal function (estimated glomerular filtration rate (eGFR) > 90ml/min/1.73m2) at biopsy and before any treatment

Results:

 A total of 28 cIgAN (mean age 11.02 years ± 3.740); median follow-up 3 years [0.84-11.55] were included.  History of macroscopic hematuria was present in 92.8%. At first evaluation, mean eGFR was 115.5 ± 18.2 ml/min/1,73m2, median UP/Cr was 0.02 [0.011-0.03] g/mmol. Microscopic or macroscopic hematuria was present in 35.7 and 64% respectively. Kidney biopsy optic microscopy showed: mesangial (M1), endocapillary (E1) or extracapillary (C1) proliferation in 53.5, 32.1 and 7% of patients, respectively. Chronic lesions were also present: glomerulosclerosis (S1) and tubular atrophy/interstitial fibrosis in 42% and 7%. Podocytopathic features were also present in 21%.

ACE inhibitors or an immunosuppressive therapy were prescribed in respectively 42.8% and 21.5 % of cases and no treatment in 35.7%. At last follow-up, median eGFR was 102 [91.63-124.4] ml/mn/1.73m2 and median UP/Cr was 0.028 [0.01-0.03] g/mmol. eGFR was < 90 in 6 patients (21.4%) and 2 (7%) had increased proteinuria (UP/Cr >0.03 g/mmol).

Conclusions:

 cIgAN with minimal to absent proteinuria at biopsy can be associated with worrisome glomerular acute and chronic lesions.