ESPN 51th Annual Meeting

ESPN 2018


 
Acute post-infectious glomerulonephritis: is it always so benign?
LORENZA LEPORE VALENTINA BRUNO 1 FRANCESCA NUZZI 1 GABRIELE MALGIERI 1 SERENA ASCIONE 1 MARIA TERESA SARAVO 1 ELENA BRESIN 2 CARMINE PECORARO 1

1- UNIT OF NEPHROLOGY AND DIALYSIS, CHILDREN HOSPITAL SANTOBONO, NAPLES, ITALY
2- IRCCS-ISTITUTO DI RICERCHE FARMACOLOGICHE "MARIO NEGRI," CENTRO DI RICERCHE CLINICHE PER LE MALATTIE RARE "ALDO E CELE DACCò," RANICA BERGAMO, ITALY
 
Introduction:

Acute Post-Infectious GlomeruloNephritis (PIGN)is a common disorder in children.The laboratory hallmark is low serum C3 level. Histologically, PIGN is characterized by acute exudative proliferation of glomeruli on Light Microscopy (LM) and C3 and Ig deposition on Immunofluorescence (IF).Most cases show recovery within a few days to weeks.In a small percentage, PIGN takes longer to resolve (atypical form) resulting in persistent hematuria and proteinuria,or even progression to end-stage kidney disease.The aim of our study is evaluating the possible role of complement dysregulation in pathogenesis of‘atypical’PIGN

Material and methods:

From 2001to2017,we retrospectively studied 201children(121 M, mean age:5.6yrs) affected by PIGN; atypical casesunderwentakidney biopsy. In selected patients, molecular analysis of complement genes was performed. The following variables were analyzedin both typical and atypical cases: sex, age, glomerular filtration rate (GFR), proteinuria, serum C3 and C4 levels.

Results:

35/201 patients (17.4%) underwent a kidney biopsy; 16/35 (45.71%) showed a morphological pattern of C3 glomerulopathy (C3G). In 13/16 (81.2%) children, a molecular analysis of complement genes was performed which revealed allelic variants and/or gene mutations related to C3G in 6 cases (p.V62I in CFH gene;p.A473V in THBD gene; new splice variant c.4851-1G>A - C3 gene; heterozygous gene mutation in CFH - p.G133R; allelic variants V62and H402 in CFH gene;homozyogusallelic variants 102G and 314L in C3 gene). Serum C3 levels were significantly lower in typical GNPI compared to atypical cases (0.34 +/- 0.02 vs 0.58 +/-0.08; p < 0.05).

Conclusions:

Patients with atypical GNPI may have anunderlyingdefective regulation of the alternative complement pathway.For that reason,kidney biopsy and molecular analysis of complement genes should be considered in atypical cases.