Clinicopathological features of IgA nephropathy in children and adults assessed by the Oxford classification and glomerular crescent lesion typing

Abstract

ObjectiveTo clarify the clinicopathological features of immunoglobulin A nephropathy（IgAN） in children and adults by categorizing crescentic lesions into cellular crescents， fibrocellular crescents and fibrous crescents based on the Oxford classification.MethodsClinicopathological data of 168 cases of pediatric IgAN（children group） and 381 cases of adult IgAN pathologically confirmed by renal biopsy between January 1， 2012 and December 31， 2022 in the First Affiliated Hospital of Henan University of Chinese Medicine were retrospectively collected. Adult IgAN patients were subdivided into the youth group and the middle-aged and older adult group. The differences and correlations of clinical classification and pathological indexes among children group， youth group and middle-aged and older adult group were compared.ResultsThe statistical results of clinical classification in the three groups showed that the proportion of nephrotic syndrome type（37.50% vs 11.99% vs 11.24%，63 cases vs 35 cases vs 10 cases）in the children group was significantly higher than that of the youth group and the middle-aged and older adult group（P<0.05）. The proportion of hematuria with proteinuria（43.49% vs 32.74% vs 29.21%，127 cases vs 55 cases vs 26 cases）was significantly higher in the youth group than that of the children group and the middle-aged and older adult group （P<0.05）. The proportion of chronic nephritis type（53.93% vs 4.17% vs 37.67%，48 cases vs 7 cases vs 110 cases）was significantly higher in the middle-aged and older adult group than that of the children group and the youth group （P<0.05）. According to the Oxford classification， significantly higher proportions of glomerular mesangial cell proliferation （76.19% vs 60.37%，128 cases vs 230 cases）， endothelial cell hyperplasia （45.83% vs 13.65%，77 cases vs 52 cases） and cellular crescent （50.00% vs 30.71%，84 cases vs 117 cases） were seen in the children group than the remaining two groups， and significantly higher proportions of glomerular segmental sclerosis（69.82% vs 44.64%，266 cases vs 75 cases），fibrous crescents （18.90% vs 8.93%，72 cases vs 15 cases）， tubular atrophy and interstitial fibrosis （29.40% vs 2.39%，112 cases vs 4 cases） were seen in the youth group and the middle-aged and older adult group than the children group （P<0.05）. The 24 h urine protein quantification was moderately positively correlated with the percentage of cellular crescent， percentage of total cellular crescent and fibrocellular crescent， and percentage of endothelial cellular hyperplasia （r= 0.65，r= 0.56，and r= 0.41，respectively； P<0.05）. The estimated glomerular filtration rate （eGFR） was moderately negatively correlated with renal tubular atrophy/interstitial fibrosis （r= -0.61，P<0.05）.ConclusionsPediatric IgAN is dominated by acute glomerular lesions， and the nephrotic syndrome type is the main clinical type. Chronic glomerular， tubulointerstitial and vascular lesions in adults are the pathological basis for the formation of the chronic nephritis type. Cellular crescents， fibrocellular crescents and fibrous crescents were scored respectively in the Oxford classification is more clinically instructive.

Keywords

• child
• adults
• iga nephropathy
• crescent