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.

中文翻译：

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新发IgA肾病成人和儿童之间的临床和组织学差异。

背景

先前的报告表明，儿童中IgA肾病（IgAN）的最初表现与成人不同。目前尚无关于临床，生物学和组织学上儿童期和成人期IgAN的系统比较。

方法

我们比较了IgAN诊断时的儿科和成人临床及组织学特征。回顾了来自巴黎两个不同中心的211名连续患者（82名儿童，129名成人）的数据。肾脏活检评分牛津分类和足细胞病变（P1）的特点。

结果

我们报告说，儿童诊断时的eGFR高于成人（89.5比64 ml / min / 1.73 m ²；p = 0.0001），但蛋白尿没有差异。肾脏活检的组织学分析发现，与成人相比，儿童肾小球系膜（M1）和毛细血管内膜（E1）的比例更高（M1 [80.7％vs. 27.9％，p = 0.0001]； E1 [71.3％vs. 30％，p = 0.0001]）。成人局灶性肾小球硬化症（S1），肾小管萎缩/间质纤维化≥25％（T1）和P1更为常见（S1 [81.5％vs. 61.3％，p = 0.0012]，T1 [49.5％vs. 1.35％，p = 0.0001]，P1 [33.8％对16.4％，p= 0.008）。儿童尿蛋白与M1，E1和C1有关（M1，p = 0.0001; E1，p = 0.0005; C1，p = 0.0014），而成年人的S1，P1和T1（S1，p = 0.0001; P1，p = 0.0001； T1，p = 0.001）。在接受类固醇治疗（41名儿童和28名成人）后，儿童（p <0.001，随访38个月）和成人（p <0.001，随访76.9个月）的蛋白尿减少，而成年人的eGFR保持稳定，但在eGFR显着增加。儿童（90.6至110 ml / min / 1.73m ²）。

结论

IgAN患儿的蛋白尿是肾小球增生性病变的标志，而其在成人中的存在通常反映出慢性病变的存在。这表明需要进行组织学评估。