This study was aimed at investigating the clinical significance of serum galactose-deficient IgA1 (Gd-IgA1) levels measured by a novel lectin-independent enzyme-linked immunosorbent assay (ELISA) using an anti-Gd-IgA1 monoclonal antibody (KM55) as a disease-specific biomarker for IgA nephropathy (IgAN) in children. Thirty-three children with IgAN, 40 with non-IgA glomerular diseases, and 38 age-matched healthy controls (HCs) were enrolled. Serum Gd-IgA1 levels were quantified by ELISA using KM55. Results were statistically compared with clinical features and pathological findings of IgAN. Serum Gd-IgA1 levels were significantly elevated in children with IgAN compared with children with non-IgA glomerular diseases and HCs. Serum Gd-IgA1 levels in children with IgAN were positively correlated with serum total IgA levels. However, the serum Gd-IgA1/total IgA ratio (Gd-IgA1/IgA) was also significantly elevated in children with IgAN. Serum Gd-IgA1 levels in children with IgAN increased in an age-dependent manner. The cutoff value of serum Gd-IgA1 levels for differentiating IgAN from non-IgA glomerular diseases was 3236 in and 5284 in , respectively. In contrast, serum Gd-IgA1/IgA was age-independent. The cutoff value of serum Gd-IgA1/IgA for differentiating IgAN from non-IgA glomerular diseases was 0.2401. Serum Gd-IgA1 levels were negatively correlated with eGFR and positively correlated with mesangial IgA deposition. In contrast, serum Gd-IgA1/IgA levels were not correlated with any clinical parameters of IgAN. In conclusion, serum Gd-IgA1 levels were significantly elevated in children with IgAN. However, those levels were age-dependent; therefore, serum Gd-IgA1 levels classified by age and/or serum Gd-IgA1/IgA might have diagnostic values in children with IgAN.

中文翻译：

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IgA肾病患儿血清半乳糖缺乏IgA1水平的临床意义。

这项研究的目的是研究使用抗Gd-IgA1单克隆抗体（KM55）作为抗凝集素独立酶联免疫吸附试验（ELISA）进行的血清半乳糖缺陷型IgA1（Gd-IgA1）水平的临床意义。儿童IgA肾病（IgAN）的疾病特异性生物标志物。入选了33例IgAN儿童，40例非IgA肾小球疾病和38例年龄匹配的健康对照（HCs）。使用KM55通过ELISA定量血清Gd-IgA1水平。将结果与IgAN的临床特征和病理结果进行统计学比较。与非IgA肾小球疾病和HCs患儿相比，IgAN患儿的血清Gd-IgA1水平显着升高。IgAN患儿的血清Gd-IgA1水平与血清​​总IgA水平呈正相关。然而，IgAN患儿的血清Gd-IgA1 /总IgA比（Gd-IgA1 / IgA）也明显升高。IgAN患儿的血清Gd-IgA1水平呈年龄依赖性增长。血清Gd-IgA1区分IgAN与非IgA肾小球疾病的临界值为3236。 和5284 in ，分别。相反，血清Gd-IgA1 / IgA与年龄无关。血清Gd-IgA1 / IgA区分IgAN和非IgA肾小球疾病的临界值为0.2401。血清Gd-IgA1水平与eGFR呈负相关，与系膜IgA沉积呈正相关。相反，血清Gd-IgA1 / IgA水平与IgAN的任何临床参数均不相关。总之，IgAN患儿的血清Gd-IgA1水平显着升高。但是，这些水平取决于年龄。因此，按年龄分类的血清Gd-IgA1水平和/或血清Gd-IgA1 / IgA对IgAN儿童可能具有诊断价值。