Galactose-deficient IgA1 in sera of IgA nephropathy patients is present in complexes with IgG
Galactose-deficient IgA1 in sera of IgA nephropathy patients is present in complexes with IgG
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DOI：
10.1038/ki.1997.361
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发表时间：
1997-08-01
影响因子：
19.6
通讯作者：
Mestecky, J
中科院分区：
文献类型：
--
作者：
Tomana, M;Matousovic, K;Mestecky, J
伊加肾病（IgAN）患者血清中的IgA 1蛋白质的半乳糖基化程度低于健康对照组。完整或去唾液酸化血清IgA 1与N-乙酰半乳糖胺（GalNAc）特异性凝集素的反应性增加。结果表明，Gal缺乏主要是位于IgA 1分子铰链区的聚糖。81名IgAN患者血清中的去唾液酸化伊加与生物素标记的凝集素HAA的结合比56名健康对照血清中的去唾液酸化伊加更有效（P < 0.0001）。67例IgAN患者和52例正常对照者的CAA检测结果相似（P < 0.001）。9例非IgA系膜增生性肾小球肾炎患者的结合模式与对照组相似。不完全半乳糖基化的IgA 1能够结合GalNAc特异性凝集素检测与IgG的复合物，如通过ELISA，尺寸排阻色谱法和蔗糖梯度超离心证明。IgA 1-IgG复合物的形成可能通过降低肝脏的消除和分解代谢降解速率来影响血清中的IgA 1水平。
IgA1 proteins from sera of patients with IgA nephropathy (IgAN) are galactosylated to a lesser degree than those from healthy controls. The increased reactivity of intact or de-sialylated serum IgA1 with N-acetylgalactosamine (GalNAc)-specific lectins. Helix aspersa (HAA) and Caragana arborescens (CAA) and de-sialylated IgA1 with Helix pomatia (HPA) and Bauhinia pulpurea (BPA) indicated that the Gal deficiency is in glycans located in the hinge region of IgA1 molecules. De-sialylated IgA from sera of 81 IgAN patients bound biotin-labeled lectin HAA more effectively than did de-sialylated IgA from 56 healthy controls (P < 0.0001). similar results were observed for 67 IgAN patients and 52 controls with second lectin, CAA (P < 0.001). The binding patterns for 9 patients with mesangial proliferative glomerulonephritis of non-IgA origin were similar to those for controls. Incompletely galactosylated IgA1 capable of binding GalNAc-specific lectins was detected in complexes with IgG as demonstrated by ELISA, size-exclusion chromatography and sucrose gradient ultracentrifugation. The formation of IgA1-IgG complexes may affect the serum level of IgA1 by reducing the rate of its elimination and catabolic degradation by the liver.