IgA缺乏与Gm同种异型的连锁关系；Gm同种异型对IgA-IgG亚类缺乏的影响。

Linkage of IgA deficiency to Gm allotypes; the influence of Gm allotypes on IgA-IgG subclass deficiency.

作者信息

Oxelius V A, Carlsson A M, Hammarström L, Björkander J, Hanson L A

机构信息

Department of Paediatrics, University Hospital, University of Lund, Sweden.

出版信息

Clin Exp Immunol. 1995 Feb;99(2):211-5. doi: 10.1111/j.1365-2249.1995.tb05534.x.

DOI:10.1111/j.1365-2249.1995.tb05534.x

PMID:7851013

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1534286/

Abstract

IgA deficiency (IgAD) is the most common immunodeficiency, characterized by an arrest in B cell differentiation. It has a sporadic occurrence or variable inheritance pattern, and is also linked to the HLA genes. IgA deficiency is sometimes associated with IgG subclass deficiency. In this study the Gm allotypes, as genetic characteristics of the IgG1, IgG2 and IgG3, were analysed in 83 Caucasian IgAD individuals. Half of the patients presented with IgG4 < 0.01 g/l compared with 5% (P < 0.001) in a healthy population. Three of the 83 had significantly low IgG2 and four had significantly low IgG3 levels. Gm allotype frequencies in IgAD deviated compared with a normal population. Of the 83 patients, 44 (53%) showed homozygous G2 m(",") expression on the IgG2 locus (33% in controls, P < 0.01). In IgAD the Gm(a,",g) haplotype was more frequent (43%) compared with controls (31%, P < 0.01). The Gm homozygous phenotype Gm(a,",g/a,",g) was most common, found in 20 of 83 patients (24%, P < 0.05) compared with controls (14%). On the other hand the Gm(f,n,b) haplotype of IgAD was rare (28%) compared with controls (45%, P < 0.001). The low IgG4, < 0.01 g/l, found in 50% of the patients, was even more frequent (56-69%) among the G2 m(",") phenotypes. IgG subclass levels were given for different Gm phenotypes of the IgAD group and compared with controls. Significantly low IgG4 was revealed in the Gm(a,",g/a,",g) phenotype (P < 0.01) and significantly low IgG2 in the Gm(a,",g/f,",b) phenotype (P < 0.01). The Gm(a,",g/f,",b) phenotype contained the three patients found with IgG2 levels < -2 s.d., and the four patients with IgG3 levels < -2 s.d. were present among those with the homozygous Gm(a,",g/a,",g) phenotype; both phenotypes with G2 m(",") on the IgG2 locus. The 'compensatory' increase of IgG was significant for both IgG1 and IgG3 in all Gm phenotypes, but in the Gm(a,",g/f,",b). Thus, the susceptibility of IgAD with the additional IgG antibody deficiencies, down-regulated IgG4 and IgG2/IgG3, is associated with Gm allotypes, especially the homozygous G2 m(",") expression on the IgG2 locus.

摘要

IgA 缺乏症（IgAD）是最常见的免疫缺陷病，其特征为 B 细胞分化受阻。它呈散发性出现或具有可变的遗传模式，并且还与 HLA 基因相关。IgA 缺乏症有时与 IgG 亚类缺乏有关。在本研究中，对 83 名高加索 IgAD 个体的 Gm 同种异型（作为 IgG1、IgG2 和 IgG3 的遗传特征）进行了分析。一半患者的 IgG4 低于 0.01 g/l，而健康人群中这一比例为 5%（P < 0.001）。83 名患者中有 3 人 IgG2 显著降低，4 人 IgG3 水平显著降低。IgAD 中的 Gm 同种异型频率与正常人群相比存在偏差。83 名患者中有 44 人（53%）在 IgG2 基因座上表现为纯合子 G2m(“)表达（对照组为 33%，P < 0.01）。与对照组（31%，P < 0.01）相比，IgAD 中 Gm(a,“,g)单倍型更为常见（43%）。Gm 纯合子表型 Gm(a,“,g/a,“,g)最为常见，83 名患者中有 20 人（24%，P < 0.05），而对照组为（14%）。另一方面，IgAD 的 Gm(f,n,b)单倍型与对照组（45%，P < 0.001）相比很少见（28%）。50%的患者 IgG4 低于 0.01 g/l，在 G2m(“)表型中更为常见（56 - 69%）。给出了 IgAD 组不同 Gm 表型的 IgG 亚类水平，并与对照组进行比较。在 Gm(a,“,g/a,“,g)表型中发现 IgG4 显著降低（P < 0.01），在 Gm(a,“,g/f,“,b)表型中 IgG2 显著降低（P < 0.01）。Gm(a,“,g/f,“,b)表型包含 3 名 IgG2 水平低于 -2 个标准差的患者，4 名 IgG3 水平低于 -2 个标准差的患者出现在纯合子 Gm(a,“,g/a,“,g)表型中；这两种表型在 IgG2 基因座上均有 G2m(“)。IgG 的“代偿性”增加在所有 Gm 表型中对 IgG1 和 IgG3 均显著，但在 Gm(a,“,g/f,“,b)中并非如此。因此，伴有额外 IgG 抗体缺乏、IgG4 和 IgG2/IgG3 下调的 IgAD 易感性与 Gm 同种异型有关，尤其是 IgG2 基因座上的纯合子 G2m(“)表达。