van Loghem E, Zegers B J, Bast E J, Kater L
J Clin Invest. 1983 Dec;72(6):1918-23. doi: 10.1172/JCI111155.
A case of familial selective IgA2 deficiency is described. The mother had no detectable IgA2, but a low level of IgA1. She had anti-alpha 2 antibodies of the IgG class. One of her daughters also lacked IgA2 with a normal level of IgA1. The analysis of the immunoglobulin haplotypes of the family suggested the deletion of the alpha 2-gene. In addition, the analysis of B lymphocytes of mother and daughter showed the absence of IgA2-bearing cells. Upon stimulation with pokeweed mitogen, the B cells differentiated into IgA1-containing plasma cells, but IgA2-containing cells were not found. The results suggest a defect in the generation of intraclonal B cell isotype diversity. The molecular basis of this phenomenon is unknown.
描述了一例家族性选择性IgA2缺乏症病例。母亲检测不到IgA2，但IgA1水平较低。她有IgG类抗α2抗体。她的一个女儿也缺乏IgA2，而IgA1水平正常。对该家族免疫球蛋白单倍型的分析提示α2基因缺失。此外，对母亲和女儿的B淋巴细胞分析显示不存在携带IgA2的细胞。在用商陆有丝分裂原刺激后，B细胞分化为含IgA1的浆细胞，但未发现含IgA2的细胞。结果提示克隆内B细胞同种型多样性产生存在缺陷。这种现象的分子基础尚不清楚。
