Outschoorn I, Rowley M J, Cook A D, Mackay I R
Centre for Molecular Biology and Medicine, Monash University, Clayton, Victoria, Australia.
Clin Immunol Immunopathol. 1993 Jan;66(1):59-66. doi: 10.1006/clin.1993.1008.
The differing capacity of subclasses of IgG to bind to protein A and protein G was used in a sequential affinity purification procedure to examine immunoglobulin isotypes and subclasses in autoimmune disease. The utility of the procedure is that affinity-purified fractions containing particular isotypes and subclasses of immunoglobulin can be analyzed for their content of autoantibodies using standard techniques. For each of four autoimmune diseases studied, chronic active hepatitis, Sjogren's syndrome, primary biliary cirrhosis, and rheumatoid arthritis, there were characteristic protein elution profiles and the various disease-specific autoantibodies showed preferential distributions among the isotypes and subclasses. Moreover there was not an absolute correlation between an increased level of a particular subclass and the occurrence of antibodies of that subclass. The occurrence of highly disease-specific immunoglobulin subclass profiles suggests that the hypergammaglobulinemia associated with autoimmunity cannot be attributed entirely to polyclonal B-cell activation. Rather, there are disease-specific alterations in isotype subclass switching which may reflect different cytokine-dependent influences on autoimmune B cells and their products.
IgG亚类与蛋白A和蛋白G结合能力的差异被用于一种顺序亲和纯化程序，以检测自身免疫性疾病中的免疫球蛋白同种型和亚类。该程序的实用性在于，可以使用标准技术分析含有特定免疫球蛋白同种型和亚类的亲和纯化级分中的自身抗体含量。对于所研究的四种自身免疫性疾病——慢性活动性肝炎、干燥综合征、原发性胆汁性肝硬化和类风湿关节炎中的每一种，都有特征性的蛋白洗脱图谱，并且各种疾病特异性自身抗体在同种型和亚类中表现出优先分布。此外，特定亚类水平的升高与该亚类抗体的出现之间不存在绝对相关性。高度疾病特异性免疫球蛋白亚类图谱的出现表明，与自身免疫相关的高球蛋白血症不能完全归因于多克隆B细胞活化。相反，同种型亚类转换存在疾病特异性改变，这可能反映了细胞因子对自身免疫性B细胞及其产物的不同影响。
