Wahren M, Ringertz N R, Pettersson I
Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden.
Scand J Immunol. 1994 Feb;39(2):179-83. doi: 10.1111/j.1365-3083.1994.tb03357.x.
The Ro/SSA and La/SSB antigens are common targets for autoantibodies found in the sera of patients with Sjögren's syndrome and SLE. The anti-Ro/SSA and anti-La/SSB antibodies often appear together but are not cross-reactive. This paper describes the humoral autoimmune response to the Ro/SSA 60 kDa protein moiety with respect to the presence of IgM and IgG1-4 antibodies. IgM antibodies to the Ro 60 kDa protein coexisted with IgG anti-Ro 60 kDa antibodies in nearly half of the sera. A similar fraction also contained IgM anti-La/SSB antibodies. The frequency of sera with IgM antibodies of both specificities was that expected from random overlap. A predominating IgG1 anti-Ro 60 kDa response was found in all patients, but anti-Ro 60 kDa antibodies of the other IgG subclasses were present also in a high number of sera. This is in contrast to the reported IgG subclass distribution of anti-La/SSB antibodies. Mapping of IgM and IgG1-4 antibody recognition of different parts of the Ro 60 kDa protein was also performed. IgM and IgG1-4 antibodies of all sera reacted with the central part of the Ro 60 kDa protein, encompassing amino acid residues 181-320.
Ro/SSA和La/SSB抗原是干燥综合征和系统性红斑狼疮患者血清中自身抗体常见的靶抗原。抗Ro/SSA和抗La/SSB抗体常同时出现，但无交叉反应。本文描述了针对Ro/SSA 60 kDa蛋白部分的体液自身免疫反应，涉及IgM和IgG1 - 4抗体的存在情况。在近一半的血清中，针对Ro 60 kDa蛋白的IgM抗体与IgG抗Ro 60 kDa抗体共存。类似比例的血清中也含有IgM抗La/SSB抗体。具有两种特异性IgM抗体的血清频率是随机重叠所预期的。在所有患者中均发现以IgG1抗Ro 60 kDa反应为主，但其他IgG亚类的抗Ro 60 kDa抗体在大量血清中也存在。这与报道的抗La/SSB抗体的IgG亚类分布情况不同。还对Ro 60 kDa蛋白不同部位的IgM和IgG1 - 4抗体识别情况进行了定位。所有血清的IgM和IgG1 - 4抗体均与Ro 60 kDa蛋白的中央部分发生反应，该部分包含氨基酸残基181 - 320。
