Ceribelli Angela, Isailovic Natasa, De Santis Maria, Gorlino Carolina, Satoh Minoru, Selmi Carlo
Division of Rheumatology and Clinical Immunology, Laboratory of Autoimmunity and Metabolism, Humanitas Clinical and Research Center - IRCCS -, via Manzoni 56, 20089, Rozzano, MI, Italy.
Department of Clinical Nursing, University of Occupational and Environmental Health, Kitakyushu, Japan.
J Transl Autoimmun. 2020 Mar 31;3:100049. doi: 10.1016/j.jtauto.2020.100049. eCollection 2020.
Serum autoantibodies are pivotal for the early detection of systemic autoimmune rheumatic diseases such as Systemic Sclerosis (SSc) and Poly/Dermatomyositis (PM/DM), and in some cases are associated with organ complications such as interstitial lung disease (ILD). A paradigmatic example is provided by the autoantibody against the Eukaryotic Initiation Factor 2B (eIF2B) that has been recently detected in SSc.
Sera from 118 patients with SSc, 8 Poly/Dermatomyositis, 2 overlap SSc/Polymyositis, 4 undifferentiated connective tissue disease-UCTD and 3 healthy controls were tested first by indirect immunofluorescence for anti-nuclear antibodies-ANA pattern. Further, we employed protein-radioimmunoprecipitation (IP) and IP- Western Blot for the detection and confirmation of anti-eIF2B antibodies. Serum findings were further correlated with the clinical features of patients.
We identified 3 SSc cases (2.5%) positive for anti-eIF2B antibodies while this autoantibody was not detected in control sera. Using protein-IP all three patients manifested the 38kD protein which is the antigenic target of anti-eIF2B antibodies, and this was associated with a cytoplasmic pattern at indirect immunofluorescence. The presence of anti-eIF2B was associated with ILD and a diffuse SSc variant, in one case in association with anti-Scl70/topoI.
Our data confirm that a small subgroup (2.5%) of patients with SSc have detectable anti-eIF2B with cytoplasmic-positive staining at immunofluorescence and this reactivity is associated with ILD.
血清自身抗体对于系统性自身免疫性风湿性疾病如系统性硬化症（SSc）和多/皮肌炎（PM/DM）的早期检测至关重要，并且在某些情况下与间质性肺疾病（ILD）等器官并发症相关。针对真核起始因子2B（eIF2B）的自身抗体就是一个典型例子，最近在系统性硬化症中被检测到。
首先通过间接免疫荧光检测118例系统性硬化症患者、8例多/皮肌炎患者、2例重叠综合征（系统性硬化症/多肌炎）患者、4例未分化结缔组织病（UCTD）患者和3例健康对照者血清中的抗核抗体（ANA）模式。此外，我们采用蛋白质放射免疫沉淀法（IP）和IP-蛋白质印迹法检测和确认抗eIF2B抗体。血清检测结果进一步与患者的临床特征相关联。
我们鉴定出3例（2.5%）系统性硬化症患者抗eIF2B抗体呈阳性，而在对照血清中未检测到这种自身抗体。通过蛋白质免疫沉淀法，所有3例患者均表现出38kD蛋白，该蛋白是抗eIF2B抗体的抗原靶点，并且在间接免疫荧光下与细胞质模式相关。抗eIF2B的存在与ILD以及弥漫性系统性硬化症变体相关，其中1例与抗Scl70/拓扑异构酶I相关。
我们的数据证实一小部分（2.5%）系统性硬化症患者可检测到抗eIF2B，免疫荧光显示细胞质阳性染色，并且这种反应性与ILD相关。
