McMorrow Fionnuala K, Wedderburn Lucy R, Chinoy Hector, Oldroyd Alexander, Lamb Janine A, Rider Lisa G, Mammen Andrew L, Casciola-Rosen Livia, McHugh Neil J, Tansley Sarah L
Department of Life Sciences, University of Bath, Bath, UK.
Research and Teaching Department, UCL GOS Institute of Child Health, London, UK.
Rheumatology (Oxford). 2025 Jun 1;64(6):3900-3905. doi: 10.1093/rheumatology/keae574.
Anti-transcriptional intermediary factor 1γ (TIF1γ) autoantibodies are associated with malignancy in adult-onset idiopathic inflammatory myopathy (IIM) and this risk is attenuated if patients are also positive for anti-specificity protein 4 (Sp4) or anti-cell division cycle apoptosis regulator protein 1 (CCAR1). In anti-TIF1γ positive dermatomyositis (DM) patients from the USA, anti-Sp4 and anti-CCAR1 autoantibody frequencies are reported as 32% and 43% in adults and 9% and 19% in juveniles, respectively. This study aims to identify the frequency of anti-Sp4 and anti-CCAR1 in adult and juvenile UK anti-TIF1γ-positive myositis populations and report clinical associations.
Serum samples from 51 UK participants with adult-onset IIM and 55 UK participants with JDM, all anti-TIF1γ autoantibody positive, and 24 healthy control samples were screened for anti-Sp4 and anti-CCAR1 autoantibodies by ELISA.
In UK adult anti-TIF1γ positive IIM patients, anti-Sp4 and anti-CCAR1 frequencies were 4% (2/51) and 16% (8/51). Both adult patients with anti-Sp4 were also positive for anti-CCAR1. In UK juveniles, anti-Sp4 was not detected and 13% (7/55) had anti-CCAR1 autoantibodies. Nineteen (37%) anti-TIF1γ positive UK adult myositis patients had cancer; neither of the two patients with anti-Sp4 autoantibodies and 25% (2/8) of anti-CCAR1 autoantibody-positive patients had cancer. No anti-Sp4 or anti-CCAR1 clinical associations were identified.
Anti-Sp4 and anti-CCAR1 autoantibodies are less common in the adult UK anti-TIF1γ-positive myositis population compared with published data from the USA, limiting their use as biomarkers for cancer risk. In patients with juvenile onset disease, anti-Sp4 is less frequent in UK patients compared with the USA, but the prevalence of anti-CCAR1 autoantibodies is similar.
抗转录中介因子1γ（TIF1γ）自身抗体与成人起病的特发性炎性肌病（IIM）中的恶性肿瘤相关，而如果患者抗特异性蛋白4（Sp4）或抗细胞分裂周期凋亡调节蛋白1（CCAR1）也呈阳性，则这种风险会降低。在美国抗TIF1γ阳性的皮肌炎（DM）患者中，据报道成人抗Sp4和抗CCAR1自身抗体频率分别为32%和43%，青少年分别为9%和19%。本研究旨在确定英国成人和青少年抗TIF1γ阳性肌炎人群中抗Sp4和抗CCAR1的频率，并报告临床相关性。
通过酶联免疫吸附测定（ELISA）对51例英国成人起病的IIM参与者、55例英国青少年皮肌炎（JDM）参与者（均为抗TIF1γ自身抗体阳性）的血清样本以及24份健康对照样本进行抗Sp4和抗CCAR1自身抗体筛查。
在英国成人抗TIF1γ阳性IIM患者中，抗Sp4和抗CCAR1频率分别为4%（2/51）和16%（8/51）。两名抗Sp4的成人患者抗CCAR1也呈阳性。在英国青少年中，未检测到抗Sp4，13%（7/55）有抗CCAR1自身抗体。19例（37%）抗TIF1γ阳性的英国成人肌炎患者患有癌症；两名抗Sp4自身抗体患者均未患癌症，抗CCAR1自身抗体阳性患者中有25%（2/8）患癌症。未发现抗Sp4或抗CCAR1与临床的相关性。
与美国公布的数据相比，抗Sp4和抗CCAR1自身抗体在英国成人抗TIF1γ阳性肌炎人群中较少见，限制了它们作为癌症风险生物标志物的应用。在青少年起病的患者中，英国患者抗Sp4的频率低于美国，但抗CCAR1自身抗体的患病率相似。
