Muscle Disease Unit, Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD.
Division of Rheumatology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
Rheumatology (Oxford). 2023 Feb 23;62(SI2):SI226-SI234. doi: 10.1093/rheumatology/keac428.
Four-and-a-half LIM domains 1 (FHL1) is a muscle-specific protein. Autoantibodies against FHL1 were recently discovered in adults with idiopathic inflammatory myopathies (IIMs) and were found to be associated with clinical features and outcomes indicative of increased disease severity. Anti-FHL1 autoantibodies have not been described in children. Here, the prevalence and clinical features associated with anti-FHL1 autoantibodies were examined in a large North American cohort of juvenile patients with IIM.
Sera from 338 juvenile IIM patients and 91 juvenile healthy controls were screened for anti-FHL1 autoantibodies by ELISA. Clinical characteristics and HLA alleles of those with and without anti-FHL1 autoantibodies were compared among those with juvenile IIM.
Anti-FHL1 autoantibodies were present in 10.9% of juvenile IIM patients and 1.1% of controls. The frequency of anti-FHL1 autoantibodies among clinical and serologic subgroups did not differ. A higher percentage of Asian patients had anti-FHL1 autoantibodies (11% vs 0.7%; P = 0.002). Myositis-associated autoantibodies (MAAs) [odds ratio (OR) 2.09 (CI 1.03, 4.32)], anti-Ro52 autoantibodies specifically [OR 4.17 (CI 1.83, 9.37)] and V-sign rash [OR 2.59 (CI 1.22, 5.40)] were associated with anti-FHL1 autoantibodies. There were no differences in other features or markers of disease severity. No HLA associations with anti-FHL1 autoantibodies in Caucasian myositis patients were identified.
Anti-FHL1 autoantibodies are present in ∼11% of juvenile IIM patients and commonly co-occur with MAAs, including anti-Ro52 autoantibodies. In contrast to adult IIM, anti-FHL1 autoantibodies in juvenile myositis are associated with V-sign rash but not with other distinctive clinical features or worse outcomes.
四半 LIM 结构域 1（FHL1）是一种肌肉特异性蛋白。最近在特发性炎性肌病（IIM）的成年患者中发现了针对 FHL1 的自身抗体，并且发现这些自身抗体与预示疾病严重程度增加的临床特征和结局相关。在儿童中尚未描述抗 FHL1 自身抗体。在此，通过酶联免疫吸附试验（ELISA）检查了一个大型北美幼年特发性肌炎患者队列中抗 FHL1 自身抗体的患病率和与其相关的临床特征。
对 338 名幼年 IIM 患者和 91 名幼年健康对照者的血清进行了抗 FHL1 自身抗体的 ELISA 检测。比较了幼年 IIM 患者中有无抗 FHL1 自身抗体的患者的临床特征和 HLA 等位基因。
抗 FHL1 自身抗体在 10.9%的幼年 IIM 患者和 1.1%的对照组中存在。在临床和血清学亚组中，抗 FHL1 自身抗体的频率没有差异。更高比例的亚洲患者具有抗 FHL1 自身抗体（11%比 0.7%；P=0.002）。肌炎相关自身抗体（MAAs）[比值比（OR）2.09（CI 1.03，4.32）]、抗 Ro52 自身抗体[OR 4.17（CI 1.83，9.37）]和 V 征皮疹[OR 2.59（CI 1.22，5.40）]与抗 FHL1 自身抗体相关。其他特征或疾病严重程度的标志物没有差异。在白种人肌炎患者中未发现与抗 FHL1 自身抗体相关的 HLA 关联。
抗 FHL1 自身抗体存在于约 11%的幼年 IIM 患者中，通常与 MAAs 共同出现，包括抗 Ro52 自身抗体。与成年 IIM 不同，幼年肌炎中的抗 FHL1 自身抗体与 V 征皮疹有关，但与其他独特的临床特征或更差的结局无关。
