Department of Immunology, Centre de Diagnòstic Biomèdic (CDB), Hospital Clínic, Barcelona, and Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona; Department of Autoimmune Diseases, Hospital Clínic, University of Barcelona, Barcelona; and Reference Centre for Systemic Autoimmune Diseases (CSUR) of the Spanish Health System, Barcelona, Spain.
Clin Exp Rheumatol. 2024 Aug;42(8):1556-1563. doi: 10.55563/clinexprheumatol/qijvcj. Epub 2023 Sep 29.
Anti-CENP-B (ACA), anti-topoisomerase I (ATA) and anti-RNA polymerase III (RP3) autoantibodies are included in the 2013 SSc-ACR/EULAR classification criteria. The detection of additional autoantibodies is of interest when those are negative. Additionally, we wonder if the IgA isotype might play a role in SSc. The aims of the study were to assess the prevalence of ACA, ATA, RP3, and Ro52 autoantibodies of IgG and IgA isotype and to describe their association with clinical manifestations in a cohort of patients with SSc.
Samples from 97 patients with SSc fulfilling the 2013 ACR/EULAR classification criteria, and 50 blood donors were included and tested for IgA and IgG isotypes of ACA, ATA, RP3, and Ro52 by FEIA.
The prevalence of IgG+IgA isotypes for the same specificity was 62.5%, 82.6%, 80.0%, 36.8%, for ACA, ATA, RP3 and Ro52, respectively. Isolated IgG was present in 35.4%, 13.0%, 20.0% and 42.1% of patients for ACA, ATA, RP3 and Ro52, respectively. Only six patients were isolated IgA for a unique specificity. Clinically, ILD tended to be associated with ATA-IgG and ATA-IgG+IgA, telangiectasias with ACA-IgG+IgA and arthritis with ACA-IgA. Indeed, digital ulcers were more frequent in ATA-IgG patients.
Most of the patients presented ACA, ATA, or RP3 autoantibodies of IgA isotype in addition to IgG. Regarding clinical relevance, Ro52-IgG+IgA and ACA-IgG had a tendency towards sineSSc phenotype, while ACA-IgG+IgA to lcSSc phenotype. Thus, if confirmed, the determination of ACA-IgA could provide a tool to stratify patients according to the cutaneous phenotype.
抗着丝粒蛋白 B（ACA）、抗拓扑异构酶 I（ATA）和抗 RNA 聚合酶 III（RP3）自身抗体被纳入 2013 年 SSc-ACR/EULAR 分类标准。当这些自身抗体阴性时，检测其他自身抗体很有意义。此外，我们还想知道 IgA 同种型是否在 SSc 中起作用。本研究的目的是评估 IgG 和 IgA 同种型的 ACA、ATA、RP3 和 Ro52 自身抗体在一组 SSc 患者中的患病率，并描述其与临床表现的关系。
纳入 97 例符合 2013 年 ACR/EULAR 分类标准的 SSc 患者和 50 名献血者的样本，采用 FEIA 法检测 IgG 和 IgA 同种型的 ACA、ATA、RP3 和 Ro52。
对于相同的特异性，IgG+IgA 同种型的患病率分别为 62.5%、82.6%、80.0%和 36.8%，分别为 ACA、ATA、RP3 和 Ro52。ACA、ATA、RP3 和 Ro52 患者分别有 35.4%、13.0%、20.0%和 42.1%的患者存在单纯 IgG 阳性。仅有 6 例患者存在单一特异性的单纯 IgA。临床上，ILD 倾向于与 ATA-IgG 和 ATA-IgG+IgA 相关，毛细血管扩张症与 ACA-IgG+IgA 相关，关节炎与 ACA-IgA 相关。事实上，ATA-IgG 患者的手指溃疡更为常见。
大多数患者除 IgG 外，还存在 ACA、ATA 或 RP3 的 IgA 同种型自身抗体。就临床相关性而言，Ro52-IgG+IgA 和 ACA-IgG 倾向于 sineSSc 表型，而 ACA-IgG+IgA 倾向于 lcSSc 表型。因此，如果得到证实，ACA-IgA 的测定可以提供一种根据皮肤表型对患者进行分层的工具。
