Servicio de Reumatología e Inmunología Clínica, Departamento de Medicina Interna, Hospital Universitario "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León, Monterrey, Mexico.
Servicio de Reumatología e Inmunología Clínica, Departamento de Medicina Interna, Hospital Universitario "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León, Monterrey, Mexico.
Reumatol Clin (Engl Ed). 2021 Jan;17(1):12-15. doi: 10.1016/j.reuma.2019.03.001. Epub 2019 Aug 6.
BACKGROUND/OBJECTIVES: Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by swelling, tenderness and destruction of synovial joints, leading to severe disability and premature mortality. The aim of the study was to determine the diagnostic accuracy of the 3 isotypes of rheumatoid factor (RF), anti-citrullinated peptide antibodies (ACPA) and the combination of both, for the diagnosis of rheumatoid arthritis (RA) in non-selected patients with inflammatory arthralgia.
We include 129 patients with inflammatory Arthalgia from a third level reference Center of rheumatic diseases in Monterrey, México. Their samples were analyzed for RF isotypes (IgA, IgG, and IgM) by ELISA (EUROINMUN), using a cut-off of 20IU/ml, and for ACPA's 5IU/ml; a medical examination was performed to obtain the definitive diagnoses of the patients. Data analysis was carried out using ROC curves for the measurement of sensitivity, specificity, for diagnostic accuracy to verify if the use of 3 RF isotypes and ACPA had a better prediction for the diagnosis of RA than use only one isotype and the ACPA alone.
The ROC showed a sensitivity and specificity of the different antibodies with different cut-off points, being the best for the IgM with 0.802 followed by ACPA, IgA and IgG with 0.771, 0.63, and 0.728 respectively without statistical difference, the sensitivity and specificity of the combination of the 4 antibodies were 81.4 and 73.66%.
In non-selected patients with inflammatory arthralgia, the combination of ACPA and isotypes of RF did not demonstrate more sensibility and specificity than IgM isoform of rheumatoid factor measurement only. We recommend that in the clinical scenario of arthralgia, where the diagnoses are Lupus, Sjogren syndrome and Osteoarthritis, RF IgM isoform is used followed by ACPA.
背景/目的：类风湿关节炎（RA）是一种慢性炎症性疾病，其特征为滑膜关节肿胀、触痛和破坏，导致严重残疾和过早死亡。本研究旨在确定类风湿因子（RF）的 3 种同种型（IgA、IgG 和 IgM）、抗瓜氨酸化肽抗体（ACPA）以及两者联合应用对于诊断非选择性炎性关节痛患者类风湿关节炎（RA）的诊断准确性。
我们纳入了来自墨西哥蒙特雷三级参考风湿疾病中心的 129 例炎性关节痛患者。通过 ELISA（EUROINMUN）分析其 RF 同种型（IgA、IgG 和 IgM）的水平，采用 20IU/ml 的截断值，以及 ACPA 的水平为 5IU/ml；通过体格检查获得患者的明确诊断。使用 ROC 曲线分析数据，以评估敏感性、特异性和诊断准确性，验证使用 3 种 RF 同种型和 ACPA 是否比仅使用一种同种型和 ACPA 对 RA 诊断具有更好的预测价值。
ROC 显示了不同抗体和不同截断值的敏感性和特异性，其中 IgM 的最佳截断值为 0.802，其次是 ACPA、IgA 和 IgG，分别为 0.771、0.63 和 0.728，无统计学差异；4 种抗体联合的敏感性和特异性分别为 81.4%和 73.66%。
在非选择性炎性关节痛患者中，ACPA 和 RF 同种型的联合应用并未比仅测量 RF IgM 同种型显示出更高的敏感性和特异性。我们建议在关节痛的临床情况下，在诊断为狼疮、干燥综合征和骨关节炎的情况下，使用 RF IgM 同种型，然后使用 ACPA。
