Extra-articular involvement (EAI) in rheumatoid arthritis (RA) is rare, severe and usually presents after years of joint involvement. Onset of RA as lung involvement has been published. We describe a series of three patients with strongly positive anti-citrullinated peptide antibodies (ACPA) and rheumatoid factor (RF) positive in the absence of joint symptoms, but with significant EAI.

中文翻译：

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在没有初始关节受累的情况下，三名血清阳性患者的类风湿性关节炎的关节外受累

类风湿性关节炎 (RA) 的关节外受累 (EAI) 罕见、严重，通常在关节受累多年后出现。已经发表了肺部受累引起的 RA 发作。我们描述了一系列三名患者，其抗瓜氨酸肽抗体 (ACPA) 和类风湿因子 (RF) 呈强阳性，但没有关节症状，但有明显的 EAI。