Department of Rheumatology, Diakonhjemmet Hospital, Oslo, Norway.
J Rheumatol. 2011 Nov;38(11):2336-41. doi: 10.3899/jrheum.110234. Epub 2011 Oct 1.
Presence and levels of antibodies contribute to the classification of rheumatoid arthritis. We investigated the longitudinal course of anti-citrullinated protein antibodies (ACPA) and immunoglobin M (IgM) rheumatoid factor (RF) during the first year after arthritis onset in patients with very short disease duration.
Patients (aged 18-75 years) with ≥ 1 swollen joint of ≤ 16 weeks' duration had assessments of ACPA (2nd generation anti-cyclic citrullinated peptide antibodies, anti-CCP2) and IgM RF at inclusion and after 3, 6, and 12 months. Frequencies of seroconversions (negative to positive and vice versa) and changes in antibody levels during followup were determined.
A total of 281 early arthritis patients (median duration of joint swelling 32 days, 14.2% ACPA positives, 12.8% IgM RF positives) with 978 longitudinally collected serum samples were included. Only 5 patients (1.8%) negative for both antibodies at baseline turned antibody-positive during followup, while 9 antibody-positive patients (3.2%) turned antibody-negative. ACPA was more stable than RF regarding both status and levels.
Antibody status (ACPA/RF) is a stable phenotype in very early arthritis, as seroconversion was only found in 5% of patients. Repeated measurement of ACPA or RF during the first year after onset of arthritis does not offer major additional information.
抗体的存在和水平有助于类风湿关节炎的分类。我们研究了疾病持续时间非常短的关节炎患者在发病后 1 年内抗瓜氨酸化蛋白抗体（ACPA）和免疫球蛋白 M（IgM）类风湿因子（RF）的纵向变化过程。
≥1 个关节肿胀≤16 周的 18-75 岁患者在纳入时和 3、6 和 12 个月时进行 ACPA（第二代抗环瓜氨酸肽抗体，抗-CCP2）和 IgM RF 评估。确定随访期间的血清转换（由阴转阳和由阳转阴）频率以及抗体水平的变化。
共纳入 281 例早期关节炎患者（关节肿胀中位数为 32 天，14.2%的患者 ACPA 阳性，12.8%的患者 IgM RF 阳性），共采集了 978 份纵向采集的血清样本。仅 5 名基线时两种抗体均阴性的患者在随访期间转为阳性，而 9 名抗体阳性患者（3.2%）转为阴性。在非常早期的关节炎中，抗体状态（ACPA/RF）是一种稳定的表型，因为只有 5%的患者发生血清转换。在关节炎发病后 1 年内重复测量 ACPA 或 RF 并不能提供更多的信息。
