Baek In-Woon, Park Kyung-Su, Kim Ki-Jo
Division of Rheumatology, Department of Internal Medicine, Ewha Womans University College of Medicine, Seoul, Korea.
St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
J Rheum Dis. 2025 Jan 1;32(1):30-37. doi: 10.4078/jrd.2024.0073. Epub 2024 Sep 2.
An association between increased erythrocyte mean corpuscular volume (MCV) and treatment response in patients with inflammatory arthritis receiving methotrexate (MTX) has been reported. We investigated the frequency of red blood cell (RBC) macrocytosis and its clinical implications regarding the initiation of biological or targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) in patients starting MTX for rheumatoid arthritis (RA).
RBC macrocytosis (MCV >100 fL) and clinical characteristics were retrospectively examined in 1,156 patients starting MTX for RA. Multivariable logistic regression analyses were performed to identify the independent predictors of RBC macrocytosis. The initiation of b/tsDMARDs was assessed using a multivariable Cox proportional hazards regression model.
RBC macrocytosis was observed in 21.6% of RA patients over 35 [8, 89] months following MTX initiation and was persistent in 63.6% of the patients during MTX treatment. Anemia coexisted in only 20.0% of the patients with RBC macrocytosis. The occurrence of RBC macrocytosis was independently associated with age, MTX dose, and concomitant use of sulfasalazine or leflunomide (all p<0.001). A higher dose of MTX and double- or triple-DMARDs therapy were more frequently used in the group with RBC macrocytosis than in the group with normal MCV. Patients experiencing RBC macrocytosis were more likely to use b/tsDMARDs (hazard ratio 1.45 [95% confidence interval 1.13, 1.87], p=0.003).
RBC macrocytosis was possibly associated with the use of b/tsDMARD and could be a supplementary marker for assessing MTX resistance.
有报道称，接受甲氨蝶呤（MTX）治疗的炎性关节炎患者红细胞平均体积（MCV）升高与治疗反应之间存在关联。我们调查了类风湿关节炎（RA）患者开始使用MTX时红细胞（RBC）大细胞性贫血的发生率及其对启动生物或靶向合成改善病情抗风湿药物（b/tsDMARDs）的临床意义。
对1156例开始使用MTX治疗RA的患者进行回顾性研究，检测RBC大细胞性贫血（MCV>100 fL）及临床特征。进行多变量逻辑回归分析以确定RBC大细胞性贫血的独立预测因素。使用多变量Cox比例风险回归模型评估b/tsDMARDs的启动情况。
在MTX启动后35[8, 89]个月内，21.6%的RA患者出现RBC大细胞性贫血，且在MTX治疗期间63.6%的患者持续存在。仅有20.0%的RBC大细胞性贫血患者合并贫血。RBC大细胞性贫血的发生与年龄、MTX剂量以及同时使用柳氮磺胺吡啶或来氟米特独立相关（均p<0.001）。与MCV正常组相比，RBC大细胞性贫血组更频繁使用高剂量MTX和双联或三联改善病情抗风湿药物治疗。出现RBC大细胞性贫血的患者更可能使用b/tsDMARDs（风险比1.45[95%置信区间1.13, 1.87]，p=0.003）。
RBC大细胞性贫血可能与使用b/tsDMARDs有关，并且可能是评估MTX耐药性的补充标志物。
