Immunology Unit, La Paz University Hospital, Madrid, Spain.
Immuno-Rheumatology Research Group, Hospital La Paz Institute for Health Research, Madrid, Spain.
Scand J Rheumatol. 2022 Mar;51(2):102-109. doi: 10.1080/03009742.2021.1914430. Epub 2021 Jun 29.
To evaluate whether serum infliximab trough levels (ITL) during the early stages of treatment are predictive of long-term clinical failure in patients with axial spondyloarthritis (axSpA).
Longitudinal observational study involving 81 patients with axSpA monitored during infliximab therapy. Serum ITL were measured before starting infliximab treatment and at weeks 2 (W2), W6 and W12 of treatment. Disease activity was assessed by Ankylosing Spondylitis Disease Activity Score (ASDAS) at baseline, W24 and W52, and every 6 months thereafter until treatment discontinuation, regardless of the reason. Non-clinically important improvement was defined by ΔASDAS<1.1. The association between serum levels during the early stages and clinical outcomes (non-clinically important improvement at W52, drug survival and drop-out due to secondary inefficacy) was investigated through logistic regression models and Kaplan Meier curves. Receiver operating characteristic (ROC) curves were employed to determine the best cut-off for serum ITL.
Out of the 81 patients, 45 (56%) did not achieve clinical improvement at W52. These patients had lower serum ITL at W12 compared to those who improved: ITL [median (IQR)]: 4.1(0.9-8.3) µg/mL vs 7.1 (4.3-11.3) µg/mL, respectively;p = 0.007). ITL<6.7 µg/mL at W12 was significantly associated with: i) not achieving clinical improvement at W52 (OR: 2.3; 95%CI: 1.3-3.9); ii) shorter drug survival (5.0 years (95% CI 3.8-6.2) vs 7.0 years (95% CI 4.8-6.9; p = 0.04), and iii) higher drop-out rates due to secondary inefficacy (OR: 3.5; 95% CI: 1.2-10.2).
Low serum ITL at W12 were associated with long-term clinical failure in patients with axSpA, due to secondary inefficacy.
评估治疗早期血清英夫利昔单抗谷浓度（ITL）是否可预测轴性脊柱关节炎（axSpA）患者的长期临床失败。
这是一项涉及 81 例 axSpA 患者的纵向观察性研究，在英夫利昔单抗治疗期间对其进行监测。在开始英夫利昔单抗治疗前和治疗的第 2 周（W2）、第 6 周（W6）和第 12 周（W12）测量血清 ITL。在基线、第 24 周和第 52 周以及此后每 6 个月（无论停药原因如何）使用强直性脊柱炎疾病活动评分（ASDAS）评估疾病活动度。无临床意义的改善定义为ΔASDAS＜1.1。通过逻辑回归模型和 Kaplan-Meier 曲线研究早期血清水平与临床结局（第 52 周无临床意义改善、药物生存率和因继发疗效不佳而停药）之间的关系。采用受试者工作特征（ROC）曲线确定血清 ITL 的最佳截断值。
在 81 例患者中，45 例（56%）在第 52 周时未达到临床改善。与改善的患者相比，这些患者在第 12 周时的血清 ITL 较低：ITL[中位数（IQR）]：4.1（0.9-8.3）µg/mL 与 7.1（4.3-11.3）µg/mL，p=0.007）。第 12 周时 ITL＜6.7µg/mL 与以下因素显著相关：i）第 52 周时未达到临床改善（OR：2.3；95%CI：1.3-3.9）；ii）药物生存率较短（5.0 年（95%CI：3.8-6.2）与 7.0 年（95%CI：4.8-6.9；p=0.04））；iii）因继发疗效不佳而停药率较高（OR：3.5；95%CI：1.2-10.2）。
由于继发疗效不佳，axSpA 患者第 12 周时血清 ITL 较低与长期临床失败相关。
