Department of Rheumatology, Indraprastha Apollo Hospitals, Delhi, India.
Department of Microbiology, Indraprastha Apollo Hospitals, Delhi, India.
Int J Rheum Dis. 2019 Sep;22(9):1638-1643. doi: 10.1111/1756-185X.13636. Epub 2019 Jun 18.
In India, many centers use infliximab at lower doses of 3-5 mg/kg without the loading dose for spondyloarthritis (SpA) patients. It is then continued on an as-required basis, rather than a fixed schedule. Our study was undertaken to see if the trough drug levels and anti-drug antibodies in patients with SpA treated with as-needed infliximab dosing correlated with the disease activity measures.
Thirty-five adult SpA patients in the age group 18-70 years were recruited. They had received three or more infusions of infliximab at 3-5 mg/kg over the past 6 to 12 months. Patient's serum tumor necrosis factor-α, trough infliximab levels and anti-drug antibodies were measured by enzyme-linked immunosorbent assay technique. The disease activity was quantified by Ankylosing Spondylitis Disease Activity Score - erythrocyte sedimentation rate/ C-reactive protein (ASDAS-ESR/CRP) scores. Correlation between quantitative variables was analyzed by the Spearman's correlation assay. The difference in mean trough infliximab and ASDAS between the drug antibody positive and negative patients was assessed using the Mann-Whitney U test.
There was a significant negative correlation between the trough infliximab levels and the ASDAS-ESR (rs = -0.57, P < 0.01) and ASDAS-CRP scores (rs = -0.53, P < 0.01). Anti-drug antibodies were positive in 68.7% of the patients and in comparison to the antibody negative patients, had significantly higher ASDAS-ESR and ASDAS-CRP scores.
Spondyloarthritis patients on low-dose, as-needed infliximab therapy, have both the trough infliximab and anti-drug antibodies correlate significantly with the measures of disease activity. We hypothesize that trough infliximab levels and anti-drug antibodies may be used to predict a suboptimal response due to secondary resistance in SpA patients.
在印度，许多中心对脊柱关节炎（SpA）患者使用较低剂量的 3-5mg/kg 的英夫利昔单抗，且不使用负荷剂量。然后按需继续使用，而不是固定方案。我们的研究旨在观察 SpA 患者接受按需英夫利昔单抗剂量治疗时的药物谷浓度和抗药物抗体与疾病活动指标是否相关。
招募了 35 名年龄在 18-70 岁之间的成年 SpA 患者。他们在过去 6-12 个月内接受了 3 次或更多次 3-5mg/kg 的英夫利昔单抗输注。通过酶联免疫吸附试验技术测量患者血清肿瘤坏死因子-α、英夫利昔单抗药物谷浓度和抗药物抗体。通过强直性脊柱炎疾病活动评分-红细胞沉降率/ C 反应蛋白（ASDAS-ESR/CRP）评分量化疾病活动度。采用 Spearman 相关分析评估定量变量之间的相关性。使用 Mann-Whitney U 检验评估药物抗体阳性和阴性患者之间的药物谷浓度和 ASDAS 差异。
药物谷浓度与 ASDAS-ESR（rs = -0.57，P < 0.01）和 ASDAS-CRP 评分（rs = -0.53，P < 0.01）呈显著负相关。68.7%的患者抗药物抗体阳性，与抗体阴性患者相比，ASDAS-ESR 和 ASDAS-CRP 评分显著更高。
接受低剂量按需英夫利昔单抗治疗的 SpA 患者，药物谷浓度和抗药物抗体均与疾病活动指标显著相关。我们假设药物谷浓度和抗药物抗体可用于预测 SpA 患者因继发耐药而导致的治疗反应不佳。
