Arthritis Research UK Pain Centre and NIHR Nottingham Biomedical Research Centre, and; Division of ROD, University of Nottingham, Nottingham, UK.
Arthritis Research UK Pain Centre and NIHR Nottingham Biomedical Research Centre, and; Division of ROD, University of Nottingham, Nottingham, UK.
J Pain. 2019 Jun;20(6):716-727. doi: 10.1016/j.jpain.2019.01.001. Epub 2019 Jan 15.
Rheumatoid arthritis (RA) is an example of human chronic inflammatory pain. Modern treatments suppress inflammation, yet pain remains a major problem for many people with RA. We hypothesized that discrete RA subgroups might display favorable or unfavorable pain trajectories when receiving treatment, and that baseline characteristics will predict trajectory allocation. Growth mixture modelling was used to identify discrete trajectories of Short Form-36 bodily pain scores during 3 years in 3 RA cohorts (Early RA Network (n = 683), British Society for Rheumatology Biologics Register Biologics (n = 7,090) and nonbiologics (n = 1,720) cohorts. Logistic regression compared baseline predictor variables between trajectories. The role of inflammation was examined in a subgroup analysis of people with normal levels of inflammatory markers after 3 years. The mean Short Form-36 bodily pain scores in each cohort improved but remained throughout 3 years of follow-up of >1 standard deviation worse than the UK general population average. Discrete persistent pain (59-79% of cohort participants) and resolving pain (19-27%) trajectories were identified in each cohort. In Early RA Network, a third trajectory displaying persistently low pain (23%) was also identified. In people with normal levels of inflammatory markers after 3 years, 65% were found to follow a persistent pain trajectory. When trajectories were compared, greater disability (adjusted odds ratio = 2.3-2.5 per unit baseline Health Assessment Questionnaire score) and smoking history (adjusted odds ratio = 1.6-1.8) were risk factors for persistent pain trajectories in each cohort. In conclusion, distinct trajectories indicate patient subgroups with very different pain prognosis during treatment for RA. Inflammation does not fully explain the pain trajectories, and noninflammatory factors as well as acute phase response predict which trajectory an individual will follow. Targeted treatments additional to those which suppress inflammation might reduce the long-term burden of arthritis pain. PERSPECTIVE: Immunosuppression decreases inflammation in RA, but pain outcomes are less favorable. Discrete persistent and resolving pain trajectories were identified after treatment, both in early and established RA. Smoking and greater disability at baseline predicted persistent pain. Identifying patient subgroups with a poor pain prognosis could enable adjunctive treatment to improve outcomes.
类风湿关节炎（RA）是人类慢性炎症性疼痛的一个例子。现代治疗方法抑制炎症，但许多 RA 患者仍然存在严重的疼痛问题。我们假设，在接受治疗时，不同的 RA 亚组可能表现出有利或不利的疼痛轨迹，而基线特征将预测轨迹分配。增长混合物建模用于确定 3 个 RA 队列（早期 RA 网络（n=683）、英国风湿病学会生物制剂登记处生物制剂（n=7090）和非生物制剂（n=1720）队列）中 3 年内短格式 36 身体疼痛评分的离散轨迹。逻辑回归比较了轨迹之间的基线预测变量。在炎症水平正常的人群亚组分析中检查了炎症的作用，这些人在 3 年后炎症标志物水平正常。每个队列的平均短格式 36 身体疼痛评分在 3 年的随访中均有所改善，但仍比英国一般人群的平均水平高出>1 个标准差。在每个队列中都确定了离散的持续性疼痛（队列参与者的 59-79%）和缓解性疼痛（19-27%）轨迹。在早期 RA 网络中，还确定了第三个显示持续低疼痛（23%）的轨迹。在 3 年后炎症标志物水平正常的人群中，发现 65%的人遵循持续性疼痛轨迹。在比较轨迹时，更大的残疾（调整后的优势比为每个基线健康评估问卷评分增加 2.3-2.5）和吸烟史（调整后的优势比为 1.6-1.8）是每个队列中持续性疼痛轨迹的危险因素。总之，不同的轨迹表明，在 RA 的治疗过程中，患者亚组的疼痛预后存在很大差异。炎症并不能完全解释疼痛轨迹，非炎症因素以及急性期反应可预测个体将遵循的轨迹。除了抑制炎症的治疗方法外，针对特定的治疗方法可能会减轻关节炎疼痛的长期负担。观点：免疫抑制可降低 RA 中的炎症，但疼痛结果不太理想。在早期和已建立的 RA 中，治疗后都确定了离散的持续性和缓解性疼痛轨迹。基线时的吸烟和更大的残疾预测持续性疼痛。确定疼痛预后较差的患者亚组可以使辅助治疗改善结果。
