Institute of Medical Psychology, Faculty of Medicine, LMU Munich, Munich, Germany.
Division of Health Promotion, Coburg University of Applied Sciences, Coburg, Germany.
PLoS One. 2020 Sep 23;15(9):e0238533. doi: 10.1371/journal.pone.0238533. eCollection 2020.
In this proof-of-concept study, we tested whether placebo effects can be monitored and predicted by plasma proteins. In a randomized controlled design, 90 participants were exposed to a nauseating stimulus on two separate days and were randomly allocated to placebo treatment or no treatment on the second day. Significant placebo effects on nausea, motion sickness, and (in females) gastric activity could be verified. Using label-free tandem mass spectrometry, 74 differentially regulated proteins were identified as correlates of the placebo effect. Gene ontology (GO) enrichment analyses identified acute-phase proteins and microinflammatory proteins to be involved, and the identified GO signatures predicted day-adjusted scores of nausea indices in the placebo group. We also performed GO enrichment analyses of specific plasma proteins predictable by the experimental factors or their interactions and identified 'grooming behavior' as a prominent hit. Finally, Receiver Operator Characteristics (ROC) allowed to identify plasma proteins differentiating placebo responders from non-responders, comprising immunoglobulins and proteins involved in oxidation reduction processes and complement activation. Plasma proteomics is a promising tool to identify molecular correlates and predictors of the placebo effect in humans.
在这项概念验证研究中，我们测试了是否可以通过血浆蛋白来监测和预测安慰剂效应。在一项随机对照设计中，90 名参与者在两天内接受了令人恶心的刺激，并在第二天随机分配接受安慰剂治疗或不治疗。我们可以验证安慰剂对恶心、晕动病以及（女性）胃活动的显著影响。使用无标记串联质谱法，鉴定出 74 种差异调节蛋白作为安慰剂效应的相关蛋白。GO 富集分析鉴定出急性期蛋白和微炎症蛋白参与其中，并且鉴定出的 GO 特征可以预测安慰剂组中恶心指数的日调整得分。我们还对可由实验因素或其相互作用预测的特定血浆蛋白进行了 GO 富集分析，并确定“修饰行为”是一个突出的命中。最后，接收者操作特征（ROC）允许鉴定出区分安慰剂反应者和非反应者的血浆蛋白，包括免疫球蛋白和参与氧化还原过程和补体激活的蛋白质。血浆蛋白质组学是一种有前途的工具，可以识别人类安慰剂效应的分子相关性和预测因子。
