Malafoglia Valentina, Raffaeli William, Ilari Sara, Gioia Chiara, Iannuccelli Cristina, Tenti Michael, Vitiello Laura, Proietti Stefania, Lupacchini Leonardo, Passacatini Lucia Carmela, Tomino Carlo, Vincenzo Mollace, Fini Massimo, Di Franco Manuela, Muscoli Carolina
Laboratory of Physiology and Pharmacology of Pain, IRCCS San Raffaele Roma, Rome, Italy.
Fondazione ISAL, Institute for Research on Pain, Rimini, Italy.
Pain Rep. 2025 May 27;10(4):e1283. doi: 10.1097/PR9.0000000000001283. eCollection 2025 Aug.
Before COVID-19 pandemic, we identified the percentage of B cells expressing the Mu-opioid receptor (Mu+ B cells) as a potential marker, named Mu-Lympho-Marker (MLM), for chronic pain (CP) in patients with fibromyalgia (FM) and osteoarthritis.
Here, we demonstrate the stability of MLM over time through a comparative analysis of biological, clinical, and psychological data collected from a subgroup of patients with FM across 2 distinct research periods.
This is an observational, longitudinal study. Fibromyalgia participants enrolled in the first study were called back for follow-up sampling. Clinical data were recorded. Pain score was reported using the Numerical Rating Scale. Mu+ B cells percentage of expression was analyzed by flow cytometry. Immunofluorescence analyses were performed to explore the cellular localization of Mu-opioid receptor. Pain-free subjects served as control group. All the participants filled out self-reported psychological tests. Data were statistically analyzed.
Mu+ B cells percentage of expression was constant in patients with FM, who consistently showed lower values than control group after 2 years (difference in the mean: 32.0 ± 4.4, t = 7.330, IC 95% [23.2-40.9], < 0.0001). Confocal microscopy analyses revealed Mu cytoplasmic localization in patients with FM. We observed no significant changes between psychological outcomes during the 2 phases of the study, nor did we find any correlations with biological findings.
Mu-Lympho-Marker could be a promising marker for CP, as seen in FM cohort, and could be helpful for accurate diagnosis and tailored rehabilitation strategies. Further studies are needed to study MLM in CP of different aetiologies.
在新冠疫情之前，我们确定了表达μ-阿片受体的B细胞（Mu+B细胞）百分比作为一种潜在标志物，命名为Mu-淋巴细胞标志物（MLM），用于纤维肌痛（FM）和骨关节炎患者的慢性疼痛（CP）。
在此，我们通过对在两个不同研究阶段从FM患者亚组收集的生物学、临床和心理数据进行比较分析，证明MLM随时间的稳定性。
这是一项观察性纵向研究。入选第一项研究的纤维肌痛参与者被召回进行随访采样。记录临床数据。使用数字评分量表报告疼痛评分。通过流式细胞术分析Mu+B细胞的表达百分比。进行免疫荧光分析以探索μ-阿片受体的细胞定位。无痛受试者作为对照组。所有参与者填写自我报告的心理测试。对数据进行统计学分析。
FM患者中Mu+B细胞的表达百分比保持恒定，2年后其值始终低于对照组（均值差异：32.0±4.4，t=7.330，95%置信区间[23.2-40.9]，P<0.0001）。共聚焦显微镜分析显示FM患者中Mu在细胞质中的定位。我们在研究的两个阶段之间未观察到心理结果有显著变化，也未发现与生物学结果有任何相关性。
如在FM队列中所见，Mu-淋巴细胞标志物可能是CP的一个有前景的标志物，并且可能有助于准确诊断和制定个性化的康复策略。需要进一步研究以在不同病因的CP中研究MLM。
