Osteoarthritis is a mechanical abnormality characterized by chronic joint pain associated with degeneration of the articular cartilage, synovitis, and local inflammation, leading to loss of function and pain. A connection exists between the peripheral nervous system and inflammatory joint degeneration. The process by which inflammation is influenced by the nervous system is known as neuroinflammation. One of the neuropeptides involved in peripheral neuroinflammation is nociceptin, a peptide related to the opioid class of substances. Nociceptin has both pro- and anti-inflammatory effects. Some studies show that nociceptin can be measured in synovial fluid, while other studies have not been able to detect it. The presence of nociceptin in synovial fluid could imply a molecular role for the neuropeptide in the joint, both physiologically as well as pathophysiologically. The goal of this pilot study was to determine whether nociceptin was present in the synovial fluid of osteoarthritic knees. Patients undergoing primary total knee arthroplasty were enrolled after Institutional Review Board approval was obtained. Synovial fluid was aspirated from patients’ operative knee joints and blood samples were obtained. A commercially available enzyme Immunoassay kit was used to test for nociceptin. A linear mixed-effects model was developed to account for the repeated measurements and baseline covariates. Least squares (adjusted) means were derived from the model to compare the sample types and to compare subgroups. Twenty patients were included in this study. Nociceptin was detected in the synovial fluid and plasma of all patients. The mean concentration (± standard deviation) of nociceptin in synovial fluid was 28.7 ± 18.2 pg/ml. The mean concentration of nociceptin in plasma was 45.2 ± 24.3 pg/ml pre-procedure, and 40.1 ± 20.6 pg/ml post-tourniquet deflation. The nociceptin concentration in synovial fluid was significantly lower than the nociceptin concentration in plasma, both pre-procedure and post-tourniquet deflation (p = 0.002 and p = 0.016 respectively). The nociceptin concentration in both plasma and synovial fluid was significantly lower in females versus males (p = 0.012). We demonstrated that nociceptin is present in synovial fluid and plasma of patients undergoing total knee arthroplasty. This implies a potential role for nociceptin in modulating inflammation in osteoarthritis. ClinicalTrials.gov , NCT02528916 . Retrospectively registered on August 19, 2015,

中文翻译：

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接受全膝关节置换术的患者的滑液中存在Noceptceptin。

骨关节炎是一种机械异常，其特征在于与关节软骨变性，滑膜炎和局部炎症相关的慢性关节痛，导致功能丧失和疼痛。周围神经系统与炎性关节变性之间存在联系。炎症受神经系统影响的过程称为神经炎症。参与周围神经炎症的神经肽之一是伤害感受肽，其是与阿片类物质有关的肽。Nociceptin同时具有促炎和抗炎作用。一些研究表明，滑膜液中可以测定Nociceptin的含量，而另一些研究则无法检测到。滑液中痛觉敏的存在可能暗示了关节中神经肽的分子作用，无论是在生理上还是在病理生理上。这项初步研究的目的是确定骨关节炎膝关节滑液中是否存在伤害感受素。在获得机构审查委员会的批准后，进行初次全膝关节置换术的患者入组。从患者手术的膝关节吸出滑液，并获得血液样本。使用市售的酶免疫测定试剂盒来测试伤害感受素。建立了线性混合效应模型以说明重复测量和基线协变量。从模型中得出最小二乘（调整后）的均值，以比较样本类型并比较子组。本研究包括20名患者。在所有患者的滑液和血浆中均检测到Nociceptin。滑液中伤害感受肽的平均浓度（±标准偏差）为28.7±18.2 pg / ml。术前血浆中伤害感受肽的平均浓度为45.2±24.3 pg / ml，止血带放气后为40.1±20.6 pg / ml。术前和止血带放气后，滑液中的伤害感受素浓度均显着低于血浆中的伤害感受素浓度（分别为p = 0.002和p​​ = 0.016）。女性的血浆和滑液中的伤害感受素浓度均明显低于男性（p = 0.012）。我们证明了接受全膝关节置换术的患者的滑液和血浆中存在Nociceptin。这暗示了伤害感受肽在调节骨关节炎中的炎症中的潜在作用。ClinicalTrials.gov，NCT02528916。追溯注册于2015年8月19日，