Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.
Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
Neurogastroenterol Motil. 2018 Oct;30(10):e13378. doi: 10.1111/nmo.13378. Epub 2018 May 24.
Serum levels of pro-inflammatory cytokines tend to be increased in irritable bowel syndrome (IBS) patients, or subgroups thereof. Still, the link between cytokine levels and IBS symptoms is unclear. We aim to determine systemic cytokine levels in IBS patients and healthy subjects (HS), confirm the presence of a subset of patients with an increased immune activity and to establish if cytokines are linked to IBS symptoms and pathophysiological factors.
Serum levels of interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF), and IL-10 were measured. All subjects reported IBS symptoms using validated questionnaires and underwent colonic sensorimotor testing. Multivariate supervised orthogonal partial least squares-discriminant analysis (OPLS-DA) and unsupervised principal component analysis (PCA) and hierarchical cluster analysis (HCA) were implemented.
Irritable bowel syndrome patients (n = 246) had higher serum levels of IL-1β, IL-6, IL-8, TNF, and IL-10 compared to HS (n = 21); however, serum cytokine profiles could not discriminate patients from HS. Moreover, cytokine levels were not correlated with symptoms among patients. Supervised OPLS-DA identified 104 patients (40% of patients) and unsupervised HCA analysis identified 49 patients (20%) with an increased immune activity indicated by elevated levels of serum cytokines compared to HS and the other patients. However, irrespective of how patients with increased immune activity were identified they were symptomatically similar to patients with no indication of increased immune activity.
CONCLUSIONS & INFERENCES: Serum cytokines are elevated in IBS patients compared to HS. Immune activation characterizes a subset of patients, but modest associations between cytokine profile and symptoms suggest immune activity does not directly influence symptoms in IBS.
血清中促炎细胞因子的水平在肠易激综合征（IBS）患者或其亚组中往往会升高。然而，细胞因子水平与 IBS 症状之间的联系尚不清楚。我们旨在确定 IBS 患者和健康对照（HS）的系统性细胞因子水平，确认存在一部分免疫活性增强的患者，并确定细胞因子是否与 IBS 症状和病理生理因素有关。
测量白细胞介素（IL）-1β、IL-6、IL-8、肿瘤坏死因子（TNF）和 IL-10 的血清水平。所有受试者均使用经过验证的问卷报告 IBS 症状，并进行结肠感觉运动测试。实施多元监督正交偏最小二乘判别分析（OPLS-DA）和无监督主成分分析（PCA）和层次聚类分析（HCA）。
与 HS（n=21）相比，IBS 患者（n=246）的血清中 IL-1β、IL-6、IL-8、TNF 和 IL-10 水平更高；然而，血清细胞因子谱无法区分患者与 HS。此外，细胞因子水平与患者的症状无关。监督 OPLS-DA 确定了 104 名患者（占患者的 40%），而无监督 HCA 分析确定了 49 名患者（占患者的 20%），与 HS 和其他患者相比，这些患者的血清细胞因子水平升高，表明免疫活性增强。然而，无论如何识别免疫活性增强的患者，他们的症状与没有免疫活性增强迹象的患者相似。
与 HS 相比，IBS 患者的血清细胞因子水平升高。免疫激活是患者的一个亚组的特征，但细胞因子谱与症状之间的适度关联表明，免疫活性不会直接影响 IBS 的症状。
