Department of Internal Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Eur J Gastroenterol Hepatol. 2012 Apr;24(4):398-405. doi: 10.1097/MEG.0b013e3283503f39.
The understanding of the mechanisms for increased immune activation in subgroups of patients with irritable bowel syndrome (IBS) is incomplete. We hypothesized that monocytes are more activated in patients with IBS than in the healthy population. We therefore examined activation phenotype and cytokine secretion of blood monocytes.
Blood samples from 74 patients with IBS and 30 controls were obtained. The activation phenotype of CD11cCD14 monocytes and cytokine secretion in serum and in peripheral blood mononuclear cells cultured with or without lipopolysaccharide was determined. Gastrointestinal and psychological symptom severity and quality of life were assessed using validated questionnaires.
Monocytes from patients demonstrated an increased expression of toll-like receptor (TLR) 2, whereas the expression on monocytes of TLR4, HLA-DR, CD40, CD80 and CD86 was comparable in patients and controls. The expression of activation markers on monocytes did not correlate with gastrointestinal or extracolonic symptom severity, but the expressions of TLR2, HLA-DR and CD86 were associated with less severe psychological symptoms and better social and physical well-being. Cytokine secretion in serum and peripheral blood mononuclear cell cultures was comparable in patients and controls. A subgroup of patients (15%) who had TLR2 and HLA-DR expression intensity above the level seen in controls reported less severe psychosocial symptoms.
Patients with IBS have increased expression of TLR2 on monocytes and the activation level on monocytes correlates with less severe psychological symptoms and better quality of life. Thus, our data implicate less importance of psychosocial factors and increased importance of immunological parameters for symptom generation in a subgroup of patients with IBS.
对于肠易激综合征（IBS）患者亚组免疫激活增加的机制尚不完全清楚。我们假设 IBS 患者的单核细胞比健康人群更活跃。因此，我们检查了血液单核细胞的激活表型和细胞因子分泌。
采集了 74 例 IBS 患者和 30 例对照者的血液样本。测定了 CD11cCD14 单核细胞的激活表型以及血清和体外培养单核细胞在外源脂多糖刺激下的细胞因子分泌情况。采用经过验证的问卷评估了胃肠道和心理症状严重程度以及生活质量。
与对照组相比，患者的单核细胞表达了更高水平的 Toll 样受体（TLR）2，而 TLR4、HLA-DR、CD40、CD80 和 CD86 的表达在患者和对照组之间是可比的。单核细胞激活标志物的表达与胃肠道或肠外症状的严重程度无关，但 TLR2、HLA-DR 和 CD86 的表达与心理症状的严重程度较轻和社会及身体福祉较好相关。患者和对照组血清及外周血单个核细胞培养中的细胞因子分泌无差异。TLR2 和 HLA-DR 表达强度高于对照组的患者亚组（15%）报告了较轻的心理社会症状。
IBS 患者的单核细胞 TLR2 表达增加，单核细胞的激活水平与较轻的心理症状和较好的生活质量相关。因此，我们的数据表明，对于 IBS 患者的亚组，心理社会因素的重要性较小，而免疫参数对症状产生的重要性较大。
