Objectives: To improve understanding of the preclinical stage of colonic inflammation by exploring the existence of a link between early inflammatory changes in the colonic mucosa and the systemic redox balance.

Methods: Clinical characteristics, a fasting blood draw, and mucosal biopsies from the right, left, and sigmoid-rectum colonic tracts collected from 28 healthy individuals (14/14 males/females) who underwent colonoscopy. Myeloperoxidase (MPO) positive cells infiltrating colonic mucosa specimens were assessed by immunohistochemistry, and patients divided into high or low MPO expressing cells/optical field groups (MPO^high or MPO^low, respectively).The systemic oxidative balance has been studied through derived-Reactive Oxygen Metabolites (d-ROMs), Biological Antioxidant Potential (BAP), and Lipoperoxide-cholesterol Oxidizing (LP-CHOLOX) tests on serum.

Results: MPO^high patients demonstrated an increased systemic oxidative stress compared to MPO^low individuals (P = 0.035), especially when MPO is referred to the left-sided colonic mucosa (P = 0.007). MPO^low subjects in the sigmoid-rectum showed a significant higher antioxidant capacity in the serum (P < 0.02). Sex-specific differences in MPO expression (male and female: 4.6 ± 3.2 and 2.6 ± 1.5 MPO-positive cells/optical field, respectively, P = 0.044), and a decreasing gradient in MPO expression moving from the cecum to the rectum (ascendant, descendant, and sigmoid-rectum: 3.7 ± 2.8, 3.1 ± 1.7, and 1.4 ± 0.5, respectively, P = 0.012) were also found and discussed.

Discussion: The study is the first demonstrating a connection between systemic redox balance and MPO expression in the colonic mucosa, according to the colonic tract and patient gender. Further research evaluating the MPO expression in the human colon and its relationship with pathological conditions could benefit from these results.

目的：通过探索结肠粘膜早期炎症变化与全身氧化还原平衡之间的联系，以增进对结肠炎症临床前阶段的了解。

方法：从28例接受结肠镜检查的健康个体（14/14男性/女性）中收集的临床特征，空腹抽血以及右，左和乙状结肠直肠粘膜活检。通过免疫组织化学评估浸润结肠黏膜标本的髓过氧化物酶（MPO）阳性细胞，将患者分为高或低MPO表达细胞/光场组（分别为MPO^高或MPO^低）。血清中的氧代谢产物（d-ROM），生物抗氧化剂潜力（BAP）和脂过氧化物胆固醇氧化（LP-CHOLOX）测试。

结果： MPO^高的患者表现出相比于MPO增加的全身性氧化应激^低个体（P  = 0.035），尤其是当MPO被称为所述左侧结肠黏膜（P  = 0.007）。乙状结肠中MPO^低的受试者在血清中显示出明显更高的抗氧化能力（P  <0.02）。MPO表达的性别特异性差异（男性和女性：分别为4.6±3.2和2.6±1.5 MPO阳性细胞/光场，P  = 0.044），并且MPO表达从盲肠到直肠的梯度递减（上升） ，其后代，和乙状结肠-直肠：3.7±2.8，3.1±1.7和1.4±0.5，分别P = 0.012）也被发现和讨论。

讨论：该研究是首次根据结肠道和患者性别证明全身氧化还原平衡与结肠粘膜中MPO表达之间的联系。评估MPO在人结肠中的表达及其与病理状况的关系的进一步研究可能会受益于这些结果。