University of Catania, Department of General Surgery and Medical Specialities, Via Santa Sofia 78, Catania 95123, Italy.
Athena Biomedical innovations, Viale Europa 139, Florence, 50126, Italy.
Br Med Bull. 2020 May 15;133(1):49-64. doi: 10.1093/bmb/ldz040.
The role of the immune system in tendon healing relies on polymorphonucleocytes, mast cells, macrophages and lymphocytes, the 'immune cells' and their cytokine production. This systematic review reports how the immune system affects tendon healing.
We registered our protocol (registration number: CRD42019141838). After searching PubMed, Embase and Cochrane Library databases, we included studies of any level of evidence published in peer-reviewed journals reporting clinical or preclinical results. The PRISMA guidelines were applied, and risk of bias and the methodological quality of the included studies were assessed. We excluded all the articles with high risk of bias and/or low quality after the assessment. We included 62 articles assessed as medium or high quality.
Macrophages are major actors in the promotion of proper wound healing as well as the resolution of inflammation in response to pathogenic challenge or tissue damage. The immune cells secrete cytokines involving both pro-inflammatory and anti-inflammatory factors which could affect both healing and macrophage polarization.
The role of lymphocytes, mast cells and polymorphonucleocytes is still inconclusive.
The immune system is a major actor in the complex mechanism behind the healing response occurring in tendons after an injury. A dysregulation of the immune response can ultimately lead to a failed healing response.
Further studies are needed to shed light on therapeutic targets to improve tendon healing and in managing new way to balance immune response.
免疫系统在肌腱愈合中的作用依赖于多形核白细胞、肥大细胞、巨噬细胞和淋巴细胞，即“免疫细胞”及其细胞因子的产生。本系统综述报告了免疫系统如何影响肌腱愈合。
我们注册了我们的方案（注册号：CRD42019141838）。在搜索PubMed、Embase 和 Cochrane Library 数据库后，我们纳入了发表在同行评议期刊上的任何证据水平的研究报告，这些研究报告报告了临床或临床前结果。我们应用了 PRISMA 指南，并对纳入研究的偏倚风险和方法学质量进行了评估。在评估后，我们排除了所有高偏倚风险和/或低质量的文章。我们纳入了 62 篇评估为中或高质量的文章。
巨噬细胞是促进适当伤口愈合以及在受到致病挑战或组织损伤时炎症消退的主要因素。免疫细胞分泌的细胞因子涉及促炎和抗炎因子，这可能影响愈合和巨噬细胞极化。
淋巴细胞、肥大细胞和多形核白细胞的作用仍不确定。
免疫系统是受伤后肌腱愈合反应中复杂机制的主要因素。免疫反应的失调最终可能导致愈合反应失败。
需要进一步的研究来阐明治疗靶点，以改善肌腱愈合，并以新的方式来平衡免疫反应。
