Abstract

Multiple sclerosis (MS) is a neuro-immunological demyelinating disease. From the immunological aspects, it is well accepted that T cells play a pivotal role in the etiology of the disease. T helper (Th) 1 and Th17 cells are thought to be the main pathogenic T cells in the pathogenesis of MS and are known as effector T cells. As the self-reactive T lymphocytes can escape clonal deletion in the thymus and subsequently are released into the periphery, there is an urgent need for peripheral tolerance, which is executed by the specialized regulatory T (Treg) cells. Interestingly, CD8(+) regulatory T (Treg) cells have also been identified among lymphocyte subtypes. The peripheral CD8(+) Treg cells frequency in MS subjects in comparison with healthy controls is the objective of the current study using the systematic review and meta-analysis. A systematic literature search was carried out using specialized biomedical databases of Pubmed, Pubmed Central, Medline, Google Scholar, Embase and SCOPUS databases without the beginning date restriction until January 2018 in English language. The results were as follows: OR 15.548 (95 confidence interval 1.954-123.742) using the random-effects model. The P value for test of significance of the total OR was examined by the z test and calculated as 0.010 (clearly considered as statistically significant). Based on our findings, the number of CD8(+) Treg cells in the blood of MS subjects is significantly different as compared to healthy controls.