Meta-analysis of the changes of peripheral blood regulatory T cell to CD4+ T cell ratio in patients with systemic sclerosis.

Current reports on the changes in peripheral blood regulatory T cell (Tregs) to CD4+ T cell ratio in systemic sclerosis (SSc) patients are varied in their conclusions. We therefore performed a meta-analysis to identify the actual change in the proportion of peripheral Tregs in SSc. Three databases, namely EMBASE, ISI web of knowledge, and Pubmed were systematically searched for relevant literature. Approximately 250 SSc patients and controls from several studies were included in this analysis. Comprehensive Meta Analysis Version 2.0 software was used to conduct the meta-analysis. Six studies were included in the meta-analysis. Results of the meta-analysis showed high degree of heterogeneity (I2 = 96.98), and a random-effect model was used in the subsequent analysis. The ratio of circulating Tregs to CD4+ T cell in SSc was lower than in controls, but not statistically significantly so (-0.61 ± 0.94, P = 0.52). Subgroup analysis did not identify any potential source of heterogeneity. This meta-analysis indicated that Tregs might play a less prominent immunosuppressive role in the immune system in SSc patients, but needs further confirmation.