T cells and cytokines in systemic sclerosis.

PURPOSE OF REVIEW: Dysregulation of both the innate and the adaptive immune systems has been identified in systemic sclerosis (SSc). However, the mechanisms underlying aberrant immune cell function remain poorly understood. T cells represent a predominant cell type in the affected tissues of patients, particularly in the early inflammatory stage of the disease. Antigen specificity of infiltrating T cells has not been identified; however, recent studies implicate specific T-cell subsets and the cytokines they produce in SSc pathogenesis by modulating the development of autoimmunity, inflammation and fibrosis.

RECENT FINDINGS: The phenotype and function of distinct T-cell subsets have been identified in the affected tissues of SSc patients as well as in SSc animal models, implying their contribution to disease process. The molecular mechanisms underlying cytokine dysregulation by specific T-cell subpopulations are also becoming clear.

SUMMARY: A better understanding of SSc pathogenesis will allow the development of novel therapeutic strategies targeting specific cell types and the pathways that are abnormally activated as well as the cytokines produced that may be directly involved with disease process. A further goal is to tailor therapy to address dysregulation specific to individual patients, leading to better efficacy and reduced toxicity.