T cell subsets and their role in the pathogenesis of rheumatic disease.
OBJECTIVE
T lymphocytes are critical to the pathogenesis of systemic rheumatic diseases. Understanding of the roles of T cells in disease has been enriched by the description of highly distinct effector subsets of CD4 T lymphocytes. The purpose of this review is to describe selected advances in the biology of T lymphocytes that are pertinent to the pathogenesis or treatment of rheumatic diseases.


RESULTS
Knowledge is expanding about not only pathogenic effector T cell subsets, such as the TH17 cells, but also of regulatory T cells (Treg), the functions of which are defective, but correctable, in several rheumatic diseases. Although the initial agent that demonstrated a role for T cells in rheumatoid arthritis was CTLA4-Ig (abatacept), use of this biologic is now expanding to other rheumatic diseases. Moreover, effects of other biologics are now understood to in part be mediated by effects on T cell subsets. Experimental model systems in rodents continue to be valuable testing grounds for future approaches to treatment of human disease. Meanwhile, the roles of effector T cell subsets are becoming clearer in conditions such as Sjogren's syndrome and scleroderma. Finally, rheumatic diseases, including rheumatoid arthritis and spondyloarthropathies, have been critical for identification of new innate-like T cell subsets.


CONCLUSIONS
Imbalances in the numbers and functions of specific T cell subsets are key pathogenic derangements in systemic rheumatic diseases, and these insights are leading to changes in clinical practice.
aUniversity of Arkansas, Little Rock, Arkansas bUniversity of Michigan, Ann Arbor, Michigan, USA.
Alison M
AM
Gizinski
David A
DA
Fox
D000069594:Abatacept; D000818:Animals; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000209:etiology / Q000628:therapy; D004195:Disease Models, Animal; D006801:Humans; D018796:Immunoconjugates / Q000627:therapeutic use; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D051379:Mice; D009220:Myositis / Q000209:etiology / Q000628:therapy; D012216:Rheumatic Diseases / Q000209:etiology* / Q000276:immunology / Q000628:therapy; D012595:Scleroderma, Systemic / Q000209:etiology / Q000628:therapy; D012859:Sjogren's Syndrome / Q000209:etiology / Q000628:therapy; D013167:Spondylitis, Ankylosing / Q000628:therapy; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D014657:Vasculitis / Q000209:etiology / Q000628:therapy
D018501:Antirheumatic Agents; D018796:Immunoconjugates; D007166:Immunosuppressive Agents; D000069594:Abatacept