CD4+CD28− T Lymphocytes Contribute to Early Atherosclerotic Damage in Rheumatoid Arthritis Patients

Abstract

Background— Peripheral blood expansion of an unusual CD4+ T-cell subset lacking surface CD28 has been suggested to predispose rheumatoid arthritis (RA) patients to develop more aggressive disease. However, the potential association between CD4+CD28 ^null T cells and early atherosclerotic changes in RA has never been investigated. Methods and Results— The number of circulating CD4+CD28 ^null cells was evaluated in 87 RA and 33 control subjects who also underwent evaluation of carotid artery intima-media thickness (IMT) and endothelial function via flow-mediated vasodilation (FMV). Patients had higher IMT and lower FMV compared with control subjects. The frequency of CD4+CD28 ^null cells was significantly higher in patients than in control subjects. Twenty patients with persistent expansion of circulating CD4+CD28 ^null cells had more marked increase of carotid artery IMT and stronger decrease of brachial artery FMV. Blockade of tumor necrosis factor-α led to a partial reappearance of the CD28 molecule on the CD4+ cell surface. Conclusions— Circulating CD4+CD28 ^null lymphocytes are increased in RA. Patients with persistent CD4+CD28 ^null cell expansion show preclinical atherosclerotic changes, including arterial endothelial dysfunction and carotid artery wall thickening, more significantly than patients without expansion. These findings suggest a contribution of this cell subset in atheroma development in RA. Moreover, the demonstration that tumor necrosis factor-α blockade is able to reverse, at least in part, the CD28 deficiency on the CD4+ cell surface may be of interest for possible innovative therapeutic strategies in cardiovascular diseases.