Preferential activation of circulating CD8+ and γδ T cells in patients with active Behçet`s disease and HLA-B51

CER3374
2008 Vol.26, N°4 ,Suppl.50
PI 0059, PF 0063
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PMID: 19026117 [PubMed]

Abstract

OBJECTIVES:
To evaluate the activation status of circulating CD4⁺, CD8⁺, and &ggr;&dgr; T cells in patients with active and inactive Behçet`s disease (BD).
METHODS:
We studied 11 subjects with active BD, 28 with inactive BD, and 13 healthy controls. The expression of CD4, CD8, pan-&ggr;&dgr;, V&dgr;1, and V&dgr;2 along with the early activation marker CD69 was analyzed by 3-color flow cytometry.
RESULTS:
Proportions of activated CD8<sup>+</sup> and &ggr;&dgr; T cells were significantly greater in patients with active BD than in those with inactive BD or healthy control subjects, but the proportion of activated CD4<sup>+</sup> T cells did not differ among these 3 groups. In addition, significantly greater proportions of the V&dgr;1<sup>+</sup> and V&dgr;2<sup>+</sup> &ggr;&dgr; T-cell subsets were activated in patients with active BD than in those with inactive BD or healthy controls; in active BD, the balance of activation between these subsets favored the V&dgr;1<sup>+</sup> T cells. No significant differences in these proportions were found between subjects with inactive BD and healthy controls. These findings were observed exclusively in patients with HLA-B51. A comparison of samples from 5 patients taken during active BD and after resolution of BD-related symptoms showed the proportions of activated CD8<sup>+</sup> and &ggr;&dgr; T cells dropped when the patients` BD became inactive.
CONCLUSIONS:
CD8⁺ and &ggr;&dgr; T cells, rather than CD4⁺ T cells, were activated in vivo in patients with active BD and HLA-B51, but not in those with inactive BD, suggesting that these potentially cytotoxic T cells play a critical role in BD flares.