Objective: Our aim was to investigate the TCR gamma delta+ subset in Behçet's disease (BD) inflammatory sites, which better reflects changes associated with the pathologic process than peripheral blood.
Methods: Forty-five patients with active BD, 10 patients with recurrent aphthous ulcers, 12 patients with rheumatoid arthritis, 5 patients with noninflammatory neurologic diseases and 15 healthy individuals were studied. Three monoclonal antibodies TCR delta 1, BB3, and A13 were used to assess the percentage of TCR gamma delta+ in peripheral blood mononuclear cells (PBMC), in bronchoalveolar lavage and cerebrospinal fluid (CSF). CD11a/CD18 was used to study adhesion molecules. TCR gamma delta+ cells isolated by immunomagnetic separation were tested for cytolytic activity against K562 target cells after interleukin 2 stimulation.
Results: The PBMC TCR gamma delta BB3+ subset was significantly increased in BD. In BD inflammatory sites, TCR gamma delta+ cells were also present, composed mainly of A13+ cells from these sites also expressed CD11a marker. TCR gamma delta+ cells from inflammatory sites displayed a higher cytotoxic activity than controls, mediated by the A13+ subset.
Conclusion: The accumulation of cytotoxic TCR gamma delta+ cells at the sites of inflammation suggests their involvement in the local injury process.