HLA-E Behcet

The knowledge of the aetiology of Behçet disease (BD), an immune-mediated vasculitis, is limited. HLA-B, mainly HLA-B51, and HLA-A molecules are associated with disease, but the ultimate cause of this association remains obscure. There is evidence that NK cells participate in the etiopathology of BD. NK cells have activator and inhibitor surface receptors, like the KIR and the NKG2 families. Classical HLA-class I molecules (A, B and C) are keys in the activity control of the NK because they are KIR ligands. Additionally, most NKG2 receptors bind HLA-E, which presents only nonapeptides derived from the signal peptide of other class-I molecules. To investigate the role of the pair HLA-E/HLA-class I in BD, we analyzed the frequency of the HLA-derivated nonapeptide forms in a cohort of 466 Behcet Disease (BD)-unrelated patients who fulfilled the 1990 International Study Group classification criteria for BD and 444 unrelated healthy individuals included in the control group. All the subjects were Spanish European recruited from 17 Spanish hospitals across the country. Besides, we analyzed an HLA-E functional dimorphism in a subgroup of 272 patients and 273 controls.