Severe and selective deficiency of interferon-γ-producing invariant natural killer T cells in patients with myelodysplastic syndromes

Here we show that patients with myelodysplastic syndromes (MDS) have a severe deficiency of glycolipid reactive Vα24⁺/Vβ11 ⁺ natural killer T (NKT) cells, but not NK cells or CD4⁺ or CD8⁺ T cells. Neither the blood nor marrow of MDS patients had detectable interferon-γ-producing NKT cells in response to the NKT ligand, α-galactosyl ceramide, although influenza-virus-specific effector T-cell function was preserved. This severe and selective deficiency of an important immune regulatory cell may contribute to the pathogenesis of MDS.