Epstein-Barr virus-specific IFNγ-producing T cells. Number of IFNγ-producing T cells per 106 peripheral blood mononuclear cells (PBMCs). (a) After pulsing with the full set of Epstein-Barr virus peptides. (b) After pulsing with latent-cycle peptides. (c) After pulsing with lytic-cycle peptides. Mean IFNγ-producing T cells per 106 PBMCs are represented by a black line. *Kruskall-Wallis test. MTX, methotrexate; RA, rheumatoid arthritis; SpA, spondylarthropathy.