Fig. 1

CMV-specific immunity in hemodialysis patients measured with T-Track® CMV (a), QuantiFERON®-CMV (b) and iTAg™ MHC Tetramers (c). a Spot-forming cells (SFC) in IFN-γ ELISpot after in vitro stimulation of PBMC from CMV-seronegative (n = 57) and CMV-seropositive (n = 67) hemodialysis patients with T-activated® aIE-1 and app65 proteins, or with medium (unst.) as a negative control. SFC levels are presented as log10-transformed values in scatter plots, including median values (horizontal black lines). The horizontal grey dashed line indicates the positivity cut-off (10 SFC / 200,000 PBMC). b CD8⁺-secreted IFN-γ levels were measured by ELISA following the stimulation of whole blood from CMV-seronegative (n = 57) and CMV-seropositive (n = 66) hemodialysis patients with HLA class I-specific peptides. Test results were considered positive when IFN-γ levels ≥ 0.2 IU/mL (grey dashed line). Indeterminate results (4/66 seropositive and 2/57 seronegative patients) are not represented; therefore the scatter plots represent the results of 62 seropositive and 55 seronegative assays. *, values ≥ 10 IU/mL cannot be quantitatively evaluated; consequently, no median values were depicted. c PBMC of CMV-seronegative (n = 45) and CMV-seropositive (n = 52) hemodialysis patients were stained with a mixture of six iTAg™ MHC class I Tetramers, and CMV peptide-specific CD8⁺ T cells were quantified by flow cytometry. Test results were considered positive when ≥ 0.1% of total CD8⁺ T cells were tetramer-positive (grey dashed line). The scatter plots show median values (horizontal black lines)