Fig. 3

No enhanced T-cell differentiation in time and lower relative telomere lengths (RTL) in immature CD4⁺ and CD8⁺ T cells. a Pie charts of normalised median frequencies of immature (blue), mature (green) and mature differentiated (red) CD4⁺ (left panels) and CD8⁺ T cells (right panels). Frequencies of immature cells were compared with HD for CD4⁺ and CD8⁺ T cells for time-point 1 and for time-point 2. P-values were calculated using the Mann- Whitney U test. *p < 0.05; **p < 0.01; *** < 0.001. b Relative telomere length (RTL) of peripheral CD4 T cell subsets (b) and CD8 T cell subsets (c) of: healthy donors (HD); multiple exposed uninfected (MEU) drug users (DU); HCV monoinfected IDU and HIV/HCV coinfected DU. RTL was measured in the first available sample since study entry (t = 1) and the most recent sample (t = 2) of MEU, HCV monoinfected and HIV/HCV coinfected DU. Subsets are depicted as follows: immature (CD27⁺CD57^-), mature (CD27^-CD57^-) and mature differentiated (CD27^-CD57⁺). HD at time point 1 and 2 are not the same individuals. The median time interval for all groups between time point 1 and 2 was 16.9 years. Medians are depicted in the plots. Wilcoxon-signed rank test was used for comparison within groups with the same individuals (MEU, HCV and HIV/HCV). Kruskall-Wallis test were used to compare between groups followed by post hoc Mann-Withney U tests