Exportation of thymic-derived newly generated naive T cells correlates with posttransplantation thymic recovery. Median (± IQR) of (A) sjTREC and (B) βTREC values as measured by quantitative RT-PCR analysis on PBMC genomic DNA at baseline (0 months, pretransplant) and at the following time points in transplanted (AHSCT, n = 26 patients at baseline, n = 15 at 6 and 12 months, and n = 11 at 18, 24, and >24 months) and nontransplanted (non-AHSCT, n = 14 patients at baseline and at 6 months, n = 13 at 12 months, and n = 8 at 18, 24, and >24 months) SSc patients. The results were expressed by log10 in 150 000 PBMCs. (C) Intrathymic T-cell division (n) as calculated using following formula: n = LOG(sjTREC/βTREC)/LOG2. *P < .05, AHSCT vs non-AHSCT (Mann-Whitney U test). §P < .05, §§P < .01 comparing posttransplant values to baseline (Wilcoxon’s). Panels D-H include transplanted patients only. (D) Percentage of CD45RA and CD31 coexpression by CD3⁺CD4⁺ T cells immunophenotyped by flow cytometry. The boundaries of the boxes indicate the 25th and 75th percentiles; the lines within the boxes indicate the median, and the whiskers mark the 10th and the 90th percentiles. (E) Mean (± SE) of RTEs absolute values (cells per microliter). *P < .05; **P < .01 comparing posttransplant values to baseline (Wilcoxon’s). (F) Correlation between absolute values of CD3⁺CD4⁺CD31⁺CD45⁺ T cells and sjTREC values (Spearman’s). Mean (± SE) percentage of Naive (CD27⁺CD45RO⁻), Central Memory (CD27⁺CD45RO⁺), Effector Memory (CD27^-CD45RO⁺), and Effector (CD27⁻CD45RO⁻) (G) CD4⁺ and (H) CD8⁺ T cells.