Nsplantation. Although the first T cell chimerism assessment in current patient was usually around day 28 after HSCT, a prior study analyzing data from Ergocalciferol patients given similar conditioning regimen demonstrated that a median of 50 CD3+ T cells of recipient origin/mL persisted on day 14 after HSCT [40]. Further, as observed by other groups of investigators [46,51,52], there was a strong inverse correlation between IL-7 69-25-0 levels and absolute lymphocyte counts [46,52], as well as a strong inverse correlation between IL-7 levels and T cell subsets on days 14 and 28 after transplantation. Other factors associated with IL-7 levels included high CRP levels, and low numbers 12926553 of transplanted T cells. Levels of IL-7 in current nonmyeloablative recipients where lower to what was observed by Thiant et al. in a cohort of 45 patients given grafts after fludarabine +2 Gy TBI (n = 18) or more intense but still reduced-intensity conditioning (n = 27) [52], and where much lower than what was observed by Dean et al. in patients given grafts after sequential chemotherapy followed by a chemotherapy/fludarabine-based reduced-intensity conditioning [53]. This apparent discrepancy is probably explained the fact than median ALC counts on day 0 were 110 (range, 10?440) cells/ml in current patient versus 0 (range, 0?22) cells/mL in the Dean et al. study, while median counts of CD3+ T cells were 0 (range, 0?900) cells/mL at the time of transplantation in Thiant et al. study. Il-15 levels were lower in nonmyeloablative patients conditioned with 2 Gy TBI than in those conditioned with 4 Gy TBI, demonstrating that the release of IL-15 was proportional to the intensity of the conditioning regimen. As observed by Thiant et al. [46,52], there was a correlation between IL-7 and IL-15 levels on day 14 (but not on day 28) after transplantation, and an inverse correlation between IL-15 levels and NK cell counts. Other factors affecting IL-15 levels included high CRP levels. Several observations demonstrate that immune recovery depended mainly on HPE the first year after nonmyeloablative conditioning regimen in current patients. Firstly, there was a strong correlation between the number of infused T cells and high counts of CD4+ and CD8+ T cells, as previously observed [43,54]. Secondly, thymic function was minimal during the first 100 days ?after allo-HSCT given that levels of naive CD4+ T cells did notsignificantly increase the first 100 days after transplantation ?despite that 
some naive T cells can undergo HPE and keep their ?naive phenotype. Third, there was a correlation between high donor age and low counts of CD3+ T cells (P = 0.04), CD4+ T cells ?(P = 0.05), and naive CD4+ T cells (P = 0.021), as previously observed in patients given grafts after nonmyeloablative conditioning [55]. Despite that, we failed to find any significant association between IL-7 and/or IL-15 levels early after transplantation and increment of T cell subset counts from days 14?8 to day 80?00, even after adjusting for potentially confounding cofactors. A number of previous studies have demonstrated that high levels of IL-7 [46,52,53] and/or IL-15 [46,52] early after transplantation correlated with subsequent occurrence of grade II V acute GVHD, while others study failed to find such an association [51,56]. The largest study including data from 153 consecutive allogeneic transplant recipients given grafts after highdose conditioning and ATG observed no correlation between IL-7 levels early after tra.Nsplantation. Although the first T cell chimerism assessment in current patient was usually around day 28 after HSCT, a prior study analyzing data from patients given similar conditioning regimen demonstrated that a median of 50 CD3+ T cells of recipient origin/mL persisted on day 14 after HSCT [40]. Further, as observed by other groups of investigators [46,51,52], there was a strong inverse correlation between 
IL-7 levels and absolute lymphocyte counts [46,52], as well as a strong inverse correlation between IL-7 levels and T cell subsets on days 14 and 28 after transplantation. Other factors associated with IL-7 levels included high CRP levels, and low numbers 12926553 of transplanted T cells. Levels of IL-7 in current nonmyeloablative recipients where lower to what was observed by Thiant et al. in a cohort of 45 patients given grafts after fludarabine +2 Gy TBI (n = 18) or more intense but still reduced-intensity conditioning (n = 27) [52], and where much lower than what was observed by Dean et al. in patients given grafts after sequential chemotherapy followed by a chemotherapy/fludarabine-based reduced-intensity conditioning [53]. This apparent discrepancy is probably explained the fact than median ALC counts on day 0 were 110 (range, 10?440) cells/ml in current patient versus 0 (range, 0?22) cells/mL in the Dean et al. study, while median counts of CD3+ T cells were 0 (range, 0?900) cells/mL at the time of transplantation in Thiant et al. study. Il-15 levels were lower in nonmyeloablative patients conditioned with 2 Gy TBI than in those conditioned with 4 Gy TBI, demonstrating that the release of IL-15 was proportional to the intensity of the conditioning regimen. As observed by Thiant et al. [46,52], there was a correlation between IL-7 and IL-15 levels on day 14 (but not on day 28) after transplantation, and an inverse correlation between IL-15 levels and NK cell counts. Other factors affecting IL-15 levels included high CRP levels. Several observations demonstrate that immune recovery depended mainly on HPE the first year after nonmyeloablative conditioning regimen in current patients. Firstly, there was a strong correlation between the number of infused T cells and high counts of CD4+ and CD8+ T cells, as previously observed [43,54]. Secondly, thymic function was minimal during the first 100 days ?after allo-HSCT given that levels of naive CD4+ T cells did notsignificantly increase the first 100 days after transplantation ?despite that some naive T cells can undergo HPE and keep their ?naive phenotype. Third, there was a correlation between high donor age and low counts of CD3+ T cells (P = 0.04), CD4+ T cells ?(P = 0.05), and naive CD4+ T cells (P = 0.021), as previously observed in patients given grafts after nonmyeloablative conditioning [55]. Despite that, we failed to find any significant association between IL-7 and/or IL-15 levels early after transplantation and increment of T cell subset counts from days 14?8 to day 80?00, even after adjusting for potentially confounding cofactors. A number of previous studies have demonstrated that high levels of IL-7 [46,52,53] and/or IL-15 [46,52] early after transplantation correlated with subsequent occurrence of grade II V acute GVHD, while others study failed to find such an association [51,56]. The largest study including data from 153 consecutive allogeneic transplant recipients given grafts after highdose conditioning and ATG observed no correlation between IL-7 levels early after tra.
