IMMUNE RECONSTITUTION AFTER HEMATOPOIETIC STEM CELL TRANSPLANTATION IN ACUTE MYELOID LEUKEMIA: THE EFFECT OF CLINICAL FETAURES
(Abstract release date: 05/19/16)
EHA Library. Rossi G. 06/09/16; 135098; PB2198
Dr. Giovanni Rossi
Contributions
Contributions
Abstract
Abstract: PB2198
Type: Publication Only
Background
The reconstitution of different immune cell subsets after allogeneic stem cell transplantation (allo-SCT) occurs at different timelines. Anyway, majority of studies following allo-SCT focused on levels of the single cell line while recovery of the entire immune system was generally reviewed. Similarly, few reports addressed on the effect of clinical factors on the restoration of immunity and studies on bone marrow (BM) samples are lacking
Aims
Thus, we prospectively investigated changes in lymphocyte and dendritic subsets after allo-SCT in BM samples with respect to minimal residual disease (MRD), GvHD, infections and HSCT type.
Methods
BM samples from patients (n=25) with acute myeloid leukemia(AML) who underwent to allo-SCT were collected from january 2012 and december 2014 at specific time-points: +1, +3 and +6 months after transplant. Lymphocyte subpopulations (B cells, hematogones,T cells, helper/inducer T cells, cytotoxic/suppressor T cells, regulatory T cells (TREGs), natural killer (NK) cells) and dendritic cells ( plasmocytoid and myeloid) were investigated using 6-color flow-cytometry. In order to assess differences in cell subsets between cases and BM healthy controls the Mann-Whitney test was applied. A p-value ≤ 0.05 was considered significant.Variation of cell subsets at + 1,+3, +6 months after transplant was evaluated using the Friedman test.Post-hoc pairwise comparisons with Bonferroni correction for multiple comparison were carried out.
Results
. Significant differences between patients and controls were found with respect to TREGs, T cells, helper/inducer T cells and NK cells. In particular, patients showed a significantly higher level of TREGs and NK and a significantly lower count of T- and helper/inducer T cells at +1 and +3 months from transplant. B cells and hematogones was significantly increased at six months from transplant while no differences between TREGs were found at this time point. Significant effect of timelines from transplant was found for B cells, regulatory T cells, T cells, helper/inducer T cells and cytotoxic/suppressor T cells. A statistically significant raise was found from + 1 to + 6 months for T cells and cytotoxic/suppressor T cells and from + 1 to +3 months for helper/inducer T cells and cytotoxic/suppressor T cells . On the contrary, a statistically significance decrease was observed at any time for TREGs count. Univariate analysis showed a statistically significant association between cytotoxic/suppressor T cell count and the presence of infection (p=0,027) with patients having viral or bacterial infection showing higher counts. No differences were found for any other association.
Conclusion
In conclusion, immune reconstitution following allo-SCT on BM samples was similar to data reported from peripheral blood.Viral and bacterial infectionsplay an important role in increasing cytotoxic/suppressor T cells.
Session topic: E-poster
Keyword(s): Acute myeloid leukemia, Allogeneic hematopoietic stem cell transplant, Immune reconstitution
Type: Publication Only
Background
The reconstitution of different immune cell subsets after allogeneic stem cell transplantation (allo-SCT) occurs at different timelines. Anyway, majority of studies following allo-SCT focused on levels of the single cell line while recovery of the entire immune system was generally reviewed. Similarly, few reports addressed on the effect of clinical factors on the restoration of immunity and studies on bone marrow (BM) samples are lacking
Aims
Thus, we prospectively investigated changes in lymphocyte and dendritic subsets after allo-SCT in BM samples with respect to minimal residual disease (MRD), GvHD, infections and HSCT type.
Methods
BM samples from patients (n=25) with acute myeloid leukemia(AML) who underwent to allo-SCT were collected from january 2012 and december 2014 at specific time-points: +1, +3 and +6 months after transplant. Lymphocyte subpopulations (B cells, hematogones,T cells, helper/inducer T cells, cytotoxic/suppressor T cells, regulatory T cells (TREGs), natural killer (NK) cells) and dendritic cells ( plasmocytoid and myeloid) were investigated using 6-color flow-cytometry. In order to assess differences in cell subsets between cases and BM healthy controls the Mann-Whitney test was applied. A p-value ≤ 0.05 was considered significant.Variation of cell subsets at + 1,+3, +6 months after transplant was evaluated using the Friedman test.Post-hoc pairwise comparisons with Bonferroni correction for multiple comparison were carried out.
Results
. Significant differences between patients and controls were found with respect to TREGs, T cells, helper/inducer T cells and NK cells. In particular, patients showed a significantly higher level of TREGs and NK and a significantly lower count of T- and helper/inducer T cells at +1 and +3 months from transplant. B cells and hematogones was significantly increased at six months from transplant while no differences between TREGs were found at this time point. Significant effect of timelines from transplant was found for B cells, regulatory T cells, T cells, helper/inducer T cells and cytotoxic/suppressor T cells. A statistically significant raise was found from + 1 to + 6 months for T cells and cytotoxic/suppressor T cells and from + 1 to +3 months for helper/inducer T cells and cytotoxic/suppressor T cells . On the contrary, a statistically significance decrease was observed at any time for TREGs count. Univariate analysis showed a statistically significant association between cytotoxic/suppressor T cell count and the presence of infection (p=0,027) with patients having viral or bacterial infection showing higher counts. No differences were found for any other association.
Conclusion
In conclusion, immune reconstitution following allo-SCT on BM samples was similar to data reported from peripheral blood.Viral and bacterial infectionsplay an important role in increasing cytotoxic/suppressor T cells.
Session topic: E-poster
Keyword(s): Acute myeloid leukemia, Allogeneic hematopoietic stem cell transplant, Immune reconstitution
Abstract: PB2198
Type: Publication Only
Background
The reconstitution of different immune cell subsets after allogeneic stem cell transplantation (allo-SCT) occurs at different timelines. Anyway, majority of studies following allo-SCT focused on levels of the single cell line while recovery of the entire immune system was generally reviewed. Similarly, few reports addressed on the effect of clinical factors on the restoration of immunity and studies on bone marrow (BM) samples are lacking
Aims
Thus, we prospectively investigated changes in lymphocyte and dendritic subsets after allo-SCT in BM samples with respect to minimal residual disease (MRD), GvHD, infections and HSCT type.
Methods
BM samples from patients (n=25) with acute myeloid leukemia(AML) who underwent to allo-SCT were collected from january 2012 and december 2014 at specific time-points: +1, +3 and +6 months after transplant. Lymphocyte subpopulations (B cells, hematogones,T cells, helper/inducer T cells, cytotoxic/suppressor T cells, regulatory T cells (TREGs), natural killer (NK) cells) and dendritic cells ( plasmocytoid and myeloid) were investigated using 6-color flow-cytometry. In order to assess differences in cell subsets between cases and BM healthy controls the Mann-Whitney test was applied. A p-value ≤ 0.05 was considered significant.Variation of cell subsets at + 1,+3, +6 months after transplant was evaluated using the Friedman test.Post-hoc pairwise comparisons with Bonferroni correction for multiple comparison were carried out.
Results
. Significant differences between patients and controls were found with respect to TREGs, T cells, helper/inducer T cells and NK cells. In particular, patients showed a significantly higher level of TREGs and NK and a significantly lower count of T- and helper/inducer T cells at +1 and +3 months from transplant. B cells and hematogones was significantly increased at six months from transplant while no differences between TREGs were found at this time point. Significant effect of timelines from transplant was found for B cells, regulatory T cells, T cells, helper/inducer T cells and cytotoxic/suppressor T cells. A statistically significant raise was found from + 1 to + 6 months for T cells and cytotoxic/suppressor T cells and from + 1 to +3 months for helper/inducer T cells and cytotoxic/suppressor T cells . On the contrary, a statistically significance decrease was observed at any time for TREGs count. Univariate analysis showed a statistically significant association between cytotoxic/suppressor T cell count and the presence of infection (p=0,027) with patients having viral or bacterial infection showing higher counts. No differences were found for any other association.
Conclusion
In conclusion, immune reconstitution following allo-SCT on BM samples was similar to data reported from peripheral blood.Viral and bacterial infectionsplay an important role in increasing cytotoxic/suppressor T cells.
Session topic: E-poster
Keyword(s): Acute myeloid leukemia, Allogeneic hematopoietic stem cell transplant, Immune reconstitution
Type: Publication Only
Background
The reconstitution of different immune cell subsets after allogeneic stem cell transplantation (allo-SCT) occurs at different timelines. Anyway, majority of studies following allo-SCT focused on levels of the single cell line while recovery of the entire immune system was generally reviewed. Similarly, few reports addressed on the effect of clinical factors on the restoration of immunity and studies on bone marrow (BM) samples are lacking
Aims
Thus, we prospectively investigated changes in lymphocyte and dendritic subsets after allo-SCT in BM samples with respect to minimal residual disease (MRD), GvHD, infections and HSCT type.
Methods
BM samples from patients (n=25) with acute myeloid leukemia(AML) who underwent to allo-SCT were collected from january 2012 and december 2014 at specific time-points: +1, +3 and +6 months after transplant. Lymphocyte subpopulations (B cells, hematogones,T cells, helper/inducer T cells, cytotoxic/suppressor T cells, regulatory T cells (TREGs), natural killer (NK) cells) and dendritic cells ( plasmocytoid and myeloid) were investigated using 6-color flow-cytometry. In order to assess differences in cell subsets between cases and BM healthy controls the Mann-Whitney test was applied. A p-value ≤ 0.05 was considered significant.Variation of cell subsets at + 1,+3, +6 months after transplant was evaluated using the Friedman test.Post-hoc pairwise comparisons with Bonferroni correction for multiple comparison were carried out.
Results
. Significant differences between patients and controls were found with respect to TREGs, T cells, helper/inducer T cells and NK cells. In particular, patients showed a significantly higher level of TREGs and NK and a significantly lower count of T- and helper/inducer T cells at +1 and +3 months from transplant. B cells and hematogones was significantly increased at six months from transplant while no differences between TREGs were found at this time point. Significant effect of timelines from transplant was found for B cells, regulatory T cells, T cells, helper/inducer T cells and cytotoxic/suppressor T cells. A statistically significant raise was found from + 1 to + 6 months for T cells and cytotoxic/suppressor T cells and from + 1 to +3 months for helper/inducer T cells and cytotoxic/suppressor T cells . On the contrary, a statistically significance decrease was observed at any time for TREGs count. Univariate analysis showed a statistically significant association between cytotoxic/suppressor T cell count and the presence of infection (p=0,027) with patients having viral or bacterial infection showing higher counts. No differences were found for any other association.
Conclusion
In conclusion, immune reconstitution following allo-SCT on BM samples was similar to data reported from peripheral blood.Viral and bacterial infectionsplay an important role in increasing cytotoxic/suppressor T cells.
Session topic: E-poster
Keyword(s): Acute myeloid leukemia, Allogeneic hematopoietic stem cell transplant, Immune reconstitution
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