SHORT-TERM CHIMERISM IN T-HELPER CELL SUBSETS AFTER ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION
(Abstract release date: 05/18/17)
EHA Library. Dubnyak D. 05/18/17; 182889; PB2176
Darya Dubnyak
Contributions
Contributions
Abstract
Abstract: PB2176
Type: Publication Only
Background
Despite the fact that almost all studies in transplant biology dedicate T-cells the chimerism in T-helper (Th) cells and its subsets such as T-regulatory (Treg) cells after allogeneic hematopoietic stem cell transplantation (allo-HSCT) has never been evaluated.
Aims
To evaluate Th, Treg and bone marrow cell short-term chimerism in allo-HSCT patients.
Methods
Between May 2015 and November 2016 there was 109 transplants in our center. The research included 24 patients with hematological malignancies (AML =14,ALL =7,MDS =2,CMML -1). The median age of patients was 33,5 (range 19 to 60) years old, female=16, male=8. Myeloablative conditioning regimen was used for 11 patients. The other 13 patients underwent reduced intensity conditioning regimen. Peripheral blood stem cells (PBSCs) as graft source was used in 9 patients, BM in 15 patients. 9 patients were transplanted from HLA-identical related donor ,15 - from unrelated matched. Сhimerism was evaluated at +30, +60, and 90-day in blood and bone marrow. Peripheral blood mononuclear cells (PBMC) were isolated using standard protocol. Cells were sequentially incubated with CD4-biotin and anti-biotin microbeads (Milteney Biotec, Germany). Next pure fraction of Treg cells (CD4+CD25high) was obtained by positive selection with the use of anti-CD25 microbeads. DNA was isolated by AmpliSens DNA-sorbB nucleic acid extraction kit. Chimerism was assessed by the STR-PCR analysis (polymerase chain reaction with a panel of primers for loci of short tandem repeats).
Results
For detailed result see Figure 1. 18 patients didn’t have any signs of relapse, graft failure or acute graft-versus host disease at all observation time. In this group on day 30 % of cells with donors genotype was - 97,17 ± 0,75; on day 60 – 95,75±2,15; on day 90- 98,21±0,80. On day 30 T-helper – 87,51 ± 3,12; on day Th 60- 90,43±3,18; on day 90 Th – 93,71± 3,03. On day 30 T-regulatory – 77,36±4,50; on day 60Treg – 82,08± 5,94; on day 90Treg – 97,71± 1,18. Four patients were diagnosed with relapse at +4 and +6 months after allo-HSCT. Two patients were diagnosed with acute GVHD.
Conclusion
Impact of chimerism in different T-helper subsets still need further investigation. We will continue our research and further results will be reported later.
Session topic: 22. Stem cell transplantation - Clinical
Keyword(s): Chimerism
Abstract: PB2176
Type: Publication Only
Background
Despite the fact that almost all studies in transplant biology dedicate T-cells the chimerism in T-helper (Th) cells and its subsets such as T-regulatory (Treg) cells after allogeneic hematopoietic stem cell transplantation (allo-HSCT) has never been evaluated.
Aims
To evaluate Th, Treg and bone marrow cell short-term chimerism in allo-HSCT patients.
Methods
Between May 2015 and November 2016 there was 109 transplants in our center. The research included 24 patients with hematological malignancies (AML =14,ALL =7,MDS =2,CMML -1). The median age of patients was 33,5 (range 19 to 60) years old, female=16, male=8. Myeloablative conditioning regimen was used for 11 patients. The other 13 patients underwent reduced intensity conditioning regimen. Peripheral blood stem cells (PBSCs) as graft source was used in 9 patients, BM in 15 patients. 9 patients were transplanted from HLA-identical related donor ,15 - from unrelated matched. Сhimerism was evaluated at +30, +60, and 90-day in blood and bone marrow. Peripheral blood mononuclear cells (PBMC) were isolated using standard protocol. Cells were sequentially incubated with CD4-biotin and anti-biotin microbeads (Milteney Biotec, Germany). Next pure fraction of Treg cells (CD4+CD25high) was obtained by positive selection with the use of anti-CD25 microbeads. DNA was isolated by AmpliSens DNA-sorbB nucleic acid extraction kit. Chimerism was assessed by the STR-PCR analysis (polymerase chain reaction with a panel of primers for loci of short tandem repeats).
Results
For detailed result see Figure 1. 18 patients didn’t have any signs of relapse, graft failure or acute graft-versus host disease at all observation time. In this group on day 30 % of cells with donors genotype was - 97,17 ± 0,75; on day 60 – 95,75±2,15; on day 90- 98,21±0,80. On day 30 T-helper – 87,51 ± 3,12; on day Th 60- 90,43±3,18; on day 90 Th – 93,71± 3,03. On day 30 T-regulatory – 77,36±4,50; on day 60Treg – 82,08± 5,94; on day 90Treg – 97,71± 1,18. Four patients were diagnosed with relapse at +4 and +6 months after allo-HSCT. Two patients were diagnosed with acute GVHD.
Conclusion
Impact of chimerism in different T-helper subsets still need further investigation. We will continue our research and further results will be reported later.
Session topic: 22. Stem cell transplantation - Clinical
Keyword(s): Chimerism
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