1. Immune Phenotype of patients long-
term after allogeneic Hematopoietic
Stem Cell Transplantation (HSCT)
Francesca Rossi
Oncology-Pathology dep.,
Huddinge Hospital
Supervisor: Dr. Michael Uhlin
Co-supervisor: Arwen Stikvoort
2. 2
Hematopoietic Stem Cell Transplantation (HSCT)
transplantation of multipotent hematopoietic stem cells (HSC)
Multipotent: they can become one of several types of cells within a given organ
Hematopoietic: they are located in the bone marrow and give rise to all other blood cells
through haematopoiesis
An HSCT can be:
Autologous: when the patient’s own HSCs are used for the transplantation
Allogeneic: when the stem cells come from another individual
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3. Procedure
1. Conditioning: administration of chemotherapeutic drugs
2. Transplant: HSC get infused into the recipient’s vein
3. Engraftment: the cells reach the sinuses in the bone barrow
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http://www.mdlingo.com/article/reduced-intensity-conditioning-improves-outcome-of-bone-marrow-engraftment
4. Possible reactions after HSCT
GVL: immune-mediated response of remission of the hematological malignancy
Graft failure: when host’s immune cell reject the donor’s cells or when part of the HSCT does not work
GVHD: when donor’s cells attack the host’s tissues
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The closest the compatibility is between donor and recipient,
the lower is the risk that complications arise
5. AIM
Determine whether the donor and patient’s immune system differed after 10
years since transplantation
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?
HSC
7. Material & Methods (1)
Groups:
1. 7 donors and 7 recipients
Unpaired
2. 5 donors and 5 recipients
Paired (donors and patients are siblings)
HSCTs took place between 1987 and 2003
Samples collected at least 10 years ago
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8. Material & Methods (2)
Samples: PBMC “ring”
removed from the blood and frozen (-180°C)
BD FACS Canto Flow cytometer
(42 different markers used)
FlowJo analysing software
Statistics:
IBM – SPSS Statistics, version 23
GraphPad Prism, version 5.00
P values <0.05
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Unpaired: Mann-Whitney (box plots)
Paired: Wilcoxon (paired scatter plots)
9. Results (1)
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CD4+ CD8-
donor recipient
0
20
40
60
80
%ofTcells
p = 0,026
CD8+ CD4-
donor recipient
0
20
40
60
80
%ofTcells
p= 0,004
A B
In a healthy person:
CD4+ > CD8+
Previous reports: shortly after
transplantation:
CD8+ > CD4+
12. CCR7 – CD45RO
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CD45RO+
CCR7+
TN TCM
TEMTTD
TN: naïve T cells express CCR7 marker (lymph nodes)
TCM: cells that guard against infections
TEM: T cells entered in contact with antigens and are
ready to enter the bloodstream to defend the body
13. Results (4)
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CCR7- CD45RO+
Donor Recipient
0
10
20
30
40
50
%ofTcells
p=0,043
CCR7- CD45RO+
Donor Recipient
0
20
40
60
%ofCD4+Tcells
p=0,043
CCR7+ CD45RO-
Donor Recipient
0
20
40
60
%ofCD4+Tcells
p=0,042
A B C
TEMs ➡️ patients > donors in T cells and CD4+ T cells (A and B)
Transplantation increases immune system reaction: mature memory T cells
TNs ➡️ donors > patients in CD4+ T cells (C)
Less T naïve cells in patients after HSCT
16. To summarize…
CD4+/CD8+ shifted
Higher levels of CD95+ in patients (in both groups)
Higher levels of TEM cells in patients and higher levels of TN in
donors
Increased levels of CD45RO+ in Treg memory cells in patients
Higher amounts of PD-1 exhaustion marker in patients’
senescent cells
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17. Considerations & Conclusions
Aspects that may influence immune system cell’s reconstitution:
Quality/quantity of mononuclear cells transplanted
Genetic disparity/compatibility between donor and recipient
Type of transplantation
Immune system’s cells after HSCT
The immune system cells in the patient are its donor’s cells
Even after many years in the patient some cell populations seem to show relevant differences
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21. Medical data of donors and patients
included in the study
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Editor's Notes
To date we have little info regarding immune phenotype long-term after HSCT:
Other papers focused on short-time after HSCT
Other papers focused on the patient’s immune phenotype only, without referring to the donor’s immune system.
…that’s why we were interested to find out the differences in the immune phenotype by comparing the donor and the recipient’s blood sample one with the other.
The P values < 0.05 denoted the presence of a statistically significant difference.
Two different comparison t-tests were performed: M-W for the 1. group (donor vs. recipients); W for the 2. group (where donors and recipient are siblings)
CD4+ T cells rely more on the thymic production of naïve T cells after HSCT.
Whereas CD8+ T cells’ reconstitution seems to arise from peripheral matured T cells.
Both these factor seem to lead to an inversion of the CD4/CD8 ratio.
To date we have little info regarding immune phenotype long-term after HSCT:
Other papers focused on short-time after HSCT
Other papers focused on the patient’s immune phenotype only, without referring to the donor’s immune system.
