3. Why to know about GvHD?
Delayed Engraftment
Delayed Immune reconstitution
Increased rate of infections
Increased cost of treatment
Increased length of hospital stay
Adverse effects of chronic immunosuppressive therapy
Increased morbidity and mortality
4. DIFFERENCE BETWEEN TA-GvHD & GvHD
Unlike GVHD after allogeneic marrow transplantation,
TA-GVHD leads to profound marrow aplasia, with a
mortality rate higher than 90%.
5. INTRODUCTION
Hematopoietic cell (marrow, umbilical cord blood or
mobilized peripheral blood) transplantation is performed
- To replace inadequate or defective blood cell production
- For adoptive immunotherapy in malignancy
- To reconstitute the immune system in immune deficiency
The number of HSCTs has increased steadily over the past two
decades due to improvements in
- Outcome
- Expanded indications
- The ability to safely perform transplantation in
older individuals
6. INTRODUCTION
Along with infection, GvHD is the leading cause of non-
relapse mortality following HSCT.
Despite improvements in GvHD prevention,
approximately 30–60% of matched sibling HSCT
recipients will develop Acute GvHD (aGvHD) and the
rates are higher for unmatched or unrelated donors
7. ROLE OF HLA IN HSCT
HLA system is generally viewed as second in importance only to
the ABO antigens in influencing the survival of transplanted
Bone marrow.
In hematopoietic progenitor cell (HPC) transplantation, the HLA
system is paramount with regard to graft rejection and graft-vs-
host disease (GVHD)
8. ROLE OF HLA IN HSCT
The role of HLA ‘compatibility’ falls into four different
areas:
1. Sufficient compatibility to permit engraftment and
prevent late rejection (with appropriate preparative
and immunosuppressive regimens)
2. Enough compatibility to minimize graft-versus-host-
disease (GVHD)
3. Ample immune reconstitution to permit
immunosurveillance
4. Sufficient immune potency to effect adoptive immune
therapy of neoplasia
9.
10. GRAFT VS HOST DISEASE (GvHD)
Complex immunological disorder caused by Donor T
Lymphocytes in allogenic HSCT
GVHD results from the recognition of host tissues as
foreign by donor immunocompetent cells
The incidence increases with greater HLA disparity
between the donor and host
Fundamental problem for allogeneic transplantation is
the close association between this complication and
the derived benefit resulting from a GVT effect
11. GRAFT VS HOST DISEASE (GvHD)
GvHD also delays the immune reconstitution in the recipient
Reports of an increased incidence of chronic GvHD if more
than 8 × 106 CD34 cells/kg are transplanted suggest that
4–8 × 106 CD34 cells/kg should be regarded as the desirable
stem cell dose.
PBSCs results in an increased incidence of chronic GvHD,
reflecting the five- to tenfold greater dose of T cells
transplanted if mobilized cells are used in preference to bone
marrow-harvested cells
12. RISK FACTORS
Characteristics of Donor and Recipient
HLA disparity
Female donor (XX) to male donor (XY)
Older age of recipient
Prior history of aGvHD
Characteristics of the transplantation protocol
More intensive preparative regimen
Source & dose of HSCT
Unmodified (T cell replete) graft
Less aggressive administration of prophylactic immunosuppressive
agents
13. RISK FACTORS
Later Intervention
Withdrawal of immunosuppressive medications
Donor T Lymphocyte infusions
To Prevent/To treat
Relapse
14. REDUCED INTENSITY CONDITIONING
Immunosuppress the host sufficiently to allow donor
engraftment, cure of disease being delivered
subsequently by the allogeneic GvL effect.
Aim of the conditioning therapy is no longer principally
to eradicate disease
19. RISK OF GvHD IN REFERENCE TO SOURCE OF
STEM CELLS
PBSC
BONE
MARROW
UCB
IN ORDER OF DECREASING POTENTIAL
20. GRAFT VS TUMOR EFFECT (GVT)
Most potent form of tumor immunotherapy currently in clinical
use
Contribute towards curative aspect of allogenic HSCT
Poorly understood
Allogeneic T cells clearly play a fundamental role in the
initiation and maintenance of the effect on neoplastic cells
mainly CD8, CD4 and NK cells (Tumour specific CTLs)
Beneficial effects seen in Leukemias , Myeloma and
Lymphomas
21. FORMS OF GvHD (Glucksberg-Seattle
classification)
ACUTE
(OCCURING
WITHIN 100 DAYS )
CHRONIC
(OCCURING AFTER
100 DAYS )
clinical manifestation and histologic findings are now the sole
factors used in defining these distinct entities
23. ACUTE GvHD
Incidence is about 20-70%
Depends upon
Conditioning regimen intensity
HLA disparity between donor and recipient
Age of the recipient
Stage of primary disease
Clinical staging is established which takes into account
the primary organ involvement (Skin,Liver,GIT)
Pathological findings do not change the grading
27. CHRONIC GvHD
Reported in 60 to 70% of allogenic recipients
Limited information available
More extensive involvement but most people recover
Involve practically all the organs
Shares common features with many autoimmune
diseases like Scleroderma, Sicca syndrome etc
28. CHRONIC GvHD PATHOPHYSIOLOOGY
Decreased number of regulatory T cells
B cell dysregulation and production of autoantibodies
Decreased negative selection of T cells
Th2 type response Th2 Cytokines Increase
THYMIC DYSFUNCTION
Acute GvHD Conditioning
35. REGULATORY T CELLS
Regulatory T cells are characterized by the
Co- expression of CD4,
High levels of surface CD25,
Master switch transcription factor called
forkhead box P3 (Foxp3) ; suppresses autoreactive lymphocytes
Ultra lowdose IL-2 for GVHD prophylaxis after allo-HSCT
mediates expansion of Tregs without diminishing antiviral and
antileukemic activity
Its still in clinical trial
36. CYTOTOXIC T CELLS
Directed against minor histocompatibility antigens and tumor
associated antigens
CD8+ cells
By in vivo/ex vivo expansion, they can give enhanced GvT
without increasing the risk of GvHD
CTL clones generation with IL21 exposure showed increased in
vivo life span with excellent tumor specific activity
37. CYTOKINE INDUCED KILLER CELLS (CIK)
Cytotoxic effector T cells , CD3+ CD56+ TCR+
Very strong non HLA restricted NK cell like cytotoxicity
Completely lack GvHD activity
Donor-derived CIK cells can be administered to
lymphoma/leukemia patients who relapsed after allo-HSCT
Still in Phase I clinical trials
38. NK CELLS
CD3- , CD56+ , CD16 + cells
Rapidly kill certain target cells without prior immunization or
MHC restriction
This cell type might prevent T cell–mediated GVHD through
killing
Some tumor cells avoid recognition by CTL by down-regulating
their expression of MHC-I, but these escape mutants
consequently become targets for NK cells (No MHC needed for
presentation)
39. EXTRACORPOREAL PHOTOPHERESIS (ECP)
ECP is a specialized procedure in which the buffy-coat layer is
collected from peripheral blood, treated with 8 methoxy-
psoralen and ultraviolet A light, and re-infused into the
patient.
Cross-linking of leukocyte DNA, prevents replication and
induces apoptosis.
ECP has complex immunomodulatory effects, including
induction of monocyte differentiation to dendritic cells,
alteration of T-cell subsets, and changes in cytokine
production profiles
41. Main effects of
ECP
Tolerogenic
dendritic cells
Anti-inflammatory
cytokine
production
Increased Treg
cells
ASFA recommends ECP for
Cutaneous manifestations
of GvHD as Category II
indication (does not
distinguish acute from
chronic)
42. MESENCHYMAL STEM CELLS
Multipotent : can differentiate into osteocytes , fibroblasts ,
chondrocytes , myocytes and adipocytes
They have inhibitory effects on the proliferation and cytotoxic
activity of immune system cells
MSCs alter the cytokine secretion profiles of effector T cells,
DCs, and NK cells, shifting it from a pro-inflammatory Th1
cytokine profile to an anti-inflammatory Th2 cytokine profile
Still in Phase III trials , have good results in Childhood
malignancies (Source of MSC : BM, HLA identical, Unrelated
donors)
43. Main effects of
MSC in GvHD
Suppresses DC
maturation and
activity
Anti-
inflammatory
cytokine
production
TGFβ,IL
10,PGE2,IL1R
Antagonist
Low CL I MHC
No CL II MHC
No Costimulatory
molecules
45. SUMMARY
Despite advances in procedure and post-transplantation
prophylaxis more than half of Allogenic HSCT patients develop
GvHD
Major cause of morbidity and mortality
Still poorly understood
Elimination of alloreactive T cells and preserving tumor and
pathogen-specific immunity will still be a major task to further
improve outcome after HSCT
46. SUMMARY
Unanswered questions remain:
How to define the appropriate cell dose for optimal
therapeutic response and minimal toxicity?
What is the best schedule to infuse these cells?
Should these be infused as a preemptive or a curative
therapeutic dose?
48. BIBLIOGRAPHY
Rossi’s principle of transfusion medicine 5th edition
Mollison’s Blood Transfusion in clinical practice 12th edition
AABB technical manual 18th edition
Hoffbrand Postgraduate Hematology 5th edition
Adoptive Immunotherapies After Allogeneic Hematopoietic
Stem Cell Transplantation in Patients With Hematologic
Malignancies – TRANSFUSION MEDICINE REVIEWS- 2015
GVHD : comprehensive review – ANTICANCER RESEARCH 2017
Notes de l'éditeur
Allogeneic hematopoietic cell transplantation (HCT) applied for the cure of hematologic malignancies is associated with 2 main risk factors for poor outcomes: (1) transplantation-related morbidity/mortality and (2) mortality from disease relapse (relapse-related mortality).
efforts to reduce graft-versus-host disease (GVHD) risk by T-cell depletion of the allograft can lower transplantation-related morbidity/mortality, but can also increase relapse
Steroids -curtailing activation of NF-kB, which increases apoptosis of activated cells
Calcineurin A inh -these drugs bind to an immunophilin (cyclophilin for cyclosporine or FKBP-12 for tacrolimus), resulting in subsequent interaction with calcineurin to block its phosphatase activity. Calcineurin-catalyzed dephosphorylation is required for movement of a component of the nuclear factor of activated T lymphocytes (NFAT) into the nucleus
Tacrolimus (PROGRAF, FK506) is a macrolide antibiotic produced by Streptomyces tsukubaensis Tacrolimus binds to an intracellular protein, FK506-binding protein-12 (FKBP-12), an immunophilin structurally related to cyclophilin
Sirolimus (rapamycin; RAPAMUNE) is a macrocyclic lactone produced by Streptomyces hygroscopicus
Mycophenolate mofetil is a prodrug that is rapidly hydrolyzed to the active drug, mycophenolic acid (MPA), a selective, noncompetitive, and reversible inhibitor of inosine monophosphate dehydrogenase (IMPDH) an important enzyme in the de novo pathway of guanine nucleotide synthesis. B and T lymphocytes are highly dependent on this pathway for cell proliferation,