1. Principle of Hematopoietic stem cell transplantation
24th January, 2018
Kleebsabai Sanpakit, MD
Division of Hematology/Oncology
Department of Pediatrics, Siriraj hospital
Mahidol University

2. Topic outline Overview and source of HSC
Type of HSCT and Matching donor / patient
Indication of HSCT in Pediatrics
Complications post HSCT : GVHD
Outcome of HSCT

3. Type of stem cells Limited to specific tissues Adult somatic SC
Multipotent
Limited to specific tissues
Adult somatic SC
(tissue specific SC)
i.e.Hematopoietic SC, neural , hepatic SC)
Pluripotent
Give rise to a variety of specialised cell types
Cannot support the development of a fetus
Embryonal SC
Totipotent
Unrestricted differentiation potential
Gives rise to all cells necessary for
development of fetal and adult organs
Fertilised egg
Developmental properties
Stem cells (SC)

5. Sources of stem cells Advantages Disadvantages - adequate SC content
- low T cell content
- adequate SC
- rapid hematopoietic
recovery
- naive SC
- very low T cell content
(immature)
- low transmission of viral infection
Disadvantages
- collect in OR, under GA
- use growth factor
- high T cell content
- only adequate wt. donor
- low SC content
- one-time collection only
- delay hematopoietic
recovery BM PB CB

6. Type of HSCT 1.

7. Type of HSCT 2. Allogenic SCT 2.1 Related allogenic SCT
2.2 Syngenic SCT
2.3 Unrelated allogenic SCT

9. c a b d c a a c Father A B DR Mother A B DR Child d b b d A A A A B B
25 % c a A B DR
25 % d A B DR a c
25 % A B DR b
25 % A B DR b d
Prob of matched siblings: 1 sibling %
2 siblings %
3 siblings %

11. Principle of HSCT
Nonmalignant diseases : replacement of abnormal hematopoietic system after myeloablative Rx with the normal HSC
Malignant diseases : allow higher and more effective doses of chemoRx to eradicate the malignant cells before rescue the BM fn. with normal HSC
: offer immunotherapy (GVT)
that can eradicate chemoresistant
malignant cells

12. Indications for HSCT in Pediatrics
Autologous HSCT
Hematologic malignancies: Relapsed NHL/HL
Solid tumors:
- Neuroblastoma stage IV
- High risk or recurrent solid tumors: medulloblastoma, rhabdomyosarcoma, Ewing’s sarcoma, primitive neuroectodermal tumor etc.
Autoimmune diseases

13. Indications for HSCT in Pediatrics
Allogeneic HSCT : Malignancies
ALL: 1st remission in high risk case
(Ph+ve ALL, MLL rearrangement with slow early response, etc.)
2nd or subsequent CR
AML: 1st CR in high risk case (ie. preceding MDS, high risk cytogenetics)
CML in chronic or early accelerated phase
JMMoL
MDS - RAEB or RAEB-t
NHL/HL: 2nd or subsequent CR or PR

14. Indications for HSCT in Pediatrics
Allogeneic HSCT: Non malignancies
Hematologic disorders:
- Hemoglobinopathies: severe thalassemia
- Bone marrow failure: severe AA, FA, cong. pure red cell anemia etc.
- Red cell enzymopathies: PK def. etc.
Immunodeficiencies: SCID, WAS, CGD etc.
Lysosomal storage diseases: Gaucher’s disease etc.
Infantile osteopetrosis
Familial hemophagocytic lymphohistiocytosis
myelofibrosis
Major obstacle: no HLA-matched related donor

15. Unrelated HSCT
Aim : expand donor pools  increased possibility to find matched unrelated donor
( 1 : 25,000 – 50,000 )
Important points : improve HLA matching system
expand donor pools
financial support
Thai National SC donor registry and Thai National
CB bank

16. Patient preparation
- infectious screening : CMV, Hepatitis B, C, HIV
- dental check up
- clear intestinal parasite, stool exam
- PPD skin test, CXR
- insertion of Hickman’s cath. (double lumens)
- sterile bowel with nonabsorbable antibiotic
- conditioning regimen
- postgrafting immunosuppression for GVHD prevention

17. Conditioning regimens
Aims 1. Eradication of the abnormal hemopoietic system :
Busulfan, Total body irradiation
2. Suppression of the immune system :
Cyclophosphamide, Fludarabine
Postgrafting immunosuppression for GVHD prevention:
1.Corticosteroids: prednisolone, methylprednisolone
2.T-cell signaling blockade:
CSA, FK506
3.Antiproliferatives: MTX, MMF
Bu, CTX = alkylating agents
Flu = antimetabolite (purine antagonist)
Corticosteroids inhibit synthesis of more than 100 proteins, but at low doses they predominantly act on antigenpresenting cells, preventing some of the early stages of graft rejection. Higher doses of corticosteroids have direct effects on T cells, and these are used to treat episodes of rejection
Cyclosporin and tacrolimus work by interacting with proteins in the intracellular T-cell signaling cascade.
- mycophenolate mofetil, and methotrexate inhibit DNA production. These drugs prevent lymphocyte proliferation, but they are not specific forT cells, and they
can cause myelotoxicity.

18. Supportive treatment
1. Reverse isolation (sterile room, laminar air flow)
2. PRC transfusion, keep Hb >10 g/dL
3. Plt conc. transfusion, keep plt > 20,000/m3
PRC and platelet – irradiated , prestoraged or Wbc filtered
4. G-CSF 10 g/kg/day until WC > 10,000/mm3 x 2 days
when ANC > 1,000/mm3 x 2 days → off isolation
5. Antibiotics for febrile neutropenia and
early Rx for any sign of infection
6. parenteral nutrition
7. psychological support

19. Engraftment Evidence - DNA analysis (Chimerism study)
- donor’s sex chromosome
- donor’s blood group
In thal pt - normalization of Hb, Hct,
reticulocyte count
- donor’s Hb type
In malignant pt - no evidence of disease
In immunodeficincy pt - normal or near normal immune function

20. Complications post HSCT
Graft rejection, graft failure
Nausea/vomiting

21. Graft versus host disease
Classification
Acute GVHD – consisting of dermatitis-enteritis and hepatitis following a BMT (usually within 30 – 40 days)
Chronic GVHD – autoimmune like syndrome consisting of impairment of multiple organs or organ systems
(collagen vascular disease)

22. Factors that influence outcome of HSCT
Underlying diseases
Type of HSCT
Dedree of HLA matched
Sources and cell doses of viable HSC
Conditioning regimen
Pre-HSCT condition of the pt: organ dysfunction
Supportive care post-HSCT