1. Stem Cell Transplantation for Primary Immunodeficiency Diseases (PID)
Amir Abbas Hedayati-Asl
Ped. Hematologist Oncologist /BMT
Tehran University of Medical Sciences, HORC-SCT
Royan Institute
Cancer Personalized Medicine Program
Stem Cell Biology and Technology Department

2. Primary immune deficiency diseases( PID) comprise a heterogeneous group of genetic disorders that affects distinct components of the innate and adaptive immune system such as:
neutrophils
macrophages
dendritic cells
natural killer cells
T and B lymphocytes
complement components
More than 200 distinct PID disorders have been identified and 276 gene have been associated with these diseases.
Spectrum of these diseases can vary from mild presentation to lethal disorders. Lethality is due to increase susceptibility to infections and malignancies.

3. Primary Immune Deficiency Diseases (PID)
Severe combined immunodeficiency (SCID)
Functional Genetic
T- B- NK- ADA deficiency /Reticular dysgenesis
T- B- NK+ RAG deficiency/SCID with Artemis
T- B+ NK- ɣ deficiency (X linked)/Jak 3 kinase deficiency
T- B+ NK+ IL7 Rɑ deficiency/ZAP70
T cell immunodeficiency / SCID variants
WASP deficiency (X linked)
CD40 ligand deficiency (X linked)
XLP (X linked)
Haemophagocytic syndromes
Immunodeficiency with partial albinism
Familial HLH
Griscelli disease
Chediak-Higashi syndrome XIAP

4. Primary Immune Deficiency Diseases (PID)
Phagocytic Cell disorders
Autoimmune/Immune dysregulatory
Schwachman’s syndrome
Granule deficiency
LAD
CGD (X linked/AR)
Kostmann’s syndrome
IFN- receptor deficiency
ALPS, IPEX
other

5. Whom to investigate?
A high index of clinical suspicion is needed to diagnose PID. Child having recurrent infections in a single anatomic location will more probably have an anatomic defect than an immune deficiency.
Unusually severe or long lasting recurrent infections or failing to respond to standard therapy, or infection with unusual organisms makes one to suspect PID.
The European Society of Immunodeficiencies (ESID) has suggested 10 warning signs for suspicion of PIDs.

6. Warning Signs Four or more new ear infections within one year.
Two or more serious sinus infections within one year.
Two or more months on antibiotics with little effect.
Two or more pneumonias within one year.
Failure of an infant to gain weight or grow normally.
Recurrent, deep skin or organ abscesses.
Persistent thrush in mouth or fungal infection on skin.
Need for intravenous antibiotics to clear infections.
Two or more deep-seated infections including septicaemia.
A family history of PID

7. How to investigate? The first-line investigations include:
A full blood count with a differential count
Lymphocyte subset analysis for CD3+, CD4+, CD8+ T lymphocytes
B lymphocytes (CD19+, CD20+)
Natural killer (NK) cells (CD16+, CD56+)
Serum immunoglobulins

8. Absence of B lymphocytes is associated with congenital agammaglobulinaemia.
Serum Ig levels lower than age-appropriate reference values suggest B-cell immunodeficiency.
However, serum specific antibody titers (usually IgG) in response to vaccine antigens is ideal to confirm an antibody- deficiency disorder.
In this method, a patient is immunized with protein antigens (e.g. tetanus toxoid) and polysaccharide antigens (e.g. pneumococcus) and pre- and post-immunization antibody levels are assessed.
Most PIDs have diminished or absent antibody responses to these antigens.

9. Age specific lymphopenia, along with markedly reduced T-lymphocyte counts, is characteristic of SCID.
Absolute lymphocyte count below 3000 per cu mm in a neonate is a useful cut off for T cell disorder.
A lymphocyte count less than 2 standard deviations below the age specific mean is abnormal.

10. Absolute neutrophil count (ANC) is greatly decreased in all types of SCN.
Nitroblue tetrazolium test (NBT) is widely used as the screening test for CGD, whereas neutrophil function assays like dihydrorhodamine response helps in confirming a diagnosis of CGD.
Diagnosis of LAD1 is straightforward and is based on flow cytometric evaluation of CD18 expression on the leucocyte surface.
Measuring haemolytic activity of the classical and alternative pathways of complement, along with C3 and C4 levels may help in the diagnosis of complement deficiencies.
Increase of TCRαβ+CD4 neg CD8 neg T cells suggests ALPS.

11. Landmark events in the field of HSCT and immune deficiency diseases
In 1968 first successful allogeneic bone marrow transplant in a patient with SCID from a histocompatible sibling donor became gold standard for HSCT
In 1973 first unrelated donor marrow transplant was performed in a patient with SCID
In 1980 first successful Haplo-identical marrow transplant was performed in SCID Patient
In 1995 Gene therapy in ADA SCID
In PIDTC report more than1,000 PID Children had received HSCT in USA

12. Clinical presentation of SCID
•1: live births usually present by 3mo of age •Early diagnosis crucial •Severe and frequent common infections or opportunist infections •Diarrhoea, dermatitis, failure to thrive •50% may be engrafted with maternal T cells •At risk of transfusion associated GVHD •Avoid BCG, (rotavirus vaccine)

13. Bubble Boy Disease: SCID
“ Bubble Boy Disease” is severe combined immune deficiency Disease ( baby born without immune system)
Children get sick with in first 4-6 months of age
Children die with in 1st year of life without definitive curative treatment
Blood and marrow transplantation can construct the Normal Immune system in these patients

14. Combined T and B cell immune deficiency
CD3γ deficiency
CD8 deficiency
ZAP-70 deficiency
Ca++ channel deficiency
MHC class I deficiency
MHC class II deficiency
Winged helix deficiency
CD25 deficiency
STAT5b deficiency
Itk deficiency
DOCK8 deficiency
Activated PI3K D
T-/B+ SCID γc deficiency, JAK3 deficiency, interleukin 7 r deficiency, CD45 deficiency, CD3δ/CD3ε deficiency.
T-/B- SCID, RAG 1/2 deficiency, DCLRE1C deficiency, ADA deficiency, reticular dysgenesis
Omenn syndrome
DNA ligase type IV deficiency
Cernunnos deficiency
CD40 ligand deficiency
CD40 deficiency
Purine nucleoside phosphorylase (PNP) deficiency

15. How I treat SCID - Choice?

16. How I treat SCID (Gaspar et al Blood 2013)
90% DFS
75% DFS
>80% survival
B cell functoin 20%
22 patients: most clinical benefit 5 developed T-ALL
70% DFS

17. Chronic granulomatous disease (CGD)
Chronic granulomatous disease (CGD) is a diverse group of hereditary diseases in which phagocytic cells are unable to form the reactive Oxygen Compounds most importantly superoxide radical due to defective phagocyte NADPH oxidase which kills ingested organisms
Aspergillus fumigatus

18. Chronic granulomatous disease (CGD)
•Symtoms
–Pneumonia, abscesses of the skin, tissues, and organs
–Suppurative arthritis, osteomyelitis, superficial skin infections such as cellulitis or impetigo
•Infections due to bacteria particularly those that are catalase-positive
–Staphylococcus aureus. Serratia marcescens.Listeria species.
–E. coli. Klebsiella species Pseudomonas cepacia, a.k.a. Burkholderia cepacia. Nocardia.
•Infections due to fungi
–Aspergillus species. Aspergillus has a propensity to cause infection in people with CGD and of the Aspergillus species, Aspergillus fumigatus seems to be most common in CGD.
–Candida species.

19. Wiskott –Aldrich Syndrome
A rare X-linked immunodeficiency disorder has variable clinical phenotype which correlates with type of WASP gene mutation.
The disease is associated with:
Progressive combined immune deficiency
Thrombocytopenia
Small sized platelets
Eczema
Increased risk of auto immune diseases and malignancy.

20. Wiskott –Aldrich Syndrome
WAS is 2nd most common PID treated with HSCT
1st patient with WAS was transplanted in 1968
Before 1990, only patients with WAS who had serious complications of disease and had matched sibling donors had HSCT.
Disease correction required both myeloid and Lymphoid engraftment thus needs myeloablative conditioning regimen.
Transplant corrects all aspects of this disease.
Transplant from matched related/unrelated donor is standard of care.

21. Severe congenital neutropenia (SCN)
Early referral for HSCT is important
If there is poor response to G-CSF, considering the high risk for AML transformation.
A study from SCN International Registry has shown overall survival of 82% in children who underwent HSCT.

22. Chediak Higashi syndrome
Children, often die during the accelerated phase of the disease. A study by Eapen et al. showed that 35 children who underwent HSCT had a 5 year overall survival of 62%.
Erythrophagocytosis might be suggestive of familial HLH, Chediak Higashi syndrome or Griscelli syndrome

23. Leucocyte adhesion deficiency (LAD)
In a review of worldwide BMT experience amongst 36 children with LAD, overall survival was 75%.
Mortality was greatest after haplo-identical transplants.

24. Haemophagocytic Syndromes
Familial Haemophagocytic Lymphohistiocytosis (FHL)
1:50 000, present with fever, hepatosplenomegaly, pancytopenia, hypertriglyceridaemia, hypofibrinogenaemia, haemophagocytosis in bone marrow
Mutation in perforin/MUNC/syntaxin genes leads to uncontrolled activation T lymphocytes
Fatal without immunosuppresive therapy and SCT
Outcome MFD/MUD/Haplo/mMUD = 71%/70%/54%/54%
Improved with inactive disease

25. Good News!

26. History of SCT for HLH since 2000: Alem/Flu/Mel RIC Improves Patient Survival

27. Lesson learnt from these studies
Diagnose these children with PID, before they get sick and encounter some serious infection, which might cause serious morbidity and mortality
Definitive therapy earliest possible time to provide to provide best chance for the cure of the disease

28. •On May 21, 2010, the Department of Health and Human Services (HHS), announced the addition of Severe Combined Immunodeficiency (SCID) in New Born Screening panel

29. Essential steps for Blood Stem cell transplant from Allogeneic Donor
•Conditioning regimen:
Myeloablative
Reduced intensity
immunosuppression alone
No therapy
•Graft source:
Bone marrow,
PBSC,
Cord blood
–T replete or T depleted grafts
•Post transplant immuno-suppression to prevent graft versus host disease and no immuno-suppression for T depleted graft
Identification of the disease correctable with allo BMT
Identification of suitable HPC donor:
1.Matched related
2.Matched unrelated
3.Haploidentical related

30. Availability of Donor
For a patient with genetic disease there is <25% chance to have histocompatible sibling who is also healthy
60 to 75% must have alternative Stem cell donor
Unrelated donor:
National Marrow Donor Program ten million volunteers, 193,474 cord blood products for 10-45% of patients.
There are no matched sibling or unrelated donor Option for those Patients : Haploidentical donor transplants

31. Gene Therapy
PID were amongst the first group of diseases to be effectively treated with gene therapy and this field has rapidly expanded over the past two decades with innovative new technologies being rapidly incorporated into clinical practice.
Correction of autologous hematopoietic stem cells (HSC) using viral vectors to deliver the appropriate transgene has changed the management landscape for these groups of patients .
The successful outcome of a number of clinical trials is bringing gene therapy towards a first line treatment option for selected conditions.
Younger, non infected patients have better outcome

32. Gene Therapy

33. Keep an eye on….. Chimerism Studies
–Must be performed and reported at 100 days, 6 month, 1 year and 2 year time-points
–Specifying the cell lineage is important
T-cells, B-cells or Myeloid cells
Center Contact for updating forms
The Chimera was, according to Greek mythology, a monstrous fire-breathing hybrid creature of Lycia in Asia Minor, composed of the parts of more than one animal.

34. Current Issues…….
Because of some transplant related morbidity mortality, the therapy is being offered only to the patients with the highest risk of the disease.
The questions…who to transplant, when to transplant, how to transplant, from whom to transplant are still not answered clearly
Therefore looking at every single patient transplanted in detail, is critical to understand the disease, its course, the best ways to treat the disease and improve the outcome of the procedure and Quality of life for these patients.

35. In Conclusion
The spectrum of presentation of these diseases varies from very mild symptoms to serious and potentially lethal illness.
Such diseases identified early in life can be potentially cured with Stem Cell Transplant and Gene Therapy
By gathering complete and accurate information about these patients and learning from it, the medical community can offer better and more appropriate therapy in the management of these patients