1. SCAFfoldChild Sickle Cell Anemia and Fetal Hemoglobin
SCAFfoldChild Sickle Cell Anemia and Fetal Hemoglobin. Genetic modifiers in an Angolan Children Cohort.
Miguel Brito
Health and Technology Research Center (H&TRC), ESTeSL/IPL
Centro de Investigação em saúde de Angola (CISA)
Lisbon, july 8th 2019

2. Miguel Brito

3. Sickle-cell disease (SCD) is the most prevalent hereditary disease in the WHO African Region.
Angola
HbS allele frequency 12%
Piel et al. 2010, Nature Communications, 1: 104
Prevalence of SCD 1.5% in Angola, with 21% carriers of S allele (Brito et al, in press).
In 2006, the WHO identified SCD as a significant public health problem in Africa that may contribute to up to 16% of under-5 mortality.
About 50%–80% of the infants born with SCD in Africa die before the age of five years, unless diagnosed and treated.
Miguel Brito

4. Painful swelling of hands and feet. Frequent infections.
SCD is caused by a structural variation of hemoglobin which results from a substitution at position 6 of the beta globin molecule (Glu to Val).
In SCD, the red blood cells become rigid and sticky due to HbS polymerization.
Clinical manifestations occur from hemolysis and vaso-occlusion phenomena (acute and chronic):
Anemia.
Episodes of pain.
Painful swelling of hands and feet.
Frequent infections.
Osteoarticular, neurological, cutaneous, cardiac, vision problems.
Delayed growth.
its clinical manifestations are very heterogeneous, with some individuals severely affected while other avoiding serious consequences
suggestive of the existence of important disease modifiers.
Miguel Brito

5. - some of them are located in HbB locus cluster, in the BCL11A gene,
The concentration of residual Fetal hemoglobin (HbF) seems to be the most important modifying factors.
Disease protective genetic modifiers act mainly through an increased HbF level
- some of them are located in
HbB locus cluster,
in the BCL11A gene,
in the HBS1L_MYB intergenic region,
in KLF1 gene,
Genetic variability in these genes seems to be responsible for the disease variability, and for the treatment response.
Other modifiers of SCD:
Alpha-thalassemia
Environmental factors
Drugs - Hydroxyurea
Miguel Brito

6. Approximately 25% of patients with SCD, do not respond to HU.
Treatment of SCD
Hydroxyurea (HU) is the only drug approved by FDA and by the European Medicines Agency for treating SCD, since drug increases HbF concentration.
Patients response to HU is highly variable, with the levels HbF induction ranging from 2% to 30%.
Approximately 25% of patients with SCD, do not respond to HU.
Genetic determinants of HU response
Miguel Brito

7. Secondary aims of the project :
Aim of the study
Use Next Generation Sequencing (NGS) to identify genetic predictors of HbF response to HidroxyUrea (HU) in Angolan children with SCD.
Secondary aims of the project :
1- Study the impact of genetic modifiers on clinical SCD phenotypes in this cohort.
Study HBB locus cluster, BCL11A, HS1L-MYB intergenic region, and KLF1 screened for variants that could be associated with HU induced HbF levels (as measured by maximum %HbF after one year with HU treatment compared to %HbF at baseline)
2- Establishing a process for the use of HU in pediatric SCD patients in Bengo, Angola
3- Support the cohort of SCD children, created in the Hospital Geral do Bengo and in
Hospital Pediátrico David Bernardino , supporting the clinicians, the laboratory and the acquisition of pharmaceuticals for free distribution (HU).
Miguel Brito

8. In progress In progress Tasks of the project
Task 1. Laboratory preparation and team training
Development of Clinical and laboratory protocols.
Selection of field team (Medical doctors, nurses, and lab technicians)
The project is being developed in CISA Caxito and in Luanda Paediatric Hospital
Task 2. Selection of Children to participate in the Study
Selection of 200 children from CISA SCD Cohort and from CADA in Luanda
Children between 3 and 12 years with SCD
Children naive for Hydroxyurea
In progress
In progress
Miguel Brito

9. In progress Tasks of the project
Task 3 . Clinical Characterization of the SCD children (every 4 months)
Growth parameters
Disease events (fever, malaria, other infections) and pain crises
Task 4. Hematological and Biochemical Characterization of SCD children (every 4 months)
Complete blood count, reticulocyte count,
Biochemical analysis, namely C reactive protein, bilirubin, LDH, AST and ALT
Task 5. Fetal Hemoglobin quantification (every 4 months)
Fetal hemoglobin quantification by HPLC
In progress
the evaluation before HU administration
Miguel Brito

10. In progress Start in December 2019 Tasks of the project
Task 6. Genetic characterization if the SCD children DNA extract from blood
NGS analysis of a panel including HB B locus cluster, HBA, BCL11A gene, HBS1L_MYB intergenic region, and KLF1 gene, is being performed in NextSeq 550 Illumina, using a Illumina enrichment method design by DesignStudio.
Task 7. Establishing a process for the use of hydroxyurea in pediatric SCD patients in Bengo
To establish a routine HU protocol, and to give support to SCD children in Luanda and Caxito
In progress
Start in December 2019
We are organizing the purchase of 146,000 doses of HU
Miguel Brito

11. Task 8. Data analysis and integration
Ethical issues
The study was approved by the ethical committee of Angola Ministry of Health.
The study was submitted to the ethical committee of the ESTeSL and to the Ethical committee of the INS Ricardo Jorge.
A written informed consent in Portuguese was presented and explained to all the guardian participants.
Miguel Brito

12. This project can greatly contribute to strength the Scientific and Clinical collaboration between Portugal and Angola , and give financial and scientific support to the cohort of SCD children in Angola.
This project could act as a scaffold for the healthy development of SCD children (SCAFfoldChild – Sickle Cell Anemia and Fetal Hemoglobin in Children).
Miguel Brito

13. SCAFfoldChild Sickle Cell Anemia and Fetal Hemoglobin
SCAFfoldChild Sickle Cell Anemia and Fetal Hemoglobin. Genetic modifiers in an Angolan Children Cohort.
Miguel Brito
Health and Technology Research center (H&TRC), ESTeSL/IPL
Centro de Investigação em saúde de Angola (CISA)
Lisbon, july 8th 2019