Transfusion in Sickle Cell Disease: Risk Factors for Alloimmunization

Study Overview
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Brief Summary
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Sickle cell patients have a high prevalence of alloimmunization. This high rate of alloimmunization can be partially explained by the existence of an antigenic difference between the predominantly Caucasian donor population and the sickle cell patients of African origin. Genetic and environmental risk factors have also been described. The main risk factors that have been shown in retrospective or cross-sectional studies are some HLA alleles, the age of the patient, the number of leukocyte-depleted erythrocyte concentrates (CED) transfused, the number of transfusion episodes, the age of the CEDs, the existence of an inflammatory event at the time of transfusion and the presence of anti-erythrocyte autoantibodies.There is also evidence of an impaired TH response but the underlying immunological mechanism is not fully understood. The aim of this study is to study the prevalence and the risk factors for anti-erythrocyte alloimmunization and to try to understand the immunological mechanisms.

Official Title
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Transfusion in Sickle Cell Disease: Risk Factors for Alloimmunization

Conditions
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Sickle Cell Disease

Intervention / Treatment
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* Procedure: Blood sampling


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Sickle cell disease patients treated within the CHU Brugmann or Queen Fabiola Children's Hospital Exclusion Criteria: None
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Screening
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Experimental group<br>Allo-immunization detected (positive response for irregular antibodies 2 to 4 weeks after a blood transfusion) | Procedure: Blood sampling<br>* Extra blood sampling at the time of a blood transfusion in order to perform the laboratory analysis<br>|
| Other: Control group<br>Allo-immunization not detected | Procedure: Blood sampling<br>* Extra blood sampling at the time of a blood transfusion in order to perform the laboratory analysis<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Irregular antibodies | Presence/abscence of irregular antibodies | 1 hour before blood transfusion | 
| Irregular antibodies | Presence/abscence of irregular antibodies | Between 2 to 4 weeks after blood transfusion | 
| C-reactive protein (CRP) | CRP dosage | 1 hour before blood transfusion | 
| Cytokine | Cytokine dosage | 1 hour before blood transfusion | 
| Cytokine | Cytokine dosage | Between 2 to 4 weeks after blood transfusion | 
| Heme oxygenase | Heme oxygenase dosage | 1 hour before blood transfusion | 
| Heme oxygenase | Heme oxygenase dosage | Between 2 to 4 weeks after blood transfusion | 
| Lymphocyte typing | Lymphocyte typing | 1 hour before blood transfusion | 
| Lymphocyte typing | Lymphocyte typing | Between 2 to 4 weeks after blood transfusion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sex | Sex | 1 hour before blood transfusion | 
| Chronic or acute blood transfusion | Blood transfusions planned at regular intervals of time (chronic transfusions) or performed in reaction to a medical issue (acute transfusion). | 1 hour before blood transfusion | 
| Blood transfusion indication | Medical reason explaining the necessity of a blood transfusion | 1 hour before blood transfusion | 
| Blood donor ethnicity | Blood donor ethnicity | 1 hour before blood transfusion | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Sickle cell disease, Allo-immunization, Blood transfusion