Platelet transfusion refractoriness in highly immunized beta thalassemia children undergoing stem cell transplantation.
Immune-mediated refractoriness to platelet transfusion is a major problem in patients undergoing HSCT. In a cohort of 50 pediatric patients affected by beta thalassemia coming from Middle East countries, we experienced a high incidence of refractoriness because of anti-HLA antibodies during post-HSCT aplasia. In a risk factors analysis, factors predicting a negative transfusion outcome were presence of spleen and the number of anti-HLA antibodies. We adopted a policy to select platelet donors by avoiding HLA antigens against which the patient had specific antibodies. Transfusion of dedicated units resulted in 26% refractoriness compared to 74% to random units (p < 0.0001). When dedicated transfusions were used, the presence of spleen did not influence transfusion outcome. Analyzing transfusion outcome depending on the degree of HLA match and ABO compatibility, 76% successful transfusions were obtained with HLA-matched- ABO compatible followed by 67% in HLA-1mismatch- ABO compatible or HLA-matched- ABO incompatible and by 46% in HLA-1mismatch- ABO incompatible. In conclusion, we provide evidence that the selection of platelet donors according to patient characteristics, anti-HLA antibodies and ABO matching, is successful in reducing platelet refractoriness in heavily alloimmunized thalassemia patients undergoing transplantation.
Marktel
Sarah
S
Pediatric Immunohematology and Bone Marrow Transplantation Unit, San Raffaele Scientific Institute, Milan, Italy. marktel.sarah@hsr.it
Napolitano
Sara
S
Zino
Elisabetta
E
Cappelli
Barbara
B
Chiesa
Robert
R
Poli
Francesca
F
Crocchiolo
Roberto
R
Ronchi
Paola
P
Rossini
Silvano
S
Ciceri
Fabio
F
Roncarolo
Maria G
MG
Fleischhauer
Katharina
K
D000017:ABO Blood-Group System / Q000276:immunology; D000293:Adolescent; D001788:Blood Grouping and Crossmatching / Q000379:methods; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D005260:Female; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D007165:Immunosuppression Therapy / Q000379:methods; D007223:Infant; D016014:Linear Models; D008297:Male; D017713:Platelet Transfusion / Q000009:adverse effects*; D012307:Risk Factors; D033581:Stem Cell Transplantation; D019172:Transplantation Conditioning / Q000379:methods; D017086:beta-Thalassemia / Q000276:immunology* / Q000628:therapy*
D000017:ABO Blood-Group System; D006680:HLA Antigens