Early occurrence of red blood cell alloimmunization in patients with sickle cell disease.
Red blood cell (RBC) alloimmunization is a major complication of transfusion therapy in sickle cell disease (SCD). Identification of high-risk patients is hampered by lack of studies that take the cumulative transfusion exposure into account. In this retrospective cohort study among previously non-transfused SCD patients in the Netherlands, we aimed to elucidate the association between the cumulative transfusion exposure, first alloimmunization and independent risk factors. A total of 245 patients received 11 952 RBC units. Alloimmunization occurred in 43 patients (18%), half of them formed their first alloantibody before the 8th unit. In patients with exposure to non-extended matched transfusions (ABO and RhD) the cumulative alloimmunization risk increased up to 35% after 60 transfused units. This was significantly higher compared to a general transfused population (HR 6.6, CI 4.2-10.6). Receiving the first transfusion after the age of 5 was an independent risk factor for alloimmunization (HR 2.3, CI 1.0-5.1). Incidental, episodic transfusions in comparison to chronic scheme transfusions (HR 2.3, CI 0.9-6.0), and exposure to non-extended matched units in comparison to extended matching (HR 2.0, CI 0.9-4.6) seemed to confer a higher alloimmunization risk. The majority of first alloantibodies are formed after minor transfusion exposure, substantiating suggestions of a responder phenotype in SCD and stressing the need for risk factor identification. In this study, older age at first transfusion, episodic transfusions and non-extended matched transfusions appeared to be risk factors for alloimmunization. Am. J. Hematol. 91:763-769, 2016. © 2016 Wiley Periodicals, Inc.
Department of Pediatric Hematology, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands.|Department of Hematology, Academic Medical Center, Amsterdam, The Netherlands.
Joep W R
JW
Sins
Department of Hematology, Academic Medical Center, Amsterdam, The Netherlands.
Bart J
BJ
Biemond
Department of Pediatric Hematology, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands.|Department of Hematology, Academic Medical Center, Amsterdam, The Netherlands.
Sil M
SM
van den Bersselaar
Department of Pediatric Hematology, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands.
H
H
Heijboer
Department of Hematology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
Anita W
AW
Rijneveld
Department of Pediatric Hematology, Erasmus MC, University Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands.
Marjon H
MH
Cnossen
Department of Hematology, Haga Hospital, The Hague, The Netherlands.
Jean-Louis H
JL
Kerkhoffs
Department of Pediatrics, Haga Hospital, The Hague, The Netherlands.
Alfred H
AH
van Meurs
Department of Pediatric Hematology, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands.|Department of Hematology, Academic Medical Center, Amsterdam, The Netherlands.
F B
FB
von Ronnen
Center for Clinical Transfusion, Sanquin Blood Supply Foundation, Leiden and Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
Saurabh
S
Zalpuri
Department of Clinical Chemistry, Erasmus MC, University Medical Center Rotterdam, The Netherlands.
Yolanda B
YB
de Rijke
Department of Experimental Immunohematology, Sanquin Blood Supply Foundation, Amsterdam, The Netherlands.
C
C
Ellen van der Schoot
Department of Experimental Immunohematology, Sanquin Blood Supply Foundation, Amsterdam, The Netherlands.
Masja
M
de Haas
Center for Clinical Transfusion, Sanquin Blood Supply Foundation, Leiden and Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
Johanna G
JG
van der Bom
Department of Pediatric Hematology, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands.|Unit of Clinical Transfusion Medicine, Sanquin Blood Supply Foundation, Amsterdam, The Netherlands.
Karin
K
Fijnvandraat
D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000097:blood / Q000150:complications / Q000628:therapy*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D017707:Erythrocyte Transfusion / Q000009:adverse effects*; D004912:Erythrocytes / Q000276:immunology; D006801:Humans; D007518:Isoantibodies / Q000097:blood* / Q000276:immunology; D009426:Netherlands; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
D007518:Isoantibodies