Intensive red blood cell transfusions and risk of alloimmunization

Authors

  • Saurabh Zalpuri,

    1. Center for Clinical Transfusion Research, Sanquin Research, Leiden, Netherlands
    2. Department of Clinical Epidemiology, Jon J. van Rood Center for Clinical Transfusion Research, Leiden, Netherlands
    3. Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
    4. Department of Medical Statistics, Leiden University Medical Center, Leiden, Netherlands
    5. Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, Netherlands
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  • Rutger A. Middelburg,

    1. Center for Clinical Transfusion Research, Sanquin Research, Leiden, Netherlands
    2. Department of Clinical Epidemiology, Jon J. van Rood Center for Clinical Transfusion Research, Leiden, Netherlands
    3. Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
    4. Department of Medical Statistics, Leiden University Medical Center, Leiden, Netherlands
    5. Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, Netherlands
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  • Henk Schonewille,

    1. Center for Clinical Transfusion Research, Sanquin Research, Leiden, Netherlands
    2. Department of Clinical Epidemiology, Jon J. van Rood Center for Clinical Transfusion Research, Leiden, Netherlands
    3. Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
    4. Department of Medical Statistics, Leiden University Medical Center, Leiden, Netherlands
    5. Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, Netherlands
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  • Karen M.K. de Vooght,

    1. Center for Clinical Transfusion Research, Sanquin Research, Leiden, Netherlands
    2. Department of Clinical Epidemiology, Jon J. van Rood Center for Clinical Transfusion Research, Leiden, Netherlands
    3. Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
    4. Department of Medical Statistics, Leiden University Medical Center, Leiden, Netherlands
    5. Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, Netherlands
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  • Saskia le Cessie,

    1. Center for Clinical Transfusion Research, Sanquin Research, Leiden, Netherlands
    2. Department of Clinical Epidemiology, Jon J. van Rood Center for Clinical Transfusion Research, Leiden, Netherlands
    3. Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
    4. Department of Medical Statistics, Leiden University Medical Center, Leiden, Netherlands
    5. Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, Netherlands
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  • Johanna G. van der Bom,

    1. Center for Clinical Transfusion Research, Sanquin Research, Leiden, Netherlands
    2. Department of Clinical Epidemiology, Jon J. van Rood Center for Clinical Transfusion Research, Leiden, Netherlands
    3. Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
    4. Department of Medical Statistics, Leiden University Medical Center, Leiden, Netherlands
    5. Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, Netherlands
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  • Jaap Jan Zwaginga

    Corresponding author
    1. Center for Clinical Transfusion Research, Sanquin Research, Leiden, Netherlands
    2. Department of Clinical Epidemiology, Jon J. van Rood Center for Clinical Transfusion Research, Leiden, Netherlands
    3. Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
    4. Department of Medical Statistics, Leiden University Medical Center, Leiden, Netherlands
    5. Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, Netherlands
    • Address reprint requests to: Jaap J. Zwaginga, Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Albinusdreef 2, Building 1, E3-Q, PO Box 9600, 2300 RC Leiden, the Netherlands; e-mail: j.j.zwaginga@lumc.nl.

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Abstract

Background

Exposure to allogenic red blood cells (RBCs) may lead to formation of antibodies against nonself-antigens in transfused patients. While alloimmunization rates are known to increase with the number of transfusions, the transfusion course in patients can vary from receiving multiple units during a single transfusion event or getting them dispersed over a long(er) period. In this study we compared the immunization risk between different transfusion intensities.

Study Design and Methods

An incident new-user cohort study was conducted among consecutive transfused patients at two university medical centers. All patients who received their first RBC transfusion within the study period from January 2005 to December 2011 were eligible. Intensive transfusions were defined as at least 5, at least 10, and at least 20 RBC units within 48 hours. Alloimmunization hazard ratios (HRs), comparing patients receiving intensive transfusions to patients never receiving intensive transfusions, were estimated.

Results

The study cohort was composed of 5812 patients who had received a median of 7 (interquartile range, 4-12) units. RBC alloantibodies were formed by 156 patients. The adjusted Cox regression HRs for alloimmunization, with number of units as the time covariate and adjusted for patient age, sex, and follow-up time after first transfusion, ranged from 0.8 to 1.2 (95% confidence interval, 0.4-2.6).

Conclusion

The occurrence of RBC alloimmunization in patients receiving intensive transfusions did not differ significantly from patients receiving nonintensive transfusions.

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