Alloimmunization From Transfusions Workup

  • Author: Eyal Oren, MD; Chief Editor: Michael A Kaliner, MD   more...
 
Updated: Jan 3, 2012
 

Laboratory Studies

Delayed hemolytic transfusion reactions

  • The most reliable laboratory sign is a failure to observe the expected posttransfusion increase in blood hemoglobin levels (approximately 1 g/dL/U) in the absence of bleeding.
  • In some cases, the loss of circulating cells can be higher than expected if only antigen-positive cells were cleared. This phenomenon results from bystander hemolysis, which is caused by the deposition of activated complement on both donor and recipient RBCs.
  • Laboratory signs of hemolysis include elevated lactate dehydrogenase, indirect bilirubin, and reticulocyte levels and decreased hematocrit and haptoglobin levels.
  • Intravascular hemolysis is characterized by the presence of free plasma hemoglobin and possibly hemosiderinuria.
  • The results of direct and indirect antiglobulin tests (ie, Coombs test) are often positive.
  • Alloantibodies can be eluted from RBCs, and their specificity can be determined. In case of hemolysis, sensitive elution techniques should be done to identify alloantibodies, even if serum antibodies are undetectable and the direct antiglobulin test is negative. Often (about 15-20%), patients with DHTR have multiple antibodies and some may be detectable only by elution.
  • Type the donor RBCs for affected antigens and re-crossmatch them with the patient's serum if segments from the transfused units are available.

Refractoriness to platelet transfusions

  • Refractoriness to platelet transfusions is defined as repeated failure to achieve the expected increment in platelet count after 2 or more platelet transfusions. The expected increment can be calculated based on the number of platelets transfused and the patient's blood volume using the formula as follows:
  • % Maximum increment = ([pretransfusion count – posttransfusion count in platelets/µL] X blood volume in mL) ÷ (number of platelets transfused, ie, number of U X 6 X 105)
    • The expected increment is 45-75% of the maximum increment, resulting from normal sequestration by the spleen.
    • Blood volume can be calculated roughly as body weight (kg) multiplied by 69 (males) or by 65 (females); the number of platelets transfused assumes an average content of 6 X 1010 platelets/U; an average apheresis unit contains the equivalent to 6 units of platelets (4 X 1011 platelets).
    • Observed increments of less than 30% at 10-60 minutes or less than 20% at 18-24 hours indicate platelet refractoriness.
    • A simple screen for platelet refractoriness is failure to achieve an increment of >5 X 109/L (5,000/µL) at 20-24 hours after transfusion of a standard platelet dose (1 unit/10 kg of pooled platelets or one single donor apheresis unit).
  • Note that many cases of refractoriness result from causes other than alloimmunization (see Differentials).
  • In general, alloimmunization results in the rapid removal of platelets and in lower counts at 10 minutes to 1 hour posttransfusion, whereas nonimmune causes mostly affect the 4- to 24-hour posttransfusion count. Mild alloimmunization, however, can be present with 1-hour increments within the reference range.
  • Microcytotoxicity assays against a panel of 30-60 different lymphocyte cells can demonstrate lymphocytotoxic anti-HLA antibodies. The percentage of cells to which the patient's serum reacts is referred to as the panel-reactive antibody (PRA) level. PRA values greater than 20% indicate significant alloimmunization to HLA antigens and correlate with an increased risk for platelet refractoriness.
  • The presence of antiplatelet antibodies can be demonstrated by flow cytometry or by immunoassays such as the modified antigen capture enzyme-linked assay, the solid-phase RBC adherence assay, and the monoclonal antibody immobilization of platelet antigens assay. Most of these assays permit screening for HLA and HPA antibodies as well as specific identification of the most commonly involved HPA antigens.
  • A negative result from platelet antibody screening indicates nonimmune causes of refractoriness.
Proceed to Treatment & Management
 
 
Contributor Information and Disclosures
Author

Eyal Oren, MD  Consulting Staff, Institute for Asthma and Allergy

Eyal Oren, MD is a member of the following medical societies: American Academy of Allergy Asthma and Immunology and American College of Allergy, Asthma and Immunology

Disclosure: Nothing to disclose.

Coauthor(s)

Jorge L Sepulveda, MD, PhD  Associate Professor of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine; Chief, Pathology and Laboratory Medicine Service, Philadelphia Veterans Affairs Medical Center

Jorge L Sepulveda, MD, PhD is a member of the following medical societies: Academy of Clinical Laboratory Physicians and Scientists, American Heart Association, and College of American Pathologists

Disclosure: Nothing to disclose.

Specialty Editor Board

Charles H Kirkpatrick  MD

Charles H Kirkpatrick is a member of the following medical societies: American Academy of Allergy Asthma and Immunology, American Association of Immunologists, American College of Physicians, American Federation for Clinical Research, American Society for Clinical Investigation, and Clinical Immunology Society

Disclosure: Dyax Consulting fee Consulting

Francisco Talavera, PharmD, PhD  Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

Samuel R Marney, Jr, MD  Director, Associate Professor, Department of Internal Medicine, Division of Allergy and Immunology, Vanderbilt University School of Medicine

Samuel R Marney, Jr, MD is a member of the following medical societies: American Academy of Allergy Asthma and Immunology, American College of Allergy, Asthma and Immunology, American College of Physicians, and Tennessee Medical Association

Disclosure: Nothing to disclose.

Timothy D Rice, MD  Associate Professor, Departments of Internal Medicine and Pediatrics and Adolescent Medicine, St Louis University School of Medicine

Timothy D Rice, MD is a member of the following medical societies: American Academy of Pediatrics and American College of Physicians

Disclosure: Nothing to disclose.

Chief Editor

Michael A Kaliner, MD  Clinical Professor of Medicine, George Washington University School of Medicine; Chief, Section of Allergy and Immunology, Washington Hospital Center; Medical Director, Institute for Asthma and Allergy

Michael A Kaliner, MD is a member of the following medical societies: American Academy of Allergy Asthma and Immunology, American Association of Immunologists, American College of Allergy, Asthma and Immunology, American Society for Clinical Investigation, American Thoracic Society, and Association of American Physicians

Disclosure: Alcon Consulting fee Consulting; Teva Consulting fee Consulting; Meda Honoraria Speaking and teaching; Ista Consulting fee Consulting; sunovian Consulting fee Consulting; dey Honoraria Review panel membership

References

  1. Henrichs KF, Howk N, Masel DS, Thayer M, Refaai MA, Kirkley SA, et al. Providing ABO-identical platelets and cryoprecipitate to (almost) all patients: approach, logistics, and associated decreases in transfusion reaction and red blood cell alloimmunization incidence. Transfusion. Sep 2 2011;[Medline]. [Full Text].

  2. Gilson CR, Zimring JC. Alloimmunization to transfused platelets requires priming of CD4+ T cells in the splenic microenvironment in a murine model. Transfusion. Oct 7 2011;[Medline].

  3. Buetens O, Shirey RS, Goble-Lee M, Houp J, Zachary A, King KE. Prevalence of HLA antibodies in transfused patients with and without red cell antibodies. Transfusion. May 2006;46(5):754-6. [Medline].

  4. Friedman DF, Lukas MB, Jawad A, Larson PJ, Ohene-Frempong K, Manno CS. Alloimmunization to platelets in heavily transfused patients with sickle cell disease. Blood. Oct 15 1996;88(8):3216-22. [Medline].

  5. Heddle NM, Soutar RL, O'Hoski PL, Singer J, McBride JA, Ali MA. A prospective study to determine the frequency and clinical significance of alloimmunization post-transfusion. Br J Haematol. Dec 1995;91(4):1000-5. [Medline].

  6. Kerkhoffs JL, Eikenboom JC, van de Watering LM, van Wordragen-Vlaswinkel RJ, Wijermans PW, Brand A. The clinical impact of platelet refractoriness: correlation with bleeding and survival. Transfusion. Sep 2008;48(9):1959-65. [Medline].

  7. Allen DL, Samol J, Benjamin S, Verjee S, Tusold A, Murphy MF. Survey of the use and clinical effectiveness of HPA-1a/5b-negative platelet concentrates in proven or suspected platelet alloimmunization. Transfus Med. Dec 2004;14(6):409-17. [Medline].

  8. Novotny VM. Prevention and management of platelet transfusion refractoriness. Vox Sang. 1999;76(1):1-13. [Medline].

  9. Slichter SJ, Davis K, Enright H, Braine H, Gernsheimer T, Kao KJ, et al. Factors affecting posttransfusion platelet increments, platelet refractoriness, and platelet transfusion intervals in thrombocytopenic patients. Blood. May 15 2005;105(10):4106-14. [Medline].

  10. Slichter SJ. Evidence-based platelet transfusion guidelines. Hematology Am Soc Hematol Educ Program. 2007;2007:172-8. [Medline].

  11. Poon MC. The evidence for the use of recombinant human activated factor VII in the treatment of bleeding patients with quantitative and qualitative platelet disorders. Transfus Med Rev. Jul 2007;21(3):223-36. [Medline].

  12. Schonewille H, Haak HL, van Zijl AM. Alloimmunization after blood transfusion in patients with hematologic and oncologic diseases. Transfusion. Jul 1999;39(7):763-71. [Medline].

  13. Werch J. Use of Rh immune globulin when transfusing large volumes of Rh-positive cells. Am J Clin Pathol. May 1999;111(5):712. [Medline].

  14. Werch J, Todd C. Resolution by erythrocytapheresis of the exposure of an Rh-negative person to Rh-positive cells: an alternative treatment. Transfusion. Jun 1993;33(6):530-2. [Medline].

  15. Wahl S, Quirolo KC. Current issues in blood transfusion for sickle cell disease. Curr Opin Pediatr. Feb 2009;21(1):15-21. [Medline].

  16. The Trial to Reduce Alloimmunization to Platelets Study Group. Leukocyte reduction and ultraviolet B irradiation of platelets to prevent alloimmunization and refractoriness to platelet transfusions. N Engl J Med. Dec 25 1997;337(26):1861-9. [Medline].

  17. Friedberg RC. Clinical and laboratory factors underlying refractoriness to platelet transfusions. J Clin Apher. 1996;11(3):143-8. [Medline].

  18. Blumberg N, Heal JM, Gettings KF. WBC reduction of RBC transfusions is associated with a decreased incidence of RBC alloimmunization. Transfusion. Jul 2003;43(7):945-52. [Medline].

  19. Delaflor-Weiss E, Mintz PD. The evaluation and management of platelet refractoriness and alloimmunization. Transfus Med Rev. Apr 2000;14(2):180-96. [Medline].

  20. Kekomaki R. Use of HLA- and HPA--matched platelets in alloimmunized patients. Vox Sang. 1998;74 Suppl 2:359-63. [Medline].

  21. Kickler T, Herman JH, eds. Current issues in platelet transfusion therapy and platelet alloimmunity. Bethesda, Md: AABB Press; 1999.

  22. Legler TJ, Fischer I, Dittmann J, Simson G, Lynen R, Humpe A. Frequency and causes of refractoriness in multiply transfused patients. Ann Hematol. Apr 1997;74(4):185-9. [Medline].

  23. Pineda AA, Vamvakas EC, Gorden LD, Winters JL, Moore SB. Trends in the incidence of delayed hemolytic and delayed serologic transfusion reactions. Transfusion. Oct 1999;39(10):1097-103. [Medline].

  24. Sayeh E, Sterling K, Speck E, Freedman J, Semple JW. IgG antiplatelet immunity is dependent on an early innate natural killer cell-derived interferon-gamma response that is regulated by CD8+ T cells. Blood. Apr 1 2004;103(7):2705-9. [Medline].

  25. Schiffer CA. Diagnosis and management of refractoriness to platelet transfusion. Blood Rev. Dec 2001;15(4):175-80. [Medline].

  26. Schonewille H, van de Watering LM, Brand A. Additional red blood cell alloantibodies after blood transfusions in a nonhematologic alloimmunized patient cohort: is it time to take precautionary measures?. Transfusion. Apr 2006;46(4):630-5. [Medline].

  27. Warkentin TE, Smith JW. The alloimmune thrombocytopenic syndromes. Transfus Med Rev. Oct 1997;11(4):296-307. [Medline].

 
Previous
Next
 
Table 1. Human Platelet-Specific Antigen Systems
Platelet Antigen SystemProtein AntigenSynonymsAllelesAntigen Frequency
HPA-1GPIIIaPlA,ZwHPA-1a = PlA1



HPA-1b = PlA2



97%



26%



HPA-2GPIbKo, SibHPA-2A



HPA-2b



99%



14%



HPA-3GPIIbBak, LekHPA-3a



HPA-3b



85%



66%



HPA-4GPIIaPen, YukHPA-4a



HPA-4b



>99%



< 1%



HPA-5GPIaBr, Hc, ZavHPA-5a



HPA-5b



99%



20%



Table 2. Frequent Clinically Significant Anti-RBC Antibodies
AntigenSystemFrequency Among All Detected AlloantibodiesFrequency of Antigen



(Whites)



Frequency of Antigen



(Blacks)



Potency*
ERh16-40%30%2%4%
Kell (Kl)Kell5-40%9%3%9%
DRh8-33%85%92%70%
cRh4-15%80%99%4%
Jk(a)Kidd2-13%77%91%0.14%
Fy(a)Duffy4-12%63%10%0.46%
CRh2-10%70%32%0.22%
eRh2-3%98%98%1%
Jk(b)Kidd2%72%43%0.06%
SMNSs1-2%55%31%0.08%
sMNSs< 1%89%97%0.06%
*Percentage of antigen-negative recipients who become alloimmunized if transfused with antigen-positive units
Previous
Next
 
 
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2012 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.