Flow cytometry can be used for several applications in transfusion medicine, including quantifying residual white blood cells and detecting antibody-bound platelets. It is useful for phenotyping red blood cells, such as detecting and quantifying RBC-bound IgG, IgM, and complement in a direct antiglobulin test. Flow cytometry can also measure CD34-positive stem cells for bone marrow transplantation and monitor engraftment. It allows for ex vivo T-cell depletion prior to transplantation. Overall, flow cytometry provides several applications for quality control of blood components and detecting various cell populations.

1. Flowcytometry in
Transfusion Medicine
DR. G.D.A. SAMARANAYAKA

3. Uses
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 WBC
 Quantitation of residual WBCs after filtration of blood products
 RBC
 Detection and quantification of RBC-bound IgG, IgM & complement (DAT)
 Quantification of RBC blood group antigen density
 Phenotyping of recipient RBCs after transfusion
 Detection and quantification of minor RBC populations
 McLeod carriers
 Determination of RBC survival after transfusion
 Diagnosis of autoimmune hemolytic anemia
 PLT
 Detection of antibody bound to platelets
 HSCT
 content of CD34-positive haematopoietic progenitor cells
 Monitoring of bone marrow transplantation engraftment
 ex vivo T-cell depletion prior to transplantation

4. HSCT
 content of CD34-positive haematopoietic progenitor cells in stem cell grafts and to measure T-
cell content prior to allogeneic transplantations.
 Possibility to perform an ex vivo T-cell depletion prior to transplantation has made it possible
to use haploidentical donors for some patient groups

5. Detection and semiquantification of erythrocyte antigens
 testing by flow cytometry in discovery of new variants of blood group antigens and also to
verify new blood group systems.
 evaluate and examine antigens within different carbohydrate blood group systems, for example
ABO, P1PK, GLOB and FORS
 Investigation of RhD expression
 D antigen expression and antigen site density in D variants
 characterizing new RHD alleles and correlating genotype with phenotype

6. Detection and semiquantification of erythrocyte antigens
 Kell - K0 phenotype, McLeod syndrome
 ABO
 define homo and heterozygosity for alleles exhibiting normal amounts of ABH antigens
 examine if alterations of ABH antigens occur during storage in the blood bank
 analyse the decrease of ABH antigen levels in leukaemia patients
 ABO discrepancies
 Detection of ABO subgroups
 minor ABO‐incompatible HSCT, where group O donor haematopoietic stem cells are
transplanted to a group A

7. Detection of mixed field reactions and minor cell populations
 Chimerism - congenital chimeric state
 Fetomaternal haemorrhage – Detection and quantification

8. Quality control of blood components
 Evaluate residual leucocytes in leucodepleted blood components
 90% of blood components should contain less than 1 × 106 leucocytes/unit
 The use of flow cytometry for quality assurance purposes in this setting was proposed and tested
in the late 1980s and early 1990s and have been used in many laboratories

9. Platelets
 Human Platelet Antigens
 Due to lack of serological reagents, HPA phenotyping by flow cytometry can only be performed
for HPA‐1a, and hence, genotyping is the preferred method for HPA typing.
 essential to have a donor cohort defined as HPA‐1a– and this can easily be achieved by flow
cytometry screening
 Platelet cross‐match
 Platelets during storage
 Several flow cytometry‐based assays have been used to evaluate storage lesions but have not
gained wide acceptance for routine use as a quality control measure. Among the activation
markers that have been tested by flow cytometry are expression of CD42b, CD62P as well as
binding of AnnexinV, PAC‐1, antifibrinogen

10. References

11. Thank You