1. Platelet Crossmatch: Role and Feasibility in Oncology Set up
Dr. Priti Desai
Associate Professor
Dept. of Transfusion Medicine
Tata Memorial Hospital, HBNI
Mumbai

2. Overview Introduction Platelet transfusion response
Platelet immunology
Alloimmunization and Refractoriness
Management of platelet needs in alloimmunized patients
TMC Experience
TRANSMEDCON 2018

3. Introduction Platelets are essential for normal hemostasis
Platelet transfusions are important for management of patients with hematological malignancies
mainly used for the prevention and treatment of hemorrhagic manifestations
TRANSMEDCON 2018

4. Platelet Transfusion Response
Some patients do not achieve desired therapeutic effects despite adequate dose and product quality
Causes for inadequate response
Immune causes
Nonimmune causes
TRANSMEDCON 2018

5. Platelet transfusion response-monitoring
Calculation of either a Corrected Count Increment or Post-transfusion Platelet Recovery
10-60 minutes and
20-24 hours after transfusion
TRANSMEDCON 2018

6. e.g. patients of hematological malignancies
Risks associated with multiple platelet transfusions
Alloimmunization to platelet antigens is a significant issue in patients who require multiple platelet transfusions;
e.g. patients of hematological malignancies
Incidence:HLA alloimmunization among patients receiving multiple transfusions ranges from 20% to 71% (AABB technical manual 18th Edi.)
TRANSMEDCON 2018
Asian J Trans Sci Jul-Dec:8(2),

7. Risks associated with multiple platelet transfusions
Platelet Refractoriness:
CCI at 1 hour post transfusion of <5000 To after two sequential ABO compatible platelet transfusion
(AABB 18th edit.)
Alloimmunization
Immune destruction of transfused platelets
Inadequateresponse to platelet transfusion
Platelet refractoriness
TRANSMEDCON 2018

8. Immunology of platelets
Platelets express a variety of immunogenic markers on the cell surface
Some are shared with
all nucleated cells in the body as
(in case of HLA antigens),
whereas others are observed to be essentially platelet specific.
HPA
ABH
Platelet Surface
HLA
Lewis P I
Antigens on Platelet surface
TRANSMEDCON 2018

9. Immunisation to HLA antigens
Incidence: 20-71% in multi-transfused
Pregnancy and Transfusion account for development of HLA alloimmunization
Antibodies to class I significantly affect the recovery and survival of transfused platelets
Risk of HLA alloimmunization is influenced by several patient and blood component factors
Underlying disease
Number and type of platelet product
Transfusion of RBC
TRANSMEDCON 2018

10. Immunization to Platelet specific antigens
In some patients poor response of platelet transfusion despite HLA matching indicates that perhaps PSA are involved
The incidence of platelet-specific antibodies varies from 2% to 11% and leucoreduction does not affect this incidence (Kickler et al, 1990; Godeau et al, 1992; Slichter,1997)
TRANSMEDCON 2018

11. Rossi’s Principles of Transfusion Medicine 4th edi
TRANSMEDCON 2018

12. Immunization to ABO blood group antigens
ABO is expressed at low levels on platelet membrane
Clinical trials comparing ABO identical to unmatched platelets in patients with cancer have suggested higher rates of refractoriness in in unmatched transfusions (AABB 18th Edit.)
TRANSMEDCON 2018

13. Managing need of Platelet Transfusions in Alloimmunized patients
Matching donor- recipient HLA antigens
Crossmatching platelets
Antigen negative platelets (HLA/HPA)
2008 Blackwell Publishing Ltd, British Journal of Haematology, 142, 348–360
TRANSMEDCON 2018

14. HLA Matched platelets
The value of HLA matching was first described in a study published in 1969
HLA-matched donors can be found either among family members or HLA typed donor registry
Traditionally, recipient and donors are matched for HLA - A and B antigens
The post transfusion increment depends on
degree of match
Grade A and BU (B1U or B2U) HLA-matched platelets are associated with the better increases in platelet count
Selection of platelet donors with antigens in the same "cross- reactive groups" (CREGs) as the patient's antigens, has been demonstrated to be nearly as successful in supporting alloimmune platelet refractoriness as HLA-matched transfusions (Grade B1X or B2UX)
Rossi’s Principles of Transfusion Medicine 4th edi
TRANSMEDCON 2018

15. HLA-antigen negative "compatible" platelets
Antibody Specificity Prediction (ASP) Method
The patient is HLA -A and B typed
The specificities of the patient’s HLA antibodies are
determined
The patient’s HLA type and HLA class I antibodies are entered into a computer that searches for compatible donors
The percent platelet recovery (PPR) was similar in HLA matched,
cross-matched and ASP-selected transfusions (Petz LD et al. Transfusion 2000;40:)
TRANSMEDCON 2018

16. Newer approach: Epitope matching protocol
HLA antigens have multiple epitopes that can be recognized by antibodies
Epitopes are short sequence linear of amino acid residues that form a cluster on a molecular surface
HLA antibodies are produced against epitopes that can be structurally defined as eplets, which are present on different HLA alleles
Thus instead of matching for HLA types, matching can be performed for epitopes
The computer program used to perform epitope based matching
TRANSMEDCON 2018

17. Challenges in HLA matching
Availability of large number of donor pool
High cost of establishing and maintaining necessary panel of several thousand HLA typed apheresis donors
Time consuming
Up to 25% -40% of HLA-matched transfusions fail to give satisfactory post-transfusion platelet increment
(Dahlke MB, Weiss KL: Platelet transfusion from donors mismatched for crossreactive HLA antigens. Transfusion 24:299,1984)
Cases of refractoriness due to anti HPA antibodies remain unaddressed
TRANSMEDCON 2018

18. Crossmatch compatible platelets
An alternative approach is to identify compatible units by cross- matching with the patient's plasma
Quick and Relatively low cost, Convenient
test can be completed before the availability of patient’s HLA type and HLA antibody testing
Need for large pool of donors can be avoided
Along with HLA, HPA compatibility can also be identified
Several investigators have reported that can improve transfusion outcome in refractory patients
TRANSMEDCON 2018

19. Platelet crossmatch-Methods
Different crossmatch techniques have been developed
Enzyme-linked immunosorbentassay (ELISA)
Flow cytometry
Solid-phase procedures (SPRCA)
TRANSMEDCON 2018

20. Flow cytometry Sensitive Uses intact platelets
Fluorescent labelled AHG is added
Fluorescence of sample is compared with negative control
TRANSMEDCON 2018

21. SPRCA Sensitive, simple, cheaper, short time frame,
Good option for platelet crossmatch for most of the centers
Able to detect antibodies (HLA/HPA) present in the serum against the donor platelets antigen
Good correlation between test results and post- transfusion platelet counts have been achieved (Rachel JM, Summers TC, Sinor LT, Plapp FV. Use of a solid phase red blood cell adherence method for pretransfusion platelet compatibility testing. Am J Clin Pathol 1988;90:63-8.)
TRANSMEDCON 2018

22. Oncology Centre Role of platelet crossmatch
For clinician and BTS - management of transfusion needs challenging
Multiple transfusion-risk of alloimmunization
Monitor increment on all transfusion event-not possible
Transfusion requirement is huge
Inventory management (group wise SDPs)
HLA matched platelet – not possible due to various reason
Cost, donor availability, time, technical expertise
Platelet crossmatch-practical
TRANSMEDCON 2018

23. TMC Experience
TRANSMEDCON 2018

24. Dr. Pranita Sontakke MD Thesis
ASSESSMENT OF PLATELET CROSSMATCH RESULTS BY SOLID PHASE RED CELL ADHERENCE ASSAY AMONG ADULT HEMATO-ONCOLOGY PATIENTS AND ITS FEASIBILITY IN A TERTIARY CARE ONCOLOGY CENTER
Dr. Pranita Sontakke
MD Thesis

25. Aims Material and Methods
To assess platelet crossmatch result by solid phase red cell adherence method and find its correlation with post-transfusion platelet count increment among adult hemato-oncology patients
To find out the feasibility of solid phase red cell adherence assay for platelet crossmatch in a tertiary care oncology center.
Total 50 Adult patients of hematological malignancies requiring platelet transfusions
Non-immune causes excluded
ABO compatible SDP units transfused
1 hr CCI measured :
A 10 minute to 1 hour CCI >7500 was considered as adequate post transfusion response and < 7500 was considered inadequate and were documented accordingly
Platelet crossmatch performed by SPRCA method
Crossmatch results were Correlated with adequate and inadequate
TRANSMEDCON 2018

26. Results Compatibility Crossmatch result Total Compatible 39
Incompatible 11 50
TRANSMEDCON 2018

27. Conclusions (SPRCA)
Statistically significant association was found between crossmatch compatibility and CCI, compatibility being the best predictor of CCI.
The time required to perform the crossmatch test by SPRCA assay was around two to three hours
The SPRCA assay is a rapid and effective method to select the compatible unit from the inventory and is feasible for an oncology set up to cater the requirement of multiple platelet transfusions to patients of hematological malignancies
TRANSMEDCON 2018

28. Dr Nidhi Sharma MD Thesis
FLOW CYTOMETRIC PLATELET CROSSMATCHING APPROACH FOR SELECTION OF PLATELETS FOR TRANSFUSION IN HEMATOPOIETIC STEM CELL TRANSPLANT PATIENTS
Dr Nidhi Sharma
MD Thesis

29. Incidence of alloimmunization
AIMS:
Incidence of alloimmunization
Response of providing crossmatched platelets versus non crossmatched platelets on CCI
Total patients enrolled (n=32)
Flow PRA performed (n=32)
EXCLUDED (n=10)
Patients evaluated for crossmatched/ un-crossmatched transfusions (n=22)
Transfusion events studied (n=52)
Crossmatched transfusions
(n=26)
Uncrossmatched
transfusions
[nine patients required none or 1 transfusion and 1 patient required plasma reduced platelets]
TRANSMEDCON 2018

30. Incidence of alloimmunization
Studies000
Patient population
Technique of PRA estimation
Incidence of alloimmunization
Our study(Sharma N et al)
HSCT recipients
Flow PRA
37.5%
TRAP Study, 1997
AML patients
LCT
17-21% (leukodepleted)
45% (non-leukodepleted)
Bajpai M et al, 2005
Hemat-oncology
60%
Pereira J et al, 1997
MAIPA
17%
Sayed D et al, 2011
Acute leukemia
ELISA
42%
This was how alloimmunization picture looked like.
TRANSMEDCON 2018

31. Conclusion (Flow cytometric crossmatch)
Crossmatched platelets were not shown to have any benefit over un- crossmatched platelets in HSCT patients
Can probably be attributed to
The study population comprising only of HSCT patients (immunosuppressed)
Absence of alloimmunization in majority of transfused patients
Since our sample size was small, further study with larger sample size may establish more conclusive evidence
TRANSMEDCON 2018

32. HLA matching at epitope level: An effective approach to provide platelet transfusion support in platelet refractory patients
Dr Anisha Navkudkar

33. Case details
Epitope matched platelets in 3 patients of haematological malignancies with immune cause of platelet refractoriness showing positive response to epitope matched platelets
Non-immune causes of platelet refractoriness like fever, sepsis, disseminated intravascular coagulation (DIC), splenomegaly and intravenous antibiotics (especially antifungal drugs such as amphotericin B) were ruled out.
TRANSMEDCON 2018

34. Conclusion (Epitope matched platelets)
It was observed in the above three cases, that epitope matched platelet transfusions showed a significant increase in CCI (1 hr)
It can be expected to benefit platelet transfusion outcome and increase the number of compatible donors for refractory patients
Because the HLA algorithm provides a quantitative method to measure donor-recipient mismatches, using this method for donor selection could expand the available donor pool while improving PLT transfusion outcomes
TRANSMEDCON 2018

35. Summary For Oncology patients requiring multiple transfusion
Preventing alloimmunization is important by using Leukodepleted platelets
Platelet crossmatch –most cost effective compare to HLA matching
Clinical correlation and communication with blood
services provider is crucial in supporting patients
TRANSMEDCON 2018

36. Thank You!!
TRANSMEDCON 2018