Platelet refractoriness

Platelet transfusion refractoriness (PTR) refers to the repeated failure to achieve satisfactory responses to platelet transfusions from random donors.

PTR is associated with the following adverse outcomes:

  • Longer hospital stays
  • Increased risk of bleeding
  • Decreased survival
  • Higher inpatient hospital costs.

1 unit (1 standard adult dose) of apheresis or pooled platelets would be expected to raise the platelet count of a 70 kg adult by 20-40 x 109/L.

If platelet count has not increased satisfactorily - determine increment using either post-transfusion platelet increment (PPI) or corrected count increment (CCI) at 10-60 mins on two occasions.

PPI = post-transfusion platelet count – pre-transfusion platelet count

CCI = (PPI x body surface area (m2)) ÷ platelet dose (x 1011)

PTR can be defined as: 2 occasions, 1 hour post-transfusion of:

  • PPI <10 x 109/L or
  • CCI <5-10 x 109/L

Continue to transfuse ABO compatible platelets as required.

Investigate and treat non-immune causes.

Sepsis

Fever

Disseminated intravascular coagulation (DIC)

Splenomegaly

Active bleeding

Medications e.g. vancomycin, amphotericin B, heparin

Graft versus host disease (GVHD)

Veno-occlusive disease (VOD)

* For platelet refractoriness attributable to non-immune causes fresh, ABO-compatible, single-donor apheresis platelets may improve platelet increment. 

Prior exposure from pregnancy, transfusions and /or transplantation

  • 80-90%: alloimmunisation to HLA antigens
  • 10-20% alloimmunisation to HPA antigens
  • 5% alloimmunisation to HLA and HPA antigens.

Other antibodies: drug dependent, ABO or autoantibodies

Continue to transfuse ABO compatible platelets as required.

Contact the Blood Service, collect samples for HLA typing and antibody testing and complete a Request for HLA/HPA compatible platelets – Clinical information form. http://www.transfusion.com.au/resource_centre/forms

Patients who are refractory to platelet transfusions due to the presence of HLA alloimmunisation.

Patients with congenital platelet function disorders such as Bernard–Soulier syndrome, Glanzmann's thrombasthenia or other congenital platelet disorders where development of HLA alloantibodies may make future platelet support very difficult.

Patients who are to undergo stem cell transplantation (sibling/unrelated) using stem cells from a donor who is not a full HLA match and where development of HLA antibodies could result in an adverse transplantation outcome.

Continue with ABO compatible products as supplied.

Re-assess non-immune causes.

Contact the Blood Service to discuss options (e.g. repeat HLA testing, HPA testing, other).

Support with HLA compatible platelets provided by Blood Service.

Note: the ‘best’ HLA selected platelets may be ABO-incompatible platelets

Monitor response – post-transfusion platelet count at 1 hour and 24 hours post transfusion.

Good response – continue with HLA compatible platelets as required; if ongoing transfusion requirements, follow-up testing approximately monthly.

Poor response – continue HLA compatible products and contact the Blood Service to discuss options (e.g. HPA testing).

Patients with thrombocytopenia due to HPA alloimmunisation i.e. neonates with fetal and neonatal alloimmune thrombocytopenia (FNAIT)

Patients who are refractory to platelet transfusions due to the presence of HPA alloimmunisation.

Continue with ABO or HLA compatible products as supplied.

Re-assess non-immune causes.

Contact the Blood Service to discuss options (e.g. repeat HLA testing/HLA compatibility assessment, HPA testing, other).

Support with HPA compatible platelets provided by Blood Service.

Note: the ‘best’ HPA selected platelets may be ABO-incompatible platelets

Monitor response – post-transfusion platelet count at 1 hour and 24 hours post transfusion.

For neonates with known or suspected FNAIT, platelet count response to transfusion should be checked within 12 hours.

For neonates with known or suspected FNAIT, random donor platelets should be used if antigen-matched platelets are not immediately available. Continued use of random donor platelets is acceptable if antigen matched platelets cannot be obtained. Because of short survival of random donor platelets, repeated transfusion is likely to be needed.

 

References:

  1. Stanworth SJ, Navarrete C, Estcourt L, Marsh J. Platelet refractoriness – practical approaches and ongoing dilemmas in patient management. British Journal of Haematology 2015;171:297–305.
  2. Hod E, Schwartz, J. Platelet transfusion refractoriness. British Journal of Haematology 2008;142:348–360.
  3. Patient Blood Management Guidelines: Module 6 Neonatal and Paediatrics. National Blood Authority. 2016 [cited 4 May 2016]. Available from: http://blood.gov.au/pbm-guidelines