Background: Platelet transfusion is a critical and often necessary aspect of managing cancer. Low platelet counts frequently lead to bleeding complications; however, the drugs used to combat malignancy commonly lead to decreased production and destruction of the very cell whose function is essential to stop bleeding.
The transfusion of allogeneic platelet products helps to promote hemostasis, but alloimmunization may make it difficult to manage other complications associated with cancer.
Methods: The literature relating to platelet transfusion in patients with cancer was reviewed.
Results: Platelet storage, dosing, transfusion indications, and transfusion response are essential topics for health care professionals to understand because many patients with cancer will require platelet transfusions during the course of treatment.
The workup and differentiation of non–immune-mediated compared with immune-mediated platelet refractoriness are vital because platelet management is different between types of refractoriness.
Conclusions: A combination of appropriate utilization of platelet inventory and laboratory testing coupled with communication between those caring for patients with cancer and those providing blood products is essential for effective patient care.
Platelets are discoid anucleate cells that measure 3 to 5 μm at their greatest diameter. They are derived from megakaryocytes in the bone marrow and contain ABO antigens on their surface.
Platelets are an essential component of hemostasis because they are responsible for forming a platelet plug, providing a framework for the formation of fibrin clots, and secreting cytokines and growth factors.1
Platelets express A and B red blood cell antigens, class I human leukocyte antigen (HLA), and platelet-specific antigens (eg, human platelet antigen [HPA]) on their surface.2,3
Platelets are available from 2 sources based on the method in which they are collected: apheresis platelets and whole blood–derived platelets. Apheresis platelets are obtained via an apheresis collection device from a single donor.
Oftentimes, 2 or 3 apheresis platelet units can be acquired during this single collection event; each of these units is considered 1 adult dose. Whole blood–derived platelets are acquired from the platelet concentrate portion of a whole blood donation. Routinely, 4 to 6 platelet concentrates are pooled together to obtain a typical dose.4
Both apheresis platelet and pooled whole blood– derived platelet units must contain a minimum of 3 × 1011 platelets per bag. These 2 products have similar clinical effects and can be interchangeably used.2,5
The leukoreduction of platelets provides several benefits, including the reduction of (1) the platelet alloimmunization rate, (2) cytomegalovirus transmission due to transfusion, and (3) febrile nonhemolytic transfusion reactions.2
Storage and Dosing
Platelets are stored in the blood bank at room temperature (68–75°F [20–24°C]) on a platelet rotator to facilitate the exchange of oxygen.
Primarily due to their risk of bacterial contamination (approximate risk: 1 per 1,000 units), platelets have a shelf life of 5 days; the day of collection is considered day 0.6 Volunteers who donate blood are tested for HIV, hepatitis B and C, and West Nile virus infections, and blood collection facilities must also screen all platelet products for bacteria,7,8 either via bacterial cultures or assessing bacterial growth by oxygen consumption measurement.1
One dose of platelets should increase the platelet count of an average-sized adult by 35,000 to 40,000/μL,9 and this increment can be measured with a post-transfusion platelet count or complete blood count.
In adult patients, platelets are dosed in units. Dosing of platelets for pediatric patients may be done based on body weight (typical pediatric platelet dose, 5–10 mL/kg).5