Incidence and management of non-immune platelet transfusion refractoriness: a narrative review

Objective: This article aimed to describe incidence and management of non-immune platelet transfusion refractoriness (PTR) by referring to existing related literature and our clinical experience. Background: Platelet transfusions are indicated to either stop serious bleeding in trauma and surgical patients (therapeutic administration) or prevent bleeding in patients with thrombocytopenia or platelet dysfunction (prophylactic administration). The effectiveness of platelet transfusion is evaluated by measurement of platelet count and post-transfusion corrected count increment (CCI). When the post-transfusion platelet count is lower than expected, PTR is suspected, which is an important issue especially in patients requiring frequent platelet transfusions such as hematological patients. Methods: The medical literature of published observational/investigational studies, randomized controlled trials or systematic reviews and meta-analyses regarding non-immune and immune PTR were searched in November 2020 and analyzed. Conclusions: PTR occurs in 30–70% of patients receiving transfusion due to various conditions of thrombocytopenia, with or without bleeding. The etiology of PTR can be separated into non-immune and immune. Non-immune PTR is more frequent than immune PTR, accounting for about two-thirds of refractory cases. If non-immune PTR is not appropriately diagnosed and managed, the subsequent platelet transfusions can elevate the risk of alloantibody production, leading to immune PTR. When PTR is suspected in patients receiving multiple platelet transfusions, potential causes of non-immune PTR should be promptly investigated prior to assessing alloimmunization profiles including anti-human leukocyte antigen (HLA) antibodies and platelet-specific alloantibodies. Appropriate management of non-immune PTR can consist of four steps: (I) Consider appropriate indication of platelet transfusion to avoid adverse events and alloimmunization, (II) investigate the causes of PTR, (III) select the best treatment plan according to the etiology of PTR, (IV) consider the coexistence of non-immune and immune causes.