The argument(s) for lowering the US minimum required content of apheresis platelet components

T he Platelet Dose (PLADO) study demonstrated that in hospitalized hematology/oncology patients, the use of low platelet doses (1.1 × 10/ m body surface area [BSA], equivalent to about 2.1 × 10/bag for a 70 kg patient) that were generally lower than the minimum US content requirement for apheresis platelets (≥3.0 × 10/unit) led to lower per-patient total number of platelets transfused than with higher doses. There was no impact on patient safety or on clinically significant bleeding. Twofold (2.2 × 10/m) and fourfold (4.4 × 10/m) higher doses increased the posttransfusion platelet count increments, decreased the number of platelet components (PCs) transfused, and prolonged the intertransfusion intervals, at the cost of consumption of a higher total number of transfused platelets per patient. Based on these data, some institutions now routinely provide one-half or variable low-platelet content units to selected patient groups. Furthermore, the US Food and Drug Administration (FDA) has licensed blood centers to ship variable-content conventional and pathogen-reduced platelets with platelet counts lower than 3.0 × 10 for interstate commerce. The current minimum apheresis PC content of 3.0 × 10/unit or more required by the FDA for quality control purposes is empirically derived based on historical manufacturing standards and is not required for pooled whole blood (WB)-derived PCs. The United States should consider the advantages of reducing its apheresis PC minimum content standard to align with international practice (≥2.5 × 10 platelets, an approx. 17% decrease from the US standard), to increase the number of units in inventories and/or reduce the pressure on blood donors, and to meet current demands that may exceed the available supply. This change would also help to compensate for the increased processing losses necessary to implement bacterial risk mitigation strategies such as large volume cultures and pathogen reduction technology. Simultaneously, a requirement to label every PC with the actual platelet content would allow clinicians to more accurately correlate and predict clinical outcomes with the platelet dose transfused.