Frequent plateletpheresis does not clinically significantly decrease platelet counts in donors.

BACKGROUND

In October 2005, the US Food and Drug Administration (FDA) issued draft guidance on collecting platelets (PLTs) by automated methods. The FDA proposed limiting collections to 24 components, rather than 24 procedures, annually with up to 3 components per procedure. The rationale was from literature suggesting frequent PLT collection resulted in significant declines in donor PLT counts. Additional requirements for minimal interdonation intervals were proposed.

STUDY DESIGN AND METHODS

Plateletpheresis records at a regional blood center with predonation PLT counts were used to assess the impact of the restriction on PLT collections. They were reviewed to demonstrate the effects of collection frequency, number of products collected, and interdonation interval on donor PLT counts. Total protein and albumin levels were compared in a subset of 24-times-per-year PLT donors and control whole-blood donors.

RESULTS

A limit of 24 components would require replacement of approximately 20 percent of the donor base to recover lost components. No clinically important decrease in PLT counts before donation was seen in donors donating multiple PLT components up to 24 times per year, regardless of interdonation interval. No frequent donor was deferred for a PLT count less than 150 x 10(9) per L. Short interdonation intervals were associated with statistically but not clinically important decreases in PLT counts. Protein levels were not distinguishable between PLT donors and controls.

CONCLUSION

The proposed restrictions are not required to prevent thrombocytopenia in frequent PLT donors and would adversely impact the supply of apheresis PLTs. Protein levels are maintained in these high-frequency donors.