What condition precludes a donor from being accepted for plateletpheresis?

A platelet count of 75 × 10^9/L in a frequent platelet donor is a key factor that precludes a donor from being accepted for plateletpheresis. This is primarily because the minimum acceptable platelet count for donation is usually set at 150 × 10^9/L, ensuring that the donor's platelet levels remain safe and healthy after the donation process. Frequent donors may naturally have a lower platelet count due to repeated collections, which can cause them to fall below the threshold required for safe donation. Consequently, accepting a donor with a platelet count at this lower level could pose a risk to their health.

Other factors like plasma loss from plasmapheresis recently or recent aspirin ingestion don't impose as stringent restrictions for plateletpheresis as ensuring the donor has adequate levels of platelets is crucial. Similarly, a very short interval since the last plateletpheresis (like 4 days) is not typically a barrier compared to the fundamental requirement of maintaining a safe platelet count for the individual donor.