platelet counts on apheresis products

[Mary Stewart Wesson]

When is everyone doing the sampling for platelet counts on apheresis products? Are you counting on Day 0 or are you waiting until you're ready to do the bacterial testing?

[Cliff]

We collect about 4000 pheresis a year. We measure on day 0.

We often feel it might be better to measure on day one after they have rocked for a day, but the few times (not scientific) that we have needed to measure on day one also, the counts are not always higher as I hypothesized.

[Deb]

We too collect the product QC sample on day 0 for our apheresis products. As these products are not centrifuged into a hard pellet like random donors, they should generally be well suspended at the end of collection. If we want a WBC count for QC we definitely do it on Day 0. If we see alot of clumping in the product....we let them rest for 1-3 hours before sampling (making sure they are very well suspended).

We have on occasion re-sampled after 12 or so hours of resuspension (ie. Day 1) if we don't believe the original QC plt yield....but unless the hematologist forgot to multiply out a dilution factor, the counts are almost always really close together.