Trm.44925

[JClausen]

What are facilities doing to meet the following checklist item? Can anyone recommend a source for calibration material? We are a hospital based donor service and our apheresis platelets are tested undiluted in the hematology department on a Sysmex. The Sysmex was shown to be linear for the undiluted apheresis product samples.

Thanks

TRM.44925 Phase I

Are platelet counts on platelet components determined, when required, using a method that has been calibrated in the expected concentration range?

NOTE: Automated whole blood hematology analyzers may yield inaccurate, non-linear results in the range of platelet counts encountered in platelet components (generally 1-2,000,000/μL). Predilution of samples from components, alone, may not avoid this problem. The entire method used for determining platelet concentrations in platelet components (including any manual manipulations in addition to the automated instrument's functions) should be calibrated periodically using a preparation of known concentration (such as provided commercially or determined through a reference method).

[rcurrie]

We use the Sysmex with undiluted specimens also. The Sysmex, as you say, has been shown to be linear for undiluted apheresis components. We have done well on the CAP survey for platelet apheresis counts.

BC

[JClausen]

What will you be doing to satisfy the new CAP checklist item?

We also do the PT testing, etc, but the new standard says to calibrate for the higher counts.

We spoke with our Sysmex technical rep and were told that a calibrator in that range is not available any where. They also do not recommend calibrating with a higher count material as it could adversely affect our patient counts. I have sent this information to the CAP but have not yet heard from them. The issue is that the checklist item specifies "calibration" rather than linearity, PT testing, etc. We could use dilution to get the apheresis counts into the calibrated range, but it does not make sense to add error due to dilution if the system is linear at the higher counts.

Thanks

[rcurrie]

We dilute and repeat to verify the high counts. That's as good as it gets. The FDA is satisfied, and that would be my answer to any CAP inspector who might question our procedure. I gave myself an Attaboy on the self check. I am satisfied with our methods, and I am pretty discriminating.

BC

[Deb]

We also use the Sysmex for our platelet QC. Our hematology supervisor found a high end calibrator that she will have completed at each 6 month calibration to verify the upper end.

If you still need info on this, contact me at dschue@altru.org and I will put you in touch.

Deb