Effective November 22, 2021, Clinical Pathology Laboratories (CPL) will discontinue reference intervals and flagging for the relative percentage WBC differentials for unit codes 1000, 1001, 1007, 1013, 1015, and 1365. This is the final planned CBC reporting update.
Under most circumstances, clinically relevant WBC elevations and decreases are defined by absolute counts rather than relative percentages. Current recommendations from the College of American Pathologists (CAP) and the Clinical and Laboratory Standards Institute (CLSI), recommend that absolute counts of the WBC differential be reported and used for patient management.
Important notes:
- Current state-of-the-art CBC instrumentation assesses many 1000’s of WBC’s in automated differentials to provide higher accuracy and precision with shorter turn-around-time for the significant majority of samples.
- The analyzer algorithms interpret signals from WBC, RBC and platelet channels to alert laboratory scientists of an abnormal pathological specimen for manual assessment of smear morphology.
- On smear review, the laboratory has specific criteria to replace automated WBC differential with manual differential and morphology.
- In the event of a manual differential, the laboratory will also provide the more precise automated absolute WBC differential count for clinical use.
- After slide review, the technologist will note if criteria are met for pathologist slide review.
Please contact your Account Representative should you have any questions regarding the changes described above.