Can you suggest utilization guidelines for repeat diffs on hematology oncology patients?
A. Katherine Galagan, MD, chief of pathology and director of clinical laboratories at Virginia Mason Medical Center, Seattle, answered a related question in the August 2008 issue of CAP TODAY, in which a reader asked whether there are accepted policies regarding the performance of repeated manual differential white blood cell counts for patients with persistent low total leukocyte counts. In her answer, Dr. Galagan referred to an article put forth by the International Society for Laboratory Hematology, in which an international group of 20 laboratorians suggested criteria for action following automated CBC and WBC differential analysis.1 For patients with repeated low leukocyte counts of <4.0 x 109/L, the group recommends a slide review (or manual differential) with the first low result and then a repeat slide review if the delta check fails within three days. The literature is rather sparse with respect to repeat manual differentials on oncology patients with very low WBC counts (<0.5
