Analytic inaccuracy resulting from hematology specimen characteristics. Three cases of clinically misleading artifacts affecting white blood cell and platelet counts.

Sporadically, hematology analyzers generate grossly erroneous results for one or several parameters of the complete blood count (CBC) because of a characteristic or peculiarity of an individual patient specimen. This article presents three cases of relatively less well-known analytic errors of this sort, falsely elevating white blood cell count and platelet count and decreasing total white blood cell count, as determined on a Coulter Aperture Impedence Analyzer. The type of alteration in the CBC parameters and the instrument histogram abnormalities seen in each of these different types of analytic inaccuracy are discussed.