A Methodical Approach to Interpreting the White Blood Cell Parameters of the Complete Blood Count

Consistent use of a methodical approach to interpreting complete blood count (CBC) results can help detect spurious results that require remedy before results are reported. It can also help ensure that no clinically important information is overlooked during diagnostic interpretation of the results. The steps for interpreting the white blood cell portion of the CBC are: Ensure that nucleated red blood cells or other conditions are not falsely affecting the white blood cell count (WBC); correct the WBC if needed, before proceeding. Examine the WBC for variations in the total number of white blood cells. Interpret absolute differential counts against appropriate reference intervals using proper terminology. If absolute counts are not available from an instrument, use relative counts (i.e. percentages) to calculate absolute values. Make note of immature cells in any leukocyte cell line reported in the differential that should not appear in normal peripheral blood. Make note of any morphological abnormalities of wbcs. Correlate the wbc findings with red blood cell and platelet findings for a complete clinical assessment of the patient's blood picture. Explanations for conducting the evaluations are provided and the above steps are applied to example cases to demonstrate how this approach is used to interpret the wbc parameters of the CBC. ABBREVIATIONS: CBC - complete blood count, dL-deciliter, fL-femtoliter, g-gram, NRBC-nucleated red blood cell, rbc-red blood cell, RNA-ribonucleic acid, wbc-white blood cell, WBC-white blood cell count, μL-microliter