Absolute versus proportional differential leucocyte counts

Comparison of absolute (cells x 10(9)/l) leucocyte differential counts with proportional (percentage) counts from the same stained films demonstrates significant disparities between these two methods of reporting results. Within reference intervals the disparities are modest but become significant in specimens with distributional abnormalities. Although neither method of reporting is formally espoused in this communication, it is suggested that use of the absolute count is more likely to provide diagnostic support.