Proposal of a new method to avoid misinterpretations in the evaluation of the leukergy test

The leukergy test has been widely used in recent years to detect the phenomenon of leucocyte aggregation in various clinical conditions. It is performed by processing some drops of blood on a slide. According to the authors proposing this test, the leucocyte aggregation is expressed as the mean of the number of aggregates detected among 300 cells of a randomly chosen tract of two slides. We noted, however, that significant differences in the percentage of leucocyte aggregates were sometimes detected between two different slides prepared from the same patient, and hypothesized that an unequal distribution of aggregates along the slide could explain this finding. To test this hypothesis we analysed separately the leucocyte aggregates of three tracts of equal size of blood smears taken from 20 patients. Three slides, numbered 1, 2 and 3, were prepared from each patient. The first tract run by the drops when placing them in the slide showed a significantly lower percentage of aggregates than the remaining tracts (p less than 0.01 post hoc Tukey test). We conclude that the distribution of aggregated leucocytes is unequal along the slide and that the evaluation of the phenomenon of leukergy should always include the count of aggregates of the proximal, intermediate and distal tract of each slide.