The effects of time from venepuncture and choice of anticoagulant on mean platelet volume estimations.

The Mean Platelet Volume (MPV) is a readily measured parameter using modern automated cell counters. Despite studies which indicate that MPV may be altered in various disease states, its widespread application has been hindered by its known dependence on factors such as time from venepuncture, choice of anticoagulant and sample storage temperature. In this report we describe the changes in MPV measured on a Technicon H1 analyser with time from sampling using two different anticoagulants under clinical laboratory conditions. Small changes in MPV with time were seen in both anticoagulants. These were statistically significant by Student's paired t-test but, on analysis of variance, were not significant compared with the variation in MPV between individuals. The well-documented effects of time, temperature and anticoagulant on MPV need not interfere with the interpretation of a result from a sample dealt with under similar conditions to those applying in this study.