Population-based platelet reference values for an Iranian population.

There are a few reports regarding the reference range for platelet indices in the populations of Iran and its neighbouring countries, but these studies were of small sample size. This study aimed at defining platelet reference values for medical research and practice. A cross-sectional survey was performed on 19,993 young adult Iranians who participated in a compulsory pre-marriage screening programme over a 6-month period. Platelet indices were measured using an automated Technicon H2 cell counter. The platelet count [given as 95% reference interval (2.5 percentile-97.5 percentile) and mean +/- standard deviation] were 145-356 x 10(9)/l (237 +/- 55.2); the platelet distribution width was 40.2-57.4% (46.9 +/- 5.7) the Plateletocrit was, 0.13-0.32% (0.22 +/- 0.05) and the mean platelet volume was 7.4-10.7 fl (9.2 +/- 2.9). The first three indices showed significant differences between males and females. The reference values of platelet indices in Iranians were found to be different from international data; they were a little lower than those in Caucasians but higher than the indices found for Africans.