Sehayek E, Ben-Yosef N, Modan M, Chetrit A, Meytes D
Department of Hematology, Edith Wolfson Hospital, Holon, Israel.
Am J Clin Pathol. 1988 Oct;90(4):431-6. doi: 10.1093/ajcp/90.4.431.
Platelet characteristics were assessed in 15 patients with essential thrombocytosis (ET), 89 patients with reactive thrombocytosis (RT), and 23 normal controls. A platelet volume distribution width (PDW) greater than or equal to 10.5 was found in 50%, 21%, and 14% of the three groups, respectively (P = 0.01 between patients with ET and patients with RT; P = 0.02 between patients with RT and controls), reflecting an excess of extreme values at both ends of the distribution. Compared with controls, the increase in platelet number in patients with RT was about twofold throughout the platelet volume range, whereas ET was characterized by a fivefold increase in small platelets less than 7.5 fL and threefold increase in larger size platelets. Mean platelet volume (MPV) was significantly lower in patients with ET versus patients with RT and in patients with RT versus controls (mean +/- SD 7.5 +/- 1.2 vs. 8.8 +/- 0.1 and 10.2 +/- 1.8 fL, respectively, P less than 0.01). Rate of in vitro platelet aggregation greater than or equal to 50% was significantly lower in patients with ET versus patients with RT and in patients with RT versus controls (0%, 23%, and 45%, respectively, P less than 0.01). Aggregation rate was positively correlated with MPV (r = 0.54; P less than 0.0001). Aggregation rate in patients with ET was significantly lower (P = 0.01) than expected from their reduced MPV alone. Despite these group differences, the overlap of individual platelet characteristics between the three groups precludes their usefulness for diagnostic purposes.
对15例原发性血小板增多症（ET）患者、89例反应性血小板增多症（RT）患者和23名正常对照者的血小板特征进行了评估。三组中血小板体积分布宽度（PDW）大于或等于10.5的比例分别为50%、21%和14%（ET患者与RT患者之间P = 0.01；RT患者与对照者之间P = 0.02），这反映了分布两端的极值过多。与对照者相比，RT患者在整个血小板体积范围内血小板数量增加约两倍，而ET的特征是小于7.5 fL的小血小板增加五倍，较大尺寸血小板增加三倍。ET患者的平均血小板体积（MPV）显著低于RT患者，RT患者的MPV也显著低于对照者（平均±标准差分别为7.5±1.2、8.8±0.1和10.2±1.8 fL，P < 0.01）。ET患者体外血小板聚集率大于或等于50%的比例显著低于RT患者，RT患者也显著低于对照者（分别为0%、23%和45%，P < 0.01）。聚集率与MPV呈正相关（r = 0.54；P < 0.0001）。ET患者的聚集率显著低于仅根据其降低的MPV所预期的水平（P = 0.01）。尽管存在这些组间差异，但三组个体血小板特征的重叠使其在诊断方面缺乏实用性。
