Lee Yoon Kyung, Yoon Hoi Soo, Lee Eun Hye, Cho Sun Young
Clin Lab. 2021 Mar 1;67(3). doi: 10.7754/Clin.Lab.2020.200715.
Mean platelet volume (MPV) is considered a marker of platelet function and is known to increase in immune thrombocytopenia (ITP). We aimed to investigate the predictive value of MPV for predicting the clinical course of ITP in children.
We retrospectively analyzed children aged < 18 years with ITP (n = 36) and healthy controls (n = 36) from June 2010 to November 2018. The subjects were stratified into: (i) Healthy controls [group I, n = 36]; (ii) Newly diagnosed ITP (nITP) and persistent ITP (pITP) [group II, n = 24]; and (iii) Chronic ITP (cITP) [group III, n = 12]. Hematological indices including MPV were measured and compared between the three groups.
The median MPV values at diagnosis in group I, II, and III were 7.20, 8.15, and 8.65 fL, respectively (p = 0.0004). Cutoff value of MPV at diagnosis differentiating group I from group II + III was 7.6 fL, and group II from group III was 8.7 fL. MPV change (ΔMPV after three months minus MPV at diagnosis) in children with nITP and pITP (n = 22) was greater than in those with cITP (n = 6) (-2.18 fL vs. 0.66 fL, p = 0.0059).
This study revealed that group III had a higher MPV than group II at diagnosis. Therefore, an initial MPV value more than 8.7 fL may be used as a predictive factor for chronicity in children with ITP. The change in MPV over time as well as MPV at diagnosis, may be regarded as a prognostic marker to predict the course of ITP in children.
平均血小板体积（MPV）被认为是血小板功能的一个指标，并且已知在免疫性血小板减少症（ITP）中会升高。我们旨在研究MPV对预测儿童ITP临床病程的价值。
我们回顾性分析了2010年6月至2018年11月期间年龄小于18岁的ITP患儿（n = 36）和健康对照者（n = 36）。将研究对象分为：（i）健康对照组[I组，n = 36]；（ii）新诊断的ITP（nITP）和持续性ITP（pITP）[II组，n = 24]；以及（iii）慢性ITP（cITP）[III组，n = 12]。测量并比较三组之间包括MPV在内的血液学指标。
I组、II组和III组诊断时的MPV中位数分别为7.20、8.15和8.65 fL（p = 0.0004）。诊断时区分I组与II + III组的MPV临界值为7.6 fL，区分II组与III组的临界值为8.7 fL。nITP和pITP患儿（n = 22）的MPV变化（诊断后三个月的MPV减去诊断时的MPV）大于cITP患儿（n = 6）（-2.18 fL对0.66 fL，p = 0.0059）。
本研究显示III组在诊断时的MPV高于II组。因此，初始MPV值大于8.7 fL可作为儿童ITP慢性化的一个预测因素。MPV随时间的变化以及诊断时的MPV，可被视为预测儿童ITP病程的一个预后标志物。
