Reliable indicators that can predict drug responsiveness in primary immune thrombocytopenia (ITP) patients are urgent. We aimed to establish a reference interval of percentage of immature platelet fraction (IPF%) and absolute immature platelet count (A-IPC), and assess their efficacy in discriminating ITP patients from controls, especially their predictive value for responsiveness to drug treatment. We retrospectively studied 72 treatment-naive adult patients with ITP who received Dexamethasone monotherapy or combination therapy. Baseline (pretreatment) information was collected from medical records. Reference intervals for A-IPC and IPF% were established based on controls and their effectiveness in discriminating ITP patients from controls was assessed. Predictive value of pretreatment IPF% and A-IPC at four co-primary endpoints of treatment response in patients were investigated. The 95% reference intervals for A-IPC and IPF% were (2.7–15.6) × 10⁹/L and 1.2%–7.3%, respectively. Both A-IPC and IPF% had excellent discrimination ability for ITP patients from controls. It showed highly statistically significant differences in pretreatment A-IPC for predicting treatment response at day 7 between responders and non-responders, but not at days 14, 21 and 28. Pretreatment A-IPC had the higher area under the ROC curve with a cut-off of 0.86 than that of IPF% with a cut-off of 14.5% in predicting the treatment response in ITP patients at day 7. Pretreatment A-IPC exhibited acceptable predictive power and could be a promising predictor of response to short-term Dexamethasone monotherapy or combination therapy at day 7 in ITP patients.

迫切需要能够预测原发性免疫性血小板减少症（ITP）患者药物反应的可靠指标。我们的目的是建立未成熟血小板分数百分比 (IPF%) 和绝对未成熟血小板计数 (A-IPC) 的参考区间，并评估其区分 ITP 患者与对照组的功效，特别是其对药物治疗反应的预测价值。我们回顾性研究了 72 名接受过地塞米松单药治疗或联合治疗的初治成人 ITP 患者。从医疗记录中收集基线（治疗前）信息。A-IPC 和 IPF% 的参考区间是根据对照建立的，并评估了它们区分 ITP 患者和对照的有效性。研究了治疗前 IPF% 和 A-IPC 在患者治疗反应的四个共同主要终点上的预测价值。A-IPC 和 IPF% 的 95% 参考区间分别为 (2.7–15.6) × 10 ⁹ /L 和 1.2%–7.3%。A-IPC 和 IPF% 对 ITP 患者与对照组均具有出色的区分能力。结果显示，治疗前 A-IPC 在预测第 7 天有反应者和无反应者的治疗反应方面存在高度统计学显着差异，但在第 14、21 和 28 天则没有差异。治疗前 A-IPC 的 ROC 曲线下面积较高，且有切口在预测第 7 天 ITP 患者的治疗反应时，与 IPF% 相比，截断值为 0.86，截断值为 14.5%。治疗前 A-IPC 表现出可接受的预测能力，可能是短期地塞米松反应的有希望的预测因子ITP 患者在第 7 天进行单一疗法或联合疗法。