Objective: To calculate the cut-off values of speed of platelet recovery and its R-squared in patients with acute myeloid leukemia (AML) after initial induction chemotherapy, which were used to predict the complete remission (CR) of the first induction chemotherapy, and guide the clinic to choose the next appropriate chemotherapy regimen as soon as possible.
Methods: A total of 117 patients with newly diagnosed AML in the Second Hospital of Shanxi Medical University were included. Patients were diagnosed by morphology, immunology, cytogenetics, and molecular biology (MICM) classification, and the risk stratification was evaluated in combination with the clinical situations of the patients at the time of admission. The peripheral platelet counts after the first induction chemotherapy were detected and the linear regression equation was used to calculate the recovery speed of platelet counts in 5 consecutive blood cell analysis before discharge. According to the ROC curve, the cut-off value between the recovery speed and the R-squared was calculated, and the cut-off value was used to divide the patients into different groups. The differences between groups were compared by Pearson χ2 test to observe the remission effect of the first induction chemotherapy.
Results: ROC curve analysis showed that the cut-off value for predicting the platelet recovery speed and its R-squared of the first induction chemotherapy to achieve remission was 4.059 5×109/(L·d) and 72.7%, the sensitivity was 77% and 63.9%, the specificity was 62.5% and 67.9%, and the Youden index was 0.395 and 0.318, respectively. The patients were divided into different groups and compared according to the above cut-off values, and the results showed statistical differences (P<0.001, P=0.001).
Conclusion: The cut-off value of platelet recovery speed and its R-squared after the first induction chemotherapy calculated by peripheral platelet count and ROC curve in AML patients can be used as an index to evaluate the remission. The faster the platelet recovery speed after chemotherapy is, the more likely patients achieve remission. The more stable the platelet recovery tendency is, the more likely patients achieve remission too.
题目: 急性髓系白血病首次诱导化疗后血小板恢复速度及其线性拟合度与化疗疗效的关系研究.
目的: 计算急性髓系白血病（AML）患者初次诱导化疗后血小板恢复速度及其线性拟合度的分界值，用于预测首次诱导化疗缓解情况，指导临床合理选择下一步化疗方案。.
方法: 纳入山西医科大学第二医院初诊AML患者117例，诊断采用MICM分型，结合患者入院时血象、年龄及合并症等综合评估危险分层。检测患者首次诱导化疗后外周血小板计数并利用线性回归方程计算出院前连续5次血细胞分析中血小板计数的恢复速度。根据ROC曲线计算恢复速度与线性拟合度的分界值，并以其分界值为界将入组的AML患者分组，利用Pearson χ2检验比较组间差异，判断首次诱导化疗缓解效果。.
结果: 使用ROC曲线分析得到预测首次诱导化疗达到缓解状态的血小板恢复速度的分界值为4.059 5×109/（L·d），灵敏度为77%，特异度为62.5%，约登指数为0.395；预测首次诱导化疗达到缓解的线性拟合度的分界值为72.7%，灵敏度为63.9%，特异度为67.9%，约登指数为0.318。根据上述分界值将患者分组并进行比较，结果显示，组间患者缓解情况比较差异均具有统计学意义（P<0.001，P=0.001）。.
结论: 应用外周血小板计数和ROC曲线计算得到的首次诱导化疗后AML患者血小板恢复速度及其线性拟合度的分界值可作为评价患者缓解的指标。化疗后血小板恢复速度越快，患者越可能达到缓解，血小板在恢复过程中的增长趋势越稳定，患者也越可能达到缓解。.
Keywords: induction chemotherapy; acute myeloid leukemia; platelet recovery speed; remission.