[The Relationship between Speed of Platelet Recovery and Its R-squared and Efficacy after First Induction...

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.

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.

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).

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.