Dynamic trajectory of platelet counts after the first cycle of induction chemotherapy in AML patients

Background Platelet counts varied over time after induction chemotherapy. We aimed to investigate the different trajectories of platelet counts after the first cycle of induction chemotherapy in patients newly diagnosed with acute myeloid leukemia. Methods and results In total, 149 individuals were included in this study. We identified four distinct trajectories using a group-based trajectory model: low- stability group (n = 27, 18.12%), low-level decrease-medium elevation group (n = 42, 28.19%), low-level decrease-high elevation group (n = 60, 40.27%), and high-level decrease-medium elevation group (n = 20, 13.42%). The baseline characteristics of the high-level decrease-medium elevation group included higher platelet count, lower white blood cell count, lower percentage of bone marrow blasts, and lower rates of complete remission after the first cycle of induction chemotherapy. Compared with the low-stability group, the hazard ratios were 0.32 (95% confidence interval, 0.15-0.68) for the low-level decrease-medium elevation group, 0.31 (95% confidence interval, 0.15-0.63) for the low-level decrease-high elevation group, and 0.35 (95% confidence interval, 0.13-0.89) for the high-level decrease-medium elevation group after adjustment for age and gender by Cox proportional hazard regression. Compared with the low-stability group, the hazard ratios were 0.33 (95% confidence interval, 0.14-0.77) for the low-level decrease-medium elevation group and 0.31 (95% confidence interval, 0.14-0.67) for the low-level decrease-high elevation group after adjustment for age, gender, white blood cell count, and bone marrow blasts. These associations persisted after adjusting for age, gender, white blood cell count, bone marrow blasts, and platelet count. Conclusion The dynamic trajectory of platelet counts after the first cycle of induction chemotherapy is a significant predictor of all-cause mortality in patients with acute myeloid leukemia. Timely intervention should be considered for the low-stability group. The low-level decrease-medium elevation and low-level decrease-high elevation groups were independent protective factors for all-cause mortality.