“Peripheral Blood Neutrophil Nadir and Time to Platelet Recovery during
Induction Chemotherapy: Predictors of Clinical Outcomes and Markers for
Optimizing Treatment Intensity in Acute Lymphoblastic Leukaemia”
Abstract
During induction of Acute Lymphoblastic Leukaemia (ALL) cytopenias lead
to frequent toxicities, treatment interruptions, and higher mortality
rates. Blood count kinetics can also be potential markers of
chemotherapy efficacy and bone marrow recovery. Understanding kinetics
of blood counts and their association with clinical outcomes can help in
optimizing weekly chemotherapy schedule according to risk of toxicity.
243 cases were analysed and baseline data, nadir, time to recovery of
counts during induction, and survival outcomes were recorded. Median age
was 15 (1-62) years. Immunophenotype was B-ALL in 71%, T-ALL in 27%.
Good steroid response (D8) was seen in 89%, CR in 79%, and induction
mortality in 12%. Median neutrophil nadir was 0.06(0-0.49) *10
9/L and median day to nadir was D17. Median time to
partial and complete platelet recovery was D18 and D25. Late neutrophil
nadir (>D15) was independent predictor of refractory
disease [OR=5.43; p=0.042)], late partial platelet recovery
(>D22) was independent predictor of poorer EFS and OS (HR =
1.63 [p = 0.020] and HR = 1.5 [p = 0.044]. Validation of blood
count kinetics as independent predictors of post-induction and survival
outcomes provides neutrophil and platelet counts as a simple,
easy-to-use tool for balancing treatment efficacy-toxicity during
induction.