Immature Reticulocyte Fraction and Absolute Neutrophil Count as Predictor of Hemopoietic Recovery in Patients with Acute Lymphoblastic Leukemia on Remission Induction Chemotherapy

OBJECTIVE: Acute lymphoblastic leukemia (ALL) encompasses a group of lymphoid neoplasms that are more common in children and arise from B-and T-lineage lymphoid precursor cells. The immature reticulocyte fraction (IRF), a new routine parameter in hematology analyzers, can give an indication of hemopoietic recovery like absolute neutrophil count (ANC). The purpose of this study was to evaluate IRF in excess of 5% was considered as IRF recovery. MATERIALS AND METHODS: In this descriptive study, 2.5 to 3 mL of EDTA blood of 45 ALL patients undergoing the remission induction phase of their treatment was sampled and analyzed with a Sysmex XE-5000 on day 1 and every second day thereafter until the day of recovery. ANC of >0.5x109/L on the day corresponding to the first of the three consecutive counts was considered as the day of ANC recovery. IRF recovery was an IRF in excess of 5%. RESULTS: The mean age of the patients was 12.04±5.30 years; 25 patients (55.6%) were male and 20 patients (44.4%) were female. On day 1 of induction remission, the mean IRF value was 9.68±1.41, while the mean ANC value was 0.077±0.061. Mean recovery day for IRF was 11.84±7.44 and mean recovery day for ANC was 17.67±8.77 (two- tailed p-value <0.0001 with 95% confidence interval). By day 28, out of 45 patients 36 (80%) showed ANC recovery, while 41 (91%) showed IRF recovery. The remaining patients who had not shown recovery by day 28 were further followed up and all of them showed recovery of both parameters by day 39. CONCLUSION: This study concluded that postinduction bone marrow hemopoietic recovery was earlier by IRF than ANC in children with ALL on chemotherapy.