Minimal Residual Disease in Pediatric Acute Lymphoblastic Leukemia

Background and ObjectiveThe detection of minimal residual disease at the end of initial therapy in Acute Lymphoblastic Leukemia to assess risk stratification is gaining clinical significance. While minimal residual disease assesses the extent of remission, remission is still defined by bone marrow morphology. The aim of this study is to determine the significance of minimal residual disease. Methods: In this cross-sectional study conducted at Zheen Oncology Center and Azadi hospital in Duhok, Iraq, data was collected from 46 patients’ records. Residual disease was detected by flow cytometry. On day 29 of induction therapy, a bone marrow sample was obtained for morphology and flow cytometry. The presence or absence of MRD was determined by using 8-color flow cytometry. Results: The median age of the study was 7 years and the male to female ratio was 1.7:1. B-cell lymphoblastic leukemia accounted for 80.43% and T-cell was 19.57%. Bloodounts at diagnosis revealed a mean white blood cell count of 74.32 x /L, mean hemoglobin level of 8.75, g/dL, and a mean platelet count of 97.84 x L. Minimal residual diease positive results were seen in 29 cases; 21 cases were of B-cell leukemia (56.75) and 8 (88.88) cases were T-cell leukemia. Minimal residual disease negative results were achieved in 17 cases; 43.24% were of B-cell origin (p value <0.001), 11.11% were of T-cell origin (p value 0.008). Remission was achieved in 81.08 cases of B-cell (p value 0.103), and 66.66 of T-cell (p value 0.403). 16.21% of B-cell leukemia passed away (p value <0.001) and 33.33% of T-cell leukemia (p value 0.065). Conclusion: Flow cytometry should be done in addition to bone marrow morphology.