Serial Evaluation of T cell Subsets in Paediatric Acute Myeloid Leukaemia- a Prospective Study.

PURPOSE: There is paucity of data regarding T-cells in paediatric AML patients. The aim of this prospective study was to evaluate trend of T-cell subset during disease course of paediatric AML patients and to see its correlation with patient characteristics and survival outcome. METHODS: T-cell subsets (CD3, CD4 and CD8) were evaluated by flow-cytometry at diagnosis, post-induction, post-treatment completion, at 3 months and 6 months post-treatment completion, and relapse in 29 pediatric AML patients. Trend of T-cells was plotted between group A (those in continuous remission) and group B (those who relapsed) patients. RESULTS: Patients with high WBC count had significantly higher number of CD3, CD4 and CD8 cell. Baseline Tcell subsets did not affect CR, EFS and OS; however, higher than median CD4 count predicted improved DFS [58% vs 25%; HR = 0.306 (0.10-0.93); P = 0.037]. On serial follow-up from post-induction till 3 months after completion of therapy, there was no difference in the absolute values of T cell subsets between group A and B patients. CONCLUSION: Our study demonstrated T cell subsets are increased in AML subjects with high WBC count. CD4 cells have a positive impact on DFS. Serial follow-up has no impact on T cell subsets. Further studies in larger patient cohorts are needed to evaluate if CD4 population may serve as an immune biomarker for AML.