[Relationship between Peripheral Blood MiR-21 and Very Early Relapse after Chemotherapy in Children with Acute...

To analyze the relationship between microRNA-21 (miR-21) expression and the risk of very early relapse post-induction chemotherapy in children with acute lymphoblastic leukemia (ALL).

A total of 110 newly diagnosed children with ALL admitted to Huanggang Central Hospital from March 2020 to September 2022 were included. All patients received induction chemotherapy according to the CCLG-2008 protocol. The patients who achieved complete response (CR) after induction chemotherapy were followed up for 18 months, with very early relapse as the endpoint event. Then the patients were divided into a relapse group and a non-relapse group. Cox regression was used to analyze the influencing factors of very early relapse after induction chemotherapy in children with ALL. ROC curve and decision curve were used to evaluate the predictive value of peripheral blood miR-21 for very early relapse after induction chemotherapy in children with ALL. Restricted cubic splines were used to analyze the dose-response relationship between peripheral blood miR-21 and very early relapse after induction chemotherapy in children with ALL.

A total of 102 children with ALL achieved CR after induction chemotherapy, among whom 24 cases (23.53%) experienced very early relapse, with a median relapse time of 14 months. The proportions of patients with high-risk stratification at initial diagnosis, extramedullary infiltration, and minimal residual disease (MRD) positivity were significantly higher in the relapse group than those in the non-relapse group; The absolute lymphocyte count (ALC) in peripheral blood was significantly lower, while the expression levels of miR-21 and lactate dehydrogenase (LDH) were significantly higher in the relapse group compared with the non-relapse group (all P <0.05). Cox regression analysis showed that very early relapse after induction chemotherapy in children with ALL was associated with medium risk and high risk at initial diagnosis, extramedullary infiltration, decreased ALC in peripheral blood, MRD positivity, as well as high expression levels of miR-21 and LDH (all P <0.05). ROC curve analysis indicated that the area under the curve (AUC) of peripheral blood miR-21 for predicting very early relapse after induction chemotherapy in children with ALL was 0.800, with an optimal cutoff value of 4.830. Restricted cubic spline analysis revealed that there was a non-linear dose-response relationship between peripheral blood miR-21 and the risk of very early relapse after induction chemotherapy in children with ALL. When the expression level of peripheral blood miR-21 exceeded 4.830, the risk of very early relapse increased with the elevation of miR-21 expression. Decision curve analysis demonstrated that combining peripheral blood miR-21 with other risk factors enhanced the predictive performance for the risk of very early relapse after induction chemotherapy in children with ALL.

Very early relapse after induction chemotherapy in children with ALL is associated with elevated expression of miR-21 in peripheral blood, and high expression of miR-21 may increase the risk of very early relapse. Detecting miR-21 before induction chemotherapy has predictive significance for very early relapse in children with ALL, and combining it with other risk factors can improve the predictive efficacy.