Relationship between minimal residual disease on the 19th day and prognosis of children with acute B-lymphoblastic leukemia
Objective To explore the relationship between minimal residual disease(MRD)on the 19th day(D19)and prognosis of children with acute B-lymphoblastic leukemia(B-ALL),as well as the correlation with related biological changes.Methods A total of 88 children with B-ALL newly diagnosed in this hospital from April 2016 to April 2020 who met the enrollment conditions were analyzed for induction therapy D19 MRD,overall survival(OS)rate,event-free survival(EFS)rate,chromosome karyotype,fusion gene and mu-tation gene.MRD≥ 0.01%was considered positive,and they were divided into MRD positive group and MRD negative group.The characteristics of OS rate,EFS rate,immunophenotype and molecular biology/cytogenet-ics were compared between the two groups over a period of 3 years.Results The 3-year OS rate and EFS rate of 88 pediatric patients were 92.0%and 86.4%,respectively.The rates of OS rate and EFS rate in MRD posi-tive group were lower than those in MRD negative group,with statistical significance(P<0.05).The detec-tion rate of CD10 in MRD positive group was lower than that in MRD negative group,and the difference was statistically significant(P<0.05).Thirty-two patients(36.4%)detected 8 types of 35 fusion genes.The de-tection rates of BCR-ABL1 and E2A-PBX1 in MRD positive group were higher than those in MRD negative group,and the differences were statistically significant(P<0.05).Among 48 cases(54.5%)of pediatric pa-tients,41 types of 91 mutated genes were detected,and the remaining mutated genes were less than 5 cases.Abnormal karyotype was detected in 18 cases(20.5%),and no mitotic phase was detected in 17 cases.There was no difference in MRD between normal and abnormal karyotype.Binary Logistic regression analysis showed that BCR-ABL1 and E2A-PBX1 were prognostic factors of children with B-ALL.Conclusion The positive D19 MRD is the influential factor of adverse OS and EFS in children with B-ALL.Both E2A-PBX1 and BCR-ABL1 have adverse effects on the prognosis of children with B-ALL.