| Objectives:The object was to investigate the correlations between absolute lymphocyte counts(ALC)on the 8th,15th,22nd,and 28th day of induction chemotherapy and early minimal residual disease(MRD)in adolescent and adult acute B lymphoblastic leukemia(B-ALL).In addition,we explored the possible reasons above combined with lymphocyte subsets before and after chemotherapy.Methods:31 adolescent and adult patients with newly diagnosed B-ALL from June 2016 to January 2019 at the First Affiliated Hospital of Kunming Medical University were enrolled in the study.Lymphocyte subsets were collected at the time of initial diagnosis and 25-35 days after completing induction chemotherapy.In addition,lymphocyte subsets of 33 healthy subjects were selected as control group.All patients were administrated a VDP(vincristin,daunorubicin,prednisone)-based protocol as induction regimen.Then we explored the correlations between bone marrow MRD levels(>0.01%is positive,<0.01%is negative)on the 25th to 35th day after the end of induction chemotherapy and ALC during induction chemotherapy.The differences between the lymphocyte subsets at the time of initial diagnosis,after the end of induction chemotherapy,and in the control group were compared.Using SPSS.25 statistical software,the difference was statistically significant at P<0.05.Results:The patients with ALC<900/μl on day 15,and/or>500/μl on day 28 of induction chemotherapy were more likely to achieve MRD negative,while the differences were statistically significant(P=0.028,0.029,respectively).The proportion and absolute counts of CD3+CD4+T cells(CD4+T cells),CD 4+/CD8+ratio,the absolute counts of CD13-CD 16+CD56+NK cells(NK cells)in the newly diagnosed patients were all lower than those in the control group excluding the proportion of CD3+CD8+T cells(CD8+T cells),which was higher than the control group.Compared with the newly diagnosed patients,the percentage of CD3+T cells,CD8+T cells,and CD4+/CD8+ratio were increased in patients who remained MRD negative after treatment.While in MRD negative patients,the ratio of CD3+ T cells,the ratio and absolute counts of CD4+ T cells and NK cells were lower than the control group,which was contrary to the ratio of CD8+T cells.The differences were all statistically significant for the P values<0.05。Conclusions:A VDP-based induction chemotherapy regimen for adolescents and adults B-ALL,higher ALC on day 15 of induction chemotherapy suggest higher MRD levels which indicate poor prognosis;Instead,ALC on day 28 of induction chemotherapy>500/μl are associated with lower levels of MRD,suggesting a good prognosis.Therefore,on the 15th and 28th day of induction chemotherapy,ALC can be used as an indicator of disease prognosis.The main reason is related to the immunity of host,including CD8+T cells and NK cells. |
