| Objective:NPM1(Nucleophosminl,nucleophosmin gene 1)is one of the common gene mutations in acute myeloid leukemia(AML).Studies have shown that NPM1 mutations in AML patients have relatively unique clinical features and prompt good prognosis.This project aims to analyze the clinical characteristics,survival rate,and prognosis of NPM1 mutations in children with AML in our hospital and provide informations for the diagnosis,treatment and prognosis of children with AML.Methods:Using a retrospective approach,a total of 97 newly diagnosed children with AML from July 1,2015 to December 31,2017 in the Department of Hematology,Kunming Children's Hospital(Kunming Medical University Children's Hospital),were selected as the study subjects.Statistical analysis of NPM1 gene mutation rate,age,gender,risk,peripheral blood leukocyte count,hemoglobin,platelet count,ratio of peripheral blood immature cells,proportion of bone marrow blasts,liver and kidney function after chemotherapy,blood after chemotherapy Routine parameters and disease-free survival time,comprehensive analysis of the clinical significance of NPM1 gene.Results:1.A total of 97 cases of childhood AML were collected in this study.There were 9 NPM1 gene mutations and the mutation rate was 9.3%in the total cases.The distribution of NPM1 positive in each subtype was as follows:M1 had 1 case,M2 had 2 cases,M4 had 2 cases,M5 had 3 cases,M6 had 1 case and 9 cases in total.The results suggested that NPM1 mutations were more likely to appear in M5 subtype.2.In this study,there were 50 male patients and 47 females.There were 3 males(33.3%)and 6 females(66.7%)in the NPM1 positive group;The average age of NPM1 positive group was 115.33±46.77 months at the initial diagnosis,and 98.88±42.46 months of NPM1 negative group.There was no significant difference between the two groups(P>0.05).3.In this study,there was no significant difference in white blood cell count(51.86±39.10×109/L,54.49±171.55×109/L,P>0.05),hemoglobin concentration(81.22±22.67g/L,81.20±15.61g/L,P>0.05),platelet count(62.22±47.19×109/L,62.38±86.48×109/L,P>0.05),ratio of peripheral blood immature cells(34±33%,39±28%,P>0.05),and percentage of bone marrow blasts(39±18%,48±19%,P>0.05)between the NPM1-positive group and the NPM1-negative group at the time of initial diagnosis.4.Among 65 children with AML who were not M3,in the NPM1 positive group 5 patients(55.6%)were at low risk,2(22.2%)were at moderate risk,2(2.2%)were at high risk,;In the NPM1 negative group,12 cases were at low risk group(21.4%),moderate risk 19 cases(33.9%),high risk 25 cases(44.6%);NPM1 positive group and negative group had no significant difference in the distribution of risk(P>0.05).5.Check liver function after chemotherapy,select AST(U/L),ALT(U/L),AST/ALT,DBIL(umol/L)as reference value.The respective average values of the above parameters in the NPM1 positive group were 36.61±20.49,20.44±26.50,2.77±1.43 and 3.07±1.07;The abovementioned datas for the negative group were 29.60±15.94,16.81±14.66,2.52±1.73,2.96±1.68.The kidney function was selected as the reference value for urea(mmol/L),uric acid(umol/L),urea/uric acid,and creatinine(umol/L).The average value of each parameter in the NPM1 positive group is 3.36±1.36,293.00±100.07,0.0132±0.0078,21.12±8.78;In the negative group,the above parameters were 3.58±1.65,314.89±115.38,0.0121 ±0.0051 and 30.10±14.30;After chemotherapy,There was no significant difference in white blood cell count,neutrophil count,hemoglobin,platelet count between NPM1 positive group and negative group.6.Completion of first course(DAE)chemotherapy and review of bone marrow on day 28,in the NPMl-positive group,7 patients(77.8%)had complete bone marrow remission,and 2 patients(22.2%)had unremission of bone marrow;In the NPM1 negative group,there were 21 cases(53.6%)of complete bone marrow remission,19 cases(19.6%)partially relieved,and 16 cases(26.8%)did not relieved.In comparison between the two groups,the bone marrow response rate of the NPM1 positive group was significantly better than that of the NPM1 negative group(P<0.05).After the second course of chemotherapy(IAE),the results of the NPM1-positive group were the same as the previous course of treatment;In the NPM1 mutation-negative group,15(26.8%)had no remission,11(19.6%)had partial remission,and 30(53.6%)had complete remission,the difference between the two groups of data was not statistically significant(P>0.05).After long-term follow-up,2 of the NPM1-positive patients died(22.2%),7 patients survived(77.8%),8 patients(14.3%)in the NPM1-negative group had died,and 3 patients(5.4%)relapsed Another 3(5.4%)were lost to follow-up.Conclusions:1.The NPM1 mutation rate in 97 children with AML in this study was 9.3%,similar to the reported mutation rate of European(11%),but higher than that in Russia(5.2%)and Argentina(4.2%)regions.2.In this study the NPM1 gene mutations are more common in the M5 subtype,followed by the M4 subtype,but rare in the M3 subtype.The result is similar to the distribution of NPMl mutation in adults(common in the M4 and M5).However,NPM1 mutations in children's AML have been reported more common in M2 subtype in some domestic studies.3.In this study,there was no significant difference in the distribution of gender and age between the positive and negative group(P>0.05).Which is different from the conclusion reported by the past research that NPM1 is more likely to appear in female patients and in older patients.4.In this study,the white blood cell counts,hemoglobin,platelet counts,percentage of immature cells in peripheral blood,and percentage of blast cells in bone marrow of AML patients with NPMl mutation were not significantly different from those of negative group.It was not consistent with the characteristics of high WBC counts,high platelet counts,and high percentage of naive cells in adults with NPM1 mutation.5.In this study,there was no significant difference in liver function,renal function,and myelosuppressive blood counts in children with AML from the NPM1 positive group after chemotherapy compared with the NPM1 negative group.6.In this study,NPM1 mutations were found in children with normal karyotypes,consistent with the conclusions reported by domestic and foreign researchs that NPM1 tends to appear in normal karyotype.7.In this study,the early CR rate of children with AML with NPM1 mutation alone are superior to those without NPM1 mutations;The DFS rate in the NPM1 positive group was slightly higher than that in the NPM1 negative group,but there was no statistical significance between the two groups of data and its long-term prognosis was affected further discussion. |
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