ABSTRACT
Objective@#To investigate the clinical features of adult B-cell acute lymphoblastic leukemia (B-ALL) with E2A-PBX1 fusion gene positive.@*Methods@#The clinical data of 91 Philadelphia chromosome negative B-ALL patients who received chemotherapy regularly in Nanfang Hospital of Southern Medical University from March 2015 to December 2017 were collected. According to the fusion gene detection results, the patients were divided into E2A-PBX1 fusion gene positive group and E2A-PBX1 fusion gene negative group. The clinical features and prognosis of both groups were retrospectively analyzed. And then E2A-PBX1 fusion gene negative group was further divided into MLL-AF4 fusion gene positive group and the other ALL groups,which were compared with E2A-PBX1 fusion gene positive group in the prognosis.@*Results@#There were 11 ALL patients with E2A-PBX1 fusion gene positive, and 80 ALL patients with E2A-PBX1 fusion gene negative. The level of lactic dehydrogenase (LDH) in E2A-PBX1 fusion gene positive group was higher than that in E2A-PBX1 fusion gene negative group [4 063 U/L (1 070- 9 554 U/L) vs. 454 U/L (103- 18 651 U/L), U=-4.700, P < 0.01], and there were no statistically significant differences in age, gender, white blood cell count and extramedullary invasion (all P > 0.05). The immunophenotypes of ALL patients with E2A-PBX1 fusion gene positive were all common B-cell phenotype. Out 4 of 7 ALL patients showed the different expression of Philadelphia-like ALL phenotype CRLF2 or phosphorylated CRKL or phosphorylated STAT5 by using flow cytometry. The complete remission (CR), minimal residual disease (MRD)-negative and the recurrence for 11 cases of E2A-PBX1 fusion gene positive group included 9, 7, 8 cases, respectively after first course of induction chemotherapy. The CR, MRD-negative and the recurrence for 80 cases of E2A-PBX1 fusion gene negative group included 71, 53, 26 cases, respectively after the first course of induction chemotherapy. There were no statistically significant differences in the CR and MRD-negative between the two groups after the first course of induction chemotherapy (P= 0.721, P= 0.487), but there was a statistical difference in the recurrence (χ2= 7.751, P= 0.012). The median follow-up time was 17 months (1-44 months), and the 1-year overall survival (OS) rate and 1-year event-free survival (EFS) rate of E2A-PBX1 fusion gene positive ALL group were lower than those of the negative group (OS: 43.6% vs. 70.0%, P= 0.020; EFS: 13.6% vs. 60.0%, P= 0.002). Subgroup analysis showed that there were no statistical differences between E2A-PBX1 fusion gene positive group and MLL-AF4 fusion gene positive group in 1-year OS rate and 1-year EFS rate (P= 0.617, P= 0.984).@*Conclusions@#E2A-PBX1 fusion gene positive rate is low in adult B-ALL patients with a good response to traditional chemotherapy in the early stage, but its cumulative recurrence rate is high. It is a high-risk cytogenetic abnormality which is similar to MLL gene rearrangement and needs to explore novel therapy strategies.
ABSTRACT
Objective To investigate the clinical features of adult B-cell acute lymphoblastic leukemia (B-ALL) with E2A-PBX1 fusion gene positive. Methods The clinical data of 91 Philadelphia chromosome negative B-ALL patients who received chemotherapy regularly in Nanfang Hospital of Southern Medical University from March 2015 to December 2017 were collected. According to the fusion gene detection results, the patients were divided into E2A-PBX1 fusion gene positive group and E2A-PBX1 fusion gene negative group. The clinical features and prognosis of both groups were retrospectively analyzed. And then E2A-PBX1 fusion gene negative group was further divided into MLL-AF4 fusion gene positive group and the other ALL groups, which were compared with E2A-PBX1 fusion gene positive group in the prognosis. Results There were 11 ALL patients with E2A-PBX1 fusion gene positive, and 80 ALL patients with E2A-PBX1 fusion gene negative. The level of lactic dehydrogenase (LDH) in E2A-PBX1 fusion gene positive group was higher than that in E2A-PBX1 fusion gene negative group [4 063 U/L (1 070 - 9 554 U/L) vs. 454 U/L (103 -18 651 U/L), U ＝-4.700, P<0.01], and there were no statistically significant differences in age, gender, white blood cell count and extramedullary invasion (all P＞ 0.05). The immunophenotypes of ALL patients with E2A-PBX1 fusion gene positive were all common B-cell phenotype. Out 4 of 7 ALL patients showed the different expression of Philadelphia-like ALL phenotype CRLF2 or phosphorylated CRKL or phosphorylated STAT5 by using flow cytometry. The complete remission (CR), minimal residual disease (MRD)-negative and the recurrence for 11 cases of E2A-PBX1 fusion gene positive group included 9, 7, 8 cases, respectively after first course of induction chemotherapy. The CR, MRD-negative and the recurrence for 80 cases of E2A-PBX1 fusion gene negative group included 71, 53, 26 cases, respectively after the first course of induction chemotherapy. There were no statistically significant differences in the CR and MRD-negative between the two groups after the first course of induction chemotherapy (P ＝ 0.721, P ＝ 0.487), but there was a statistical difference in the recurrence (χ2 ＝ 7.751, P ＝ 0.012). The median follow-up time was 17 months (1-44 months), and the 1-year overall survival (OS) rate and 1-year event-free survival (EFS) rate of E2A-PBX1 fusion gene positive ALL group were lower than those of the negative group (OS: 43.6% vs. 70.0%, P ＝0.020;EFS: 13.6% vs. 60.0%, P ＝ 0.002). Subgroup analysis showed that there were no statistical differences between E2A-PBX1 fusion gene positive group and MLL-AF4 fusion gene positive group in 1-year OS rate and 1-year EFS rate (P ＝ 0.617, P ＝ 0.984). Conclusions E2A-PBX1 fusion gene positive rate is low in adult B-ALL patients with a good response to traditional chemotherapy in the early stage, but its cumulative recurrence rate is high. It is a high-risk cytogenetic abnormality which is similar to MLL gene rearrangement and needs to explore novel therapy strategies.
ABSTRACT
The translocation of(1;19)(q23;p13)leading to E2A-PBX1 gene fusion,is one of the most common translocations in pediatric B-ALL. Fusion of the E2A-PBX1 gene forms a specific transcription factor activating the pre-B cell receptor,allowing the pre-B cells to self-renew. This process acts as a leukemia initiation factor. Simultaneously,it can combine a second mutation to activate the genetic damage activating kinase driven signaling pathway. Thereby clonality of precursor B cells proliferated abnormally,which will lead to the occur-rence of leukemia. This article summarizes the secondary mutations and kinases associated with E2A-PBX1 posi-tive recurrent patients,and provides help for targeted therapy in recurrent patients.
ABSTRACT
Las leucemias agudas representan un grupo heterogéneo de hemopatías malignas que pueden ser de origen linfoide o mieloide en dependencia del clon celular que da lugar al proceso maligno. Sin embargo, existen casos de leucemias agudas con fenotipo mixto donde coexisten características propias de más de un linaje celular y que se conocen hoy como leucemias agudas de fenotipo mixto. Se presenta el caso de un paciente que se diagnosticó como una leucemia aguda híbrida linfoide B/mieloide mediante citometría de flujo. Se encontró la presencia del gen de fusión E2A-PBX1 que se forma como consecuencia de una traslocación entre los cromosomas 1 y 19. El paciente, un niño de 20 meses de nacido, falleció a los 12 días de iniciados los primeros síntomas clínicos. Se conoce que esta anormalidad cromosómica está asociada a un pronóstico desfavorable, principalmente por la grave afectación del sistema nervioso central como en efecto ocurrió. Hasta donde se alcanzó a revisar, no se encontró un reporte similar en la literatura de una leucemia aguda híbrida linfoide B/mieloide positiva al gen defusión E2A-PBX1(AU)
The acute leukemias are an heterogenous group of malignant hemopathies diseases characterized by excessive proliferation of an inmature cellular clon. Depending of the myeloid or lymphoid origin of such clon, the acute leukemia could be classified in myeloid or lymphoid respectivement. However, there are cases of acute leukemias with mixed phenotype where immunologic markers of more than on elineage are present. In the patient of this report was founded a mixed immunophenotype pattern by flow cytometry and the entity was classified as acute hybrid lymphoid B/ mieloid leukemia. Basedon theinicial diagnostic of acutelymphoidleukemia, the molecular studydiscoveredthepresence of E2A-PBX1 fusion gen. That molecular anomaly is formed as consequence of a traslocation between the1 and 19 chromosomes. The patient, a child of 20 months, died 12 days afte rthe first clynic symptoms begining. E2A-PBX1 fusion gen is associated to unfavorable outcome, mainly because the severe damage at the central nervous system as in fact it occurred. Until it was possible review, no any similar report was founded about a case of acute hybrid lymphoidB/myeloid leukemia positive to the E2A-PBX1 fusion gen(AU)
Subject(s)
Humans , Male , Infant , Leukemia, Biphenotypic, Acute/complications , Leukemia, Biphenotypic, Acute/diagnosis , Leukemia, Biphenotypic, Acute/immunology , Case Reports , Leukemia, Biphenotypic, Acute/mortalityABSTRACT
PURPOSE: We studied the E2A-PBX1 positivity in t(1;19)-positive childhood acute lymphoblastic leukemia (ALL) patients during chemotherapy and follow-up period to evaluate the clinical implications of minimal residual disease (MRD) and the effect of delayed intensification chemotherapy on long-term survival. METHOD: Fifty-six bone marrow or peripheral blood samples collected retrospectively or prospectively before or during chemotherapy from 14 childhood ALL patients who had t(1;19) or E2A-PBX1 transcript at initial diagnosis were studied for the presence of E2A-PBX1 by RT- PCR. All patients received delayed intensification chemotherapy regardless of standard prognostic grouping for childhood ALL to evaluate its effect on the improvement of long-term survival. RESULTS: There were 11 t(1;19)-positive cases documented by karyotyping and 3 E2A-PBX1 transcript-positive cases amplified by PCR from the initial bone marrow samples. There were 11 cases of FAB L1 and 3 cases of L2. Immunophenotypic classification revealed 10 cases of group V, 2 cases of group IV, and 1 case of group III. Among 11 cases with documented karyotype, 9 cases (81.8%) had der(19)t(1;19) and the other 2 had balanced t(1;19). Fifty-six samples collected at 2 to 7 different time points of 14 patients revealed 4 cases of MRD immediately after completion of induction chemotherapy despite hematologic complete remission. Three of these cases relapsed eventually, and 1 was lost to follow-up. Among 12 cases who received adequate delayed intensificiation chemotherapy, 10 are alive in complete remission. CONCLUSION: MRD detection by RT-PCR amplification of E2A-PBX1 transcript was feasible, and the sample after completion of induction chemotherapy was most informative for the prediction of long-term survival and relapse. The presence of MRD after completion of induction chemotherapy conferred poor prognosis. The addition of delayed intensification chemotherapy to standard chemotherapy regimen could abolish the adverse effect of t(1;19) in childhood ALL patients.