Myosin 1g as a high-risk biomarker in a pediatric patient with lineage switch from acute lymphoblastic leukemia to myeloid phenotype / Miosina 1g como un marcador de alto riesgo en una paciente pediátrica con cambio de linaje de leucemia linfoblástica aguda a fenotipo mieloide

Abstract Background: Myosin 1g (Myo1g) has recently been identified as a potential diagnostic biomarker in childhood acute lymphocytic leukemia (ALL). Case report: We describe the case of a 1-year-old Mexican female patient. Although initially studied for hepatomegaly, an infectious or genetic etiology was excluded. Liver biopsy showed infiltration by neoplastic B-cell precursors (BCPs), and bone marrow (BM) aspirate showed 14.5% of BCPs. In a joint session of the oncology, hematology, and pathology departments, low-risk (LR) BCP-ALL of hepatic origin with aberrant myeloid markers was diagnosed. Although treatment was initiated, the patient presented early with BM relapse. Modest overexpression of Myo1g was observed from the onset. However, at the end of the steroid window, expression increased significantly and remained elevated during this first relapse to BM. The parents refused hematopoietic stem cell transplantation, but she continued chemotherapy. After a second BM relapse at 5 years of age, the phenotype switched to myeloid. Her parents then opted for palliative care, and the patient died two months later at home. Conclusions: This case shows the potential use of Myo1g in clinical practice as a high-risk indicator. Myo1g monitoring may reveal a high risk and relapse trend, even when typical parameter values are not altered: Myo1g could be used to classify patients from low to high risk from diagnosis, allowing patients to promptly receive the best treatment and potentially modifying prognosis and survival.

Resumen Introducción: Recientemente se ha identificado a miosina 1g (Myo1g) como un potencial biomarcador de diagnóstico en la leucemia linfoblástica aguda (LLA) infantil. Caso clínico: Se describe el caso de una paciente mexicana de 1 año de edad. Aunque inicialmente se estudió por hepatomegalia, se descartó una etiología infecciosa o genética. La biopsia hepática mostró infiltración por precursores de células B neoplásicas (PCB) y un aspirado de médula ósea (MO) mostró 14.5% de PCB. En una sesión conjunta de los departamentos de oncología, hematología y patología, se diagnosticó PCB-LLA de bajo riesgo de origen hepático con marcadores mieloides aberrantes. Aunque se inició tratamiento, la paciente presentó tempranamente recaída de MO. Se observó una modesta sobreexpresión de Myo1g. Sin embargo, al final de la ventana de esteroides, la expresión aumentó considerablemente y permaneció elevada durante esta primera recaída a MO. El trasplante de células madre hematopoyéticas fue rechazado por los padres, pero se continuó con la quimioterapia. Tras una segunda recaída de MO a los 5 años, el fenotipo cambió a mieloide. Sus padres optaron entonces por cuidados paliativos y la paciente falleció dos meses después en su domicilio. Conclusiones: Este caso muestra el potencial uso de Myo1g como indicador de alto riesgo en la práctica clínica. El seguimiento de Myo1g puede revelar una tendencia de alto riesgo y recaídas, incluso cuando los valores de los parámetros rutinarios son aparentemente normales; Myo1g podría utilizarse para clasificar a los pacientes de bajo a alto riesgo desde el diagnóstico, lo que permitiría que los pacientes reciban el mejor tratamiento de manera oportuna, modificando potencialmente el pronóstico y la supervivencia.

Lineage switch of acute myeloid leukemia to T-Cell acute lymphoblastic leukemia – A unique case report

“Lineage switch” is term described when leukemic cells on relapse exhibit a new phenotype, where losses of one lineage defining markers with simultaneous gain of another lineage defining markers occur. Relapse of acute leukemia is although a very common event, lineage switch occurs and reported very rarely in such cases. The pathogenesis involved in this phenomenon remains unclear; however plasticity of hematopoietic progenitor affected by intrinsic and extrinsic environmental cues can be a possible explanation. In most of the cases at the time of relapse conversion of B-acute lymphoblastic leukemia (ALL) to acute myeloid leukemia (AML) occurs. Here, we presented an unusual case of 10 year old boy with AML switched to T-ALL upon relapse, which is very rare and not well documented till date in literature. The diagnosis was further supported by morphologic, cytochemistry and flowcytometric immunophenotyping (FCM-IPT). Prognosis and survival of such cases remains poor even by the use of standard chemotherapy.

Advances of multi-targeted chimeric antigen receptor T cells in malignant tumors / 中国肿瘤临床

China has the highest incidence of malignant tumors and associated mortality worldwide; efforts are underway to reduce their recurrence rate and fatality. However, single-target chimeric antigen receptor (CAR) T cells used in the treatment of malignant tumors are prone to antigen target loss, tumor recurrence, and other limitations. Presently, multi-target CAR-T cells that can identify and target two or more tumor-related antigens have been developed in China and in the rest of the world; these cells can be used to effectively avoid antigen escape and prevent tumor recurrence. In this review, we have focused on the progress in multi-target CAR-T strategies currently being developed and tested for the treatment of malignant tumors. We have also discussed the advantages of multi-targeted CAR-T cell therapies and measures to overcome limitations, such as tumor recurrence after single-targeted CAR-T-cell treatment; we have also analyzed the therapeutic effects of multi-targeted CAR-T-cell treatments combined with other regimen. The use of multi-target CAR-T cells as a new therapeutic option to improve anticancer efficacy and reduce cancer progression, has also been proposed.

Cambio de linaje de leucemia linfática aguda (LLA) a leucemia mieloide aguda (LMA): Reporte de un caso / Lineage switch from acute lympheal leukemia (ALL) to acute myeloid leukemia (AML): Report of a case

Introducción: La Leucemia Linfática Aguda (LLA) representa la enfermedad maligna pediátrica más frecuente, que representa al menos el 25% de los casos de cáncer infantil. El cambio de linaje de Leucemia Linfática Aguda a Leucemia Mieloide Aguda (LMA) representa aproximadamente 6 a 9% de los casos recidivados, y se observa con mayor frecuencia en pacientes infantiles. Reporte de caso: un paciente de varón de 9 años con Diagnóstico inicial de LLA- B de Muy Alto Riesgo, recae con LMA tras 1 año 9 meses de recibir tratamiento con Quimioterapia y radioterapia profiláctica. Conclusión: Existen diferentes mecanismos que podrían explicar el cambio de linaje entre leucemia linfática aguda a leucemia mieloide aguda; en nuestro paciente podríamos hablar de posibles factores que influenciaron en el cambio de linaje: progenitores bipolares, selección clonal, Quimioterapia.

Introduction: Acute Lymphatic Leukemia (ALL) represents the most frequent pediatric malignant disease, representing at least 25% of childhood cancer cases. Lineage switch from Acute Lymphatic Leukemia to Acute Myeloid Leukemia (AML) represents approximately 6 to 9% of recurrent cases, and is observed more frequently in children. Case report: a 9-year-old male patient with an Initial Diagnosis of Very High Risk ALL-B, relapses with AML after 1 year 9 months of receiving treatment with chemotherapy and prophylactic radiotherapy. Conclusion: Thereare different mechanisms that could explain the Lineage switch between acute lymphocytic leukemia to acute myeloid leukemia; in our patient we could talk about possible factors that influenced the Lineage switch: bipolar progenitors, clonal selection, chemotherapy.

Early Lineage Switch from T-Acute Lymphoblastic Leukaemia to Common B-All

Leukaemic stem cells have heterogenous differentiation potential. The immunophenotypes of blast cells are usually consistent throughout the disease course even at relapse. Rarely, blast cells may undergo a ‘lineage switch’ during the course of disease especially during relapse. We would like to highlight such a case in a 10-year old boy who presented with a two weeks history of lethargy, poor appetite, low grade fever, respiratory distress, cardiac failure, generalized oedema and hepatosplenomegaly. Full blood count showed a leucocyte count of 41.5x109/L and platelet count of 37x109/L. The peripheral blood film showed presence of numerous blast cells. Bone marrow aspiration revealed a hypercellular marrow, which consisted of mainly blast cells with high nuclear to cytoplasmic ratio and inconspicuous nucleoli. Immunophenotyping and cytochemistry results were consistent with the diagnosis of T-cell acute lymphoblastic leukaemia. The patient achieved remission after treatment with UK ALL 97 protocol, regime B chemotherapy. However, he relapsed seven months after the initial diagnosis with 26% blast cells in the bone marrow aspirate. The majority was L1 blast cells admixed with some L2 blast cells. Immunophenotyping was consistent with common precursor B acute lymphoblastic leukaemia. The treatment was changed to a more lineage specific chemotherapy. Nonetheless, the patient never achieved remission and was planned for palliative management. This case illustrated a unique and rare case of rapid lineage switch from T-cell acute lymphoblastic leukaemia to common precursor B-cell acute lymphoblastic leukaemia.

Lineage Switch at Relapse of Childhood Acute Leukemia: A Report of Four Cases

Lineage switch in acute leukemia is an uncommon event at relapse, and therefore rarely reported in the literature. Here, we have described the clinical laboratory features of four cases in which the cell lineage switched from acute lymphoblastic leukemia (ALL) to acute myeloid leukemia (AML). One patient was initially diagnosed with B-ALL, switched to T-ALL at the first relapse, and eventually, AML at the second relapse. A lineage switch represented either relapse of the original clone with heterogeneity at the morphologic level or emergence of a new leukemic clone. Further sequential phenotypic and cytogenetic studies may yield valuable insights into the mechanisms of leukemic recurrence, with possible implications for treatment selection.

Erythroleukemia Relapsing as Precursor B-cell Lymphoblastic Leukemia / 대한진단검사의학회지

AML relapsing as ALL has rarely been reported. We describe the case of a 62-yr-old man who was diagnosed with erythroleukemia with a complex karyotype and achieved complete hematologic and cytogenetic remission after induction chemotherapy. However, 4 months after the initial diagnosis, he showed relapse with blasts showing a different morphology and immunophenotype and was diagnosed with precursor B-cell ALL. The relapsing precursor B-cell ALL presented with the same leukemic clones as the primary erythroleukemia. Cytogenetic analysis of his bone marrow (BM) at the time of the primary erythroleukemia showed complex karyotypic abnormalities, including monosomy 5 and monosomy 7. At relapse, his BM showed reemergence of these leukemic clones of complex karyotypic abnormalities with clonal switch. To our knowledge, this is the first case of a lineage switch from erythroleukemia to ALL.

A Case of Lineage Switch from Acute Lymphoblastic Leukemia to Acute Myeloid Leukemia / 대한진단검사의학회지

Lineage switch from acute lymphoblastic leukemia (ALL) to acute myeloid leukemia (AML) is very rare. We report a case of a 9 yr-old ALL patient relapsed as acute myelomonocytic leukemia. At the initial diagnosis, the blast cell morphology and immunophenotype were consistent with the diagnosis of typical ALL (L1 subtype according to FAB classification). The BCR-ABL fusion gene was not found by reverse transcription-PCR. Complete remission (CR) was achieved after induction and consolidation chemotherapy (Children's Cancer Study Group 1891 protocol, CCG1891). Nine months, which is a very short time compared with other cases in the literatures, after the diagnosis of ALL, she relapsed with completely different blasts (typical AML, M4 according to FAB classification) in morphology, cytochemistry, and immunophenotyping. The karyotype has changed from 56,XY,+X,+Y,+Y,+4,+8,+10, +14,+17,-20,+21,+21,+21[6]/57,idem,+Y[19] to 46,XY,t(8;16)(p11.2;p13.1)[19]/46,XY[1], showing unrelated chromosomal abnormality to the karyotype at the initial diagnosis. Moreover, both findings were quite specific for each common cell ALL and acute myelomonocytic leukemia. These findings support that this case is completely different leukemic clones occurred at each leukemic expression. The treatment with AML 2000 protocol chemotherapy failed, and he underwent the chemotherapy with the combination of high dose cytarabine and mitoxantrone and has been in CR state for 21 months, until now.