Response to Tyrosine Kinase Inhibitors in Patients with BCR-ABL1 Positive Chronic Myeloid Leukemia; 13.5 Years’ Experience at Patan Hospital, Nepal

Background:Since the advent of Tyrosine Kinase Inhibitor (TKI), well controlled studies in developed world have shown that the life expectancy of patients with CML is comparable to normal people without the disease. But long-term follow up studies are lacking in resource poor setting. Methods:This is a retrospective follow up study looking at the molecular response and resistance to Tyrosine Kinase Inhibitors (TKI) in patients enrolled in the Max Access Program since February 2003 till March 2017. Patients with twoor more BCR-ABL1 levels by Karyotyping/ fluorescent in situ hybridization (FISH) / reverse transcriptase polymerase chain reaction (RT-PCR) were included. At baseline, complete blood count (CBC), renal function test (RFT), and liver function test (LFT) were evaluated. Bone marrow aspiration and biopsy for morphology, cytogenetic analysis by Karyotyping/FISH and/or molecular analysis by RT-PCR were also done if these tests were not performed earlier. FISH or RT-PCR was done on peripheral blood every 3–12 months as necessary if the patient could afford. Patients with warning response/failure underwent BCR-ABL1 Resistance Mutation Analysis (IRMA).Results:Three hundred and forty six (346) patients had two or more BCR-ABL1 monitoring tests done. Optimal response was seen in 49.42%. Similarly, suboptimal response and failure were seen in 16.5% and 34% respectively. Overall Survival is 89.6% (at 1.8 -165 months, mean 62 months) . If only CML related events is considered survival is 95.9%. Seventy seven (77) patients with a total of 80 BCR-ABL1 domain Imatinib Resistance Mutation Analyses (IRMA) showed 19 different types of mutations with the most common being T315I mutation (8 and 19.5%). About 22.25% of the total patients showed resistance to Glivec out of which 10.98% showed mutations. Nine patients underwent trial for treatment free response (TFR) and 5 of them relapsed between 2-8 months.Conclusions:Despite all the odds of having financial problem, accessibility problem due to distances, transportation, etc. and difficulty monitoring with routine BCR-ABL1 and IRMA, our findings show that the outcome of TKI therapy in our CML patients is comparable to well controlled studies done elsewhere. Overall survival, molecular and cytogenetic responses and mutations in our patients who developed resistance as well as TFR are also similar to other studies. The resistance rate of 22.25% is slightly higher compared to other studies in developed world. This is mainly because of poor monitoring due to unavailability of the test including IRMA in our country and affordability until 2012. It proves that TKI is very effective in CML even in a resource-poor, developing country

Role of ancillary techniques in diagnosis, therapy and prognosis of a case of precursor B-cell acute lymphoblastic leukemia in an elderly patient

The chromosomal abnormality of Philadelphia chromosome is mostly seen in Chronic Myeloid Leukemia (CML). But it is observed that the Philadelphia chromosome (Ph), t(9,22), is the most common cytogenetic abnormality in adult patients with acute lymphoblastic leukemia (ALL), occurring in about 20% to 30 % of all cases. Patients with Ph-positive ALL have breaks in the minor breakpoint region, m?BCR (exons 1?2) lead to a short fusion proteins (p190) and is most frequently associated with Ph chromosome- positive ALL. They have an increased risk for central nervous system (CNS) involvement, an aggressive clinical course and poor prognosis. Historically, they had an inferior outcome when compared with their Ph-negative counterparts. Adult Ph+ patients achieve Complete Remission rates comparable to Ph? ALL patients with standard chemotherapy, but the remissions are short and survival poor. The addition of tyrosine kinase inhibitors (TKIs) including imatinib has dramatically improved outcomes. We are presenting this case report of t(9;22), p190 BCR-ABL1 positive ALL in an elderly female patient of south Gujarat.

Expression of B7-H6 in peripheral blood and bone marrow of patient with chronic myeloid leukemia and its clinical significance / 中国输血杂志

【Objective】 To investigate the expression level of B7-H6 in peripheral blood and bone marrow of patient with chronic myeloid leukemia (CML), and to analyze its association with clinicopathological characteristics and prognosis. 【Methods】 A total of 120 CML patients from January 2010 to May 2013 were selected as study subjects. The expression of B7-H6 mRNA in CML peripheral blood and bone marrow pre- and 3-, 6-, 12-month-posttreatment was detected by quantitative real time PCR, and its correlation between prognosis and clinicopathological factors was analyzed. 【Results】 The expression level of B7-H6 mRNA in the PB, BMMCs of CML patients was lower than that of the normal population (P0.1%(P<0.0001) or without CCR (P<0.001). The expression level of B7-H6 in BMMCs was negatively correlated with the BCR-ABL1/ABL level (r=–0.260, P<0.05). Signifiant difference in PFS was observed between patients with high expression level of B7-H6 (not reached, HR: 0.06, 95% CI =0.03-0.37) and low expression level (81 months, HR: 15.58, 95% CI =2.68-30.23) in BM (P<0.05). 【Conclusion】 The low expression of the B7-H6 gene in CML is correlated with BCR-ABL1 copy number and responsiveness to treatment, and monitoring of B7-H6 expression may be used to evaluate CML prognosis, progression and treatment efficacy.

H396P mutation in chronic myeloid leukaemia patient on nilotinib – A case report

@#Introduction: The advent of BCR-ABL1-targeted therapy with the tyrosine kinase inhibitor (TKI), for example, imatinib and nilotinib, marked a turning point in the therapy of chronic myeloid leukaemia (CML). However, a substantial proportion of patients experience primary or secondary disease resistance to TKI. There are multifactorial causes contributing to the treatment failure of which BCR-ABL1 kinase domain mutation being the most common. Here, we describe a case of a CML patient with H396P mutation following treatment with nilotinib. Case: A 60-year-old woman presented with abdominal discomfort and hyperleukocytosis. She was diagnosed as CML in the chronic phase with positive BCR-ABL1 transcripts. Due to the failure to obtain an optimal response with imatinib treatment, it was switched to nilotinib. She responded well to nilotinib initially and achieved complete haematological and cytogenetic responses, with undetectable BCR-ABL1 transcripts. However, in 4 years she developed molecular relapse. Mutation analysis which was done 70 months after commencement of nilotinib showed the presence of BCRABL1 kinase domain mutation with nucleotide substitution at position 1187 from Histidine(H) to Proline(P) (H396P). Currently, she is on nilotinib 400mg twice daily. Her latest molecular analysis showed the presence of residual BCR-ABL1 transcripts at 0.22 %. Discussion/conclusion: This case illustrates the importance of BCR-ABL1 mutation analysis in CML patients with persistent BCR-ABL1 positivity in spite of treatment. Early detection and identification of the type of BCRABL1 mutation are important to guide appropriate treatment options as different mutation will have different sensitivity to TKI.

Identificación de alteraciones moleculares en pacientes Venezolanos con diagnóstico de leucemia linfoblástica aguda / Identification of molecular alterations in Venezuelan patients with acute lymphoblastic leukemia diagnosis

La Leucemia Linfoblástica Aguda (LLA) es la neoplasia más frecuente en edad pediátrica. En los últimos años, entre el 15 y 20% de los pacientes fracasan en el tratamiento. Conocimientos en citogenética y biología molecular repercuten de manera importante en la determinación del pronóstico y del esquema de tratamiento adecuado. En Venezuela existe un conocimiento limitado en cuanto a la genética molecular de esta alteración onco-hematológica. El objetivo del trabajo fue evaluar las alteraciones genéticas más frecuentes en pacientes venezolanos con diagnóstico clínico de leucemia linfoblástica aguda. Se realizó un estudio transversal, descriptivo y prospectivo de 2006 a 2014, en el que se evaluaron las translocaciones ETV6/RUNX1, MLL/AF4, TCF3/PBX1, BCR/ABL1, así como las mutaciones en los genes PAX5 y FLT3 mediante el uso de diferentes tipos de PCR. Ciento treinta pacientes con diagnóstico clínico de leucemia linfocítica aguda fueron incluidos en el estudio. Se identificaron alteraciones moleculares en 56 pacientes (43,1%), en los que observamos la presencia de una o varias alteraciones en conjunción en un mismo paciente. Las alteraciones identificadas fueron t(12;21) (11,5%), t(4;11) (8,5%), t(1;19) (10%), t(9;22) (20,8%), ITD-FLT3 (14,8%), mutación P80S (4,2%) y S77del (4,2%) en el gen PAX5. La prevalencia de BCR/ ABL, es una de las más altas que ha sido descrita hasta ahora en casos de LLA donde la mayor parte de la población está conformada por pacientes pediátricos. Estos resultados representan el primer estudio molecular de la LLA en Venezuela, sentando las bases para el diagnóstico y seguimiento de la enfermedad en su población.

Acute Lymphoblastic Leukemia (ALL) is the most common neoplasm in pediatric age. In recent years, between 15 and 20% of patients failed in their treatments. Knowledge on cytogenetics and molecular biology has an important impact on the determination of the prognosis and the appropriate treatment scheme. In Venezuela there is limited knowledge regarding the molecular genetics of this onco-hematological alteration. The aim of this work was to evaluate the most frequent genetic alterations in Venezuelan patients with a clinical diagnosis of acute lymphoblastic leukemia. A cross-sectional, descriptive and prospective study was carried out from 2006 to 2014, in which the translocations ETV6/RUNX1, MLL/AF4, TCF3/PBX1, BCR/ABL1, as well as mutations in the PAX5 and FLT3 genes were evaluated through the use of different types of PCR. One hundred and thirty patients with a clinical diagnosis of acute lymphocytic leukemia were included in the study. Molecular alterations were identified in 56 patients (43.1%), in which we observed the presence of one or several alterations in conjunction in the same patient. The alterations identified were t(12; 21) (11.5%), t(4; 11) (8.5%), t(1; 19) (10%), t(9; 22) (20.8%), ITD-FLT3 (14.8%), P80S mutation (4.2%) and S77del (4.2%) in the PAX5 gene. The prevalence of BCR/ABL is one of the highest described so far in cases of ALL where most of the population is made up of pediatric patients. These results represent the first molecular study of ALL in Venezuela, laying the foundations for the diagnosis and monitoring of the disease in its population.

Advances in Philadelphia chromosome-like acute lymphoblastic leukemia / 上海交通大学学报（医学版）

Philadelphia chromosome-like acute lymphoblastic leukemia (BCR-ABL1-like ALL) is a newly defined ALL subtype in 2009. It is Philadelphia chromosome (Ph)/BCR-ABL1-negative and characterized by a set of gene expression profile which is highly similar to that of Ph/BCR-ABL1-positive ALL. However, there is no definitive unified diagnostic criteria yet. BCR-ABL1-like ALL is generally resistant to chemotherapy, with a high relapsed rate and poor prognosis. It harbors a diverse range of genetic alterations that affect cytokine receptor and/or signal transduction pathway of tyrosine kinase. Overexpression of CRLF2, JAK-STAT pathway abnormalities and ABL-class gene rearrangements are the most common. These genetic aberrations could be therapeutic targets. Both in vitro and in vivo experiments and clinical data support the efficacy of targeted therapy. Beside conventional multi-drug chemotherapy, the combination of targeted therapy, cellular immunotherapy and allogeneic hematopoietic stem cell transplantation is promising to improve the prognosis of BCR-ABL1-like ALL. In this paper, the research status of BCR-ABL1-like ALL is described from five aspects: definition, diagnosis, clinical characteristics, molecular biological characteristics and treatment.

Combination of axitinib with dasatinib improves the outcome of a chronic myeloid leukemia patient with BCR-ABL1 T315I mutation / 中南大学学报(医学版)

Chronic myeloid leukemia (CML) is one of the most common hematological malignancies and characterized by the formation of Philadelphia (Ph) chromosome. Recently, tyrosine kinase inhibitors (TKI) treatment greatly improved the prognosis of CML. However, the options may be limited when a patient develops traditional TKI resistance or gene mutation. Herein, we reported a case. A 38-year-old male CML patient developed a BCR-ABL1 gene mutation of T315I after 2.5 years of TKI treatment, including imatinib and dasatinib. We adjusted the treatment with the combined application of dasatinib and axitinib. BCR-ABL1 gene copies dropped down and achieved an early molecular response at 2 months later. Subsequently, he received hematopoietic stem cell transplantation. Axitinib and dasatinib were applied for another half year after the allogeneic hematopoietic stem cell transplantation (allo-HSCT). Two years after the allo-HSCT, the BCR-ABL1 gene was still undetectable. It provided a successful example in treating CML patients carrying BCR-ABL1 T315I mutation via combination of axitinib with conditional TKI.

Prognostic significance of a normal karyotype in adult patients with BCR-ABL1-positive acute lymphoblastic leukemia in the tyrosine kinase inhibitor era

OBJECTIVE: The occurrence of cryptic Philadelphia (Ph) chromosome translocation is rare in BCR-ABL1-positive acute lymphoblastic leukemia (BCR-ABL1+ ALL) and is of unknown significance in the tyrosine kinase inhibitor (TKI) era. METHODS: We retrospectively studied a series of adult patients receiving TKI-based therapy to evaluate the prognostic impact of the normal karyotype (NK) (n=22) in BCR-ABL1+ ALL by comparison with the isolated Ph+ karyotype (n=54). RESULTS: There were no statistically significant differences in clinical characteristics and complete remission rate between the two groups. Compared with the isolated Ph+ group, the NK/BCR-ABL1+ group had a higher relapse rate (55.0% versus 29.4%, p=0.044). Overall survival (OS) and disease-free survival (DFS) were significantly shorter in the NK/BCR-ABL1+ group than in the isolated Ph+ group [median OS: 24.5 versus 48.6 (months), p=0.013; median DFS: 11.0 (months) versus undefined, p=0.008]. The five-year OS and DFS for patients with NK/BCR-ABL1+ were 19.2% and 14.5%, respectively; those for patients with isolated Ph+ were 49.5% and 55.7%, respectively. Thirty-four (44.7%) patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) in this study. Among the patients who received allo-HSCT, the median OS and DFS in the NK/BCR-ABL+ group (n=9) were 35.5 and 27.5 months, respectively, while those in the isolated Ph+ group (n=25) were undefined. There was a trend of significant statistical difference in the OS between the two subgroups (p=0.066), but no significant difference in the DFS. Multivariate analysis revealed that NK was independently associated with worse OS and DFS in BCR-ABL1+ ALL patients [Hazard ratio (HR) 2.256 (95% confidence interval (CI), 1.005-5.066), p=0.049; HR 2.711 (95% CI, 1.319-5.573), p=0.007]. CONCLUSION: Our results suggest that the sub-classification of an NK could be applied in the prognostic assessments of BCR-ABL1+ ALL. In addition, allo-HSCT should be actively performed to improve prognosis in these patients.

Isocromosoma Filadelfia en dos pacientes con leucemia mieloide crónica / Philadelphia isochromosome in two patients with chronic myeloid leukemia

RESUMEN El cromosoma Filadelfia (Ph por su abreviatura del inglés "Philadelphia") se presenta en más del 90 % de los pacientes con leucemia mieloide crónica. Un cromosoma Ph extra es una de las alteraciones secundarias comúnmente observada como evolución clonal de la enfermedad y se puede presentar como un derivativo adicional o un isocromosoma del 22 derivativo. Es una alteración adquirida durante la progresión de la enfermedad con implicación pronóstica. Se presentan dos casos con diagnóstico de leucemia mieloide crónica, resistentes al tratamiento con mesilato de imatinib. En el estudio cromosómico con técnica de banda G se observaron en ambos pacientes líneas celulares con dos isocromosomas del derivativo del 22, 2ider (22) t (9; 22). El primer caso falleció en crisis blástica y el segundo luego de no responder al tratamiento de primera línea, se le indicó nilotinib pero su evolución fue no satisfactoria. Las alteraciones cromosómicas secundarias están asociadas con un impacto negativo en la supervivencia y progresión a fase acelerada y crisis blástica de la enfermedad.

ABSTRACT The Philadelphia chromosome (Ph) is present in more than 90% of patients with chronic myeloid leukemia. An extra Ph chromosome is one of the secondary alterations commonly observed in clonal evolution and it could be as na additional derivative or anisochromosome of the derivative. It is na alteration acquired during the progression of the disease with prognostic implications. We present two cases with a diagnosis of chronic myeloid leukemia, Who showed resistance to treatment with imatinib mesylate. In both patients,the chromosomal study with G-band technique, show cell lines with two isochromosomes from the derivative of 22, 2ider(22)t(9; 22). The first case died in blast crisis and to the second after not responding to the first line treatment, was precribed nilotinib but the evolution was unsatisfactory. Secondary chromosomal alterations are associated with a negative impact on survival and the progression to accelerated phase and blast crisis of the disease.

Mutations in the breakpoint cluster region-Abelson murine leukemia 1 gene in Brazilian patients with chronic myeloid leukemia

ABSTRACT Introduction: Mutations in the breakpoint cluster region-Abelson murine leukemia 1 gene are the leading cause of resistance to treatment with tyrosine kinase inhibitors in chronic myeloid leukemia patients. Mutations have been detected throughout the extension of the kinase domain of this gene and it is important to investigate their positions because there may be a difference in clinical relevance. Objective: To evaluate mutations in the transcripts of the BCR-ABL1 gene in Brazilian patients with chronic myeloid leukemia under tyrosine kinase inhibitor treatment in the Hospital de Clínicas of the Universidade Federal do Paraná. Methods: This retrospective observational cross-sectional study analyzed mutation data of BCR-ABL1 gene transcripts. Three hundred and thirty peripheral blood samples from 193 patients were evaluated with the search for mutations being achieved by Sanger sequencing. Results: Sixteen mutation types were identified in 48/193 (24.87%) patients with T315I (20.83%) being the most common. Furthermore, four polymorphisms (T240T, K247R, E275E and Y275Y) were identified. The highest incidence of mutations (19/53: 35.85%) occurred in the P-loop of the tyrosine kinase domain, whereas no mutation was found in the A-loop. In 43/48 (89.58%) patients only one mutation was found and more than one mutation was found in 5/48 (10.42%). The simultaneous presence of two mutations (E189G/V299L and E255K/T315I) was observed in 2/5 patients while the different mutations were seen in sequential samples of the other three patients (Y253Y/T315I, T315I/E255K and E255K/T315I). Conclusions: This molecular characterization contributed to the identification of the resistance profile to tyrosine kinase inhibitors in Brazilian patients, thus enabling the use of adequate therapeutic strategies in a timely manner.

Detección de mutaciones en el dominio tirosina quinasa de BCR-ABL1 en pacientes colombianos con leucemia mieloide crónica LMC, resistentes al imatinib / Detection of BCR-ABL1 tyrosine kinase domain mutations in chronic myeloid leukaemia patients with Imatinib resistance in Colombia

Resumen Introducción: Las mutaciones en el dominio BCR-ABL1, tirosina quinasa (TK) son mecanismos importantes de resistencia de los inhibidores de la tirosina quinasa (ITK) en pacientes con leucemia mieloide crónica (LMC). Objetivo: Determinar el tipo y la frecuencia de las mutaciones en el dominio tirosina quinasa del gen BCR-ABL1, asociadas con falla en la respuesta al tratamiento con imatinib en pacientes con LMC y correlacionar el perfil de mutaciones con los hallazgos clínicos, demográficos, respuesta citogenética y respuesta molecular. Materiales y métodos: Se realizó un estudio descriptivo de tipo prospectivo en pacientes con LMC en tratamiento con IMATINIB a quienes se les realizó cariotipo y análisis de mutaciones del dominio BCR-ABL1 mediante la técnica de PCR anidada. Resultados: De los 23 pacientes estudiados en cuatro se encontraron mutaciones: dos presentaron la mutación E255K, uno presentó la mutación H396P y otro presentó doble mutación L387L y T389P. Las mutaciones E255K que se ubican en la región P-loop y H396P en A-loop se asocian con mal pronóstico. La mutación T389P localizada en la región A-loop no está informada en algunas bases de datos. Conclusiones: En este estudio encontramos cuatro mutaciones en el dominio tirosina quinasa (E255K, H396P, L387L y T389P) que podrían aportar información valiosa y guiar las decisiones de tratamiento. Es importante destacar que esta investigación de análisis mutacional del dominio BCR-ABL es la primera que se realiza en el país con la particularidad adicional de cubrir una población triétnica.

Abstract Mutations in the BCR-ABL1 tyrosine kinase domain mutations, are one of the principal mechanisms associated with tyrosine kinase inhibitors (TKI) resistance in patients with chronic myeloid leukaemia (CML). Objectives: To determine the type and frequency of mutations in the tyrosine kinase domain of the BCR-ABL1 gene associated with failure to respond to treatment with Imatinib and Imatinib in patients with CMK, and to correlate the mutation profile with the clinical and demographic variables, as well as the cytogenetic and molecular response. Materials and methods: A descriptive prospective study was carried out on patients with CML treated with Imatinib. Karyotyping and analysis of the BCR-ABL1 domain mutations were performed on the patients using nested PCR. Results: Four types of mutations were found in the 23 patients studied, of which two of them were the E225 mutation, one with the H396P mutation, another with a double mutation L387L and T389P. Both the E255K mutation located in the P-loop region, and H396P mutation in the A-loop region, are associated with a poor prognosis. The T389P mutation located within A-loop region has not been reported in any of the databases. Conclusions: Four mutations were found in the tyrosine kinase domain (E255K, H396P, L387L and T389P) were found in this study. These findings provide valuable information and as a guideline to help make treatment decisions. It is important to point out that this analytical study on mutations of the BCR-ABL domain is the first one carried out in the country and, specifically, in a tri-ethnic population.

Chronic kidney disease in the BCR-ABL1-negative myeloproliferative neoplasm: a single-center retrospective study

BACKGROUND/AIMS: Renal complications related to BCR-ABL1-negative myeloproliferative neoplasms (MPNs) have not been examined fully in Asian populations. METHODS: We analyzed estimated glomerular filtration rate (eGFR) and its changes with time retrospectively in patients with BCR-ABL1-negative MPN from 2005 to 2015. RESULTS: The prevalence of chronic kidney disease (CKD) was 11% (6.6% having stage 3 and 4.4% having stage 4). In a linear regression analysis of eGFR versus time (years), overall, patients showed increased eGFR (mL/min/1.73 m2) by 0.51 (95% confidence interval [CI], –0.30 to 1.33; p = 0.22). Patients with polycythemia vera (PV), and those treated with hydroxyurea, showed statistically significant increases in eGFR (1.59; 95% CI, 0.28 to 2.90; p = 0.22 in PV; and 1.55; 95% CI, 0.56 to 2.54; p = 0.22 in treatment with hydroxyurea). In total, 17 patients (20.5%) showed rapid loss of eGFR (7.0 × 109 /L) and high monocyte (> 0.7 × 109 /L) counts (76.5% vs. 50%, p=0.05; 52.9% vs. 28.8%, p= 0.06, respectively). More patients had high serum lactate dehydrogenase (> 500 U/L) levels (52.9% vs. 25.8%, p = 0.03) at diagnosis. CONCLUSIONS: CKD is prevalent in patients with BCR-ABL1-negative MPN. Active cytoreductive therapy has the potential to improve kidney function in BCR-ABL1-negative MPN.

Genomic Profiling of Chronic Myelogenous Leukemia: Basic and Clinical Approach

Chronic myeloid leukemia (CML) is a hematological stem cell cancer driven by BCR-ABL1 fusion protein. We review the previous and recent evidence on the significance of CML in diagnostic and clinic management. The technical monitoring of BCR-ABL1 with quantitative real time-PCR has been used in assessing patient outcome. The cytogenetic mark of CML is Philadelphia chromosome, that is formed by reciprocal chromosomal translocations between human chromosome 9 and 22, t(9:22) (q³⁴:q¹¹). It makes a BCR-ABL1 fusion protein with an anomaly tyrosine kinase activity that promotes the characteristic proliferation of progenitor cells in CML and acute lymphoblastic lymphoma. The targeting of BCR-ABL1 fusion kinase is the first novel paradigm of molecularly targeted curing.

Evaluation of a new flow cytometry based method for detection of BCR-ABL1 fusion protein in chronic myeloid leukemia

BACKGROUND: Philadelphia chromosome, a hallmark of chronic myeloid leukemia (CML), plays a key role in disease pathogenesis. It reflects a balanced reciprocal translocation between long arms of chromosomes 9 and 22 involving BCR and ABL1 genes, respectively. An accurate and reliable detection of BCR-ABL fusion gene is necessary for the diagnosis and monitoring of CML. Previously, many technologies, most of which are laborious and time consuming, have been developed to detect BCR-ABL chimeric gene or chromosome. METHODS: A new flow cytometric immunobead assay was used for detection of BCR-ABL fusion proteins and applicability, sensitivity, reliability, efficacy and rapidity of this method was evaluated. RESULTS: From February 2009 to January 2014, a total 648 CML patients were investigated for the status of BCR-ABL1 protein. Among them, 83 patients were enrolled for comparative study of BCR-ABL1 positivity by three routinely used procedures like karyotyping, and quantitative real time PCR (RT-PCR) as well as immunobead flow cytometry assay. BCR-ABL protein analysis was found consistent, more sensitive (17% greater sensitivity) and reliable than the conventional cytogenetics, as flow cytometry showed 95% concordance rate to RT-PCR. CONCLUSION: BCR-ABL fusion protein assay using a new flow cytometric immunobead might be useful in the diagnosis and monitoring CML patients.

A Case of Acute Promyelocytic Leukemia with Co-existence of BCR-ABL1 and PML-RARA Rearrangements Detected by PCR

Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML) characterized by PML-RARA fusion and specific morphology. The BCR-ABL1 rearrangement is mainly observed in patients with chronic myeloid leukiemia (CML). However, it is also found in patients with acute lymphoblastic leukemia (ALL) and in a few patients with AML. However, it is very rarely observed in patients with APL. Here, we report a case of APL with t(15;17) and co-existence of PML-RARA and BCR-ABL1. Further study with more cases is warranted to find the right treatment and prognostic significance.

Patrones de hibridación del gen de fusión BCR/ABL1 en pacientes cubanos con leucemia / Hybridization patterns of BCR / ABL1 gen in cuban patients with leukemia

Introducción: la leucemia mieloide crónica (LMC) se caracteriza por la presencia de la translocación t(9,22) que resulta en la formación del gen de fusión BCR/ABL1. En ocasiones esta alteración genética puede asociarse con deleciones en secuencias del cromosoma 9 derivativo y otras variantes que no se observan con la citogenética convencional, pero pueden ser detectadas mediante la técnica de hibridación in situ por fluorescencia (FISH). Objetivo: describir los patrones de hibridación en pacientes positivos a la t(9;22) a partir de la introducción de la técnica de FISH para el estudio de las leucemias en Cuba. Métodos: se estudiaron muestras de sangre medular de 36 pacientes con LMC y ocho con leucemia linfoblástica aguda (LLA), en el Instituto de Hematología e Inmunología. Se empleó la sonda LSI BCR/ABL1 Dual Color Dual Fusion. Resultados: entre los pacientes con LMC, dos muestras resultaron no útiles para el diagnóstico y 18 fueron positivas para el BCR-ABL1, una de ellas mostró un patrón de hibridación atípico. Todas las muestras de pacientes con LLA resultaron negativas. En un paciente con impresión diagnóstica de LMC BCR-ABL1 negativo, se observó un patrón de señales que sugiere trisomía del cromosoma 9. Conclusiones: la incorporación de la técnica de FISH para el estudio del transcripto BCR/ABL1 en pacientes con LMC y LLA permitió detectar su presencia y la existencia de patrones de señales atípicos, los que pudieran no ser detectables mediante la citogenética convencional y tener significación pronóstica(AU)

Introduction: Chronic myeloid leukemia (CML) is characterized by the t(9;22) translocation resulting in the formation of BCR/ABL1 fusion gen. Sometimes this genetic alteration can be associated to deletions in sequences of derivative chromosome 9 and other variants detected by fluorescence in situ hybridization (FISH) technique. Objective: To describe hybridization patterns in patients positive to t(9;22) after the introduction of FISH at the leukemia study in Cuba. Methods: The bone marrow samples of 36 patients with diagnosis of CML and eight patients with acute lymphoblastic leukemia (ALL) were studied at the Cytogenetics Laboratory of the Institute of Hematology and Immunology. The BCR/ABL Dual Color Dual Fusion probe was used. Results: The sample of two CML patients were non-useful for diagnosis and 18 were t(9;22) positive, one with an atypical pattern of signals. All the ALL patients were negative. In one negative CML patient was observed a pattern of signals suggestive of trisomy 9. Conclusions: Incorporation of FISH for the BCR/ABL1 transcript study in CML and ALL patients allowed us to detect its presence and the existence of different patterns of signals which could be no detectable by conventional cytogenetic and could have prognostic significance(AU)

Characteristics of hematologic malignancies with coexisting t(9;22) and inv(16) chromosomal abnormalities

BACKGROUND: The coexistence of t(9;22)(q34;q11.2) and inv(16)(p13q22) chromosomal abnormalities is extremely uncommon, and only a small number of such cases have been reported. Here, we characterized 7 cases of hematologic malignancy exhibiting t(9;22) and inv(16) coexistence. METHODS: We reviewed the cytogenetic data for hematologic malignancies treated at the Catholic Blood and Marrow Transplantation Center between January 2004 and June 2013. We identified 7 cases exhibiting t(9;22) and inv(16) coexistence. In addition, we analyzed mutations in the IKZF1, NPM1, FLT3, N-RAS, K-RAS, c-KIT, and TP53 genes. RESULTS: Four cases of chronic myelogenous leukemia (CML; 1 chronic phase, 2 accelerated phase, and 1 blast phase) and 3 cases of acute myeloid leukemia (AML; 1 de novo and 2 therapy-related) were identified. The percentages of circulating blasts and bone marrow eosinophils were higher in AML cases than in CML cases (53% vs. 5% and 30% vs. 5.5%, respectively). The proportions of each chromosomal abnormality were used along with follow-up karyotyping results to identify secondary changes. In BCR/ABL, a p210 fusion transcript was associated with CML, whereas a p190 fusion transcript was associated with AML. One patient with AML harbored 2 mutations: c-KIT D816V and TP53 E11Q. All patients except 1 with CML blast phase sustained clinical remission after treatment, which included an imatinib mesylate regimen. CONCLUSION: This study shows that observations of bone marrow morphology, initial and follow-up cytogenetic studies, and karyotyping of BCR/ABL1 and CBFB/MYH11 provide valuable information for characterizing hematologic malignancies exhibiting t(9;22) and inv(16) coexistence.

Fluorescence in situ hybridization patterns of BCR/ABL1 fusion in chronic myelogenous leukemia at diagnosis.

Background : Chronic myelogenous leukemia (CML) is characterised by the t(9;22)(q34;q11.2) which results in the formation of the BCR/ABL1 fusion gene. Occasionally, the t(9;22) may be associated with submicroscopic deletions of chromosomes 9 and/or 22 which appear to be associated with a worse prognosis. Three or four-way variant t(9;22) may also occur. All these changes as well as gain of the Philadelphia chromosome which represents disease progression can be detected by fluorescence in situ hybridization (FISH) analysis. FISH analysis at presentation is used to determine the number of cells with BCR/ABL1 fusion and establish whether the patterns are typical or atypical. Response to therapy can then be monitored by serial testing. Patients and Methods : The study group consisted of all patients diagnosed or suspected to have CML who had interphase FISH analysis at presentation on peripheral blood/bone marrow using a commercially available BCR/ABL1 dual colour, dual fusion probe. The study was performed at a tertiary hospital in India between 2004 and 2010. Results: There were 1076 diagnostic samples which were positive for BCR/ABL1 fusion. Typical dual fusion signals (two fusions, one red and one green, 2F1R1G) were seen in 801 cases (74 %). Atypical signal patterns were seen in 275 cases (26%). These were: 1F1R2G (4%), 1F2R1G (2.5%) and 1F1R1G (11%) representing deletions of the derivative 9 involving chromosome 9 sequences, chromosome 22 sequences, or both respectively; 3F1R1G (6.5%) usually representing gain of an additional Philadelphia chromosome and 1F2R2G (1%) representing a three- or four-way variant translocation. More than one signal pattern was seen in 1%. Conclusions: Our findings were similar to the literature with respect to the distribution of signal patterns except that we had a lower number of patients with variant translocations. While each signal pattern is typically associated with a particular abnormality, there can be more than one explanation for each pattern. Hence, metaphase FISH analysis is the "gold standard" for the interpretation of signal patterns.

A Case of Concomitant Inv(3)(q21q26) and Cryptic BCR/ABL1 Rearrangement in the Blast Crisis of Chronic Myeloid Leukemia

Structural abnormalities of the long arm of chromosome 3 (3q) have been associated with elevated platelet count and hyperplasia of megakaryocytes with dysplasia in various hematological malignancies. Some cases of chronic myeloid leukemia (CML) may acquire inv(3) (q21q26) or t(3;3)(q21;q26), and such a finding usually indicates accelerated or blast phase of their disease. We report a case of concomitant inv(3) (q21q26) and cryptic BCR/ABL1 rearrangement in the blast crisis of CML. The patient was 17-year-old male and showed marked leukocytosis and thrombocytosis at admission. Leukocyte differentials showed eosinophilia, basophilia and increased blasts. The bone marrow was hypercellular with granulocytic hyperplasia, and dysmorphic megakaryocytes were frequently observed. Conventional cytogenetic analysis revealed only an inv(3)(q21q26) and no Philadelphia chromosome was observed. FISH and RT-PCR analyses confirmed cryptic BCR/ABL1 rearrangement. The patient responded poorly with imatinib and induction chemotherapy, and expired during the course of 2nd chemotherapy with increased dose of imatinib.

A Case of Atypical Chronic Myeloid Leukemia with the JAK2V617F Mutation

Atypical chronic myeloid leukemia (aCML) is a rare leukemic disorder that shows myelodysplastic and myeloproliferative features simultaneously. The Janus kinase 2 gene V617F mutation (JAK2V617F) in aCML has been the source of much controversy. Some JAK2V617F positive cases have been reported but others observed no JAK2V617F mutation in aCML as defined by WHO classification. Recently, we experienced a case of aCML with JAK2V617F mutation with typical myelodysplastic/myeloproliferative features in peripheral blood and bone marrow aspirates. The karyotype was normal and no BCR/ABL1, PDGFRA or PDGFRB gene rearrangement was noted with FISH analysis. JAK2V617F mutation of the case was identified with amplification refractory mutation system PCR and direct sequencing. We also studied JAK2V617F mutation status in 3 additional cases of previously diagnosed aCML in our institution, but no mutation was identified.