Quimioterapia intensiva asociada a imatinib en leucemia linfoblástica aguda del adulto, Philadelphia positivo. Experiencia en un hospital público / Intensive chemotherapy with tyrosine kinase inhibitors in philadelphia-positive acute lymphoblastic leukemia

Background: Before the advent of tyrosine kinase inhibitors (TKIs), patients with Philadelphia-positive Acute Lymphoblastic Leukemia (Ph+ALL) had a poor prognosis. The association of TKIs to intensive chemotherapy (CT) improved outcome. Aim: To evaluate results of an intensive CT protocol including TKI in a public hospital in Santiago, Chile. Material and Methods: All patients with Ph+ALL diagnosed between January 2010 and February 2019, and who met inclusion criteria for intensive CT, received the Ph+ALL national protocol in association with imatinib and were included in this analysis. Results: Thirty-five patients aged 15 to 59 years received treatment. Complete response (CR) was obtained in 97%. Measurable residual disease (MRD) was negative in 61% (19/31 evaluable cases) during follow-up, and 55% (16/29) were MRD (-) before three months. Relapse was observed in 13 cases. Three patients underwent allogeneic hematopoietic stem cell transplant (HSCT), two in CR1. The overall survival (OS) and event-free survival (EFS) at three years were 52 and 34%, respectively. In patients who achieved MRD negativity before three months, no statistically significant differences in OS (64 and 42% respectively, p = 0.15) or EFS (35 and 32% respectively, p = 0.37) were observed. Conclusions: The prognosis of Ph+ALL improved with the association of imatinib to intensive CT. MRD-negative status before three months in this series was not significantly associated with better outcomes. Our series suggests that the Ph+ALL national protocol associated to TKI is a therapeutic alternative with high CR and aceptable MRD (-) rates.

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.

Patients' perceptions about diagnosis and treatment of chronic myeloid leukemia: a cross-sectional study among Brazilian patients / Percepções dos pacientes sobre diagnóstico e tratamento da leucemia mieloide crônica: estudo transversal entre pacientes brasileiros

CONTEXT AND OBJECTIVES: Chronic myeloid leukemia (CML) requires strict daily compliance with oral medication and regular blood and bone marrow control tests. The objective was to evaluate CML patients' perceptions about the disease, their access to information regarding the diagnosis, monitoring and treatment, adverse effects and associations of these variables with patients' demographics, region and healthcare access. DESIGN AND SETTING: Prospective cross-sectional study among CML patients registered with the Brazilian Lymphoma and Leukemia Association (ABRALE). METHODS: CML patients receiving treatment through the public healthcare system were interviewed by telephone. RESULTS: Among 1,102 patients interviewed, the symptoms most frequently leading them to seek medical care were weakness or fatigue. One third were diagnosed by means of routine tests. The time that elapsed between first symptoms and seeking medical care was 42.28 ± 154.21 days. Most patients had been tested at least once for Philadelphia chromosome, but 43.2% did not know the results. 64.8% had had polymerase chain reaction testing for the BCR/ABL gene every three months. 47% believed that CML could be controlled, but 33.1% believed that there was no treatment. About 24% reported occasionally stopping their medication. Imatinib was associated with nausea, cramps and muscle pain. Self-reported treatment adherence was significantly associated with normalized blood count, and positively associated with imatinib. CONCLUSIONS: There is a lack of information or understanding about disease monitoring tools among Brazilian CML patients; they are diagnosed quickly and have good access to treatment. Correct comprehension of CML control tools is impaired in Brazilian patients.

CONTEXTO E OBJETIVOS: Leucemia mieloide crônica (CML) exige estrita adesão à medicação oral e ao monitoramento do sangue e da medula. O objetivo foi avaliar percepções de pacientes com leucemia mieloide crônica (LMC) sobre a doença, seu acesso à informação sobre diagnóstico, monitoramento e tratamento, efeitos adversos e a associação destes com dados demográficos, geográficos e de acesso a tratamento. DESENHO E LOCAL: Estudo prospectivo transversal realizado com pacientes de LMC cadastrados na Associação Brasileira de Leucemia e Linfoma (Abrale). MÉTODOS: Pacientes com LMC recebendo tratamento do sistema público de saúde foram entrevistados por telefone. RESULTADOS: Entre os 1.102 pacientes entrevistados, os sintomas mais frequentemente levando à busca de consulta foram fraqueza e fadiga. Um terço foi diagnosticado por exames de rotina. O tempo entre sintoma inicial e procura por ajuda foi de 42,28 ± 154,21 dias. A maioria foi testada pelo menos uma vez para o cromossomo Filadélfia, mas 43,2% não sabiam os resultados. 64,8% fizeram exame de reação em cadeia da polimerase para o gene BCR/ABL a cada três meses. 47% acreditavam que LMC pode ser controlada, mas 33,1% acham que não há tratamento. Cerca de 24% disseram que ocasionalmente interrompem o tratamento. Imatinibe associou-se com náusea, câimbra e dor muscular. Aderência auto-reportada associou-se significativamente com hemograma normal e positivamente com uso de imatinibe. CONCLUSÕES: Falta informação ou compreensão sobre monitoramento entre pacientes com LMC; eles recebem diagnóstico rapidamente e têm bom acesso ao tratamento. A correta compreensão das ferramentas de controle em LMC está prejudicada entre eles.

Diversity of breakpoints of variant Philadelphia chromosomes in chronic myeloid leukemia in Brazilian patients

Background: Chronic myeloid leukemia is a myeloproliferative disorder characterized by the Philadelphia chromosome or t(9;22)(q34.1;q11.2), resulting in the break-point cluster regionAbelson tyrosine kinase fusion gene, which encodes a constitutively active tyrosine kinase protein. The Philadelphia chromosome is detected by karyotyping in around 90% of chronic myeloid leukemia patients, but 5-10% may have variant types. Variant Philadelphia chromosomes are characterized by the involvement of another chromosome in addition to chromosome 9 or 22. It can be a simple type of variant when one other chromosome is involved, or complex, in which two or more chromosomes take part in the translocation. Few studies have reported the incidence of variant Philadelphia chromosomes or the breakpoints involved among Brazilian chronic myeloid leukemia patients. Objective: The aim of this report is to describe the diversity of the variant Philadelphia chromosomes found and highlight some interesting breakpoint candidates for further studies. Methods: the Cytogenetics Section Database was searched for all cases with diagnoses of chronic myeloid leukemia during a 12-year period and all the variant Philadelphia chromosomes were listed. Results: Fifty (5.17%) cases out of 1071 Philadelphia-positive chronic myeloid leukemia were variants. The most frequently involved chromosome was 17, followed by chromosomes: 1, 20, 6, 11, 2, 10, 12 and 15. Conclusion: Among all the breakpoints seen in this survey, six had previously been described: 11p15, 14q32, 15q11.2, 16p13.1, 17p13 and 17q21. The fact that some regions get more fre- quently involved in such rare rearrangements calls attention to possible predisposition that should be further studied. Nevertheless, the pathological implication of these variants remains unclear. .

Leucemia linfoblástica aguda estirpe B Philadelphia negativa en adolescentes y adultos jóvenes: Resultados del Protocolo Terapéutico LLA 15-30, Programa Nacional de Cáncer del Adulto (PANDA), Ministerio de Salud, Chile / Adolescent and young adult Philadelphia negative B cell acute lymphoblastic leukemia: Results of the Chilean protocol LLA 15-30

Background: Intensified treatment of Philadelphia chromosome negative acute lymphoblastic leukemia (Ph(-)ALL) in adolescents by pediatric teams, with fve years disease free survival (DFS) rate of 65%, encouraged the use of intensified protocols in patients between 15 and 30 years, improving the DFS from 45% to 60-80%. The protocol LLA 15-30 for patients between 15 and 30 years with Ph(-)ALL, based on the Children’s Oncology Group (COG) protocol AALL0232 resulting in a five years DFS of 78%, was started in 2007 by the PANDA national program. Aim: To report the results of the prospective cohort study evaluating the results of this protocol four years after its implementation. Patients and Methods: Between January 2007 and December 2010, 68 Ph(-) ALL patients, aged between 15-30 years (75% males) were incorporated. Survival was evaluated using Kaplan-Meier and log-rank tests. Results: Fifty percent of patients were of high risk. A complete response was achieved in 91%, early death occurred in 6% and induction failure in 3%. Median follow-up was 23 months. Overall survival, disease free survival and relapse rates at 35 months were 61.8, 67.5% and 31% respectively. Conclusions: LLA 15-30 protocol significantly improved three-year overall survival from 31 to 62%. The 20% difference observed with AALL0232 protocol is explained by the high rate of relapse. Improving provider and patient compliance with protocols may eliminate this gap.

Evolución clonal en la leucemia mieloide crónica / Clonal evolution in chronic myeloid leukemia

Evolución clonal en la leucemia mieloide crónica se denomina a la presencia de alteraciones cromosómicas adicionales al cromosoma Filadelfia. Ocurre aproximadamente en el 30 por ciento de los pacientes en fase acelerada y en el 80 por ciento de los pacientes en crisis blástica. Es considerada un criterio de la fase acelerada de la enfermedad. Aunque se plantea que su presencia implica peor pronóstico, su significado es controversial y está en dependencia de la alteración citogenética específica, su frecuencia en el cariotipo, la asociación con otras alteraciones citogenéticas y clínicas de progresión, relación con el tiempo en que aparece en la evolución de la enfermedad y los tratamientos empleados

Clonal evolution in chronic myeloid leukemia is defined as the presence of a variety of additional, nonrandom chromosomal abnormalities besides the Philadelfia chromosome. It occurs in approximately 30 percent of patients in accelerated phase and 80 percent of patients in blastic phase. It is considered a criterion for accelerated phase. Although it is associated with a poor prognosis, its significance is controversial. It depends on the specific cytogenetic abnormality, its frequency in karyotype study, the association with other progression clinical and cytogenetic alterations, its relationship with the time of appearance during the course of the disease and the therapy used

Association of HLA antigens and BCR-ABL transcripts in leukemia patients with the Philadelphia chromosome

OBJECTIVE: This study aimed to verify the association between human leukocyte antigens and the bcr-abl fusion protein resulting from t(9;22)(q34;q11) in chronic leukemia myeloid and acute lymphoblastic leukemia patients. METHODS: Forty-seven bcr-abl positive individuals were evaluated. Typing was performed bymicrolymphocytotoxicity and molecular biological methods (human leukocyte antigens Class I and Class II). A control group was obtained from the data of potential bone marrow donors registered in the Brazilian Bone Marrow Donor Registry (REDOME). RESULTS: Positive associations with HLA-A25 and HLA-B18 were found for the b2a2 transcript, as well as a tendency towards a positive association with HLA-B40 and a negative association with HLA-A68. The b3a2 transcript showed positive associations with HLA-B40 and HLA-DRB1*3. CONCLUSION: The negative association between human leukocyte antigens and the BCR-ABL transcript suggests that binding and presentation of peptides derived from the chimeric protein are effective to increase a cytotoxic T lymphocyte response appropriate for the destruction of leukemic cells.

Resultados citogéneticos en pacientes con leucemia mieloide crónica / Cytogenetic results in patients with chronic myeloid leukemia

Introducción: La leucemia mieloide crónica es una enfermedad mieloproliferativa caracterizada por 3 fases evolutivas. La evaluación citogenética de la enfermedad permite confirmar el diagnóstico y establecer el pronóstico. Objetivo: Reportar los resultados del estudio citogenético de 180 pacientes con diagnóstico clínico de leucemia mieloide crónica y correlacionarlos con las 3 fases de dicha neoplasia. Métodos: El análisis cromosómico de las muestras de médula ósea se realizó por las técnicas de bandas G y los cariotipos se clasificaron según los criterios del Sistema Internacional de Nomenclatura Cromosómica. Resultados: El 94 por ciento de los pacientes estudiados presentó la translocación t(9;22), que apareció con mayor frecuencia en los individuos en fase crónica (87,5 por ciento). En contraste, las anomalías cromosómicas secundarias al cromosoma Philadelphia resultaron las más frecuentes en los que estaban en fase acelerada y en crisis blástica (81,5 por ciento y 96 por ciento, respectivamente). Los resultados obtenidos confirman la relación que existe entre las alteraciones cromosómicas y las diferentes fases evolutivas de la leucemia mieloide crónica

Introduction: The chronic myeloid leukemia is a myeloproliferative disease characterized by three progressive phases. Its cytogenetic analysis assessment allows us to verify the diagnosis and to establish the prognosis. Objective: To report the cytogenetic results from 180 patients clinically diagnosed with chronic myeloid leukemia and correlate them with the three phases of such neoplasia. Methods: The chromosomal analysis of bone marrow samples was performed using the techniques of G bands and the karyotypes were classified according to the criteria of the International System of Chromosomal Nomenclature. Results: The 94 percent of study patients had the translocation t(9:22) more frequent in subjects in chronic phase (87,5 percent). In contrast, the chromosomal anomalies secondary to Philadelphia chromosome were the more frequent ones in those cases in accelerated phase and of blast crisis (81.5 percent and 96 percent), respectively. Results obtained confirm the relation existing among the chromosomal alterations and the different evolution phases of chronic myeloid leukemia

Leucemia meloide crónica: diagnóstico y tratamiento / Chronic myeloid leukemia: diagnosis and treatment

La Sociedad Americana de Cáncer estima que se diagnosticaron 5.050 nuevos casos de leucemia mieloide crónica (LMC) en Estados Unidos durante el 2009. Cerca de 470 personas en los Estados Unidos murieron a causa de la enfermedad en 2009, con un rango de edad de 45 a 55 años, y una razón hombre - mujer de 1,4:1. Este tipo de leucemias representa entre el 15-20% de todas las leucemias, con una incidencia de 1 a 2 casos por cada 100.000 adultos. Más del 50% de los pacientes con LMC serán asintomáticos al momento del diagnóstico y tendrán una esperanza de vida del 39% comparado con la población de adultos sanos. La LMC afecta principalmente a los adultos y se asocia a una anormalidad cromosómica llamada Cromosoma Filadelfia, el cual crea un gen anormal llamado BCR-ABL, que codifica una proteína anormal llamada tirosina kinasa, y se cree que ésto produce que las células afectadas por la leucemia crezcan y se desarrollen. La enfermedad presenta tres fases: crónica, acelerada y blástica. Cada una de estas fases difiere en su tiempo de duración, presentación clínica y respuesta al tratamiento. Tanto la fase acelerada, como la fase blástica son consideradas fases avanzadas, y el 15% de los pacientes con LMC se encontraran en una de estas fases en el momento de ser diagnosticados. El imatinib es el primer inhibidor sintético múltiple de tirosin-kinasa. La unión de este fármaco se logra en los sitios de unión de ATP, de la conformación BCR-ABL kinasa inactivos, logrando una inhibición del crecimiento e induciendo apoptosis de las células que expresan esta conformación. Un 20 a 30% de los pacientes a los que se les administra imatinib presentaran resistencia. El dasatinib® (BMS-354825) es la primera terapia autorizada por la FDA como tratamiento de la LMC resistente o intolerante a imatinib.

The American Cancer Society estimates that 5.050 new cases of chronic myeloid leukemia (CML) were diagnosed in United States in 2009. About 470 persons in the United States will die of chronic myeloid leukemia in 2009, with an age range going from 45 to 55, a mean from 53 to 55, with less than 10% under 20 years, with a male to female proportion of 1,4:1. This kind of leucemia represents between 15-20% of all leukemias, with an incidence of 1 to 2 cases per each 100,000 adults. More than 50% of the patients diagnosed with chronic myeloid leukemia will be asymptomatic at the time of the diagnosis and will have a life expectancy less than 39% if they compared to healthy adults. CML affects adults principally and it is associated to a chromosomal abnormality called the Philadelphia Chromosome, which generates an abnormal gene called BCR-ABL. This gene produces an abnormal protein called Tyrosine-Kinase, believed to cause growth and development in the cells affected by the leukemia. The disease has 3 phases: chronic, accelerated and blastic. Each phase has a differ different duration time, clinical presentation and response to treatment. The accelerated phase and blastic phase are considered advanced phases, and 15% of the total patients will have reached those phases at the time of the chronic mieloide leukemia diagnosis. Imanitib is the first multiple synthetic Tyrosine Kinase inhibitor. The union of this medication to the ATP binding sites of the inactive BCR-ABL Kinase conformation achieves the inhibition of the growth and induces apoptosis of the cells that express that conformation. Approximately 20 to 30% of the patients to whom Imatinib is administered will develop resistance. Dasatinib (BMS-354825) is the first therapy authorized by the FDA as a treatment of the CML which is resistant or intolerant to Imatinib.

Frequencies of BCR-ABL1 fusion transcripts among Sudanese chronic myeloid leukaemia patients

The incidence of one or other rearrangement in chronic myeloid leukemia (CML) patients varies in different reported series. In this study we report the frequencies of BCR-ABL1 fusion transcript variants studied in 43 CML patients from Sudan. The study includes 46 Sudanese patients, three of which negative for the BCR-ABL1 fusion transcript. More than half of 43 positive patients showed b2a2 fusion transcript (53.5 percent), while (41.9 percent) showed b3a2 transcript and the remaining (4.6 percent) coexpression of b3a2/ b2a2 and b3a2/b2a2/e19a2. We detected neither coexpression of p210/p190 nor e1a2 alone. Male patients showed a tendency to express b2a2, while female tende to express b3a2 (p = 0.017). Moreover, a single nucleotide polymorphism was detected in BCR exon 13 in one out of four patients and this patient showed only b2a2 expression. In conclusion, we observed a significant correlation between sex and type of BCR-ABL1 transcript, an observation that deserves further investigation.

Methylation status of the SOCS 1 and JUNB genes in chronic myeloid leukemia patients / Padrão de metilação dos genes SOCS 1 e JUNB em pacientes com leucemia mieloide crônica

Alterations in the methylation status of genes may contribute to the progression of Chronic Myeloid Leukemia (CML). In this study, the methylation status in exon2 of SOCS- 1 and promoter regions of both SOCS- 1 and JUNB were evaluated in CML patients. The methylation status of these genes was analyzed using methylation- specific Polymerase Chain Reaction (MSP) in 30 samples from CML patients, 30 samples from these same patients after hematopoietic stem cell transplantation (HSCT) and 30 samples from healthy controls. The samples of CML patients presented methylation as follows: JUNB gene (3.3 percent), promoter region of the SOCS- 1 gene (6.6 percent) and exon2 of the SOCS- 1 gene (46.6 percent). The samples of the healthy individuals presented methylation (10 percent, P = 0.002) only in exon 2 of the SOCS- 1 gene. After transplantation, patients presented alterations in the methylation status of the promoter region of the SOCS- 1 gene (6.6 percent), exon2 of SOCS- 1 (46.6 percent) and the promoter region of the JUNB gene (16.6 percent). Methylation of the promoter regions of the SOCS- 1 gene and the JUNB gene is not a frequent event in CML. In contrast, SOCS- 1 gene methylation in exon2 is a frequent event, susceptible to alterations in status after HSCT with possible implications for the progression of this disease.

Alteração no padrão de metilação gênica pode contribuir para a progressão da leucemia mielóide crônica (LMC). Neste estudo, o padrão de metilação no exon 2 do gene SOCS- 1 e região promotora de ambos SOCS- 1 e JUNB foram avaliadas em pacientes com LMC. O padrão de metilação desses genes foi analisado usando a técnica " methylation- specific polymerase chain reaction (MSP)" em 30 amostras de pacientes com LMC, 30 amostras desses mesmos pacientes após transplante de medula óssea (TMO) e 30 amostras controle de indivíduos saudáveis. As amostras de pacientes com LMC apresentaram o seguinte padrão de metilação: gene JUNB (3.3 por cento), região promotora do gene SOCS- 1 (6.6 por cento) e exon2 do gene SOCS- 1 (46.6 por cento). Amostras dos indivíduos saudáveis apresentaram metilação somente no exon 2 do gene SOCS- 1 (10 por cento, P = 0.002). Após o transplante, os pacientes apresentaram alterações no padrão de metilação da região promotora do gene SOCS- 1 (6.6 por cento), no exon2 do gene SOCS- 1 (46.6 por cento) e na região promotora do gene JUNB (16.6 por cento). Metilação das regiões promotoras dos genes SOCS- 1 e JUNB não é um evento frequente em LMC. Em contraste, metilação no exon 2 do gene SOCS- 1 apresenta- se como um evento frequente, suscetível a alterações no padrão de metilação após TMO.

Avaliação laboratorial da doença residual mínima na leucemia mielóide crônica por Real-Time PCR: [revisão] / Evaluation diagnosis of minimal residual disease in chronic myeloid leukemia by Real-Time PCR: [review]

A leucemia mielóide crônica (LMC) representa 15 por cento das leucemias e apresenta três fases: crônica, acelerada e crise blástica. A partir da análise citogenética, pode ser identificado o cromossomo Philadelphia, característico da LMC. O transplante de células-tronco é o único tratamento curativo, mas é acompanhado de altas taxas de morbimortalidade, dificultando sua aplicação. A doença residual mínima é de grande importância para avaliar a resposta ao tratamento, tanto na verificação de doença residual, quanto na identificação de pacientes com alto risco de recaída. Muitas técnicas específicas têm sido introduzidas para detectar as translocações ou os produtos do cromossomo Philadelphia. A mais sensível é a Real-Time PCR, que detecta uma célula leucêmica em 10(5) células normais. O objetivo deste trabalho foi realizar uma revisão bibliográfica sobre a LMC, dando ênfase à utilização da técnica por Real-Time PCR.

Chronic myeloid leukemia (CML) represents about 15 percent of all leukemias and has three phases: the chronic phase, accelerated phase and blast crisis. After cytogenetic analysis, the Philadelphia chromosome, characteristic of CML, can be identificated. Stem cell transplantation is the only curative treatment for CML, but it is accompanied by high levels of morbimortality, difficulting its application. The minimal residual disease is very important for the evaluation of the response to treatment, to verify the residual disease and also to identify patients with a high risk of relapse. Many specific techniques have been introduced for the detection of translocations or products of the Philadelphia chromosome; the most sensitive being Real-Time PCR which detects 1 leukemia cell in 10(5) normal cells. The aim of this study was to perform a bibliographic review of CML, with emphasis on the utilization of the Real-Time PCR technique.

Tratamiento con imatinib y el farmacogenotipo CYP3A4 en relación con la expansión clonal Ph(+) en leucemia mieloide crónica (LMC) / Imatinib treatment and pharmacogenotype CYP3A4 in relation with the clonal expansion Ph(+) in chronic myeloid leukemia (CML)

Introducción: imatinib es un inhibidor de la tirosina-kinasa BCR-ABL que revolucionó el tratamiento de pacientes con leucemia mieloide crónica (LMC) positivos para cromosoma Philadelphia (Ph+). Este medicamento se metaboliza principalmente por la enzima CYP3A4, cuyo gen presenta variaciones interindividuales tipo SNPs que pueden interferir con la efectividad del tratamiento, como son los polimorfismos CYP3A4*1B y CYP3A4*2 que han mostrado influencia significativa en la actividad metabólica de esta importante enzima farmacológica. Objetivos: Evaluar la frecuencia de polimorfismos de importancia farmacogenética en el gen CYP3A4 en una población de pacientes con LMC tratados con imatinib y en una población control de 164 personas. Correlacionar el genotipo con la evolución de la expansión clonal Ph(+) y la duración del tratamiento. Metodología: Genotipificación PCR-RFLP para los SNPs CYP3A4*1B y CYP3A4*2. Bandeo replicativo tipo RBHG para la evaluación citogenética de blastos espontßneos con o sin presencia del marcador Ph(+). Resultados: Los análisis citogenéticos revelaron una correlación directa entre el tiempo de tratamiento con imatinib y el porcentaje de reducción de blastos Philadelphia (+). Las genotipificaciones evidenciaron que la presencia del polimorfismo CYP3A4*1B no influye en la respuesta citogenética de los pacientes Ph+ tratados con imatinib, y que el polimorfismo fármaco relevante CYP3A4*2 estß ausente en esta población colombiana de controles y pacientes. Conclusiones: El farmacogenotipo CYP3A4*2 (exón 7) no afecta la respuesta citogenética positiva inducida por el imatinib en pacientes con LMC, en quienes la frecuencia de células Ph(+) por lo general se reduce en relación directa con la duración del tratamiento.

Introduction: Imatinib is an inhibitor of the BCR-ABL tyrosine-kinase that has dramatically changed the treatment of patient with Chronic myeloid leukemia (CML) positive for the Philadelphia chromosome (Ph+). This compound is mainly metabolized by the cytochrome CYP3A4 enzyme, coded by a gene with individual variations that could interfere with the effectiveness of the treatment, due to the fact that particular single nucleotide polymorphisms (SNPs), i.e., CYP3A4*1B y CYP3A4*2, have shown to exert a significant influence on the metabolic activity of this pharmacologically important enzyme.Objective: Evaluate the frequency of pharmacogenetically important polymorphisms in the CYP3A4 gen in a Colombian population of patients with CML being treated with this novel drug (Imatinib), in parallel with a control population of 164 healthy individuals. Correlate the evolution of the clonal expansion Ph(+) with the presence of these SNPs and the length of treatment.Methodology: PCR-RFLP genotyping for the CYP3A4* 1B y CYP3A4*2 SNPs. RBHG replication banding for the evaluation of the presence of the Ph(+) markers in spontaneous mitotic blasts.Results: A positive cytogenetic response and/or correlation was detected between the length of the imatinib treatment and a reduction in the percentage of Ph(+) blasts. Genotyping indicate that CYP3A4*1B polymorphism does no affect the cytogenetic response in imatinib treated Ph(+) patients, and that the pharmacorelevant CYP3A4*2 SNP is not present in this population of patients and controls (N=194). Conclusions: The pharmacogenotype CYP3A4*2 (exon 7) does not affect the induced positive cytogenetic response triggered by the imatinib treatment, that generally induces a reduction in Ph(+) blasts en relation with the duration of the treatment.

Chronic myeloid leukaemia at the University Hospital of the West Indies A 17-year review / Leucemia mieloide crónica en el Hospital Universitario de West Indies un estudio de 17 años

OBJECTIVE: To determine the presenting features and evolution of patients diagnosed with chronic myeloid leukaemia between 1983 and 1999 at the University Hospital of the West Indies. METHODS: Forty-one records were retrospectively analyzed for the patients' demographics, reasons for referral, clinical features, laboratory investigations and the time to blast transformation and death. RESULTS: Seventy-one per cent were males and 29% were females. The male to female ratio was 2.4:1. The median age at presentation was 37 years (range 14-81 years). Seventy-eight per cent of the patients presented in the chronic phase. Weight loss and splenomegaly were the most frequent presenting features being seen in 54 and 83 per cent respectively. The median survival was 36 months. CONCLUSION: In this study, the clinical features and evolution were comparable to existing data. Improved accrual and routine Philadelphia chromosome testing would provide a more accurate reflection of the status of CML in our population.

OBJETIVO: Determinar los rasgos presentes y la evolución de los pacientes diagnosticados con leucemia mieloide crónica entre 1983 y 1999 en el Hospital Universitario de West Indies. MÉTODOS: Cuarenta historias clínicas fueron analizadas respectivamente en busca de los datos demográficos de los pacientes, las razones para la remisión de casos, las características clínicas, las investigaciones de laboratorio y el tiempo hasta la transformación blástica y la muerte. RESULTADOS: El setenta y uno por ciento eran varones y el 29% eran hembras. La proporción varones-hembras fue 2.4:1. La mediana de la edad en el momento de la presentación fue de 37 años (rango 14-81 años). Setenta y ocho por ciento de los pacientes se presentaron en la fase crónica. Pérdida de peso y esplenomegalia fueron las características más frecuentemente observadas en el 54 y el 83 por ciento respectivamente. La mediana de la supervivencia fue 36 meses. CONCLUSIÓN: En este estudio, las características clínicas y la evolución fueron comparables con los datos existentes. El mejoramiento de la acumulación y las pruebas de rutina para identificar el cromosoma Filadelfia, reflejarían con mayor precisión el estatus de la LMC en nuestra población.

Análise citogenética e FISH no monitoramento da LMC em tratamento com inibidores da tirosino quinase / Cytogenetics and FISH monitoring CML during tyrosine kinase inhibitors treatment

O monitoramento de tratamento com inibidor da tirosinoquinase (TK) tem sido feito com os objetivos de avaliar o sucesso da terapia e de definircondutas específicas nos casos nos quais não se obtem a remissão da LMC; naqueles em que ocorre a perda da remissão previamente alcançada, na eventualidade ou não de suspensão da medicação; quando há a evolução clonal a despeito da terapia ou o aparecimento de alterações clonais nas células Philadelphia (Ph)-negativas. Recomenda-se a avaliação citogenética aos três ou seis meses de instituição da terapêutica e, a partir daí, a cada seis meses até a remissão citogenética completa. Uma vez alcançada a remissão citogenética, o monitoramento passa a ser porPCR quantitativo em tempo real (PCR em tempo real, porém o cariótipo deve ser realizado a cada ano para a detecção de perda de resposta, alterações clonais em células Ph-negativas ou evolução clonal. Com efeito, só o cariótipo pode monitorar a aquisição de alteração clonal associada à progressão da doença. No presente manuscrito são também discutidos: Ph-variantes, deleção no derivado 9q e aparecimento de alterações clonais nas células Ph-negativas, situações menos freqüentes, mas que merecem monitoração mais amiúde.

Tyrosine kinase inhibitor treatment monitoring is performed in order to evaluate the success of therapy and to allow specific changes in cases in which remission was not obtained, was lost after being achieved with or without drug interruption, when clonal evolution occurs despite therapy or when clonal abnormalities are detected in Ph-negative cells. It is recommended to perform marrow karyotyping at three or six months after starting therapy and then at six-month intervals until complete cytogenetic remission (CCR) is achieved. Once in CCR, quantitative real time PCR is the method of choice for monitoring, but karyotyping should be performed every year to detect loss of response, clonal evolution or clonal abnormalities in Ph-negative cells. In fact, only karyotyping can monitor the acquisition of clonal aberrations related to disease progression. In this article situations less frequently found, but deserving close monitoring, such as variant Ph, deletion on derivative chromosome 9q and clonal aberrations in Ph-negative cells are also discussed.

Monitoração molecular da Leucemia Mielóide Crônica na era do imatinibe / Molecular monitoring of Chronic Myeloid Leukemia in the imatinib era

Nos últimos dez anos, o tratamento da leucemia mielóide crônica (LMC) passou por uma grande mudança com a introdução da terapia alvo, onde o mesilato de imatinibe (MI) atua inibindo a atividade tirosina quinase do transcrito BCR-ABL produto este do cromossomo Filadélfia (Ph). Esta revolução terapêutica obrigou que técnicas moleculares, até então de uso restrito na oncohematologia, como a reação em cadeia da polimerase em tempo real (RQ-PCR), fossem necessárias para monitorar o sucesso terapêutico ou a detecção precoce da perda de resposta ao MI. Nesta revisão estão delineados, de forma resumida, os principais procedimentos quanto à monitoração dos pacientes com LMC em tratamento com o MI segundo o Consenso Brasileiro de LMC.

Treatment of chronic myeloid leukemia (CML) has changed since the introduction of imatinib mesylate (IM) 10 years ago. IM acts as a target therapy against the BCR-ABL gene by inhibiting its tyrosine kinase activity. This revolution in treating CML compels the introduction of molecular techniques, such as real time quantitative polymerase chain reaction (RQ-PCR) to monitor the response to IM by providing an accurate measurement of the degree to which the BCR-ABL transcript is reduced or an early detection of loss of response identified by a rising level of BCR-ABL. In this review, we summarize the Brazilian CML consensus regarding the main procedures used to monitor CML patients treated with IM.

Leucemia Linfoblástica Aguda Filadélfia positiva / Phyladelphia positive Acute Lymphoblastic Leukemia

O cromossomo Filadélfia (Ph1) é a alteração citogenética mais comum da Leucemia Linfoblástica Aguda do adulto (LLA). Esta alteração citogenética predomina nos adultos com mais de 50 anos e na LLA de origem na célula B, principalmente CD10 positiva. O diagnóstico requer a análise citogenética e a pesquisa do mRNA do gene BCR-ABL no sangue periférico ou na medula óssea. A LLA Ph1 apresenta uma sobrevida global em cinco anos inferior a 20 por cento quando tratada com protocolos para LLA. Os poucos casos de cura ocorrem nos pacientes submetidos ao transplante alogênico de medula óssea (TMO). A adição do imatinibe à quimioterapia resultou em melhora na taxa de remissão completa, maior taxa de remissão molecular completa, maior número de pacientes aptos para realizar o TMO, uma maior sobrevida livre de eventos e maior sobrevida global, embora o tempo de seguimento seja ainda muito curto. Entretanto, a taxa de recaídas e o aparecimento de mutações do BCR-ABL resistentes ao imatinibe ainda são preocupantes. No futuro, novos inibidores de tirosina quinase poderão ser incorporados ao tratamento da LLA Ph1.

The Philadelphia chromosome (Ph1) is the most frequent abnormality in acute adult lymphoblastic leukemia (ALL). Ph1 positive ALL is more frequent in over 50-year-old adults, in B-cell ALL and CD10-positive ALL. Diagnosis is based on the identification of the BCR-ABL gene mRNA in peripheral blood or bone marrow. The 5-year overall survival of patients with Ph1 positive ALL treated with chemotherapy alone is less than 20 percent. A few cases may be cured by allogeneic stem cell transplantation. The addition of imatinib to the chemotherapeutic treatment has resulted in more complete remissions, more complete molecular responses, more patients able to perform stem cell transplantation, better event-free survival and better overall survival, although the study follow-up period is very short so far. High relapse rates and the emergence of BCR-ABL mutants resistant to imatinib are still significant. In the future, newer tyrosine-kinase inhibitors may be added to the chemotherapy.

The impact of addictional chromosomal abnormalities in response to imatinib mesylate therapy for chronic myeloid leukemia

Imatinib induces a complete cytogenetic response in more than 80% of newly diagnosed patients with chronicmyeloid leukemia (CML) in the chronic phase (CP) and in 41% of patients in the first chronic phase after failureof interferon- treatment. However, some patients do not respond completely. Therefore, according to moststudies, drug resistance in CML patients treated with imatinib is correlated with cytogenetic abnormalities acquiredduring treatment. In this study we analyzed 48 CML patients treated with imatinib mesylate after interferon- resistance in order to elucidate the impact of additional chromosomal abnormalities prior to imatinib in response to therapy. Cytogenetic abnormalities in addition to the Philadelphia chromosome (Ph) were detected in 33.3% of patients. Patients with Ph as the sole cytogenetic abnormality prior to imatinib therapy presented a major cytogeneticresponse and significantly longer median overall survival (p=0.006) than patients with additional chromosomalabnormalities. Therefore, in this group of patients, another choice of treatment should be considered, such as stemcell transplantation or combination regimens as appropriate. The present study indicates the importance of detecting a double Ph chromosome prior to imatinib therapy. Patients showing this abnormality did not respond to imatinib, thus indicating the abnormality's association with resistance. Our study suggests that classical cytogenetic analysisis still an important tool prior to and during follow-up of CML patients treated with imatinib.

Imatinibe induz à resposta citogenética completa em cerca de 80 por cento dos pacientes diagnosticados com leucemia mielóide crônica (LMC) em fase crônica (FC), e em 41 por cento dos pacientes em primeira FC após falha do tratamento com interferon-alfa. Alguns pacientes, entretanto, não respondem completamente. Em muitos estudos, a resistência à droga em pacientes tratados com imatinibe é correlacionada a alterações cromossômicas adquiridas durante o tratamento. No presente estudo, foram analisados 48 pacientes tratados com imatinibe após resistência ao interferon-alfa, com o objetivo de verificar o impacto das alterações cromossômicas adicionais ao Philadelphia (Ph), prévias à terapia com imatinibe. Alterações adicionais foram detectadas em 33,3 por cento dos pacientes. Pacientes com somente o cromossomo Ph apresentaram melhor taxa de resposta citogenética e sobrevida global significativa maior quando comparados com os pacientes que apresentavam alterações cromossômicas adicionais antes do início da terapia com imatinibe. Assim, nesse grupo de pacientes, a escolha de outra conduta terapêutica, como o transplante de células tronco-hematopoéticas ou regime de combinação de drogas, pode ser indicada. O presente estudo indica a importância do duplo Ph antesdo início da terapia com imatinibe. Todos os pacientes com esta alteração não responderam ao tratamento, sendo a mesma associada à resistência à droga. Este estudo sugere que a citogenética clássica permanece como uma ferramenta importante no monitoramento de pacientes portadores de LMC tratados com imatinibe.