Pre-analytical parameters associated with unsuccessful karyotyping in myeloid neoplasm: a study of 421 samples

Cytogenetics is essential in myeloid neoplasms (MN) and pre-analytical variables are important for karyotyping. We assessed the relationship between pre-analytical variables (time from collection to sample processing, material type, sample cellularity, and diagnosis) and failures of karyotyping. Bone marrow (BM, n=352) and peripheral blood (PB, n=69) samples were analyzed from acute myeloid leukemia (n=113), myelodysplastic syndromes (n=73), myelodysplastic syndromes/myeloproliferative neoplasms (n=17), myeloproliferative neoplasms (n=137), and other with conclusive diagnosis (n=6), and reactive disorders/no conclusive diagnosis (n=75). The rate of unsuccessful karyotyping was 18.5% and was associated with the use of PB and a low number of nucleated cells (≤7×103/µL) in the sample. High and low cellularity in BM and high and low cellularity in PB samples showed no metaphases in 3.9, 39.7, 41.9, and 84.6% of cases, respectively. Collecting a good BM sample is the key for the success of karyotyping in MN and avoids the use of expensive molecular techniques.

[ relationship between FLT3 mutations and complete remission of AML patients referring to Shariati hospital]

FLT3 gene is a member of class III receptor Tyrosine Kinase, which is expressed in most patients with acute myeloid leukemia [AML]. Mutations of FLT3 such as Internal Tandem Duplication [ITD] and point mutation of the D835 are the most common genetic defects in myeloid leukemia. These two mutations in patients with MLA and their effect on survival rate were studied for the first time in Iran. DNA was extracted from the blood or bone marrow samples of 100 patients with AML from October 2008 to September 2009. For further analysis, PCR was performed to determine the prevalence of these mutations and their association with prognosis. Moreover, t and x[2] statistical tests were applied for data analysis. According to the results, 15% of patients revealed FLT3-ITD mutations and 8% showed mutation of D835 in FLT3 gene. In terms of achieving complete remission [CR], patients with mutation of ITD had more chance than those without such mutation [83.5% versus 53.3%]. The white blood cell count was significantly higher in the ITD[+] [mean = 73,646/ml] than ITD[-] patients [mean = 26,580/ml]. The results indicate that FLT3-ITD mutations may reduce the chances of Complete Remission [CR] in patients; however, FLT3-ITD mutation is an important factor in selecting appropriate treatment

Screening of C-kit gene mutation in acute myeloid leukaemia in northern India

Acute Myeloid Leukaemia [AML] is a cancer of blood-forming cells in bone marrow. C-kit gene is a Receptor Tyrosine Kinase class III [RTK] that is expressed by early hematopoietic progenitor cells and plays an important role in hematopoietic stem cell proliferation, differentiation and survival. It is known that c-kit is a proto-oncogene and the activating c-kit mutations are likely to contribute in the development of leukaemia in humans. Exon 11 of c-Kit gene is the frequent site for mutations in different kinds of tumours. In order to determine the frequency and prevalence of exon 11 mutations in 51 AML cases, we have done polymerase chain reaction-single-strand conformational polymorphism followed by direct DNA sequencing. The c-kit mutations in exon 11 were detected in 15.68% [8/51] in AML cases. We have detected totally ten missense mutations in eight AML cases those include Lys550Asn, Tyr568Ser, Ile571Leu, Tyr578Pro, Trp582Ser and Arg588Met and novel missense mutations at codons Ile563Lys and Val569Leu. Mutations at codons Ile571Leu and Trp582Ser was found in two independent cases. The presence of c-kit mutations in our study adds to investigative spectrum of AML cases. Since the c-kit mutations are seen in other malignancies, mutations in exon 11 of the c-kit gene might be involve in pathogenesis and represent useful predictive genetic marker in AML. Further studies in larger group of cases possibly will be required to determine the prognostic implications and to investigate how these mutations are co-related to the progression and pathogenesis of AML

Assesment of FLT3-gene mutations among children with acute leukemia

FLT3-gene mutations cause leukemic cells to proliferate uncontrollably and leads to a poor prognosis. The aim of this study was to explore appropriate at diagnostic molecular tests and to screen mutations that occur in patients with acute leukemia. In this basic study, 91 children with acute myeloid leukemia [AML] and acute lymphoid leukemia [ALL] were investigated for FLT3-gene mutations, including ITD mutation [Internal Tandem Duplication] and the point mutation that is coded by exon 17. ITD mutation in FLT3 receptor was analyzed by PCR [Polymerase chain reaction] in 11, 12 exons and 11 intron using designed primers. For analysis of point mutation of Exon 17 in FLT3 receptor gene, the genomic DNA of patient was amplified using the PCR. Resulted PCR products were studied by ECORV enzyme and restriction length polymorphism [RFLP]. In cases of positive ITD, the sequencing method was applied. Of 91 acute leukemia patients, ITD mutation was observed in 7 cases. Two of 91 patients had point mutation of D835. Distribution of ITD and point mutation of D835 mutation was not identical in FAB subtypes. FLT3-gene mutations are prevalent mutation in children with acute leukemia. So, it can be decided about the treatment after molecular diagnosis of this mutaions, independent of FAB classification and before the treatment get started

Acute leukemia in early childhood

Acute leukemia in early childhood is biologically and clinically distinct. The particular characteristics of this malignancy diagnosed during the first months of life have provided remarkable insights into the etiology of the disease. The pro-B, CD10 negative immunophenotype is typically found in infant acute leukemia, and the most common genetic alterations are the rearrangements of the MLL gene. In addition, the TEL/AML1 fusion gene is most frequently found in children older than 24 months. A molecular study on a Brazilian cohort (age range 0-23 months) has detected TEL/AML1+ve (N = 9), E2A/PBX1+ve (N = 4), PML/RARA+ve (N = 4), and AML1/ETO+ve (N = 2) cases. Undoubtedly, the great majority of genetic events occurring in these patients arise prenatally. The environmental exposure to damaging agents that give rise to genetic changes prenatally may be accurately determined in infants since the window of exposure is limited and known. Several studies have shown maternal exposures that may give rise to leukemogenic changes. The Brazilian Collaborative Study Group of Infant Acute Leukemia has found that mothers exposed to dipyrone, pesticides and hormones had an increased chance to give birth to babies with infant acute leukemia [OR = 1.48 (95 percentCI = 1.05-2.07), OR = 2.27 (95 percentCI = 1.56-3.31) and OR = 9.08 (95 percentCI = 2.95-27.96)], respectively. This review aims to summarize recent clues that have facilitated the elucidation of the biology of early childhood leukemias, with emphasis on infant acute leukemia in the Brazilian population.

Detection of single nucleotide insertion of BCR/ABL region in imatinib-resistant human myelogenous leukemia SR-1 cells

Imatinib mesylate is a selective Bcr/Abl kinase inhibitor and an effective anticancer agent for Bcr/Abl-positive chronic myelogenous leukemia. Most patients in chronic phase maintain durable responses; however, many in blast crisis fail to respond, or relapse quickly. Mutations within the BCR/ABL kinase domain are the most commonly identified mechanism associated with relapse. To overcome the imatinib resistance in CML, many investigators have tried to clarify molecular mechanism for imatinib resistance in cells of patients who failed to respond to imatinib. Our aim was to invesitigate underlying mechanism for imatinib resistance in SR-1 cells, which were derived from a CML patient in blast crisis. We detected the new mutation of BCR/ABL, resulting in premature termination and loss of BCR/ABL fusion protein expression, which might be possible mechanism for the resistance to imatinib in SR-1 cells.

Monosomy 7 in patients with aplastic anemia and paroxysmal nocturnal hemoglobinuria with evolution into acute myeloid leukemia.

We report two cases of Thai patients with aplastic anemia/paroxysmal nocturnal hemoglobinuria (AA/PNH) who subsequently developed acute myeloid leukemia (AML) at their terminal phase. Monosomy 7 was demonstrated upon karyotypic analysis of bone marrow in both cases at the time leukemia developed The first patient was a 25-year-old man diagnosed with AA at age 14, recovered from AA at age 15, developed PNH at age 21 and turned into AML at age 25. The second patient was a 27-year-old man diagnosed with PNH at age 22, developed severe AA at age 25 and turned into AML at age 27. This latter patient received anti-lymphocyte globulin when he developed severe AA but did not respond well whereas the first patient fully recovered from AA with anabolic hormone treatment. Time to diagnosis of AML in the patient who received immunosuppressive therapy was strikingly shorter than that who received conventional androgen therapy (2 years vs 11 years after AA, respectively). The presence of monosomy 7 in leukemic cells of both patients emphasizes its central role in the development of AML from AA/PNH. However, other factors such as choice of AA/PNH therapy and patients response may modulate the time to emergence of monosomy 7-carrying AML clone and frank leukemia. Further studies into the biologic and genetic mechanisms involved in the development of leukemic clone arising from AA/PNH should be explored.

Asociación HLA clase I y leucemia en pacientes mestizos del estado Zulia, Venezuela

Resumen. La asociación entre los Alelos Leucocitarios Humanos (HLA) clase I (A, B, C) y las Leucemias Linfoides Agudas y Mieloides, se determinó mediante la técnica de Reacción en cadena de la polimerasa con iniciadores de secuencia específica (PCR-SSP) en un grupo de 60 pacientes y 30 controles sanos. Los valores obtenidos se expresaron como frecuencias alélicas y haplotipicas. Se utilizaron como métodos estadísticos la prueba de Chi-cuadrado corregida, test de Fisher, riesgo relativo y la fracción etiológica. Se observó una asociación positiva significativa de los alelos HLA-B*39 (RR = 16,184, p = 0,0237) y HLA C*03 (RR =5,0; p = 0,0127) con las Leucemias Mieloides (aguda y crónica). Así mismo se encontraron asociaciones positivas de los haplotipos de 2 loci: HLA-A*02-C*03 (RR = 6,0; p = 0,0153), A*24-C*03 (RR = 16,184; p = 0,0237), B*40-C*03 (RR = 10,706; p = 0,0021) y un haplotipo de 3 loci: HLA-A*02-B*40-C*03 (RR = 8,11; p = 0,0102) con las Leucemias Mieloides. No se evidenció ningún tipo de asociación con la Leucemia Linfoide Aguda. No se observaron asociaciones negativas con ningún tipo de Leucemia.

Abstract. The Human Leukocyte Allele (HLA) Class I (A, B, C) and Acute Lymphoid Leukemia and Myeloid Leukemia association, was determined by polymerase chain reaction - sequence specific primers (PCR-SSP) in 60 patients and 30 healthy controls. The results were reported as allelic frequencies and haplotype. The Chi-square corrected, Fisher’s Test, Relative risk and etiologic fraction were calculated. A significant positive association was showed between HLA-B*39 (RR = 16.184; p = 0.0237) and HLA C*03 (RR =5.0; p = 0.0127) alleles and Myeloid Leukaemia. Positive associations between haplotypes 2 loci: HLA-A*02-C*03 (RR = 6.0; p = 0.0153), A*24-C*03 (RR = 16.184; p = 0.0237), B*40-C*03 (RR = 10.706; p = 0.0021) and haplotype 3 loci: HLA-A*02-B*40-C*03 (RR = 8.11; p = 0.0102) and Myeloid Leukemia were found. No association was evident in Acute Lymphoid Leukemia. No negative association with Leukemias were observed.

Chromosomal abnormalities in leukemia in Iran: a pilot study

Objective-To carry out cytogenetics investigations on bone marrow and peripheral blood samples obtained from patients with leukemia. Methods-A total of 35 bone marrow or blood samples from all types of leukemia patients was referred to the Cytogenetic Laboratory of Tehran University of Medical Sciences. The referral centers were the Hematology and Oncology Centers in Shariati Hospital and the Children's Medical Center. Cell culturing including high resolution [HR] and Giemsa banding [G-bands by trypsin using Giemsa strain; GTG] were carried out according to standard protocols. Chromosome analysis was performed following international system for human cytogenetics nomenclature [ISCN] guidelines [1995]. Results-Among the 28 cases, chromosomal abnormality rate was 50% in acute myelogenous leukemia [AML], 80% in acute lymphocytic leukemia [ALL], 83% in chronic myelocytic leukemia [CML] and 100% in the Lymphoproliferative disease [LPD] groups. Two patients in the myeloproliferative disease [MPD]/CML group had normal karyotype and were therefore treated as MPD. The types of observed chromosomal abnormality were translocation 15/17 in AML-M3 patients, double trisomy 8 and 13 in an AML patient, hyperdiploidy of 50- 55 of chromosomes in a child with ALL, a double abnormality of Philadelphia and t 7/8 in a CML patient at blast stage and a complex variant Philadelphia translocation of a t4/9/22 in a CML patient. Conclusion-Despite being a pilot study with a small number of samples, the majority of patients demonstrated chromosomal abnormalities comparable to previously reported cases in other countries. The type of chromosomal abnormality was relevant to diagnosis and stage of the disease

Seguimiento citogenético e hibridización in situ (FISH) en la enfermedad mínima residual / [Cytogenetic and in situ hybridization (FISH) follow-up in minimal residual disease]

Cytogenetic studies are an important tool for diagnosis, prognosis and minimal residual disease (MRD) follow up specially in oncohematology. Conventional cytogenetics, also known as G banding technique, brings complete information for the spectrum of aneuploidies and structural changes present in malignant cells with a sensitivity of 1-5

depending on the number of metaphases analyzed. FISH technique with a higher sensitivity, 10(-2)-10(-4), attempts to make up for one of the principal limitations of G banding which is the absence of metaphases, thus employing different probes and allowing the study of interphase nucleus. Our patients were monitored with both methodologies during the course of the disease looking for MRD. FISH is the best methodology for quantifying the abnormal clone until we can apply quantitative PCR routinely. It will also be important for the follow up of rearrangements for which we do not yet have molecular determinations available. Our findings are coincident with those of other research groups in the need of evaluating higher series of patients with different pathologies in order to arrive at conclusions allowing us to predict relapse with any certainty.

TGF-beta1 inhibition of apoptosis through the transcriptional up-regulation of Bcl-X(L) in human monocytic leukemia U937 cells

To characterize the TGF-beta1 response of monocytic leukemia cells, we analyzed the effects of TGF-beta1 on cell proliferation, differentiation, and apoptosis of human monoblastic U937 cells. Treatment of cells with TGF-beta1 in the absence of growth factors significantly enhanced cell viability. Flow cytometric analysis of DNA content and CD14 expression revealed that TGF-beta1 does not affect cell proliferation and differentiation. Consistent with these results was the finding that no transcriptional induction of Cdk inhibitors such as p21Waf1, p15Ink4b, and p27Kip1 was detected following TGF-beta1 treatment. Interestingly, however, pretreatment of TGF-beta1 significantly inhibited Fas-, DNA damage-, and growth factor deprivation-induced apoptosis. This antiapoptotic effect was totally abrogated by anti-TGF-beta1 antibody. Quantitative RT-PCR analysis demonstrated a dose- and time-dependent transcriptional up-regulation of Bcl-X(L), suggesting its implication in the TGF-1-mediated antiapoptotic pathway. We also observed elevated expression of c-Fos and PTEN/MMAC1. But, no detectable change was recognized in expression of c-Jun, Fas, Fadd, Fap-1, Bcl-2, and Bax. Taken together, our study shows that TGF-beta1 enhancement of cellular viability is associated with its antiapoptotic effect, which may result from the transcriptional up-regulation of Bcl-X(L).

Estudio de los haplotipos HLA en leucemias / Study of HLA haplotypes in leukemias

Se determinaron las combinaciones alélicas de los genes HLA A y B en 144 pacientes con leucemias; 89 con leucemia linfoide aguda (LLA), 28 con leucemia mieloide aguda (LMA) y 27 con leucemia mieloide crónica (LMC), estraficados fenotípicamente en blancos, negros y mestizos, para evaluar la posible asociación entre los haplotipos HLA y esas enfermedades. Se utilizaron como controles 276 personas aparentemente estratificados también por el color de la piel. Los haplotipos A2-B12, A9-B12 y A2-B35 fueron los más frecuentes en el grupo total de enfermos y en los individuos blancos con LLA. La combinación de las especificidades A2 y B5 mostró un desequilibrio de asociación en el conjunto de enfermos y en los sujetos blancos con LMA

Estudio citogenético en médula ósea de 26 casos de leucemia mieloide crónica en pacientes del Hospital San Juan de Dios / Cytogenetic study in Bone Marrow of twenty six cases of Leukemia Myeloid Chronic in patients of the Hospital San Juan de Dios

Se presentan los resultados citogenéticos obtenidos en médula ósea de veintiseis pacientes con leucemia mieloide crónica. Veintiun pacientes fueron tratados, con el medicamento quimioterapéutico convencional, tres con alfa interferón y dos recibieron transplante de médula ósea. Se inicia la importancia de las técnicas citogenéticas en este tipo de paciente y en la valoración de resultados de estos tratamientos.

Detecçäo de mRNAs quiméricos BCR/ABL em pacientes portadores de leucemia mielóide crônica, leucemia linfóide aguda/mielóide aguda pela reaçäo de polimerizaçäo em cadeia (PCR) / Detection of BCR/ABL chimeric mRNAs in patients with chronic myeloid leukemia, acute lymphocytic leukemia/ acute myeloid by polimerase chain reaction (PCR)

A leucemia mielóide crônica (LMC) é uma doença caracterizada pela proliferaçao e acumulaçao de células mielóides e seus precursores, induzida pela transformaçao neoplásica de uma célula hematopoética pluripotente, a stem-cell. Esse clone possui uma anormalidade citogenética que se caracteriza pela translocaçao recíproca entre os cromossomos 9 e 22 [t(9;22) (q34;q11)], resultando na formaçao do cromossomo Philadelphia (Ph1). O resultado dessa translocaçao é a justaposiçao do gene BCR com o protooncogene ABL, originando um gene híbrido que codifica uma proteína anormal com atividade tirosina quinase exacerbada. A reaçao de polimerizaçao em cadeia (PCR) baseada na amplificaçao do cDNA híbrido BCR/ABL tem sido considerada um meio altamente sensível e específico para detecçao dessa patologia, em nível molecular. O RNA total foi extraído pelo método de isocianato de guanidina, de leucócitos de sangue periférico e (ou) medula óssea. A primeira fita (cDNA) foi sintetizada utilizando primer complementar à regiao 3' do mRNA quimérico BCR/ABL, transcriptase reversa (Super Script II - Gibco-BRL) segundo sugestao do fabricante. A reaçao de PCR foi realizada em duas etapas: a primeira utilizando primers complementares à regiao BCR e ABL, num total de 25 ciclos com temperatura de 94 graus Celsius, 49 graus Celsius e 72 graus Celsius para desnaturaçao, anelamento e extensao, respectivamente; na segunda etapa foram utilizados primers internos aos primeiros (Nested-PCR) num total de 35 ciclos com temperatura de anelamento de 60 graus Celsius (primers sintetizados pela Genomic - Engenharia Molecular, SP). O controle de todo o procedimento técnico foi realizado pela amplificaçao de uma regiao do gene ABL. A presença de bandas características da LMC foram visualizadas após eletroforese em gel de poliacrilamida 6 por cento e coloraçao por brometo de etídio. O método foi considerado extremamente sensível e rápido para a detecçao da t(9;22) quando comparada com a citogenética convencional.

Alteraçöes citogenética como fatores prognósticos em leucemias mielóides agudas / Cytogenetic abnormalities as prognostic factors in acute myeloide leukemia

O estudo das alteraçoes cromossômica nas leucemias mielóides agudas (LMA) vem-se tornando importante no diagnóstico e na caracterizaçao de subtipos, pois associam-se a características clínicas, morfológicas e imunológicas definidas à resposta a tratamento e à sobrevida. OBJETIVO. O presente trabalho objetiva avaliar a importância relativa das alteraçoes citogenética em portadores de LMA. MATERIAL. Foram estudados, ao diagnóstico, 13 pacientes com LMA e com idade mediana igual a 38 anos. O estudo citogenético foi realizado em material medular.RESULTADOS. Os subtipos FAB M1 e M2 foram o mais freqüentes (61,6 por cento). A análise citogenética mostrou cariótipo anormal em 61,5 por cento dos casos e, dentre estes, apenas 15,3 por cento tinham alteraçoes indicadoras de bom prognóstico [t(l5;17) e t(8;21)]. Na data de avaliaçao do estudo havia três pacientes vivos, dois em remissao completa contínua e um em segunda remissao. A sobrevida mediana global foi de 7 meses. Os pacientes foram divididos em dois grupos: um intitulado "bom prognóstico", que englobou cinco indivíduos com cariótipo normal e dois com as translocaçoes t(l5;17) e t(8;21), e outro, "mau prognóstico", com oito pacientes com alteraçoes cromossômicas desfavoráveis. O grupo "bom prognóstico" teve sobrevida mediana de nove meses, enquanto outro, de 6,2 meses, mas sem diferença estatisticamente significante (p= 0,180084), provavelmente devido ao pequeno número de casos em cada grupo. Entretanto, ao se analisar os casos em separado nota-se que os pacientes com translocaçoes (8;21) e (15;17), tidas como de bom prognóstico, tiveram sobrevidas mais longas. CONCLUSAO. Concluímos que o trabalho evidenciou sobrevida desigual entre os dois grupos, ressaltando a importância da análise citogenética que permite distinguir o paciente que terá evoluçao favorável.

Fisiopatologia e tratamento da leucemia mielóide crônica: novos conceitos e perspectivas / Physiopathology and treatment of chronic myeloid leukemia: new concepts and perspectives

Descobertas recentas sobre a atividade do gene quimérico BCR/ABL têm auxiliado na elucidaçäo de diversos mecanismos envolvidos na gênese e progressäo da leucemia mielóide crônica (LMC). Apesar de a LMC ser ainda, uma doença incurável para os pacientes que näo podem submeter-se a um transplante alogênico de medula óssea, a sobrevida geral tem aumentado progressivamente, devido especialmente a medidas capazes de prolongar a fase crônica. A técnica de reaçäo da polimerase em cadeia (PCR) para a detecçäo do gene quimérico BCR/ABL tem sido um teste bastante valioso para a identificaçäo de casos Philadelphia negativos que apresentam o rearranjo genético ao nível molecular e para a detecçäo de doença residual mínima, especialmente em indivíduos transplantados. Novas formas de tratamento devem traduzir-se em maior sobrevida nos próximos anos quando utilizadas em estágios precoces da doença: transplante autólogo de células-tronco com células mobilizadas e coletadas após quimioterapia em altas doses, o uso de interferon e a terapia gênica. O interferon já é a droga de escolha para o tratamento da maioria dos pacientes...

Simplified method for the analysis of cellular karyotype and phenotype in leukemias

The objective of this study was to develop a simplified method for the simultaneous analysis of cellular karyotype and phenotype which would permit the identification of cell origin. We studied 6 patients with AML, 3 with CML (one of which was in blastic transformation) and one ALL. We used a method in which the suspension of bone marrow cells was incubated in TC 199 medium with colchicine and with hypotonic solution formed from glycerol, NaCl, KCl, CaCl2, MgCl2 and sucrose. The slides were prepared from this cell suspension by cytospin and stained for peroxidase, PAS, esterases and iron. The karyotype was studied by direct method and culture. It was possible to relate the cytogenetic marker with cytochemistry characteristics in the same cell in 3 cases, showing the feasibility of cytochemistry techniques in cytogenetical preparations. The best preparations were found through peroxidase. The presence of iron granules allowed identification of erythroblastic lineage in the combined staining. Mitosis with a marker chromosome of leukemic clone in an AML cell with negative peroxidase probably showed a proliferation of more primitive precursor not sufficiently differentiated to show markers