Occurrence of the JAK2 V617F mutation in the WHO provisional entity: myelodysplastic/myeloproliferative disease, unclassifiable-refractory anemia with ringed sideroblasts associated with marked thrombocytosis.

The JAK2/V617F mutation has been noted in essential thrombocytemia. We investigated 19 cases with refractory anemia with ringed sideroblasts (RARS), including three RARS with thrombocytosis (RARS-T). Only the RARS-T patients showed this mutation. More cases need to be analyzed to determine the prevalence of the JAK2/V617F mutation in RARS-T.

[Evaluation of V617F mutation of JAK2 in negative chromosome Philadelphia chronic myeloproliferative disorders]. / Valoración de la mutación V617F del gen JAK2 en síndromes mieloproliferativos crónicos con cromosoma Filadelfia negativo.

BACKGROUND AND OBJECTIVE: Polycythemia vera (PV) and essential thrombocytemia (ET) are chronic myeloproliferative diseases (MPD) characterized by overactive hemopoiesis. A single point mutation of JAK2 (Val617Phe) has been detected in PV, ET and myelofibrosis (MF). The aim of this work was to investigate the JAK2 mutation in patients with MPD and to compare the results to those of the endogenous formation of BFU-E erythroid colonies (EEC). Finally, different sources of hematopoietic cells to obtain DNA were evaluated. PATIENTS AND METHOD: In this work 146 patents were studied (81 MPD: 27 PV, 28 ET, 11 MF and 15 with myeloid chronic leukemia). Moreover, 28 patients showed secondary polycythemias or reactive thrombocytosis, 8 MPD/myelodysplastic syndromes and 29 other disorders. In 54 patients, EEC were also evaluated. Peripheral blood cells were used as source of DNA in 122 patients, bone marrow in 33, cells from BFU-E in 14 and cells from EEC in 24 patients. Their DNA samples were analyzed using an allele-specific polimerase chain reaction methodology. RESULTS: The JAK2 mutation was present in 96% of PV patients, 59% of ET and 63.6% of MF. None of the remaining patients showed this mutation. Diagnostic agreement was excellent between EEC and the mutation (kappa index = 0.93; 97% positive agreement and 95% negative agreement). DNA was obtained in 119 out of 122 samples from peripheral blood, in all patients with bone marrow, and in 50% of patients with BFU-E or EEC. In 7 cases, samples from different cell sources were studied. Their results were identical. CONCLUSIONS: The V617F mutation of JAK2 is present in most of PV patients and half of those with MF or ET. There is an excellent concordance with the EEC results.

Genetics of lymphocytes influences the emergence of second cancer in chronic lymphocytic leukemia.

BACKGROUND: Patients affected by chronic lymphocytic leukemia (CLL) have an increased risk of developing a second cancer. There is not a definitive explanation for this phenomenon, although some hypotheses have been postulated. The aim of the present work was to assess the presence of second cancer in untreated patients with CLL who were cytogenetically characterized, and secondly to investigate if there is a correlation between the genetics of CLL and the emergence of second cancer. PATIENTS AND METHODS: We performed conventional cytogenetics and Fluorescent in situ hybridization analyses in a series of 106 patients. RESULTS: We observed that nearly 8% of cases developed second cancer, mostly epithelial tumors. The majority of them presented two common features, del(13)(q14.3) and the presence of at least two genetic alterations. CONCLUSION: We suggest that the genetic background of CLL, particularly the presence of several genetic alterations, influences the emergence of second cancer in patients affected by CLL.

Structural rearrangements of trisomies are a risk marker of clinical progression in hyperdiploid multiple myeloma.

BACKGROUND: Hyperdiploid multiple myeloma (HMM) is being characterized by the presence of several trisomies and a low incidence of immunoglobulin heavy chain rearrangements. It has not well defined what specific steps are associated with disease progression. We present two patients that showed some primary trisomies rearranged as a step of cytogenetic and clinical progression. This prompted us to review cytogenetic results from all patients referred to our hospital to assess the importance of this phenomenon in HMM. PATIENTS AND METHODS: We carried out conventional cytogenetics in all patients. In four cases we also performed spectral karyotype (SKY) and arm-specific chromosome painting (ASP). RESULTS: We demonstrate that in two patients some primary trisomies became along the disease course structurally altered and this coincided with clinical progression. We observed this phenomenon in more than 60% of HMM cases diagnosed at our laboratory. CONCLUSION: We propose structural rearrangements of trisomies as a biological marker of progression in HMM.

Valoración de la mutación V617F del gen JAK2 en síndromes mieloproliferativos crónicos con cromosoma Filadelfia negativo / Evaluation of V617F mutation of JAK2 in negative chromosome Philadelphia chronic myeloproliferative disorders

Fundamento y objetivo: La mutación V617F en el gen de la tirosincinasa JAK2 está implicada en la génesis de algunos síndromes mieloproliferativos crónicos (SMP) como la policitemia vera (PV), la trombocitemia esencial (TE) y la mielofibrosis (MF) idiopática. Se ha valorado el papel diagnóstico de esta mutación en los SMP y se ha comparado con la formación espontánea de colonias eritroides (BFU-E-ESP). Pacientes y método: Se incluyó a 146 pacientes, de los que 81 presentaban SMP (27 PV, 28 TE, 11 MF y 15 leucemia mieloide crónica), 28 con eritrocitosis secundaria o trombocitosis reactiva, 8 SMP/síndromes mielodisplásicos y 29 con otras hemopatías. En 54 casos se valoró también la BFU-E-ESP. La fuente de las células hemopoyéticas para obtener ADN fue la sangre periférica en 122 pacientes, la médula ósea en 33, las unidades formadoras de colonias eritroides con estimulación con eritropoyetina en 14 y las BFU-E-ESP en 24. La mutación V617F se efectuó usando una reacción en cadena de la polimerasa específica de alelo. Resultados: El 96% de las PV, el 59% de las TE y el 63,6% de las MF presentaron dicha mutación. La concordancia diagnóstica entre BFU-E-ESP y la mutación fue excelente (índice kappa = 0,93; acuerdo en lo positivo del 97% y acuerdo en lo negativo del 95%). Se pudo valorar la mutación en 119 de los 122 pacientes en que se usó sangre periférica, en los 33 en que se usó médula ósea y en la mitad de aquellos en que se utilizaron las colonias eritroides como fuentes de ADN. Conclusiones: La mutación V617F del gen JAK2 está presente en casi todas las PV y en la mitad de las TE y de las MF. Hay una excelente concordancia entre la presencia de esta mutación y BFU-E-ESP. Finalmente, se puede usar diferentes fuentes celulares en la obtención de ADN para el estudio de esta mutación

Background and objective: Polycythemia vera (PV) and essential thrombocytemia (ET) are chronic myeloproliferative diseases (MPD) characterized by overactive hemopoiesis. A single point mutation of JAK2 (Val617Phe) has been detected in PV, ET and myelofibrosis (MF). The aim of this work was to investigate the JAK2 mutation in patients with MPD and to compare the results to those of the endogenous formation of BFU-E erythroid colonies (EEC). Finally, different sources of hematopoietic cells to obtain DNA were evaluated. Patients and method: In this work 146 patents were studied (81 MPD: 27 PV, 28 ET, 11 MF and 15 with myeloid chronic leukemia). Moreover, 28 patients showed secondary polycythemias or reactive thrombocytosis, 8 MPD/myelodysplastic syndromes and 29 other disorders. In 54 patients, EEC were also evaluated. Peripheral blood cells were used as source of DNA in 122 patients, bone marrow in 33, cells from BFU-E in 14 and cells from EEC in 24 patients. Their DNA samples were analyzed using an allele-specific polimerase chain reaction methodology. Results: The JAK2 mutation was present in 96% of PV patients, 59% of ET and 63.6% of MF. None of the remaining patients showed this mutation. Diagnostic agreement was excellent between EEC and the mutation (kappa index = 0.93; 97% positive agreement and 95% negative agreement). DNA was obtained in 119 out of 122 samples from peripheral blood, in all patients with bone marrow, and in 50% of patients with BFU-E or EEC. In 7 cases, samples from different cell sources were studied. Their results were identical. Conclusions: The V617F mutation of JAK2 is present in most of PV patients and half of those with MF or ET. There is an excellent concordance with the EEC results