Prothrombin Segovia: a new congenital abnormality of prothrombin

A family with a new congenital dysprothrombinemia is presented. The propositus is a 21-yr-old man who presented simultaneously with hemartrosis of the left knee and an extensive hematoma following a minor trauma. Prothrombin time and activated partial thromboplastin time were prolonged. Prothrombin activity was very low when measured by biological assay using physiological activators (7% by one-stage method and 20% by two-stage method) or a Russel's viper venom-cephalin mixture (23%), Notechis scutatus scutatus venom (15%) and Echis carinatus venom (17%); in contrast, the level was found to be borderline to normal using Taipan viper venom (64%) and normal by both staphylocoagulase and immunologic methods. Family studies revealed consanguinity between the propositus' mother and father and both presented a 50% reduced prothrombin level when physiological activators or Echis carinatus viper venom were used. A line of identity between normal and abnormal prothrombin was observed on immunodiffusion. The migration of the abnormal prothrombin was less anodic and was not changed by the addition of calcium. The patient's serum showed 3 bands in the bidimensional immunoelectrophoresis system, whereas normal serum showed only 2 bands. The term prothrombin Segovia is proposed to define this new prothrombin abnormality.     

Identification of a novel recurrent gain on 20q13 in chronic lymphocytic leukemia by array CGH and gene expression profiling

BackgroundThe presence of genetic changes is a hallmark of chronic lymphocytic leukemia (CLL). The most common cytogenetic abnormalities with independent prognostic significance in CLL are 13q14, ATM and TP53 deletions and trisomy 12. However, CLL displays a great genetic and biological heterogeneity. The aim of this study was to analyze the genomic imbalances in CLL cytogenetic subsets from both genomic and gene expression perspectives to identify new recurrent alterations.Patients and methodsThe genomic imbalances and expression levels of 67 patients were analyzed. The novel recurrent abnormalities detected with bacterial artificial chromosome array were confirmed by FISH and oligonucleotide microarrays. In all cases, gene expression profiling was assessed.ResultsCopy number alterations were identified in 75% of cases. Overall, the results confirmed FISH studies for the regions frequently involved in CLL and also defined a new recurrent gain on chromosome 20q13.12, in 19% (13/67) of the CLL patients. Oligonucleotide expression correlated with the regions of loss or gain of genomic material, suggesting that the changes in gene expression are related to alterations in copy number.ConclusionOur study demonstrates the presence of a recurrent gain in 20q13.12 associated with overexpression of the genes located in this region, in CLL cytogenetic subgroups.     

Continuous oral cytarabine ocfosfate with interferon-α-2b for patients with newly diagnosed chronic myeloid leukaemia: a pilot study

Recombinant(R) interferon alpha (r-IFN-alpha) has been shown to be an effective drug for chronic myeloid leukaemia (CML). However, higher response rates can be achieved using cytarabine along with r-IFN-alpha. YNK01 is a derivative of cytosine arabinoside for oral administration. So far, the only published experience with continuous YNK01 was in advanced CML (10 cases). We have performed a pilot study to evaluate the efficacy and toxicity of the combined therapy r-IFN-alpha and daily oral YNK01 in patients with newly diagnosed Ph+ CML. Ten previously untreated patients were included in the study. Among those patients evaluable for cytogenetic response, 87% (seven out of eight) reached a major cytogenetic response with four reaching complete cytogenetic response (50%). The most significant side-effects were gastrointestinal. Macrocytic anaemia was observed in three patients. In conclusion, continuous oral administration of YNK01 in combination with IFN-alpha is safe and can result in high-cytogenetic response rates.     

Leukemias with megakaryoblastic involvement: clinical, hematologic, and immunologic characteristics

The clinical, hematologic, and phenotypic features of 28 patients with acute leukemia with megakaryocytic involvement (AMKL) were analyzed. The prevalence of this type of leukemia in the entire series was 11.6%, with a higher incidence among patients with acute transformation of a previous myeloproliferative disorder (MPD) (24%) than among the transformed myelodysplastic syndrome (13%) patients. The incidence in the "de novo" ANLL was 8% and 16% among secondary leukemias. The presence of bone marrow fibrosis together with low WBC and normal or increased platelet counts despite a severe anemia are the most relevant features in these patients who otherwise displayed an apparently poor prognosis. Megakaryoblasts were morphologically recognized more frequently in the acute transformations of MPD than in de novo ANLL. Only two cases were considered pure AMKL, and in the remaining 26 patients, megakaryoblasts coexisted with other granulomonocytic and/or erythroid populations. Antiglycoprotein IIIa (anti-GPIIIa) (C17) and anti-GPIIb/IIIa (CDw41-, J15-) antibodies are probably the best markers for AMKL, although the monoclonal antibody against GPIX (FMC25) was also positive in a majority of cases but in a lower percentage of cells. On the other hand, megakaryoblasts were generally negative for granulocytic or monocytic markers (CD13, CD14, CD15); the expression of HLA-DR antigens in these cells was variable. Our present results indicate that megakaryoblastic involvement is more common than previously recognized. This is true not only in acute transformed leukemias but also in de novo ANLL. Although the diagnosis of these cases should be based on megakaryocytic markers, it is often possible to suspect a diagnosis according to certain clinical and hematologic features.     

In vitro growth in acute myeloblastic leukaemia: relationship with other clinico-biological characteristics of the disease

The in vitro growth characteristics of a large series of acute myeloid leukaemia (AML) patients and their relationship with other clinical and biological disease characteristics were analysed. Patients with AML were studied, 181 with de novo AML and 45 with secondary AML (24 myelodysplastic syndrome, sAML-MDS, 21 myeloproliferative disorder, sAML-MPD). Leukaemic colony forming units (L-CFU) were assayed by plating peripheral blood (PB) blast cells in methyl-cellulose and using LCM-PHA as stimulant. In each case parallel cultures were made with and without stimulating factors. Plating efficiency (PE) was defined as the number of clusters plus colonies/10⁵ cells plated. Autonomous growth (AG) was the number of colonies plus clusters growing without stimulant. The autonomous proliferative index (API) was calculated as the number of clusters + colonies without stimulating factor divided by the number of clusters + colonies with stimulating factor. No significant differences in the PE between de novo and secondary AML were found. Autonomous growth was significantly higher in sAML-MPD. The FAB subtype M3 leukaemias displayed a significantly greater PE and a significantly lower API when compared with the other FAB subgroups (P = 0.0002). Upon analysing the relationship with the immunophenotype, only CD33 expression showed a significant relationship with the in vitro growth pattern; CD33⁺ cases displayed a higher PE (P = 0.0002) and AG (P = 0.0003) than CD33^? cases. When patients were grouped according to the level of rh123 efflux (MDR1) it was observed that cases with >30% elimination showed a higher AG and API than those with <30% (P = 0.03). Finally we found that patients with higher API (>0.05) displayed a significantly shorter overall survival as compared with patients with API < 0.05 (P = 0.04). The in vitro study properties of clonogenic cells produces relevant clinical information of leukaemic cell biology in AML patients.