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F Uettwiller

Publications and source records attributed to F Uettwiller.

7 recordsLinked to original sources

Modification of topoisomerase genes copy number in newly diagnosed childhood acute lymphoblastic leukemia.

Topoisomerase genes were analyzed at both DNA and RNA levels in 25 cases of newly diagnosed childhood acute lymphoblastic leukemia (ALL). The results of molecular analysis were compared to risk group classification of children in order to identify molecular characteristics associated with response to therapy. At diagnosis, allelic imbalance at topo-isomerase IIalpha (TOP2A) gene locus was found in 75% of informative cases whereas topoisomerase I and IIbeta gene loci are altered in none or only one case, respectively. By semi-quantitative Polymerase chain reaction, we found a 2.5 to 8-fold TOP2A gene amplification in 72% of the children, which was correlated to gene overexpression in every case. These results show that TOP2A gene amplification is a frequent event in ALL at diagnosis. Interestingly, we also identified a small population of children that do not present TOP2A gene amplification or gene overexpression and who are significantly associated with very high risk classified patients showing glucocorticoid resistance. In conclusion, characterization of TOP2A gene status in childhood ALL at diagnosis provides useful complementary information for risk assessment.

Adolescent↗

Emergence of unusual cytogenetic abnormalities under interferon-alpha therapy in patients with chronic myelogenous leukemia.

New treatments that may change the course of a disease or have potential carcinogenicity can result in the emergence of new cytogenetic or clinical disorders. We report here the cytogenetic evolution of 52 cases of Philadelphia (Ph)-positive myelogenous leukemia (CML) receiving interferon-alpha (IFN-alpha) therapy compared with that of 59 Ph-positive CML cases treated with busulfan (BU) or hydroxyurea (HY). Twenty-one percent of the CML patients receiving IFN-alpha displayed unusual secondary abnormalities, among which alteration of the long arm of chromosome 3, del(7), and del(9) were recurrent. The frequency of these unusual secondary changes was significantly higher than in CML cases after Bu or Hy treatment (P = 0.02). Three of the 11 IFN-alpha-treated CML patients displayed cytogenetic evolution in the chronic phase and, in two cases, the cytogenetic findings were transient, inasmuch as they disappeared upon withdrawal of IFN-alpha. In addition, a majority of cytogenetic abnormalities involved chromosome 3 at bands 3q21 and 3q26, which corresponds to the locus of EVI1, a gene implicated in the development or progression of human myeloid leukemias. Possible explanations include: toxicity of IFN-alpha by effect on bone marrow stroma, immune-modulating effects of IFN-alpha, and mutagenic effects of IFN-alpha. The mechanisms underlying these cytogenetic changes remain to be elucidated. However, our data suggest that IFN-alpha induces additional cytogenetic abnormalities even in the chronic phase through its immune-modulating effects and that these unusual cytogenetic abnormalities do not alter the history of CML.

Adolescent↗

Mosaic 46,XY/92,XXYY,del(5)(q13 q34) in an adult lymphoblastic leukemia.

Usually the chromosome anomalies encountered in ALL are modal number abnormalities (hyperdiploidy or hypodiploidy) and structural anomalies such as t(8;14), t(11;14), t(9;22), t(1;19) and del(6p). The 5q- syndrome is mainly associated with myelodysplastic syndromes and with ANLL (M1, M2, M3). We report the case of a patient presenting with a mosaic karyotype 46,XY/92,XXYY,del(5)(q13 q34) in the following proportion 1/3 normal mitoses and 2/3 tetraploid mitoses.

Aged↗

Membrane markers, karyotypic abnormalities, ultrastructure and functional properties of lymphocytes in a case of 'D-cell' chronic lymphatic leukemia.

D cells are lymphocytes bearing both receptors for the third complement component and the ability to form spontaneous rosettes with SRBC. We report the case of a patient with a D-cell chronic lymphatic leukemia who presented a long evolution without treatment and whose leukemic cell characteristics have been extensively studied. Cytogenetic analysis showed numerous karyotypic abnormalities among leukemic cells; all metaphases were hypodiploid and arranged in four different clones; seven marker chromosomes were present. The cells were found to bear human T-cell specific antigen, the T helper/inducer phenotype, HLA-A and HLA-B determinants, but no HLA-DR antigens. They displayed a high proliferative response to PHA and Con A, no response to PWM stimulation, and possibly the capacity of allogeneic stimulation in the mixed lymphocyte culture system. Assays for cell-mediated cytotoxicity in the CML system, and for K and NK activities were negative.

Antigens, Surface↗

[Auer bodies and Ph1 chromosome: chronic myeloid pseudoleukemia?].

In 4 cases, the probable diagnosis was that of a chronic myeloid leukaemia (CML) in a blast crisis, because of the sudden acute onset and the presence of the Ph 1 chromosome. In each case, however, there were Auer bodies in the blasts, an unusual finding in CML. Cytological and cytochemical examination led respectively to the diagnosis of an M2 acute myeloblastic leukaemia (AML), according to the FAB classification, to that of a pre-leukaemia progressing to an M2 AML, to that of a M3 promyelocyte leukaemia, with numerous monocytes and finally, in one case, the diagnosis lay between a possible acute crisis of CML with Auer bodies or an acute myelo-monocyte leukaemia. These atypical findings did not conform to the classic picture of CML and cannot be classified as such in spite of the presence of the Ph 1 chromosome. To consider them as true CML would be to run a risk of distorting the haematological evolutive and therapeutic aspects of this disease.

Adult↗