Nouvelle revue francaise d'hematologie最新文献

The variable number of tandem repeats (VNTR) of St14 (DXS52) on the human X-chromosome was analysed using the polymerase chain reaction (PCR) method. Screening of 78 X-chromosomes in 56 healthy Chinese individuals revealed the existence of at least seven different alleles in the the Chinese population, the corresponding amplified fragments and frequencies being 700 bp (60.3%), 1220 bp (1.3%), 1300 bp (2.6%), 1390 bp (11.5%), 1570 bp (12.8%), 1630 bp (6.4%) and 1690 bp (5.1%). Total theoretical heterozygous rate was 60%. Compared to Caucasians, this Chinese population showed a markedly higher occurrence of low molecular weight fragments and a relatively low occurrence of high molecular weight fragments. Study of this polymorphism in 14 suspected haemophilia A carriers revealed half of them to be heterozygous. Thus, St14 VNTR analysis by PCR should prove to be a useful tool in the genetic diagnosis of haemophilia A in China.

Secondary non-Hodgkin's lymphoma of the heart (SNHLH) are more frequent than primitive non-Hodgkin's lymphoma and represent the third most common malignant tumour of the heart in autopsy studies. Cardiac involvement usually occurs as a late manifestation in patients with disseminated disease. Initial cardiac lymphoma, defined as cardiac involvement at initial diagnosis with concomitant extracardiac localizations, have nevertheless been reported in approximately 42 cases. The present paper concerns two patients with non-Hodgkin's B-cell lymphoma where cardiac involvement occurring 3 and 6 years after initial diagnosis constituted the unique site of relapse. These cases differ from previous reports of the literature by the predominance of extranodal localizations at initial diagnosis and the late onset of cardiac involvement. Clinical and radiological findings were otherwise in accordance with those usually described in such patients. Transthoracic echocardiography revealed the cardiac tumour in the first case, but in the second case transoesophageal echocardiography and magnetic resonance imaging (MRI) were required to demonstrate its presence. As in most reports, the site of tumour involvement was the right cardiac cavity and histology showed high grade B-cell non-Hodgkin's lymphoma. Polychemotherapy, associated with radiotherapy in the second case, led to partial or complete remission of the cardiac tumour without recurrence within the months of follow-up, although both patients died of their disease within one year.

In the present study, we report the case of a patient displaying an abnormal chromatin clumping (ACC) syndrome, a rare disease which shares features with both myeloproliferative and myelodysplastic disorders. Although various non specific cytogenetic abnormalities have been observed in ACC, the presence of a Ph1 chromosome has not been reported. In our patient, despite a lack of Ph1, PCR analysis of blood and bone marrow samples revealed a BCR-ABL rearrangement. These results indicate that at least some cases of ACC syndrome could represent a form of Ph1-negative chronic myeloid leukaemia.

Bernard-Soulier syndrome (BSS) is a rare hereditary recessive autosomal bleeding disorder characterized by a prolonged bleeding time, giant platelets, thrombocytopenia, normal platelet aggregation in response to ADP and no agglutination in response to ristocetin. This disease is due to absence or abnormality of the platelet membrane glycoprotein GPIb-IX-V, the receptor for von Willebrand factor. All four genes encoding the complex have been cloned and 17 forms of BSS have to date been characterized at the functional, immunological and molecular levels. The mutations can be divided into two main groups. Firstly, mutations located in leucine rich repeats (LRR), responsible for conformational modifications of the molecule, in some cases higher sensitivity to proteases and loss of adhesive function of the receptor, which is expressed at lower than normal levels at the platelet membrane. When mutations affect the LRR of GPIbalpha, the presence of the other chains varies from normal to residual amounts. When mutations affect the LRR of GPIX, expression of the other chains is strongly diminished, suggesting that GPIX plays a major role in the stability of the complex. A second type of mutations leads to synthesis of a truncated molecule lacking the transmembrane domain and absence of its expression at the platelet surface, while the other chains are present in residual amounts. Expression of recombinant proteins in eukaryotic cells has recently confirmed the results derived from studies of natural mutations. Separate expression of each chain can be obtained, although the presence of all subunits is required for full expression.

The present paper describes six cases of lymphoproliferative disorders (LPD) occurring after bone marrow transplantation. Treatments were ineffective and disease was rapidly fatal in all patients, although immunotyping of cells in blood, bone marrow or cerebrospinal fluid was helpful to establish the diagnosis of LPD. Monoclonality was demonstrated in the 4 cases which it was possible to analyse. Herpes virus genome was present in tumoral cells of 4 in 4 cases tested for EBV, one in 3 cases tested for CMV, one in 3 cases tested for HHV6 and 3 in 3 cases tested for HSV. Patients developing LPD should benefit from earlier diagnosis and new therapeutic approaches such as donor lymphocyte infusions, while further studies are necessary to elucidate the role of Herpes viruses in the pathogenesis of LPD.

CD34 positive (CD34+) cells contain all hematopoietic progenitors from stem cells to committed precursors. Therefore the transplantation of purified bone marrow or blood CD34+ cells is sufficient for hematopoietic recovery after a myeloablative radiochemotherapy. Using different techniques, CD34+ progenitors can be induced to undergo terminal differentiation in a stroma-free liquid culture system in the presence of cytokines. In the present study, we have evaluated the functional potential of CD34+ blood progenitors after ex-vivo expansion cultures. CD34+ cells were isolated from 16 samples (PBSC n = 8 and Cord Blood (CB) n = 8) using either ISOLEX 50 (n=6), CEPRATE LC CD34 kit (n = 6) or MICROCELLECTOR T-25 Stem Cell kit (n = 4). CD34+ cells were cultured for seven days in the presence of 500 UI/ML of IL-1, 10 ng/ml of IL-3 and 10 ng/ml of SCF. We obtained an 8-fold expansion of nucleated cells. We observed a 59-fold expansion of GM-CSF responsive committed precursors, a 4.4-fold expansion of IL-1+IL-3+SCF+Epo responsive multilineage progenitors and a 2.2-fold expansion of the 5-FU resistant quiescent progenitors. We did not observe any significant difference in the amplification/expansion parameters between cultures initiated with CD34+ cells from PBSC or CB. Our data show that cytokine mediated ex-vivo expansion of blood CD34+ cells can produce a large number of committed precursors without affecting the compartment of the most immature progenitors. These results suggest that cytokine-mediated amplification technology could be of great interest in the autologous transplantation setting.

Certain neoplasias can induce unregulated erythropoietin (EPO) secretion which results in secondary erythrocytosis. Pheochromocytoma associated with erythrocytosis constitute a rare condition, where the secondary red cell abnormality is believed to be due to tumour EPO secretion. In one such case of pheochromocytoma related erythrocytosis, quantitative determination of serum EPO by enzyme immunoassay was combined with immunohistochemical examination of tumour tissue sections to locate the site of EPO secretion. EPO levels were initially high but decreased after tumour surgery, while immunolocalization showed EPO to be secreted by the neoplastic cells.