Hematology and cell therapy最新文献

A 7.5 year old boy with myelodysplastic syndrome (MDS) of CMML type associated with trisomy 8 and elevated hemoglobin F (Hb F) value is presented. Hematological evaluation of the patient revealed that the Hb was 10 g/dl, MCV 110 FL, platelets 58 X 10(9)/l, WBC 5.4 X 10(9)/l with 24% atypical monocytes. Karyotype analysis revealed 47, XY, +8. Hb F value was 21% which was distributed heterogeneously among red cells. PCR amplified cDNA copies of circulating reticulocyte mRNA were used to measure the relative amounts of alpha-, beta-, and gamma- globin. There was marked increases in both alpha/beta mRNA ratio (20%) and gamma/(gamma+beta) mRNA ratio (35%) in the patient compared to normal subjects. The study indicated that increased transcription of alpha and gamma genes are partly responsible for the elevation of Hb F in MDS.

We present an initial experiment in the teaching of haematology using the problem-based learning technique in the third year of medicine at the Bobigny Faculty of Medicine (Université Paris-Nord). This new approach to the clinical and bioclinical teaching of medicine is used in several hundred medical faculties throughout the world. It is based on students' integrated learning of concepts (scientific, clinical, psycho-social) through patient problems. The method alternates group meetings with a tutor and individual learning. Sixty-eight students with no previous training in haematology and eight tutors (eight groups) took part in this experiment, which lasted five weeks (with no other teaching) and enabled them to study ten patient problems representing the bulk of the objectives pursued in this discipline. The preparation of students and teachers for this experiment is described, as well as its conduct and the results obtained. These show that the problem-based learning students performed better in their clinical problem-solving examinations than did students from a previous year who had been taught using traditional methods for the same period of time. The comparison does not indicate, however, that problem-based learning students had any advantage in the acquisition of factual information. The high degree of satisfaction of the students beginning their third year and of tutors in respect of this experiment constitutes a very favourable point. The limitations of the experiment and the teaching method itself are also discussed.

Our main goal was to evaluate the CD34+ dose in patients undergoing haemotopoietic stem celltransplantation and its results in terms of recovery of neutrophile and platelet counts, transfusion requirements, days of fever, antibiotic requirements and length of hospital stay. We studied 38 consecutive patients with haematological malignancies transplanted at our Department, from Feb. 96 through Sept. 98. The CD34+ cell quantification technique was standardized, using a modification of the ISAGHE 96 protocol. Patients were sorted into three groups according to the CD34+ count administered: a) between 3 and 5 x 10(6) cells/kg; b) between 5 and 10 x 10(6) cells/kg; c) > 10 x 10(6) CD34+ cells/kg. As a secondary end point, results were assessed according to the number of aphereses required to arrive at the target count of CD34+, separating those patients that required only 1 or 2 aphereses versus those requiring 3 or more. Finally, an analysis was made of the results of transplantation comparing the different sources of stem cells (PBSC versus PBSC + B.M.). The best results were obtained in the group with cells between 3 and 5 x 10(6) CD34+. No statistically significant advantages were found in the group with cells over 5. The supra-optimal dose of more 10 x 10(6) would yield no additional beneficial results, while they can imply a greater infusion of residual tumor cells. The number of aphereses had no impact on engraftment. Results obtained with PBSC transplants were better than those with BM+PBSC in terms of neutrophile and platelet recovery. The number of CD34+ cells remains the main element in stem cell transplantation to evaluate the haematopoietic recovery after engraftment. Minimum and optimum yields remain unclear. Centers should establish their own optimal dose based on local methodologies and outcomes, maximizing costs and benefits.

Several mutations prevent the expression of p53 in the human lymphoblastoid T cell line Jurkat. Restoration of p53 in Jurkat cells had no effect on the cell growth but markedly increased the amount of apoptosis induced by gamma-irradiation. Inhibition of RNA synthesis using 5,6-dichlorobenimidizole riboside had little effect on apoptosis induced by irradiation in the presence of p53 and did not affect the p53-independent apoptotic pathway. Expression of p53 also had no effect on the expression levels of proteins such as Fas, GADD45, Bax, Bcl-2, Bcl-x(L) or p53 induced proteins (PIGS) in resting cells or after irradiation. Activation of protein kinase C by phorbol 12-myristate 13-acetate produced an almost complete inhibition of p53-independent apoptosis following irradiation, whereas no significant effect was observed on the rate of p53-induced apoptosis. Although phorbol 12-myristate 13-acetate strongly induced p21 and stabilised p53 in the resting transfected Jurkat cells, neither apoptosis nor cell arrest was observed. In summary, this work shows that p53 enhances the radiosensitivity of Jurkat cells through an apoptotic process that is triggered by irradiation and is largely independent of RNA synthesis and protein kinase C activation. Apoptosis in p53- negative Jurkat cells is strongly inhibited by PMA indicating that the pathway triggered by p53 may be distinct from apoptotic pathways used in its absence.

Since 1990 we have treated 60 patients with standard-dose fludarabine for chronic lymphocytic leukemia (B-CLL), on a compassionate basis. Three patients developed grade IV neurologic complications after treatment, with demyelination of white matter on magnetic resonance imaging (MRI) in patient # 1, diffuse demyelination, abnormal oligodendroglia and enlarged astrocytes at brain biopsy in patient no 2, and progressive multifocal leukoencephalitis (PML) with JC virus on brain biopsy in patient # 3. The neurotoxicity of fludarabine was often observed after administration of high doses (90-120 mg/m2). At standard doses (18-25 mg/m2) neurologic complications were observed in very few cases (0.2%). PML was observed in only 0.52% of patients with chronic lymphocytic leukemia (CLL), particularly those with advanced CLL. Our findings are consistent with the results of published studies and show an increase in neurologic complications in patients with advanced CLL treated with fludarabine. This increased vulnerability is probably multifactorial, but may be secondary to the immunodeficiency.

The extent of megakaryocytopoiesis (Mk-poiesis) and clinical outcome are evaluated in 14 patients with severe refractory chronic immune thrombocytopenia (rchr ITP). Three out of 14 patients died due to hemorrhage. The number of bleeding episodes and the number of treatment modalities proved to be both sensitive prognostic survival parameters (p < 0.05). Thirty two corticosteroid responsive chr ITP patients (chr ITPPR), 15 not treated patients (chr ITP(NT)) and 14 healthy volunteers (C) served as a control. There was a significant difference in the platelet count between the study groups (p < 0.05). The number of megakaryocytes and promegakaryoblasts per mm3 of bone marrow were significantly lower in rchr ITP patients (p < 0.05) than in chr ITP(PR) and in chr ITP(NT) group, thus implying an inadequate Mk-poiesis in rITP chr patients. From the data presented here it may be suggested that the inadequate Mk-poiesis is operating in rchr ITP.

AC133 antibody provides an alternative to CD34 for the selection and characterization of cells necessary for engraftment in transplant situations. We studied the effect of stem cell factor (SCF), interleukin 3 (IL-3) and interleukin 11 (IL-11) on the ex vivo expansion of human CD34+/AC133+ progenitors isolated from leukapheresis products from chemotherapy plus granulocyte-colony-stimulating factor (G-CSF) -mobilized adult donors. MiniMACS AC133+ isolated cells contained a mean of 85% (80-90) AC133+ cells. Enriched AC133+ cells co-expressed CD34+ 80%, CD71low 36.6% and CD33+ 6.6%. After a seven-day ex vivo expansion in the presence of SCF + IL-3 + IL-11, the number of cells increased 19 times. These cells expressed a mean 12% CD34+ and 74% CD71+ (23% CD 71high) and 59% CD33+. This means that the absolute number of CD34+ cells increased slightly, the number of CD33+ increased 100 times and cells with high density CD71high (23%) appeared. These cells represent the cells committed to erythroid differentiation. The increase in the number of CFU-GM with various combinations of cytokines SCF + Il-3 + IL-11 will be discussed. The number of CFU-GM in culture after a seven-day ex vivo expansion in the presence of SCF + IL-3 + IL-11 increased 45 times.

As part of the evaluation of the GEN.S (Coulter), we compared the Mean Corpuscular Volume (MCV) to the Mean Spherized Corpuscular Volume (MSCV) assessed during the reticulocyte count procedure under hypo-osmotic conditions. A sub-group of patients with hereditary spherocytosis (HS) was singled out: in all of them, the MSCV became smaller than the MCV. As the cell volume normally increases in red cells derived from other patients in the same conditions, we decided to further study the reason for this particular behaviour of HS red cells. Whereas normal red cells are able to undergo an osmotic expansion, the spherocytes reach a critical osmotic volume leading to cell fragmentation consistent with the decrease of MSCV. This fortuitous finding is likely to be a reliable improvement for the routine screening of HS.

Prognostic assessment of B-cell chronic lymphocytic leukemia (CLL) patients is generally based on either Rai or Binet clinical staging systems. However, new biological parameters which reflect the clinical heterogeneity of disease are under investigation. Cellular and molecular features including tumor cell proliferation, immunophenotype, adhesion molecules expression and release, karyotypic abnormalities and biological findings of increased angiogenesis have been correlated with tumor mass and survival. It is not clear, however, whether the newly identified prognostic parameters will eventually replace clinical variables representative of tumor mass. More likely, biological parameters might be incorporated into clinico-prognostic models thus leading to the formulation of a clinico-biological system for CLL.