Nouvelle revue francaise d'hematologie最新文献

Haemophagocytic syndrome is a heterogenous disease characterized by disordered macrophage activation associated with viral, bacterial or parasitic infection. The few reports of haemophagocytosis occurring in the presence of mycobacterial infection show a high mortality rate and we present two further cases notable for their favourable issue. Rapidity of diagnosis and immediate treatment could explain the avoidance of a fatal outcome.

The present article describes how it is possible to elucidate the essential cellular machines controlling directed migration. Investigations are performed with cells like granulocytes, fibroblasts or neural crest cells and these cells are found to contain two independent types of machines, a steerer (controller without feedback) for the speed and an automatic controller (controller with feedback) for the angle of migration. The first intracellular signal is the distribution of membrane bound receptors occupied by kinesis stimulating molecules from the extracellular space. Motile force is produced by a linear motor supplied by the chemically amplified first intracellular signal (total number of occupied receptors). When properties of the cellular steering device are investigated, results show the angle of migration to be corrected by an automatic controller and an asymmetric distribution of occupied receptors to be the first intracellular signal for directed migration. Properties of the goal-seeking device are also investigated. As in many different types of technical machines, the cellular machinery operates in a cyclic manner which in the case of granulocytes a measuring cycle of 8 s and a response cycle of approximately 60 s. These cellular machines may be understood in terms of a self-ignition mechanism where the renewal of membrane bound receptors is the essential step.

Crohn's disease (CD) has been occasionally reported to be associated with myelodysplastic syndromes (MDS) or acute myeloid leukaemia (AML). From October 1991 to June 1993, four AML patients with a previous history of CD but no history of MDS were referred to our institution. Three presented AML with a monoblastic proliferation (one AML4 and two AML5). Cytogenetic analysis revealed a normal karyotype in two patients, an inv(16) in another and a del(11)(q24-25) in the fourth. Interestingly, the three patients with AML4/AML5 had not received high doses of immunosuppressive agents, prior CD therapy ranging from 1 to 4 months sulfasalazine with additional azathioprine in one case.

Bone marrow purging with cyclophosphamide derivatives in autologous bone marrow transplantation has demonstrated that the killing of leukemic cells and simultaneous preservation of normal progenitor cells depends on a number of parameters, in particular the haematocrit, nucleated cell concentration and nature of the cells. We have previously described a reliable experimental procedure for in vitro bone marrow treatment, based on individual adjustment of the drug dosage. The present study reveals an inhibitory action of plasma on the toxicity of mafosfamide to normal haematopoietic progenitor cells. In an initial series of 42 successive patients, determination of the CFU-GM lethal dose 95% (CFU-GM LD 95) showed this parameter to be inversely correlated to the nucleated cell concentration (NCC) (p < 0.001). Assuming the plasma content of the buffy coat cells (BC) to be higher in the less rich marrow samples, we then investigated the role of plasma in progenitor cell sensitivity to the drug. Results were as follows: (1) in the presence of 60% autologous or allogeneic plasma, CFU-GM LD 95 was increased by a factor of 2.18 +/- 0.35 or 1.98 +/- 0.23 respectively as compared to controls in a solution of 2% bovine serum albumin (p = 0.014), (2) this observation remained valid whatever the origin of the plasma and (3) the same was true whatever the nature of the cells, derived from normal donors or patients with haematological malignancies. These data suggest that plasma contains an inhibitor(s) of mafosfamide.(ABSTRACT TRUNCATED AT 250 WORDS)

An acquired circulating anticoagulant with anti-factor V activity appeared in a 29 year old AIDS patient with widespread Kaposi's sarcoma following 21 days of fresh frozen plasma therapy for haemolytic and uraemic syndrome. Residual factor V activity was very low (< 5% of normal). However, the inhibitor was of low titre (0.5 Bethesda Units/ml), while antigenic factor V levels remained at 100%. Dot blotting with human factor V and polyvalent and specific immunoglobulin antisera showed the antibody to belong to the IgG class. Haemostatic tests in vitro were only partly corrected by addition of washed human platelets and despite transfusion of large amounts of platelets the patient died from massive pulmonary haemorrhage. This would appear to be the first documented case of an anti-factor V inhibitor occurring in an AIDS patient.

In 34 patients with peripheral occlusive arterial disease, circulating levels of endothelial cell markers were compared with the ischemic status. Unlike tissue plasminogen activator and plasminogen activator inhibitor, plasma levels of thrombomodulin were closely related to both transcutaneous oxygen pressure (p = 0.01) and the graded clinical stages of disease (p = 0.02). Levels of von Willebrand factor were correlated only with the transcutaneous oxygen pressure (p = 0.04). Since thrombomodulin and von Willebrand factor constitute markers of endothelial cell damage, the extent of endothelial injury would appear to be determined by the ischemic status.

The majority of low grade non-Hodgkin's follicular lymphoma undergo clinical progression to intermediate and high grade lymphoma, but the molecular mechanisms involved in this transformation are not yet well understood. In this article, we describe the case of a 66 year old man with follicular non-Hodgkin's lymphoma (NHL), in whom a centroblastic leukaemic transformation led to death in six months, despite a transient period of remission. At the time of transformation, cytogenetic analysis revealed the original coexistence of t(14;18)(q32;q21) and t(8;22)(q24;q11). These results were confirmed by fluorescent in situ hybridization, while molecular analysis showed a BCL2-JH rearrangement but failed to detect a c-myc rearrangement or any additional p53 mutation. Our observations would therefore suggest other mechanisms to be involved in the transformation of follicular NHL.