[Von Willebrand disease type 3 falsely diagnosed as hemophilia A: a case report]. / Maladie de von Willebrand type 3 faussement diagnostiquée en hémophilie A modérée : à propos d'une observation.

The von Willebrand disease type 3 can be confused with hemophilia A because a very low level of factor VIIIC, we will report the case of patient with von Willebrand disease type 3 treated as moderate hemophilia A.

La maladie de von Willebrand type 3 s'accompagne d'une diminution du taux du facteur VIIIC qui peut être confondu dans certaines situations avec une hémophilie A. Nous rapportons le cas d'un patient présentant une maladie de von Willebrand type 3 suivi et traité comme un hémophile A modéré durant toute son enfance.

[Evaluation of the analyzer of hematology Beckman Coulter® HmX™ in the university hospital of Oran]. / Évaluation de l'analyseur d'hématologie Beckman Coulter® HmX™ dans le centre hospitalo-universitaire d'Oran.

INTRODUCTION: The choice of an automaton of haematology is a determining stage, which has to take into account at the same time the quality of the results and the economic imperatives: workload, structure and organization of the laboratory. MATERIAL AND METHODS: [corrected] It is in this spirit that we estimated during a period of 3 months the analyzer of haematology: the HmX™ Coulter with boatman of samples of the company Beckman. This automaton realizes the blood numeration, the formula leukocytic and the reticulocyte count. At first, we estimated the appropriate characteristics of device. Secondly, we estimated the relevance, the sensibility and the specificity of the alarms by comparing with the reference method, which is the optical microscopy. For that purpose, 125 blood smears resulting from service of haematology and from resuscitation were examined in optical microscopy. The technical tests were realized according to the recommendations of the International committee for evaluation of automatons of haematology. RESULTS: The analytical performances were satisfactory in particular the big interval of linearity and the absence of contamination. As regards the evaluation of the alarms system: rate of rejection is 63%, the sensibility 86%, the specificity 70%, the positive predictive value 80%, the negative predictive value 78% and the efficiency 80%. The alarms myelaemia and atypical lymphocytes were never sources of false negatives. The alarms erythroblasts and platelet aggregates did not engendered positive forgery. The blast cell alarm was responsible for a single case of false negative. CONCLUSION: The faithfulness of automaton is satisfactory: the absence of contamination, the big interval of linearity for the leukocytes, the red blood cells and the platelets as well as a good relevance of the alarms with regard to the anomalies found on the peripheral blood smear. From the user-friendliness and practicability point of view, the HmX™ Coulter was deeply appreciated.

Influence of teniposide on platelet functions in vitro.

Teniposide added to citrated platelet-rich plasma reduced platelet aggregation induced by collagen, but did not interfere with ADP-induced aggregation. The availability of platelet factor 3 was decreased irrespective of inducer. Reptilase clot retraction induced by ADP or collagen was reduced. Teniposide did not interfere with platelet adhesion to glass. It did not release lactic dehydrogenase from the cytoplasm of platelets. Coagulation factors were not affected.

Relationship between platelet aggregation and plasma beta-thromboglobulin levels in arterio-vascular and renal diseases.

The incidence of second wave of platelet aggregation induced by a small dose of ADP (1 mumol/l) was compared with plasma levels of beta-thromboglobulin in 81 normal individuals, 34 patients with acute myocardial infarction, 11 patients with acute cerebrovascular disease and 26 patients with renal disease. Platelet hyperaggregability was observed in 7% of normal individuals. Plasma levels of beta-thromboglobulin were higher in normal individuals over 60 years of age (48 vs. 32 micrograms/l). In contrast, hyperaggregability was observed in 79% of patients with acute myocardial infarction and in 64% of those with acute cerebrovascular disease. Median plasma levels of beta-thromboglobulin were also significantly elevated in patients with acute myocardial infarction (82 micrograms/ml) or acute cerebrovascular disease (99 micrograms/l). Levels of beta-thromboglobulin in plasma were significantly higher in those patients who demonstrated hyperaggregability. In patients with renal disease only 12% had signs of hyperaggregability. Nevertheless their plasma levels of beta-thromboglobulin were elevated (76 micrograms/l) and correlated with the serum creatinine values. These investigations indicate that patients with acute myocardial infarction or stroke have hyperreactive platelets and evidence of increased platelet inactivation in the circulation. However, evaluation of increased levels of beta-thromboglobulin requires consideration of renal function.

Platelet count and mean platelet volume in an Algerian population indicating a low prevalence of Mediterranean macrothrombocytopenia.

Platelet count was 225 X 10(9)/l in 225 healthy male Algerians and 263 X 10(9)/l in 208 females. The mean platelet volume was 9.15 fl in the males and 9.30 in the females. The figures agree with those obtained in a British and an American population, but differed from those of an Australian population of immigrants from Mediterranean countries, essentially Italy and Greece. The prevalence of Mediterranean thrombocytopenia must therefore be low in Algeria.

Influence of cis-platinum on some platelet functions in vitro.

Cis-platinum added to citrated platelet rich plasma in vitro did not influence the aggregation of the platelets, their adhesion to glass, their release of platelet factor 4 or availability of platelet factor 3 and acid phosphatase. Neither any effect on the uptake of 14C-serotonin, the reptilase clot retraction or the coagulation system has been observed.

Influence of dianhydrogalactitol on some platelet functions in vitro.

Platelet-rich plasma was incubated with dianhydrogalactitol (DAG) in vitro. This moderately diminished platelet aggregation induced by adrenaline and to a smaller degree by adenosine diphosphate /ADP) or collagen. The availability of platelet factor 3 induced by ADP, adrenaline or collagen was decreased irrespective of the inducer. The release of platelet factor 4 was unaffected. Reptilase clot retraction induced by ADP or collagen was slightly inhibited. Uptake of 14C-serotonin was slightly decreased. Uptake of 14C-adenine was normal. Platelet adhesion onto glass was not depressed. DAG did not release lactic dehydrogenase from the cytoplasm of the platelets. Coagulation factors were not affected.