Increased in vitro platelet aggregation in hypertriglyceridemias

Platelet aggregation induced by ADP and collagen was monitored in 25 patients with increased serum levels of triglycerides (7 HLPs type IIb, 14 type IV, 4 type V patients) and compared with a group of 10 normolipidaemic control persons. Platelet aggregation was studied simultaneously in platelet rich plasma (PRP) by both turbidometric and impedance technique and also in whole blood (WB) by the impedance method. Whereas platelet aggregation testing by turbidometry was limited by the optical density of the plasma samples in hypertriglyceridemia, the aggregation process could easily be registered in PRP and WB using the impedance method. Threshold aggregatory concentrations with both agonists were significantly lower for all three groups of HLP.

Critical evaluation of platelet aggregation in whole human blood

Platelet aggregation studies generally are performed in platelet-rich plasma (PRP) by the turbidometric method. The authors compared this technic with the recently introduced impedance aggregometry in PRP and whole blood (WB). In healthy controls there was a good correlation between the two technics when aggregation was induced by ADP or collagen. As compared with PRP, platelets in WB were more sensitive to the aggregating effect of thrombin, ristocetin, and arachidonic acid. Platelet sensitivity to prostacyclin was increased in WB. The anti-platelet effect of a single oral dose of aspirin could be detected for a longer period in WB than in PRP. Platelet aggregation tests in WB from patients with platelet dysfunctions showed the same response pattern to different aggregating agents as in PRP. In contrast to turbidometry, the impedance method in PRP and WB enabled registration of platelet aggregation in a dose-dependent fashion in a sample from a patient with severe hyperlipoproteinemia. It is concluded that platelet aggregation can be studied conveniently with the impedance method in the more physiologic medium of WB. Providing the same information as the well-established turbidometry, the time-sparing impedance method needs less citrated blood. Moreover, our results show an increased sensitivity of the WB system to some aggregating and anti-platelet agents.

Protein C antigen in prothrombin complex concentrates: content, recovery and half life

Protein C, a potent anticoagulant, has been detected in large amounts in some prothrombin complex concentrates (PCC). We extended these findings to eight PCC commercially available in West Germany detecting 0.82 to 1.92 plasma equivalent units of protein C antigen (PC:Ag) per unit factor IX. Infusion of PCC in four patients on stable oral anticoagulation resulted in a recovery of 58.6 +/- 10.9%. Estimated from the decrease in plasma levels of PC:Ag half life was 7.9 +/- 0.6 h.

Hyperdiploidy of 54 chromosomes with double Ph1 chromosome in lymphoid chronic myelocytic leukemic blast crisis

Cytogenetic analysis of bone marrow cells in a 40-year-old man revealed a mosaic of two cell lines during blast crisis: one diploid with typical Ph1 chromosome (46 XY Ph1) and one with hyperdiploidy of 54 chromosomes with double Ph1 chromosome, trisomy 4, 6, 8, 18, 21 and duplication of the sex chromosomes X and Y. Immunological characterization showed common acute lymphoblastic leukemia antigen in 90% of the blasts. In spite of intensive chemotherapy the patient died in a third blast crisis 15 months after the first blast crisis, 3 months after successfully treated central nervous system relapse.

Effects of BM 13.177, a new antiplatelet drug in patients with atherosclerotic disease

Seven males with atherosclerotic disease received daily 1.6 g of the thromboxane antagonist BM 13.177 in two separate oral dosages over a period of four days. The drug significantly reduced elevated plasma levels of thromboxane B2, beta-thromboglobulin and platelet factor 4, whereas thromboxane B2 generation was only slightly depressed. BM 13.177 inhibited platelet aggregation by collagen, and to a minor degree the second wave of ADP induced aggregation. Platelet sensitivity to prostacyclin and aggregation by ristocetin were not altered. Bleeding time was prolonged. All effects disappeared within 24 hours after the last application of the drug. No side effects were noted. Thus BM 13.177 appears to be a safe and effective new antiplatelet drug.

[Nomifensin-induced immune haemolytic anaemias (author's transl)]

Two cases of immune haemolytic anaemia and acute renal failure induced by nomifensine are reported. The two female patients had been under continuous nomifensin therapy because of reactive depressions. In both cases nomifensine had been discontinued and the clinical reactions--immune haemolytic anaemia and acute renal failure--started immediately after they had taken again a capsule of nomifensine. In one case the patient's serum contained a potent antibody which agglutinated her red blood cells in presence of nomifensine in the antiglobulin test.

Evaluation of hypercoagulability after remission induction chemotherapy of acute leukemia

In 20 patients with acute leukemia the thrombin-mediated fibrin monomer complexes (SFMC) were determined before and after remission induction chemotherapy for several weeks to assess the extent of hypercoagulability. Increased levels of SFMC were observed in patients with high leukocyte cell counts after induction chemotherapy which may reflect the release of thromboplastic material from destructed leukemic cells. Patients with low leukocyte counts showed only a moderate increase in SFMC. A low concentration of antithrombin III (< 20 mg/100 ml) or a drop from a previously normal value was a prognostic unfavorable sign. An elevated level of plasmin-mediated fibrin-split-products could not be related to the course of therapy.