Studies in the area of thrombocytopenic purpura reported from K. Selleng and co-researchers
2007 OCT 29 -- According to recent research published in the American Journal of Hematology, "'The pathogenesis of very severe thrombocytopenia in bacterial endocarditis is uncertain. We report a 50-year-old male with platelet counts < 10 x 10(9)/I and fragmentation hemolysis complicating Staphyloccoccus epidermidis pacemaker endocarditis with a giant vegetation." "Antibiotics, corticosteroids, high-dose intravenous gammaglobulin, and plasmapheresis (for initially-suspected thrombotic thrombocytopenic purpura) failed to produce significant platelet count increase. However, therapeutic-dose heparin anticoagulation was associated with a platelet count increase from <10 to similar to 40 x 10(9)/I, with parallel reduction in thrombin-antithrombin complexes (from 8.9 to 3.5 mu g/I), facilitating surgical intervention. The thrombocytopenia promptly resolved following surgical removal of the vegetation. Culture supernatant from S. epidermidis isolated from the patient's blood induced monocytes to express procoagulant activity (assessed by factor Xa generation) equivalent to lipopolysaccharide (1 mu g/ml), with half-maximal activation seen with culture supernatant diluted to 1:12,800. These data are consistent with previous animal models of endocarditis demonstrating staphylococci-induced procoagulant changes in monocytes," wrote K. Selleng and colleagues. The researchers concluded: "This case demonstrates that heparin anticoagulation can be therapeutic in infective endocarditis-associated severe thrombocytopenia in a non-bleeding patient, and that such therapy may ameliorate the platelet count enough to permit surgical intervention." Selleng and colleagues published their study in American Journal of Hematology (Very severe thrombocytopenia and fragmentation hemolysis mimicking thrombotic thrombocytopenic purpura associated with a giant intracardiac vegetation infected with Staphylococcus epidermidis: role of monocyte procoagulant activity induced by bacteri. American Journal of Hematology, 2007;82(8):766-771). For additional information, contact T.E. Warkentin, Hamilton Health Science General Site, Hamilton Reg Laboratory Med Program, Room 1-180A, 237 Barton St. E Hamilton, Hamilton, ON L8L2X2, Canada. The publisher's contact information for the American Journal of Hematology is: Wiley-Liss, Division John Wiley & Sons Inc., 111 River St., Hoboken, NJ 07030, USA. Keywords: Canada, Hamilton, Cardiology, Coronary Artery Disease, Endocarditis, Heart Disease, Hematology, Hemolysis, Intracardiac, Myocarditis, Thrombocytopenia, Thrombocytopenic Purpura. This article was prepared by Cardiovascular Week editors from staff and other reports. Copyright 2007, Cardiovascular Week via NewsRx.com.
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