title: Treatment of refractoriness to platelet transfusion by protein A column therapy.
abstract: Ten thrombocytopenic patients (platelets < 10-24 x 10(9)/L) who were refractory to platelet transfusion were investigated for their responsiveness to staphylococcal protein A column therapy. Nine patients had previously been treated with steroids, intravenous immune globulin, and/or other forms of immunosuppressive therapy without improvement in their transfusion response. All patients were receiving multiple platelet transfusions without achieving 1-hour corrected count increments (CCIs) > or = 7500. Eight patients had antibodies that reacted with platelets and were directed against HLA class I antigens, ABO antigens, and/or platelet-specific alloantigens. Plasma (500-2000 mL) from each patient was passed over a protein A silica gel column and then returned to the patient. Patients received from 1 to 14 treatments. A positive response to protein A therapy was defined as at least a doubling of the pretreatment platelet count and/or two successive 10- to 120-minute posttransfusion CCIs > or = 7500. Following plasma treatments, 6 of 10 patients responded with daily platelet counts that averaged 48 +/- 11 x 10(9) per L as compared with counts of 16 +/- 7 x 10(9) per L (p < 0.0005) before treatment. Posttransfusion CCI values determined in four of these patients averaged 2480 +/- 810 and 10,010 +/- 3540 (p < 0.005) before and after treatment, respectively. In contrast, among the four unresponsive patients, platelet counts averaged 10 +/- 9 and 13 +/- 10 x 10(9) per L (p = NS), respectively, while posttransfusion CCIs were 700 +/- 1410 and 1520 +/- 2460 (p = NS), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis.
authors.forename: D J
authors.initials: DJ
authors.lastname: Christie
authors.forename: R B
authors.initials: RB
authors.lastname: Howe
authors.forename: S S
authors.initials: SS
authors.lastname: Lennon
authors.forename: S C
authors.initials: SC
authors.lastname: Sauro
mesh_terms: D000328:Adult; D000368:Aged; D016824:Antigens, Human Platelet / Q000276:immunology; D016913:Blood Component Transfusion; D002648:Child; D005260:Female; D006801:Humans; D007022:Hypotension / Q000209:etiology; D007163:Immunosorbent Techniques / Q000009:adverse effects; D007518:Isoantibodies / Q000097:blood; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D013205:Staphylococcal Protein A / Q000009:adverse effects / Q000627:therapeutic use*; D013921:Thrombocytopenia / Q000628:therapy; D014581:Urticaria / Q000209:etiology
chemical_list: D016824:Antigens, Human Platelet; D007518:Isoantibodies; D013205:Staphylococcal Protein A