title: A comparison of volume-reduced versus standard HLA/HPA-matched apheresis platelets in alloimmunized adult patients.
abstract: BACKGROUND
  Our blood bank prepares, on indication or request, a volume-reduced (VR) platelet (PLT) product with greater than 95% reduced plasma content and a 15-fold higher PLT concentration, potentially minimizing adverse reactions due to plasma, in particular for human leukocyte antigen (HLA)/human PLT antigen (HPA)-matched PLTs when minor ABO incompatibility cannot be avoided. Here we compared the clinical effectiveness of VR apheresis PLTs (APs) with standard APs.
  
  
  METHODS
  We performed a single-center cohort study among consecutive alloimmunized patients who received either HLA/HPA-matched standard APs and/or VR-APs between 1994 and 2008. The endpoints were corrected count increments (CCIs), time to next transfusion, and frequency of adverse reactions. The CCI of VR PLTs was calculated using the PLT dose before volume reduction. Using a random effects model, 851 transfusions to 68 patients were evaluated for CCI and 731 transfusions to 64 patients for time to next transfusion. The frequency of reported adverse reactions was compared between the groups.
  
  
  RESULTS
  The 1-hour CCI was 23% (95% confidence interval [CI], 9%-42%; p < 0.001) lower and the 24-hour CCI was 17% (95% CI, -11% to 59%; p = 0.278) lower after VR-APs. The mean time to next transfusion was similar: standard APs, 3.1 days (95% CI, 2.7-3.5); and VR-APs, 2.8 days (95% CI, 2.5-3.2). Eight adverse reactions were reported: 4 of 619 in the standard AP group and 4 of 1202 in the VR-AP group.
  
  
  CONCLUSIONS
  VR-APs showed lower 1- and 24-hour CCIs than standard-APs, which can be largely explained by the lower PLT dose of VR-APs. The benefits of plasma reduction should seriously be outweighed given these lower increments.
authors: Department of Transfusion Medicine, Sanquin Blood Services, Plesmanlaan 1a, 2333 BZ, Leiden, the Netherlands. a.honohan@sanquin.nl
authors: Aine
authors: A
authors: Honohan
authors: Bert
authors: B
authors: Tomson
authors: Johanna
authors: J
authors: van der Bom
authors: René
authors: R
authors: de Vries
authors: Anneke
authors: A
authors: Brand
mesh_terms: D000328:Adult; D000368:Aged; D016824:Antigens, Human Platelet / Q000276:immunology*; D015331:Cohort Studies; D005260:Female; D006650:Histocompatibility Testing; D006801:Humans; D007518:Isoantibodies / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D017713:Platelet Transfusion / Q000009:adverse effects*; D010983:Plateletpheresis; D013997:Time Factors
chemical_list: D016824:Antigens, Human Platelet; D007518:Isoantibodies