["In order to assess the impact of leukocyte reduction, all transfusion reactions reported at Liege Teaching Hospital's Blood Bank 2 years before and after the implementation of universal leukocyte reduction of red blood cells concentrates which started-up on 1 January 2005 were evaluated.", "A retrospective analysis of transfusion reactions from 1 January 2003 to 31st December 2006 was undertaken. Data were collected from computerized reports, which were entered as soon as a transfusion reaction was reported. Symptoms were classified in different reaction's categories. Blood cultures, antibody screening and direct antiglobulin test were performed. Differences between the two time periods, before (2003-2004) and after (2005-2006) universal leukoreduction were determined by the Chi-square test and significance was defined as a p value less than 0.05.", 'During period before the implementation of systematic leukoreduction, 68.7% of red blood cells transfused were leukoreduced. A total of 365 transfusion reactions in 91,996 red blood cells units transfused (0.4%) were reported, of which 266 were classified as febrile non-hemolytic transfusion reactions (72.9%), followed by allergic reactions (7.1%) and miscellaneous reactions (3.8%). When comparing the two-time periods, the rate of all transfusion reactions in general significantly decreased from 0.49 to 0.31% (p<0.001). Therefore, universal leukocyte reduction significantly reduced the rates of febrile non-hemolytic transfusion reactions (0.35% versus 0.24%; p=0.002) and allergic reactions (0.05% versus 0.01%; p<0.001).'] Does [ The effect of leukocyte-reduction on the transfusion reactions to red blood cells concentrate ]?