Platelet Aggregation in Blood Donors

One hundred eighteen consecutive volunteer donors to a Red Cross Mobile Collecting Center were questioned about ingestion of medication prior to blood donation. Blood samples were collected from each donor and platelet aggregation measured. Forty-three (36%) gave a history of having taken a drug known to affect platelet function, the most common of which was acetylsalicylic acid. Of these, 88 per cent had abnormal platelet aggregation. A total of 59 per cent of the blood donors were found to have abnormal aggregation. When 50 control subjects were asked one week prior to testing not to take any medication, only one had abnormal aggregation. This study indicates that in our area the majority of blood donors have abnormal platelet aggregation due to ingestion of medication.