Frequency of Kell antigen in donor blood bags used in Adult Thalassemia Center

Alloimmunization is one of the side effects of regular blood transfusion in thalassemic patients. We studied the frequency of Kell antigen in donor blood bags used in Adult Thalassemia Clinic in Tehran. Our aim was to screen Kell antigen on the blood bags which came for use in Adult Thalassemia Clinic. First, we recorded the bag number with which we could access the characteristics of the blood donors such as sex, age, number of donation, and so on. Then, for Kell study, we used anti Kell kit on each cord detached from the blood bags. The results were collected and analysed by SPSS18.In our one year cross sectional study, we checked Kell antigen for 11557 blood bags 98.7% were for male and 1.3% for female. The minimum age of our donors was 17 years old and maximium 65. Out of the total number of blood donors, 19.6 % were first time, 27.4% had the history of prior donation, and 52.9% were repeated donors. In our kell study for K or KEL1 antigen, we had 96.2% Kell negative bags and 3.8% were Kell positive. We had the rate of less than 4% positivity of Kell antigen on our donors showing more than 96% Kell negativity. However, for the reduction of the risk of alloimmunization in chronically transfused patients, it is better to check all bags for Kell antigen and prevent the use of Kell positive bags.