Although it is not clear what causes the reaction, according to the magazine New Scientist, the blood that causes it “appears to come primarily from people who have been exposed to a variety of blood groups in the past, such as... people who have had multiple transfusions. ”
لكنّ الخبراء يخامرهم شعور بأن الرقم الفعلي اكبر بكثير ،‏ لأن عددا كبيرا من العاملين في مجال الرعاية الصحية لا يميِّزون اعراض هذه الحالة .‏