I was reading about blood donations on the NHS website and I saw A- was the universal platelet donation type.
Why is this? Does your blood type affect your platelets? Surely A+ platelets would be the same as A- because the rh factor only affects the red blood cells, right?
So why would A- be coming considered universal platelet donor and not A+?
Platelets themselves carry ABO antigens but not Rh; however, donor platelet bags always contain some RBC. A Rh Positive donor Platelets would carry enough Rh Positive RBC to cause alloimmunization and anti-D production in an Rh Negative patient.