My daughter experienced anaphylaxsis during platelet transfusions shortly after she was diagnosed with very severe aplastic anemia about 7 years ago. Check the National Institutes of Health (NIH) website at nih.gov. One of the institutes deals with blood diseases. My daughter's hematologist also brought in a research immunologist when she had these reactions. Since her reactions were so extreme, they stopped trying random donor platelet transfusions. After a while, she was able to tolerate matched donor platelets, although her body still destroyed them. I suspect you will hear that you have some autoimmune response to blood transfusions. If you want to keep in touch, please feel free to do so. Best of luck.