Quoted from the NIH: Normally, the immune system helps protect the body, but with Crohn's disease the immune system can't tell the difference between normal body tissue and foreign substances. The result is an overactive immune response that leads to chronic inflammation. I have never heard someone say Crohn's isn't an autoimmune disease.
For the neonate with FMAIT, platelet transfusion is the treatment of choice and should be given to normalise the platelet count in an infant with ICH or to treat severe throbmobocytopaenia in infants without ICH. Platelets used for neonates with FMAIT should be negative for the implicated platelet-specific antigen.
Cancer and some cancer treatments can reduce the number of platelets in the blood. This can increase your risk of bleeding and may cause: nosebleeds; bruising; heavier periods; bleeding gums; other more serious problems. If the number of platelets in your blood (your platelet count) is too low, doctors may recommend a platelet transfusion. Platelets come from people who donate their blood. You will need to sign a consent form to say you give permission for the doctors and nurses to give you a transfusion.