What's it called when there's an immune response to your own plasma where your body attacks its own plasma?

? Serum sicknesses: Probably this is what you meant by your question. Serum sickness is simply a type of immune reaction when immune complexes in plasma fight other protein complexes formed usually after exposure to a foreign protein, which can be either a drug such penicillin or sulpha or antiserum given for passive immunization as in case of exposure to rabies or hepatitis B. Hope this answers your query