The Antigenic Properties of Insulin

The establishment of insulin as a complete and soluble protein1anticipated its property as an antigen. The allergic reactions that are often associated with its clinical use indicate that it is active in this respect. The greater prevalence of hypersensitivity to insulin preparations when they first began to be generally used as compared to substances now in use is probably to be attributed to the presence of extraneous substances that have for the most part been eliminated with the development of better processes of manufacture. Nevertheless reactions, both general and local, do still occur with the refined substances and present a baffling problem in the treatment of diabetes. Commercial preparations of insulin are derived from either beef or pork tissues or indiscriminately from both. Studies of cases of hypersensitivity to insulin show that most of them are sensitive to the insulin protein itself, although some show sensitization to the