An iatrogenic autoantibody: immunological responses to `pituitary snuff' in patients with diabetes insipidus

In the treatment of patients with diabetes insipidus, due to a variety of causes, by nasal insufflation of `pituitary snuff' (porcine or bovine, acetone-dried posterior pituitary), asthma may develop and immediate reactions are given on skin testing with the treatment material, In addition, in patients with or without asthma, precipitating antibodies have been found in the serum capable of reacting with heterologous serum protein constituents of the pituitary snuff, and also with antigens of homologous and heterologous pituitary gland. Immunofluorescence studies have shown that antibodies are present not only to heterologous tissues (bovine and porcine) but also to human tissue—in particular to antigens in the pituitary. Inhalation of the heterologous pituitary antigens has thus led to the appearance of `hetero-stimulated', `autoreactive' antibodies against the homologous pituitary. These antibodies are related to the treatment and not to the original causation of the disease.