The induction of antibodies to human luteinizing hormone by contaminated clinical pituitary hormone preparations.

Three children with hypopituitarism had elevated LH levels measured by RIA which were incompatible with their stage of sexual maturation. Each of the children had been administered parenteral pituitary hormone preparations: one patient, human (h) GH for 3 2/1 yr; one patient, bovine TSH twice to evaluate thyroid responsiveness; and two patients, posterior pituitary extract by nasal insufflation for 7 5/12 ad 4 9/12 yr to treat diabetes insipidus. Each of these children had developed antibodies of the immunoglobulin G class which bound [125I]hLH in vitro in a displaceable fashion. In two of the patients, the antibody reacting with hLH was found after therapy with pituitary hormones of bovine or porcine origin and before treatment with hGH, while on child had received only hGH therapy. These antibodies interfered in the assay for hLH and were responsible for the spurious elevations of serum immunoreactive hLH. None of these children had undergone spontaneous puberty, including at least one who may not have been gonadotropin deficient. To reduce the risk of generating high potency neutralizing antibodies, only highly purified, monomeric pituitary hormone preparations or pure synthetic hormone preparations should be used for diagnosis and chronic replacement therapy.