Autoantibodies to vasopressin secreting cells (AVP-¢) in children with idiopathic diabetes insipidus of central origin

Abstract

To investigate the role of autoimmunity in the pathogenesis of idiopathic DI, antibodies (Ab) to AVP-¢ have been evaluated in the serum of 57 patients. After clinical and neuroradiological investigation patients were classified into : idiopathic (n=23), DI with central lesion (n=19) and familial or DIDMOAD syndrome (n=13). Sera were tested for the presence of AVP-¢-Ab by indirect immuno-fluorescence using fresh human fetal hypothalamus as substrate. Absence of extinction of the reaction by AVP indicate that Ab are not directed to the hormone itself but to some component of the AVP-¢. AVP-¢-Ab were present in 10 (43.5%) idiopathic cases (3 of them had associated endocrine autoimmune disease : hypothyroidism, Type I diabetes and thyroiditis). Among the symptomatic cases 3 had AVP-¢-Ab, 2 of them having histiocytosis-X. None of the familial or DIDMOAD cases had AVP-¢-Ab. In conclusion: Autoimmunity may play a role in the etiology of idiopathic DI as shown by the presence of AVP-¢-Ab and associated autoimmune disease. Presence of AVP-¢-Ab in histiocytosis-X is intriguing and may be due to an autoimmune reaction induced by histiocytosis-X cells bearing histocompatibility antigen and infiltrating the hypothalamus.