DETECTION OF VASOPRESSIN CELL ANTIBODIES IN SOME PATIENTS WITH AUTOIMMUNE ENDOCRINE DISEASES WITHOUT OVERT DIABETES-INSIPIDUS

OBJECTIVE Cytoplasmic autoantibodies to vasopressin cells (AVP) have b een detected in patients with idiopathic central diabetes insipidus an d only in one patient with endocrine autoimmune diseases without clini cal diabetes insipidus. The aim of this study was to look for AVP cell antibodies (AVP-cell-Ab) in human sera of a large population of autoi mmune endocrine disease patients without diabetes insipidus and to tes t whether an occurrence of these antibodies in some patients can be as sociated with partial impairment of posterior pituitary function. MEAS UREMENT Sera from 410 patients (310 females, 100 males, age range 10-4 6 years) with autoimmune endocrine disorders (260 with thyroid autoimm une disease, and 150 with insulin dependent diabetes mellitus) without clinical diabetes insipidus, and from 100 normal subjects, were inves tigated for hypothalamic autoantibodies by an indirect immunofluoresce nce method. Positive sera were subsequently tested with specific rabbi t anti AVP serum. RESULTS None of controls, but five out of 410 patien ts (1.2%) were AVP-cell-Ab positive. All positive and nine negative fr om the 410 screened patients were tested for posterior pituitary funct ion. Two out of five AVP-cell-Ab positive patients showed partial diab etes insipidus. CONCLUSION AVP cell antibodies can be shown in some pa tients with endocrine autoimmune disease without diabetes insipidus an d can sometimes be associated with findings of partial posterior pitui tary dysfunction. This suggests that clinical diabetes insipidus could be preceded by a long subclinical period characterized only by the oc currence of AVP-cell-Ab in the sera associated or followed by alterati ons in functional tests. Longitudinal studies are needed to confirm th is hypothesis.