| Abstract: | A 43 year old man with diabetes insipidus who showed panhypopituitarism and marked hypergammaglobulinemia due to histiocytosis X is reported. His low basal plasma adrenocorticotropin (ACTH) and growth hormone (GH) failed to respond to insulin-induced hypoglycemia. His basal serum thyroid hormone level was below normal and normal basal plasma thyrotropin (TSH) showed a delayed response with normal peak value to TSH-releasing hormone (TRH). Normal basal plasma pituitary gonadotropin also showed a delayed response with normal peak value to luteinizing hormone-releasing hormone (LH-RH). Suppression of plasma prolactin (PRL) by levodopa (l-dopa) was impaired and elevation of basal plasma PRL was noted at the second admission. These results, combined with diabetes insipidus, suggested that the panhypopituitarism in these patients was hypothalamic in origin. The polyclonal hypergammaglobulinemia was characterized by elevated serum IgG and IgE levels which returned to normal after corticosteroid treatment with concomitant clinical improvement. Elevated serum IgE levels, tissue and peripheral eosinophilia, and the effectiveness of corticosteroid therapy support the hypothesis that some allergic mechanism may be involved in the pathogenesis of this disease. |
