A 47-year-old man presented with a 1-month history of hemoptysis. DI was diagnosed 30 years ago. No structural causes were found on CT scanning and pituitary MRI. A water-deprivation test 5 years ago following desmopressin withdrawal confirmed isolated ADH deficiency (clinical dehydration, polyuria, and urine osmolality<100 mOsm/kg). Past history included renal TB and HIV infection diagnosed 31 and 24 years ago, respectively. He received a full course of anti-TB therapy and had been stable (undetectable viral load, CD4 count 700-800 cells/mL last 3 years) on antiretroviral therapy (tenofovir disoproxil fumarate 300 mg, emtricitabine 200 mg, one tablet/d; lopinavir 200 mg, ritonavir 50 mg, two tablets/d; and lamivudine, 300 mg/d). Eunatremia was maintained by desmopressin therapy (10 μg intranasally twice daily), initiated at diagnosis 30 years ago.