7282 Arginine-Vasopressin Deficiency And Long COVID: A Causal Or A Coincident Relationship?

Abstract Disclosure: R.S. Medeiros: None. Introduction: Arginine-vasopressin deficiency (AVP-D) has been reported in few case reports as a very rare complication of COVID-19 and SARS-COV2 immunization. Long COVID is defined as signs, symptoms, and conditions that develop after COVID-19, and it can affect several organs and systems. Autopsy studies showed SARS-COV2 genetic sequence in degenerated neurons of hypothalamus, and expression of angiotensin-converting enzyme type 2 in median eminence capillaries and paraventricular nucleus have also been demonstrated. Clinical Case: A 47-year-old male presented with polydipsia (8 L/day) and polyuria 8 weeks after non-severe COVID-19. Past medical history was relevant for untreated dyslipidemia. He denied past head trauma, surgery or radiotherapy. Family history was unremarkable. Biochemical evaluation revealed normal glucose, serum electrolytes, renal and hepatic parameters; urine osmolality was 160 mOs/Kg and 24h urinary volume was 10350 mL. Basal pituitary surveys were also normal. A water deprivation test was performed but stopped after 2 hours due to development of hypernatremia (Na+ 146 mEq/L), serum osmolality of 311 mOs/Kg (reference: 280-300) and urine osmolality of 105 mOsm/Kg. After 20 ug intranasal desmopressin urine osmolality increased to 357 mOsm/Kg. A contrast-enhanced MRI revealed an absent posterior pituitary bright spot and thickening of the pituitary stalk suggesting infundibulo-neurohypophysitis. Further biochemical and imaging surveys excluded infectious and infiltrative causes of AVP-D; however, due to elevated serum iron (204.0 ug/dL; reference: 65-175) and transferrin saturation (68%; reference: 15-45%), genetic screening of hemochromatosis by next-generation sequencing of all hemochromatosis-associated genes (HFE, HJV, HAMP, TFR2 and SLC40A1) revealed a heterozygotic variant c.187C>G p.(His63Asp) in HFE, a genotype not associated with iron overload. He started oral desmopressin 0.2 mg/day, to which he showed a prompt response, titrated to 0.8 mg/day (in 3 divided doses). Conclusion: Although molecular and histologic confirmation of SARS-COV2 infundibulo-neurohypophysitis could not be investigated, a strong temporal relationship and the absence of an alternative diagnosis renders plausible the inclusion of AVP-D in the myriad of manifestations of long COVID. Further studies with patients recovered from COVID-19 are necessary to gain a better understanding on the epidemiology, pathophysiology and clinical course of this very rare endocrine association of SARS-COV2 infection with infundibulo-neurohypophysitis. Presentation: 6/3/2024