Endocrine Abstracts

JOINT1155

Introduction: Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have been rapidly developed with several novel and conventional technologies. The full profile of adverse effects is yet to be elucidated. Recently, there are sporadic but increasing reports of endocrinopathy in relation to SARS-CoV-2 vaccination, including a few cases of pituitary abnormalities such as hypophysitis. Hypophysitis following SARS-CoV-2 vaccination is exceptionally rare with less than ten cases being reported in the literature and typically presents as arginine vasopressin (AVP) deficiency emerging shortly after vaccine administration.

Aim: We present a novel rare case of infundilo-neurohypophysitis related to SARS-COV-2 vaccination which led to permanent isolated AVP deficiency.

Case Presentation: A 31-year-old previously healthy man presented with polyuria and polydipsia twenty days after his third dose of SARS-COV-2 vaccine with mRNA type (Moderna). He reported increased urine output and liquid intake, almost 7 liters per day. The previous two doses of SARS-COV-2 vaccine administrated to the patient, nine and seven months before, were viral rector type (AstraZeneca). On admission physical examination was normal. Biochemical tests and endocrine work up revealed no other abnormalities except for low urine osmolarity. Sella region magnetic resonance imaging (MRI) revealed diffusely enlarged pituitary gland and thickening of the pituitary stalk. Additionally, the bright spot of the neurohypophysis was not visible. After exclusion of the majority of causes of hypophysitis and taking in consideration the time-related symptoms in the absence of other symptoms, AVP deficiency was suspected in the context of SARS CoV-2 vaccine induced hypophysitis. Thus, treatment with oral desmopressin (DDAVP) was commenced, leading to rapid resolution of symptoms and also confirming our provisional diagnosis of AVP deficiency. Currently, at 3-year-follow-up there is persistence of pituitary stalk thickening on MRI with no other abnormalities. and the patient necessitates treatment with DDAVP 60 mg twice daily in order to remain asymptomatic.

Conclusion: Although rare, there are limited data suggesting a possible association between SARS CoV-2 vaccination and the development of AVP deficiency. Increased vigilance among clinicians is crucial for early recognition and intervention. To date, AVP deficiency following the SARS CoV-2 vaccine is a rare, temporally linked event with its pathophysiology still hypothetical. Further studies are needed to explore a potential causal relationship.