This infectious disease, primarily characterized by respiratory symptoms, has brought to light a myriad of other manifestations, including its impact on various organs and systems.
Among these lesser-discussed consequences is its influence on the endocrine system, specifically hypophysitis – a rare condition that affects the pituitary gland.
In this article, we explore the connection between COVID-19 and hypophysitis, delving into the mechanisms of viral entry, the role of the ACE2 receptor, the potential for panhypopituitarism, and the importance of recognizing and treating endocrine complications following COVID-19 infection.
The Virology of SARS-CoV-2
SARS-CoV-2, the virus responsible for COVID-19, is a member of the coronavirus family, known for its spike (S) protein. This S protein plays a pivotal role in viral entry into host cells. Of particular significance is a region on the S protein that binds to the extracellular domain of angiotensin-converting enzyme 2 (ACE2). This interaction allows the virus to infiltrate host cells, initiating the infection process.
ACE2 Expression Throughout the Human Body
While COVID-19 is primarily characterized by respiratory symptoms, it is essential to understand that ACE2 receptors are extensively expressed in numerous human tissues and organs. These receptors can be found in the heart, lungs, kidneys, testes, brain, and various other organs. This widespread distribution explains the diverse array of symptoms and organ involvement seen in COVID-19 patients, extending far beyond lung inflammation.
Endocrine Implications of ACE2 Expression
A Rare Case of Hypophysitis Post-COVID-19
One such case that highlights the interaction between COVID-19 and the pituitary gland is that of a 31-year-old healthy female athlete. She developed hypotension and symptomatic hypoglycemia while flying from Barbados to Miami. Her medical history revealed that she had experienced a mild symptomatic COVID-19 infection seven months prior. She was also four months post-partum, experiencing lactation difficulties and a lack of menstruation following her COVID-19 recovery. Furthermore, she reported a depressive state, loss of appetite, and progressive weight loss.
Laboratory work-up revealed a series of hormonal imbalances indicative of endocrine dysfunction. Central adrenal insufficiency was evident, with low ACTH and serum cortisol levels. Secondary hypothyroidism was diagnosed, characterized by elevated TSH and low free T4 levels. Magnetic resonance imaging (MRI) of her brain showed an empty sella and slight nodular thickening of the pituitary stalk, leading to a presumptive diagnosis of hypophysitis.
Treatment and Recovery
The patient’s rapid clinical improvement following corticosteroid replacement therapy underscored the role of pituitary dysfunction in her presentation. Her hypoglycemia, hypotension, and anorexia resolved, but diabetes insipidus emerged. Subsequent laboratory tests confirmed panhypopituitarism, including hypogonadotropic hypogonadism, hypoprolactinemia, and growth hormone deficiency.
Conclusion
This case serves as a poignant reminder of the varied and sometimes insidious nature of COVID-19’s impact on the human body. While respiratory symptoms remain the hallmark of the disease, the presence of ACE2 receptors in numerous tissues and organs raises the potential for widespread complications.
Pituitary involvement, as demonstrated in this case, is an uncommon yet noteworthy sequelae of COVID-19. As the medical community continues to grapple with the aftermath of the pandemic, it is crucial to maintain a high index of suspicion for endocrinopathies like hypophysitis in patients with persistent non-specific symptoms following COVID-19 infection. Early recognition and treatment are essential for improving the quality of life and long-term outcomes for these individuals.
reference link : https://academic.oup.com/jes/article/7/Supplement_1/bvad114.1264/7290890
