Etanercept, a tumor necrosis factor (TNF)-alpha inhibitor for arthritis treatment, may have delayed the development of olfactory and gustatory dysfunction in a Covid-19 patient with ankylosing spondylitis (AS), a local medical case report showed.
The report, written by a research team led by Professor Lee Sang-jin at the Rheumatology Department of Kyungpook National University’s School of Medicine, was published in the Journal of Korean Medical Science with the title of “Olfactory and Gustatory Dysfunction in a COVID-19 Patient with Ankylosing Spondylitis Treated with Etanercept: Case Report.”
The researchers said a female AS patient, who had been treated with etanercept, reported a loss of smell and taste after contracting the Covid-19 virus.
The patient was diagnosed with AS in March 2017. According to the report, her symptoms abated after receiving nonsteroidal anti-inflammatory drugs (NSAIDs) and disease-modifying anti-rheumatic drugs such as sulfasalazine and methotrexate.
After contacting a Covid-19 patient, she was diagnosed with Covid-19 on March 3. Earlier, she received the last etanercept injection on Feb. 20.
She self-isolated on March 3, the day she got confirmed with the virus infection. During her self-isolation, on March 25, she had AS symptoms and self-administered etanercept. After testing negative for Covid-19 on April 6 and 7, she was released from isolation.
However, on April 5, she felt a decreased sensation of taste, including sweet, salty, and sour taste, and visited a neurologist for an objective examination.
During the exam, she could perceive the smell of ground coffee beans. However, after an administration of 50 percent dextrose water, the doctor could identify moderately decreased smell intensity and severely disturbed sweet taste. Her other cranial nerves were normal, and a brain magnetic resonance imaging (MRI) showed no abnormalities.
The research team speculated the use of the TNF-alpha inhibitor after Covid-19 infection could have delayed the dysfunction of smell and taste.
“Hypotheses for pathologic mechanisms of olfactory and gustatory dysfunction during COVID-19 infection are not clear. However, angiotensin-converting enzyme 2 (ACE2) receptors seem to have a key role,” the research team said.
Although TNF-alpha inhibitors should be discontinued during severe infections, etanercept was reported to have a protective effect on olfactory inflammation in a mouse model, the researchers noted.
“Etanercept treatment in inducible olfactory inflammation mouse showed functional and histological recovery by inhibiting TNF-alpha induced inflammatory cascade,” the medical team said.
However, it is unclear whether etanercept positively or negatively affects the course of COVID-19 in humans, especially the development of olfactory and gustatory dysfunction, until more studies come out, they added.
<© Korea Biomedical Review, All rights reserved.>