- Researchers say changes in genes may be responsible for long haul COVID-19 symptoms.
- They say the spike proteins on the novel coronavirus may alter gene expressions after they infect healthy cells.
- Experts say this research, if verified, could be an important step in better understanding long haul symptoms.
When much of the world began shutting down in March 2020, Ashley McLaughlin, 22, was in Morocco, working for the Peace Corps.
She caught a flight home to New Jersey while she could, began a 2-week quarantine, and almost immediately lost her senses of taste and smell.
She and many of the 170 workers in her group tested positive for COVID-19. In her case — 14 months later — the disease still has her reeling.
“Initially, I lost my taste and smell for six days and had only minor other symptoms. Not sick in the traditional sense,” McLaughlin told Healthline. “Unfortunately, strange symptoms followed me the next few months, including COVID toes, rashes, strange exercise intolerance, and brain fog until mid-summer, when a stress and exercise-intensive day led to a full relapse into long COVID, where I was in and out of the hospital and completely debilitated otherwise.”
More than a year after testing positive, McLaughlin hasn’t been able to work. She’s restricted to her home and some days to bed. She’s what scientists call a COVID long-hauler, a condition that has mostly baffled researchers during the early part of the pandemic.
Study looks at gene expression
New research now suggests that the novel coronavirus can cause long-term gene expression changes in otherwise healthy cells.
The finding suggests why some people like McLaughlin experience symptoms long after clearing the infection.
“We found that exposure to the SARS-CoV-2 spike protein alone was enough to change baseline gene expression in airway cells,” Nicholas Evans, a master’s student working in the laboratory of Sharilyn Almodovar at the Texas Tech University Health Sciences Center, said in a statement.
“This suggests that symptoms seen in patients may initially result from the spike protein interacting with the cells directly,” he explained.
The research hasn’t been peer-reviewed or published yet. Evans presented it last week at the American Society for Biochemistry and Molecular Biology‘s annual meeting.
A virus that works quickly
The coronavirus that causes COVID-19 is covered in tiny spike proteins that bind with receptors on cells, starting a process that allows the virus to release its genetic material into healthy cells.
Dr. Javeed Siddiqui, co-founder and chief medical officer at TeleMed2U, told Healthline the virus’ ability to mutate rapidly is problematic, similar to influenza’s ability to mutate.
Only COVID-19 works more quickly.
“As SARS-CoV-2 is an RNA virus. It does not have ‘proof reading’ when it replicates,” Siddiqui said. “As such, random mutations occur. The unique aspect of this virus is the speed of mutation rate and the act that ‘viable’ mutations have become so prominent. SARS-CoV-2 mutations have now become more prominent and the primary circulating virus in many areas. This is very concerning.
“A more appropriate term for ‘long haul syndrome’ is ‘post-COVID syndrome,” Siddiqui added. “Post-acute COVID-19 is a multisystem disease that occurs after an acute illness.”
How genes are altered
The researchers at Texas Tech found that cultured human airway cells exposed to high and low concentrations of purified spike protein showed differences in gene expression that remained even after cells recovered.
The top genes included ones related to inflammatory response.
“Our work helps to elucidate changes occurring in patients on the genetic level, which could eventually provide insight into which treatments would work best for specific patients,” Evans said.
McLaughlin said that more than a year after contracting the virus, she’s doing better within “these limits my body now seems to have.” She received the Pfizer vaccine in April.
“I went from being a completely healthy and active 22-year-old working abroad in Morocco, to completely debilitated at 23,” she said.
Siddiqui told Healthline that moving forward, the study would be useful for researchers.
“These findings are very important. Better understanding the pathophysiology and the symptoms of post-COVID syndrome (are) important clinically and to assist in developing future treatment options,” he said.