An American woman who previously beat cancer had COVID-19 for a year, doctors say, in a case study they hope will help scientists understand how immunocompromised people are affected by the virus.
TORONTO -- An American woman who previously beat cancer had COVID-19 for a year, doctors say, in a case study they hope will help scientists understand how immunocompromised people are affected by the virus.
In a pre-print report on medRxiv that has yet to be peer-reviewed entitled “Year-long COVID-19 infection reveals within-host evolution of SARS-CoV-2 in a patient with B cell depletion,” researchers and doctors document their findings from treating the patient at the National Institutes of Health (NIH) in Maryland.
The patient, a 47-year-old woman who was successfully treated for lymphoma with cell therapy three years earlier, was hospitalized with COVID-19 in early 2020. In the months that followed, she became a patient of infectious disease specialist Dr. Veronique Nussenblatt at NIH.
“It took a while to be able to diagnose her,” Nussenblatt said in a telephone interview with CTVNews.ca Friday, outlining how the medical team realized that their patient presented a unique case.
Nussenblatt said initial tests for the SARS-CoV-2 virus were negative, despite the patient displaying symptoms, which then led to them doing a bronchoscopy to take lower respiratory tract samples which came back positive.
“She continued to have symptoms on and off after she left the hospital,” Nussenblatt said. “When we would test her, her test would come back positive, but a very low positive – at that time during the pandemic we knew that some people who had previously been infected with SARS-CoV-2 could have positive tests for some time after infection, especially patients who are immunocompromised.”
The patient, due to her past treatment for cancer, had very few “B cells,” a type of immune cell that creates antibodies to help fight off infection and help the immune system function.
Nussenblatt said that so much time had elapsed since the patient was first diagnosed with COVID-19 that as time progressed her team initially were looking for things other than a persistent infection of the coronavirus.
“We were trying to rule out other infections that she might have,” she explained, adding that one train of thought was the patient had a type of pneumonia that is seen in patients after they have COVID-19 known as “cryptogenic organizing pneumonia.”
To that end, the team treated the patient with steroids and noted her symptoms and her CT scans got moderately better, “but with no major change,” Nussenblatt said.
“At that point it still wasn’t on our radar that his could be COVID-19 after so long,” she said.
Things changed in March 2021.
“We realized something was wrong with out thinking when her test came back positive [in March] but a higher positive, with higher results. That to me suggested that she still had COVID-19 but it was getting more active or she had a new infection with SARS-CoV-2.”
At that point, Nussenblatt said, she enlisted the help of her colleague Dr. Elodie Ghedin, a molecular virologist who works at NIH and studies the genomes of the SARS-CoV-2 virus.
Ghedin and Nussenblatt did a sub-genomic PCR test on samples from the patient and found a surprise.
“The sub-genomic PCR looks for genetic material that should only be present if the virus is live, and so that told me that she actually has an active infection with SARS-CoV-2, but I didn’t know if it was the original one or a new one,” Nussenblatt said. “Dr. Ghedin helped determine that and sequenced the virus and found that it was actually the same virus the whole time.”
The patient had been infected in 2020 with one of the first versions of SARS-CoV-2 in North America, which by early 2021 was no longer circulating, the report says.
In addition, sequencing revealed two new mutations of the spike protein in the patient’s cells, which the report says “highlight the importance of analyzing viral evolution in protracted SARS-CoV-2 infection, especially in immunosuppressed hosts and the implication of these mutations in the emergence of viral variants.”
While other viruses have been known to infect immunocompromised people for longer periods of time, “we tend not to see that with respiratory viruses,” she said.
In the case of Nussenblatt’s patient, she eventually recovered and has had multiple negative COVID-19 tests since the NIH team treated her the second time around.
“She’s not 100 per cent, but she’s much better - she’s off any oxygen,” Nussenblatt said, who spoke with the patient last week. “All the markers of an active infection are gone and she doesn’t have any symptoms anymore – all her tests are negative and the inflammatory markers in her blood have normalized.”
And despite having COVID-19 for a year, Nussenblatt said that to her knowledge, no one who was in close contact with the patient was affected.
Nussenblatt said the case, while rare, helps doctors ands scientists understand how the virus can affect immunocompromised people and what resources are needed to gather data on the phenomenon.
“That was a big lesson, that immunocompromised patients can actually have SARS-CoV-2 infection for a long time,” she said. “You know that has major implications for their treatment and also for infection control… we were lucky that we had access to sub-genomic PCR testing, which not everybody has access to easily, because that really helped us determine whether or not there was a virus there.”
Nussenblatt said she hopes that this case study “puts the possibility of this happening on other people’s radar.”
“We're still learning so much,” she said. ”COVID- 19 is really testing our knowledge about how to treat patients and the assumptions that we make in clinical care.”