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People who have had COVID for a long time may be reacting more strongly to non-SARS-CoV-2 viruses than to SARS-CoV-2 they have encountered in the past. study Researchers at Harvard Medical School suggest.
The long COVID, also called acute sequelae of COVID-19 (PASC), causes a range of symptoms that persist for at least four weeks after the initial SARS-CoV-2 infection, they write on the preprint server medRxiv. In an interview, four authors described his long-term research on possible mechanisms of COVID.
Dr. Jonathan D. Herman
“Immunity to endemic coronaviruses other than COVID may play a role in who develops PASC,” co-authors Jonathan D. Harman, MD, PhD, Said. “Although much remains to be understood, it is surprising that the back-boosting of the immune response to coronavirus OC43 was uniquely enhanced in PASC patients.”
“In this study, individuals with PASC preferentially generated stronger responses to previously encountered cold-causing coronaviruses,” said the co-lead authors. Dr. Galit AlterSaid.
Dr. Garritt Alter
“Instead of generating strong SARS-CoV-2 immunity, they could have enhanced their response to another coronavirus and become less effective at clearing SARS-CoV-2. Surprisingly. , most people were vaccinated, and they still maintain this. Abnormal antibody responses — pointing to a new therapeutic route for treating PASC,” Alter said. increase.
Humoral immunity provides clues to long COVID origins
Although one fifth of COVID-19 patients progress to long-term COVID, it is not well understood which patients develop PASC and why.
“Antibodies represent powerful biomarkers that have been used for decades to diagnose disease. However, antibodies also provide a powerful source of information about previous infections. “Use pointed to the presence of incomplete antibody responses to SARS-CoV–two in PASC patients,” said Alter.
Researchers reviewed the medical records of patients at Boston’s Mass General Brigham Health Care System, including referrals from rheumatologists of participants diagnosed with COVID-19 outside the MGB system after March 1, 2020. Did.
They focused on patients with systemic autoimmune rheumatic disease (SARD). The reason is that their propensity for inflammation and autoantibody production may make them more susceptible to PASC and enrich for specific inflammatory-driven endtypes.
All 43 participants had COVID-19 without hospitalization or SARD.Patients treated only fibromyalgia, Osteoarthritis, mechanical back paingout, or pseudogout Persons without SARD were excluded from the study.
Overall, 79% of participants were female and 35% were female. rheumatoid arthritis19% had psoriatic arthritisand 95% had received the COVID-19 vaccine.
Researchers used systems serology to perform comprehensive antibody profiling against SARS-CoV-2 and a panel of endemic pathogens or common vaccine antigens.
Long-term COVID patients showed distinct immune responses
Overall, 17 patients developed PASC and 26 did not, and patients with PASC had a distinct humoral immune response. Patients with PASC:
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They had less inflammation and had SARS-CoV-2 antibodies with weak Fc-gamma receptor binding.
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They had a significantly expanded and more inflammatory antibody response to the endemic coronavirus OC43.When
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It initiated a more vigorous IgM response and developed an expanded inflammatory OC43 S2-specific Fc receptor binding response. This was associated with cross-reactivity between SARS-CoV-2 and common coronaviruses.
Dr. Jeffrey A. Sparks
“Strengths of this study include the detailed phenotyping of post-COVID-19 cases, specifically to classify the presence or absence of PASC, and the depth and breadth of antibody profiling. We were able to identify ,” co said. – senior author Jeffrey A. Sparks, MD, MMSc.
“However, this study was limited in its size to investigate different types of PASC that may have biological differences, such as fatigue and pulmonary symptoms. All patients who did had pre-existing rheumatic disease,” he admitted.
Dr. Sachary S. Wallace
“A significant fraction of COVID-19 patients will develop PASC, which can have a significant impact on their health and quality of life,” co-lead authors said. Zachary S. Wallace, MD, MS“Given the high risk of COVID-19 in many patients with rheumatic diseases, it is important to understand the pathogenesis of PASC in this vulnerable population to enable future diagnostic and therapeutic advances.” is.”
Dr. Davey Smith
Davey Smith, MDProfessor of Medicine at the University of California, San Diego, Director of Infectious Diseases and Global Public Health, was not involved in the study.
“There may be a link between previous non-SARS-CoV-2 coronavirus infections and PASC,” he added. By understanding , we can develop treatments for this condition.
“This paper is a preprint and should be peer-reviewed,” said Smith. “There are many factors that need to be scrutinized. For example, there is no universally accepted definition of PASC. How did that affect this study?”
Dr. Mark CameronAn associate professor in the Department of Population and Quantitative Health Sciences at Case Western Reserve University in Cleveland called it a strong study by a strong group, but it’s a preprint before peer review.
Dr. Mark Cameron
“In this first study, scientists focused on people who had rheumatic disease before they contracted COVID-19. Hopefully long-term we know that COVID is immunologically similar when diagnosed — a single ‘endtype’ or group of patients with similar clinical presentations and backgrounds,” he said.
“Our immune system’s memory may not be able to effectively fight new viruses that are very similar to viruses we’ve seen before. It can lead to a variety of problems, such as the poor recovery seen in pneumonia,” he said.
“OC43 probably emerged in the late 1800s and may have caused a pandemic of severe respiratory disease between 1889 and 1890. influenzaCameron recalled. “OC43 still exists as an endemic coronavirus, usually causing mild or moderate upper respiratory tract infections.”
COVID-19 immunity is complex and previous SARS-CoV-2 infection is not guaranteed [protection]especially as new subspecies emerge, he added.
“This study may help us better understand the risks and possible mechanisms associated with COVID-19 and long COVID-19 in the face of previous coronavirus infections,” he said. He could also guide future COVID-19 treatments and vaccines. ”
The authors plan further related studies.
This study received grant support and anonymous donations. Alter, Sparks, and Wallace report financial ties to the pharmaceutical industry. All other authors, and Davey and Cameron, reported no conflicts of interest with the study.
This story was originally MDedge.compart of the Medscape Professional Network.
