A study from Cedars-Sinai’s Smidt Heart Institute suggests that immune system dysfunction may be the cause of a long COVID-19. The study found that patients with long-term COVID-19 produced antibodies against the virus for an extended period after vaccination, with particularly high levels of nucleocapsid antibodies. The implications of this sustained immune response are still unclear, and researchers are now searching for a definitive biomarker to diagnose and understand the long COVID-19.
The results show that people with long A new study by researchers at Cedars-Sinai’s Smidt Heart Institute suggests that the long COVID-19 may be caused by a malfunction in the immune system.
The study, published in the journal BMC Infectious Diseasesfound that after people who had had COVID-19 for a long time received the COVID-19 vaccine, they produced antibodies against the
Long COVID-19, a condition in which people experience COVID-19-related symptoms three months or more after initial infection with the virus that causes COVID-19, is estimated to affect 65 million people worldwide. . Common symptoms include fatigue, shortness of breath, and cognitive dysfunctions such as confusion and forgetfulness. Some symptoms can have debilitating effects.
To study the immune response of people with long COVID-19, investigators analyzed blood samples from 245 people diagnosed with long COVID-19 and 86 people who had COVID-19 and fully recovered. All study participants had received one or two doses of a COVID-19 vaccine regimen.
“We looked at part of the immune system response, antibody production, which is mediated by immune cells called B cells,” Le explained.
Specifically, investigators looked at two types of antibodies that attack the virus that causes COVID-19. One of them is called the spike protein antibody, which attacks a protein outside the virus. The other is the nucleocapsid antibody, which attacks the part of the virus that allows it to replicate.
Investigators found that people diagnosed with long COVID-19 produced higher levels of spike protein and nucleocapsid antibodies than people without long COVID-19. Eight weeks after receiving a dose of the COVID-19 vaccine, antibody levels in people without COVID-19 for a long time began to decline, as expected. People with long-term COVID-19, however, continued to have elevated antibody levels, particularly nucleocapsid antibodies.
“What you would expect after receiving a COVID-19 vaccination is an increase in your spike protein antibody levels, but you would not expect a significant increase in core antibody levels” , said Susan Cheng, MD, MPH, Erika J. Glazer. Chair in Women’s Cardiovascular Health and Population Sciences, Director of the Institute for Healthy Aging Research in the Department of Cardiology at the Smidt Heart Institute, and lead author of the study. “It would also be expected that these levels would eventually decline and not persist as long after vaccination.”
Although this study shows that the long COVID-19 affects the immune system, it is too early to draw definitive conclusions from these results, according to the study authors.
“Theoretically, producing these antibodies could mean that people are better protected against infection,” Le said. “We also need to investigate whether the elevated immune response correlates with the severity or number of long COVID-19 symptoms.”
Investigators continue to study blood samples from people who have had COVID-19 for a long time. They hope to identify a measurable molecule that could be used to diagnose long COVID-19 and better understand the biological processes that cause it.
Reference: “Post-COVID-19 conditions alter a person’s immune response” by Sandy Joung, Brittany Weber, Min Wu, Yunxian Liu, Amber B. Tang, Matthew Driver, Sarah Sternbach, Timothy Wynter, Amy Hoang, Denisse Barajas, Yu Hung Kao, Briana Khuu, Michelle Bravo, Hibah Masoom, Teresa Tran, Nancy Sun, Patrick G. Botting, Brian L. Claggett, John C. Prostko, Edwin C. Frias, James L. Stewart, Jackie Robertson, Alan C. Kwan, Mariam Torossian, Isabel Pedraza, Carina Sterling, Caroline Goldzweig, Jillian Oft, Rachel Zabner, Justyna Fert-Bober, Joseph E. Ebinger, Kimia Sobhani, Susan Cheng and Catherine N. Le, February 16 BMC Infectious Diseases.
DOI: 10.1186/s12879-023-08060-y
Other Cedars-Sinai investigators who worked on the study include Sandy Joung; Min Wu; Yunxian Liu, Ph.D.; Matthew Driver; Sarah Sternbach; Timothy Wynter; Amy Hoang; Denisse Barajas; Yu Hung Kao; Briana Khuu; Michael Bravo; Hibah Masoom; Teresa Tran; Nancy Sun; Patrick G. Botting; Jackie Robertson; Alan C. Kwan, MD; Mariam Torossian, MD; Isabelle Pedraza, MD; Carina Sterling, NP; Caroline Goldzweig, MD; Jillian Oft, MD; Rachel Zabner, MD; Justyna Fert-Bober, PhD; Joseph E. Ebinger, MD; and Kimia Sobhani, PhD.
Funding: The study was funded by Cedars-Sinai, the Erika J. Glazer Family Foundation, Sapient Bioanalytics, LLC, and the National Institutes of Health (award numbers K23-HL153888 and R01-HL131532).