COVID-19, which has killed 1.7 million people worldwide, does not follow a uniform path.
Many infected patients remain asymptomatic or have mild symptoms. Others, especially those with comorbidities, can develop severe clinical disease with atypical pneumonia and multiple system organ failure.
Since the first cases were reported in December 2019, the SARS-CoV-2 virus that causes COVID-19 has surged into a pandemic, with cases and deaths still mounting. Ongoing observational clinical research has become a priority to better understand how this previously unknown virus acts, and findings from this research can better inform treatment and vaccine design.
The researchers obtained blood samples and clinical data from 46 hospitalized COVID-19 patients and 39 non-hospitalized individuals who had recovered from confirmed COVID-19 infection. Both groups were compared to healthy, COVID-19-negative controls. Importantly, most individuals in the hospitalized group had active SAR-CoV-2 viruses in their blood and were in the hospital at the time of sample collection. All individuals in the non-hospitalized group were convalescent at the time of sample collection.
From the blood samples, researchers were able to separate specific immune cell subsets and analyze cell surface markers. From this complex information, immunologists can analyze how each individual's immune system is responding during infection and during convalescence. Some of these results can reveal whether immune cells have become activated and exhausted by the infection. Exhausted immune cells may increase susceptibility to a secondary infection or hamper development of protective immunity to COVID-19.
In addition, the researchers were able to analyze changes over time, in two ways. The first was observing changes in surface markers over time, defined as days since the onset of symptoms for non-hospitalized samples. The second was directly comparing the frequencies of these markers between the first and second clinic visits for non-hospitalized patients who had blood samples collected at two sequential timepoints.
The most surprising finding involved non-hospitalized patients. While the researchers saw upregulated activation markers in hospitalized patients, they also found several activation and exhaustion markers were expressed at higher frequencies in non-hospitalized convalescent samples.
Looking at these markers over time, it was apparent that immune dysregulation in the non-hospitalized individuals did not quickly resolve. Furthermore, the dysregulation of T cell activation and exhaustion markers in the non-hospitalized cohort was more pronounced in the elderly. "To our knowledge," the researchers reported, "this is the first description of sustained immune dysregulation due to COVID-19 in a large group of non-hospitalized convalescent patients."
For details of the comprehensive look at immune cells subsets during and after COVID-19 infection in hospitalized and non-hospitalized people, see the study, which includes an in-depth characterization of the activation and exhaustion phenotype of CD4+ T cells, CD8+ T cells and B cells.
The B and T cells from both patient cohorts had phenotypes consistent with activation and cellular exhaustion throughout the first two months of infection. And in the non-hospitalized individuals, the activation markers and cellular exhaustion increased over time. "These findings illustrate the persistent nature of the adaptive immune system changes that have been noted in COVID-19 and suggest longer-term effects that may shape the maintenance of immunity to SARS-CoV-2."
A question now being explored, the researchers say, is whether these observed immunologic changes are associated with symptoms experienced well beyond the acute infection, often described as "Long COVID."
https://www.uab.edu/news/research/item/11780-sustained-cellular-immune-dysregulation-in-individuals-recovering-from-covid-19
https://www.jci.org/articles/view/140491
http://sciencemission.com/site/index.php?page=news&type=view&id=publications%2Fsustained-cellular&filter=22
Sustained cellular immune dysregulation in individuals recovering from COVID-19
- 1,282 views
- Added
Edited
Latest News
New deep brain stimulation…
By newseditor
Posted 07 Jun
Rare disease's DNA-damaging…
By newseditor
Posted 07 Jun
Different brain Cells respo…
By newseditor
Posted 07 Jun
Key mechanism for maintaini…
By newseditor
Posted 06 Jun
How tumor stiffness alters…
By newseditor
Posted 06 Jun
Other Top Stories
Arginine depletion and radiotherapy eliminates brain tumor in anima…
Read more
Noninvasive imaging could replace electrodes in epilepsy surgery pl…
Read more
Can machine-learning models overcome biased datasets?
Read more
How rhythmic brain activities shape our perception
Read more
Distinct structural domains in MUNC long non-coding RNA regulate ge…
Read more
Protocols
Long-term expandable mouse…
By newseditor
Posted 07 Jun
Clinical and CSF single-cel…
By newseditor
Posted 05 Jun
ChatGPT-assisted deep learn…
By newseditor
Posted 04 Jun
Turning the tide in aggress…
By newseditor
Posted 03 Jun
Mapping medically relevant…
By newseditor
Posted 01 Jun
Publications
Disordered clock protein in…
By newseditor
Posted 07 Jun
Identification of molecular…
By newseditor
Posted 07 Jun
Deep brain stimulation of s…
By newseditor
Posted 07 Jun
Inherited C-terminal TREX1…
By newseditor
Posted 07 Jun
YIPF3 and YIPF4 regulate au…
By newseditor
Posted 07 Jun
Presentations
Hydrogels in Drug Delivery
By newseditor
Posted 12 Apr
Lipids
By newseditor
Posted 31 Dec
Cell biology of carbohydrat…
By newseditor
Posted 29 Nov
RNA interference (RNAi)
By newseditor
Posted 23 Oct
RNA structure and functions
By newseditor
Posted 19 Oct
Posters
A chemical biology/modular…
By newseditor
Posted 22 Aug
Single-molecule covalent ma…
By newseditor
Posted 04 Jul
ASCO-2020-HEALTH SERVICES R…
By newseditor
Posted 23 Mar
ASCO-2020-HEAD AND NECK CANCER
By newseditor
Posted 23 Mar
ASCO-2020-GENITOURINARY CAN…
By newseditor
Posted 23 Mar