Can genetics explain why some COVID-19 patients are worse off than others?

MAY 16, 2020 /
PRNEWSWIRE
BIOON/BIOON/A NEW PRELIMINARY STUDY SUGGESTS THAT GENETIC
DIFFERENCES IN CERTAIN
MAY DISTINGUISH PEOPLE WITH SEVERE COVID-19 FROM THOSE WHO ARE INFECTED WITH COVID-19 BUT HAVE LITTLE COUGHINGHowever, experts say the study is still in its early stagesthe immune system can respond to viruses, thanks in part to specific genes that help cells identify strange bacteria entering the bodyThese genes, known as human leukocyte antigens (HLA) genes, contain instructions to build proteins that bind to certain parts of the pathogen; Once immune cells are trained to identify these sites, they quickly begin to make antibodies that target and destroy the invadingbacteriain everyone, the HLA gene encodes three different types of proteins; in other words, HLAs have a variety of flavors, and depending on the HLAs you have, your body may be better or worse prepared to fight certainbacteria-- including the SARS-CoV-2 virus that causes COVID-19image source: https://cn.bing.com
in a new study published April 17 in Journalof Virology, researchers used computer models to predict which combination of HLAs might be best combined with SARS-CoV-2, and which combination is best suitedif certain HLAs can bind a large portion of the virus's protein, "we expect more protective immune responses," said study authors Abhinav Nellore and Reid Thompson, who led the computational study at Oregon Health and Science UniversityBetter binding means that viral proteins are more likely to be supplied to immune cells and promote the production of specific antibodies"If this interaction is unstable, you don't have an appropriate (immune) response," said DrShokrollah Elahi, associate professor in the Department of Dentistry at the University of Alberta and associate professor ofof medical microbiology andimmunology He was not involved in the study Elahi added But a stable combination alone does not guarantee the best immune response, and if HLA combines a viral protein that is critical to virus replication and survival, subsequent antibody activity is likely to target the virus more effectively than another less important protein "This is an issue that we did not mention in our analysis," authors note Instead, the team focused on predicting the extent to which different HLA types would be combined with SARS-CoV-2 Their analysis identified six HLA types with the ability to effectively combine different SARS-CoV-2 protein sequences, and three with low binding capabilities Specifically, an HLA type called HLA-b?46:01 has the lowest predictive power to combine with SARS-CoV-2 found the same HLA in a 2003 study published in the journal BMC Medical Genetics The study assessed patients infected with SARS-CoV, a closely related coronavirus that caused outbreaks of Severe Acute Respiratory Syndrome (SARS) in the early 2000s The study found that the presence of HLA-B-46:01 was associated with severe infection cases in a group of Asian-American patients The team noted in their paper that more clinical data are needed to confirm the link -- as does Nellore and Thompson, as well as new studies on SARS-CoV-2 "The biggest limitation of our study is that it was done entirely on a computer and did not involve clinical data on COVID-19 patients," authors said Unless the findings we present here are clinically proven, they should not be used for any clinical purpose "
in the body, we have a lot of things interacting, the human immune system is a huge and complex puzzle, HLAs are just one of them To better understand the various immune responses to COVID-19, Elahi and his team aim to assess the signs of immune system activity in infected patients and classify the proportion of the types of immune cells present in their bodies These so-called immunological characteristics can help determine when and why disease sits in certain patients, taking into account age, gender, and other demographic factors Elahi added that clinical data can be evaluated in conjunction with genetic data collected from the same patient Similarly, Nellore and Thompson said, "COVID-19 testing should be combined with HLA typing whenever and wherever" to help determine the relationship between different HLA types and the severity of symptoms They say collaboration with gene testing companies, biobanks and organ transplant registries could also provide an opportunity to study HLA types in larger populations "In good conscience, we can't predict who will be more or less infected with the virus, because we haven't analyzed any clinical outcome data related to hlA types to determine if our predictions are correct," the authors said They added that if future studies support the idea that some HLA genes protect people from viral infections, while others put patients at greater risk, the latter may be the first to be vaccinated image source: https://cn.bing.com
"In addition to giving priority to the elderly or people with pre-existing conditions, priority can be given to people with certain HLA genotypes, because SARS-CoV-2 virus is more likely to cause them more severe symptoms." The authors then analyzed the degree of binding between HLAs and SARS-CoV-2, as well as with other coronaviruses, such as coronaviruses that cause the common cold and frequent human infections They identified SARS-CoV-2 and several bits of viruses shared by at least one common virus, suggesting that exposure to one virus may protect the body from another virus to some extent " If someone has been exposed to a more common coronavirus before and has the correct HLA type.. In theory, then, they may also produce an early immune response to the new SARS-CoV-2 "On the other hand, exposure to similar viruses may make the body less resilient to new viruses, for example, "an old set of tools used by the body is not suitable for solving new problems." (biovalleybioon.com) References: CansexplainwhysomecoVID-19patientsfaress? 2, Austin Nguyen.
Humanleukocytadededemapfor SARS-CoV-2
journalofVirology.2020.DOI: 10.1128/JVI.00510-20
3, BMCMedicals.2003.