Scientists around the world study the blood plasma of people diagnosed with Covid-19 in search of biomarkers that indicate the patient’s risk of developing the severe form of the disease.
A research group at the University of São Paulo (USP) has identified changes in molecules present in the blood that may be associated with the worsening of coronavirus infection. The results of the research, which had the support of the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), were published in the Journal of Proteome Research.
At the São Carlos Institute of Chemistry, at the University of São Paulo (USP), the team coordinated by Professor Daniel R. Cardoso analyzed the blood plasma of 110 patients with flu-like symptoms who were admitted, still in 2020, at the Hospital of the Federal University of Sao Paulo (Unifesp).
Among these individuals, 57 were not infected with the coronavirus (called a control group), while 53 tested positive for the disease. Among those infected, ten had complications and were admitted to the intensive care unit (ICU) and two did not survive the infection.
In infected patients, it was possible to observe variations in the concentration of six substances (metabolites) naturally produced by our bodies and found in the blood : glycerol, acetate, 3-aminoisobutyrate, formate, glucuronate and lactate. How much the greater the imbalance in the amount of these metabolites at the beginning of the infection, the more severe the health conditions of people have become.
“What we saw in patients who progressed to severe cases of Covid-19 is that there was a more accentuated change in the concentration of these compounds when they sought medical care,” says Banny Correia, a postdoctoral fellow at USP and one of the authors of the article.
According to Cardoso, by monitoring the amount of these six substances produced by different metabolic pathways, it is possible to have a prognosis on how severe the infection will be. “That way, when the patient seeks help, the doctor can predict through a clinical examination if he will need hospitalization and, thus, act quickly to prevent the evolution of the disease”, he evaluates.
According to the professor, the coronavirus causes changes in different metabolic processes in the human body, in particular in the energy production pathways, regardless of the SARS-CoV-2 variant.
“The SARS-CoV-2 virus infects the cell, alters its metabolism and uses energy pathways to replicate. From this, variations occur in the amount of those six substances, with some having their concentration reduced and others increased. The degree of imbalance in the concentration of these compounds indicates how much metabolism was affected, allowing us to predict whether the patient’s clinical conditions will worsen”, he reports.
Technique used
In the research, blood samples were analyzed by high-field nuclear magnetic resonance spectroscopy – a technique that requires sophisticated equipment present in one of the laboratories of the USP institute.
According to the researchers, however, the evaluation can also be done through simple clinical tests performed in laboratories and hospitals, focusing specifically on the panel of metabolites identified in the research. “The result is ready quickly”, emphasizes Banny.
The researchers’ expectation is that the new method will become a protocol adopted by hospitals in the future. To validate the technique, in the next steps of the research, the scientists plan to expand the number of blood plasma samples to be evaluated and include new groups in the study, such as those vaccinated who contract Covid-19, for example.
Another goal is to include gender and age information in the statistics. “In addition to Covid-19, this type of analysis could help to discover marker metabolites that predict severity in other viral infections and help a faster response in future pandemics”, concludes Cardoso.