New test finds so far invisible antibodies to COVID-19

A new “extreme” sensitivity test developed in a Spanish hospital is able to detect previously invisible antibodies against covid-19 in patients who have overcome the virus and who apparently had not generated any immunity.

Based on a finger, the innovative test was designed by researchers in hematology and immunology at Alicante General Hospital (east) Fabián Tarín, Francisco Marco and Paula Piñero as part of the Biomedical and Health Research Institute of ‘Alicante (Isabial).

This breakthrough, published in the prestigious magazine Scientific reports, had the collaboration of the company Vitro Diagnóstica and the Incliva Health Research Institute of Valencia (east). “To date, we had evidence that a minority percentage of people with a proven infection (around 5%), especially mild, asymptomatic or immunocompromised, did not appear to develop antibodies and likely remained unprotected upon reinfection. possible “Tarín commented.

This technique, more sensitive than conventional ones, reveals that “Almost half of these patients have antibodies in small amounts, invisible to other techniques, and therefore may have some protection against SARS-CoV-2”, he pointed out.

For him, Detection of these low levels of undetectable antibodies in other tests provides valuable information for the medical strategy of these patients who, in fact, could be protected from the most severe version of the disease if reinfection occurs.

The work of Tarín, Marco and Piñero is based on cell lines obtained by genetic engineering in the laboratories of the Spanish state entity Consejo Superior de Investigaciones Científicas (CSIC) and is based on a test known as flow cytometry which only requires a microliter of blood. taken from the finger.

Francisco Marco, member of the Spanish Society of Immunology, pointed out that the test visualizes an “essential” type of antibody, the IgA type, which remains for up to eight months after infection in the vast majority of patients and constitutes the first barrier against the virus.

This is due to the fact it is located in mucous membranes such as saliva or breast milk, where it is able to block germs to prevent infection.

The scientist warned, in any case, that “We must not let our guard down” because the presence of the antibodies “does not guarantee the individual indefinite protection” against the virus and its new variants.

Even taking these precautions into account, Paula Piñero assured that the first results obtained so far in vaccinated patients “indicate that the patients inoculated with the different vaccines show a vigorous response”.

The greater ability to detect antibodies by the test could be particularly useful for studying the degree of protection in immunocompromised or cancer patients, who theoretically develop weaker immune responses, are more unprotected and exposed to severe forms of infection. .

(with EFE information)

KEEP READING: