Covid, a ‘spy’ virus predicts the severity of the disease

It is called Torque Teno Virus (Ttv), it is one of the viruses most frequently present in the human organism, a common host also in monkeys and domestic animals. Its presence has not been associated with any known disease, but its excessive replication is considered a sign that something is wrong with the immune system, an indicator of immunosuppression. In Brazil, the germ has been studied in relation to Covid-19. Because scientists believe it may be a useful biomarker: the levels of Ttv – noted the authors of a research published in ‘Plos One’ – appear to be higher in people infected with Sars-CoV-2. And “the higher the Ttv title, the longer people remained ill. Symptoms disappeared as the viral load decreased,” explained Maria Cássia Mendes-Correa, professor at the Faculty of Medicine and first author of the paper. The correlation between high Ttv burden and immunosuppression has already been used in medicine, in contexts such as monitoring transplant patients taking drugs to prevent organ rejection. The study by the team from the University of Sao Paulo suggests that this value can also be used as an indicator of the severity of Covid and recovery from the disease. “We used samples from 91 patients diagnosed with Sars-CoV-2 and 126 people with flu symptoms who tested negative for Covid,” explained Mendes-Correa. In non-infected with Covid, “Ttv remained stable throughout the symptomatic period.” The study was conducted under the auspices of the São Caetano Corona Program, an online platform set up for remote monitoring of the inhabitants of São Caetano do Sul ( city ​​in the São Paulo metropolitan area) with Covid symptoms. Analyzing patient samples, researchers at the university’s Institute of Tropical Medicine observed that the TTV load may actually “serve as an indicator of the progression and outcome” of Covid. “The more symptomatic the patient, the greater the TTV load in the sample,” Mendes-Correa said. “Covid-19 appears to lead to a certain degree of immunosuppression causing an imbalance of the immune system and this promotes the replication of Ttv.” The discovery could in the future help improve the diagnosis and prognosis of Covid. “We are all looking for ways to obtain a rapid and accurate diagnosis – concludes the scientist – One possibility is to develop a kit that doses several biomarkers of the disease at the same time and then evaluate the results with the aid of algorithms. The measurement of the Ttv titer. is one of several tests that could be included in these algorithms “.