Covid: genes against malaria protect against contagion
Liguria. The Computational and Chemistry Biology team of the Italian Institute of Technology (Iit) together with the Molinette hospital of the Città della Salute of Turin, the Giannina Gaslini Institute of Genoa and the Policlinico of Palermo, recently published a study in the international journal Frontiers In Medicine which highlights a genetic relationship between Covid-19 and malaria.
The work hypothesizes one inverse correlation of some variants in genes associated with the onset of malaria with the spread of Covid-19, suggesting that such variants at the genetic level may confer protection from coronavirus infection. In summary, it was highlighted that in the areas that in the past were affected by malaria, the incidence of Covid-19 was much lower.
Malaria and Covid-19 are different diseases, both due to infections: the first caused by a plasmodium, the second by a virus, Sars-CoV-2, now well known although it has only appeared on the world stage for just over a year. . The coexistence, on the other hand, between plasmodium and man has lasted much longer, at least for 50,000 years, in the territories of the world where the mosquito that transmits plasmodium to man is present. In Italy malaria has now disappeared, but until the 1950s it was endemic in many coastal areas of southern Italy and the islands, as well as in marshy areas, such as those at the mouth of the Po.
The theory of the research team led by Andrea Cavalli is that genes that are able to protect the population from malarial infection may also provide a form of protection for Sars-CoV-2 infection. The research also sought to explain the biological effect that these genetic variations can exert on Sars-CoV-2 infection and disease progression. suggesting potentially useful therapeutic possibilities. The study thus opened up new theoretical knowledge on the relationship between host genetics and Covid-19.
“The idea of deepening the link between Covid and malaria – explains one of the authors of the study, Antonio Amoroso, geneticist at the Molinette hospital and at the University of Turin – came by observing the frequency of Covid-19 in the Italian regions, with wide fluctuations between northern regions, in Lombardy for example 8.1% of the population has contracted the disease , and the southern ones, where Covid-19 has almost halved the frequency: 4.4% of Sicilians got sick, 3.4% of Sardinians or 3.3% of Calabrians. Since mortality data were available in the Italian provinces at the beginning of the 20th century, it was possible to compare the mortality from malaria at the time with the current frequency of Covid-19. A very clear connection was obtained: in the territories where malaria deaths were more frequent at the beginning of the last century, Covid patients are less frequently registered today, and vice versa. At the beginning of the last century, every hundred thousand subjects died of malaria 73 in Sardinia, 24 in Sicily and 32 in Calabria, while there were none in Lombardy or Piedmont. The provinces of the Po delta were also plagued by malaria, with mortality at the beginning of the last century similar to the southern regions. But even the spread of Covid more than 100 years later spared the provinces of Ferrara, where cases of Covid-19 represent 6.5% of the population, and of Rovigo, with 5.9% of the population tested Covid positive. “
“We know very well how living with malaria has selected some genetic characteristics that made it possible to better resist malarial infection and which consequently benefited the individuals who possessed them – clarifies Manlio Tolomeo, co-author of the study and doctor at the Policlinico di Palermo – the hypothesis we put forward was therefore that some of the genetic characteristics that had been selected to be advantageous for the malarial infection could also help in better fighting the coronavirus “.
“To prove this hypothesis – he illustrates Andrea Cavalli, Head of the Computational and Chemistry Biology team of the Italian Institute of Technology and coordinator of the research team – we made use of the data already available from the scientific community, both in relation to the genetic variants of protection against malaria, we selected fifty, and related the characteristics of the genome of a thousand healthy individuals belonging to about fifty different populations, for which the frequencies of Covid-19 were also available “.
“Starting from these data and from the experience in the study of genetic diseases, we then went in search of the most frequent variants in the populations less affected by Covid-19 and that were able to have an impact on the behavior of genes – they specify Marta Rusmini and Paolo Uva, co-authors of the work and researchers at the Clinical Bioinformatics Unit of the G. Gaslini Institute – and therefore potentially advantageous against coronavirus. This study contributes to deepen the relationship between genetics and susceptibility to Covid-19 and provides a solid methodological approach that can be applied for future studies directly on the DNA of Covid patients “.