Obesity, high blood pressure and diabetes are known risk factors for developing complications from Covid-19. Now, researchers from Tel Aviv University have added another.

Carriers of the genetic mutations PiZ and PiS are at a high risk for severe illness if they contract Covid-19. These mutations lead to deficiency in the protein alpha1-antitrypsin, which protects lung tissues from damage in case of severe infections.

Other studies have already associated this deficiency with inflammatory damage to lung function in other diseases. The TAU research is the first to look at the correlation between PiZ and PiS mutations and Covid-19.

The researchers analyzed data from 67 countries, finding a significant positive correlation between the prevalence of the two mutations in the population and Covid-19 mortality rates.

Prof. David Gurwitz and his team from TAU’s Sackler Faculty of Medicine wanted to find out why the mortality rate in East and Southeast Asian countries, as well as in Sub-Saharan Africa, is lower than in other parts of the world.

The population in many countries in Europe and North and South America, it turns out, have a relatively high percentage with the PiZ and PiS mutations. The PiZ variant is found primarily in northern European countries while PiS is more common in southwest Europe. The mutations are rare to non-existent in Asia, however, and the corresponding mortality rate is also lower.

Belgium and Spain have the highest percentage of people with the genetic anomalies – 17 out of every 1,000 people carry the PiZ mutation. The Covid-19 mortality rate for Belgium, as of September 2020, was 860 per million. In Spain, it was 640 per million.

In the United States, 15 people per 1,000 are carriers and 590 out of every million died of Covid-19.

In Italy and Sweden, 13 people per 1,000 carry the mutation and the fatality rates there are 620 and 570 per million, respectively.

That contrasts sharply with Japan, where prevalence of the mutations is negligible and only 9 out of every million died from Covid-19. The numbers are similar in China, South Korea, Taiwan, Thailand, Vietnam and Cambodia, according to the researchers.

The research was conducted on information from Johns Hopkins University Coronavirus Resource Center database.

The researchers propose clinical trials. If the correlation from the database analysis is proven correct in follow-up studies, it should lead to population-wide screening to identify carriers of PiZ and PiS mutations, the researchers recommended.

Individuals carrying the mutations should be advised to take extra precautions and might also be prioritized for vaccination once a vaccine is available.

“Our observations suggest that alpha‐1 antitrypsin deficiency alleles [a variant form of a gene] may contribute to national differences in Covid‐19 infection, severity, and mortality rates,” the research team concludes.

In addition to Gurwitz, the research team included Prof. Noam Shomron and MSc candidate Guy Shapira.

The results were was published in the September 2020 issue of the FASEB Journal.