A team of researchers from the USA may have discovered what makes people with Down syndrome both more resistant and more vulnerable to viral infections. The mechanism appears to be linked to type 1 interferon signaling. An important part of the immune system, interferons act with greater or lesser intensity in individuals with Down syndrome due to the duplication of chromosome 21 that triggers the syndrome during embryonic development.<\/p>\n\n\n\n

\u201cUsually, too much inflammation means autoimmune disease, and immune suppression usually means susceptibility to infections,\u201d said study coordinator Dusan Bogunovic of the Icahn School of Medicine at Mount Sinai Hospital, New York.<\/p>\n\n\n\n

\u201cWhat is unusual is that individuals with Down syndrome are both inflamed and immunosuppressed, a paradox of sorts. In our research, we discovered how this is possible.\u201d Bogunovic and colleagues published a paper<\/a> on the subject in a recent issue of the journal Immunity<\/em>.<\/p>\n\n\n\n

In patients with the syndrome, it is common for two apparently contradictory situations to occur. They appear to experience certain types of infections, such as influenza A, shingles, and intestinal infections, significantly less frequently than the general population.<\/p>\n\n\n\n

However, once infected with a pathogen, they often face an increased risk of complications, hospital admission, and death. This seems to be especially true for viruses that affect the respiratory tract, such as respiratory syncytial virus (RSV) and SARS-CoV-2.<\/p>\n\n\n\n

Before the pandemic began in 2020, infections accounted for 20\u201340% of deaths in people with Down syndrome, while this figure was just 4.5% for the rest of the population.<\/p>\n\n\n\n