Children between the ages of 4 months and 2 years old who have had covid-19 are more likely to have antibodies that attack insulin-producing cells, a feature of type 1 diabetes.
Insulin, an essential hormone that regulates the body’s blood sugar levels, is produced in the pancreas by islets of Langerhans, which are areas mainly made up cells called beta cells. In some cases, however, the body can develop an autoimmune response to these islets and produce autoantibodies against them.
Too many of these autoantibodies being created over time will kill enough islets to trigger the onset of type 1 diabetes, where the body is unable to produce its own insulin. “The presence of these autoantibodies more or less means that there’s a 100 per cent path to [type 1 diabetes],” says Anette-Gabriele Ziegler at the Technical University of Munich in Germany.
One of the risk factors for type 1 diabetes is thought to be some viral infections, including SARS-CoV-2, the virus that causes covid-19. A rise in diabetes cases linked to covid-19 has been reported, but the mechanism behind it isn’t known, although some have been proposed.
For example, some viruses may be able to infect the beta cells, changing them and triggering an autoimmune response. Alternatively, some parts of a virus may be so similar to the structure of beta cells that the immune system ends up fighting the virus and the insulin-secreting cell.
To investigate the link, Ziegler and her colleagues monitored 885 children between the ages of 4 months and 2 years old, who were all identified as having at least a small risk of developing islet autoantibodies. Of the cohort, 170 children were found to have SARS-CoV-2 antibodies, suggesting that they had caught covid-19 at some point.
The researchers found that the children who had SARS-CoV-2 antibodies were twice as likely to develop islet autoantibodies as those who hadn’t been infected. Children who caught covid-19 before they were 18 months old had a 5 to 10 times higher risk of developing the autoantibodies – making them the most at-risk group.
“We would love to see if vaccinating children from 6 months can prevent the autoimmunity that leads to type 1 diabetes,” says Ziegler. “We believe there’s very strong possibility that preventing this early infection could very much alter whether children develop the disease.”