The latest discovery of acute hepatitis in children of unknown cause: or related to the new coronavirus superantigen

Recently, at least 348 cases of severe acute hepatitis of unknown cause in children have been reported in the UK, EU, US, Israel and Japan. Most children present with early gastrointestinal symptoms and later develop jaundice and, in some cases, acute liver failure. To the confusion of scientists, the hepatitis A, B, C, D and E viruses were not found in these children. The latest research shows that it may be related to the superantigen of the new coronavirus.

The so-called super antigen (SAg) is a class of substances that can activate a large number of T cell clones and generate a strong immune response with only a very low concentration (≤10-9 times M). Compared with ordinary antigens, superantigens do not require conventional intracellular antigen presentation and have no MHC restriction.

According to the difference of activated cells, superantigens can be divided into T cell superantigens and B cell superantigens, and according to their different sources, T and B cell superantigens can be divided into endogenous (viral) antigens and exogenous (viral) superantigens. bacterial type) superantigens.

According to reports from Israel, 12 unidentified childhood hepatitis cases have recently been reported in the country. The above cases came from different locations across the country and did not show the characteristics of clustered infection. The main symptoms are severe liver infection and marked elevation of liver enzymes, usually accompanied by jaundice, and gastrointestinal symptoms in some cases. At present, these cases have all been discharged. Among them, 2 cases at Schneider Children's Hospital underwent liver transplantation due to liver failure, and the remaining cases improved rapidly after receiving steroid drug treatment.

Of the 12 cases identified in Israel, 11 had contracted the virus within a year. Although there is no clear evidence that the unidentified hepatitis is related to the new coronavirus, several Israeli medical experts have expressed doubts in interviews with the media that there is a link between the two. Glasberg, director of the Pediatric Liver Transplant Center at Schneider Children's Medical Center, said that after ruling out all possibilities, all the cases found had in common that they were infected with the new coronavirus about three and a half months before the onset of hepatitis. Severe COVID-19 infection is known to damage the liver, so this unidentified hepatitis may be one of the long-term symptoms of COVID-19.