Hepatitis of Mysterious Children Discovery Important Clues!

Text ｜ Xinyu

Virus -related virus 2 Picture Source: LAGUNA Design

In response to two independent studies of children with liver injury or hepatitis, almost all children with sick children have a virus called adrenal -related virus 2 (AAV2). Almost all children with hepatitis have a genetic variation that affects its immune response.

AAV2 is a common virus, but people have previously believed that this virus does not cause any disease. AAV2 can integrate its own DNA into the genome of the infected cells, thereby staying in the body indefinitely.

However, AAV2 is quite unusual, and it can only be copied when other viruses, such as adenovirus or herpes virus exist. Emma Thomson, University of Glasgow, believes that it is unclear that AAV2 is the cause of hepatitis and is only an indicator of adenovirus infection.

These discoveries show that AAV2 or other viruses may cause liver injury through an unknown immune mechanism. "Hepatitis caused by virus may have the cause of immune media. We need more work to verify this assumption." Thomson said.

She suspected that a small number of cases in the study had not found adenovirus infection for many years. In Scotland, due to the restrictions on the prevention and control measures of the new crown, the number of adenovirus infections is lower than usual. Once the measures are relaxed, adenovirus infection will reach a peak, which may cause many cases of hepatitis at the same time.

In April of this year, Scotland reported a group of child liver injury cases. These damage was not caused by the usual hepatitis virus. The child had gastrointestinal symptoms such as diarrhea at first and developed into hepatitis in the next few weeks.

In order to find out the cause, the THOMSON team studied 9 children of hepatitis, 12 healthy children of the same age, and 13 children infected with adenovirus but no liver injury, and sequenced all DNA and RNA in their blood samples Essence

It was found that nine children with hepatitis were found in AAV2, but they were not found among other children. Four children can get liver samples, and AAV2 exists in the liver of the 4 children.

The research team also found that 8 of the nine children carried a genetic variant called HLA-DRB1*04: 01, which could affect the immune system's response to infection. In Scotland, only 16%of people exist in this mutation.

The team led by Judith Breuer, the University of Children's Health of the University of London, also made similar studies. Compared with 28 children with hepatitis and blood samples of other 136 children.

It was found that the blood of 27 children was AAV2 of 27 children, and there was no AAV2 in the blood samples of other children or only a very low level of AAV2.

The Breuer team also found AAV2 RNA in 5 liver samples, but it was impossible to find viral protein or virus particles under electron microscope.

He believes that this indicates that there is an indirect virus mechanism that requires international cooperation to conduct larger -scale research to prove these discoveries and find out the potential mechanism.

Related thesis information:

https://doi.org/10.1101/2022.07.19.22277425

"China Science News" (2022-07-27 The original title "Mysterious Children's hepatitis may be related to" harmless "virus"))

Edit | Zhao Lu

Capture | Zhihai

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