According to, a complex combination of factors can cause cases of childhood hepatitis that have puzzled doctors in recent months. Two little, New research..
The study is based on only a few dozen cases and has not yet been peer-reviewed or published in scientific journals. Nonetheless, they are a virus known as adeno-associated virus 2 (AAV2), a typical benign virus in which children who develop a serious, unexplained case of liver inflammation need a second “helper.” It suggests that you may have been infected with two different viruses at the same time, including the virus for replication.
Previously discovered in many children with mysterious hepatitis reported during the last year, the adenovirus is a common helper virus for AAV2.
Scientists have found that many of the children studied also had relatively rare versions of genes that play important roles in the immune response.
Together, the findings suggest a possible explanation for hepatitis: a small subset of children with this particular genetic mutation are double-infected with AAV2. Helper viruses, often adenoviruses, cause an abnormal immune response that damages the liver.
Understand hepatitis
Hepatitis, a liver inflammation commonly caused by viruses, is associated with many complex factors, side effects, and stigmas.
Still, researchers admitted that the study was based on a small number of children in only one region of the world (UK) and that no causal relationship was proven.
“There’s still a lot we don’t know,” said Dr. Antonia Ho, senior clinical lecturer at the MRC University of Glasgow Virus Research Center and one of the authors of the new study.
But she added: “Since there are few answers to the cause, I felt I needed to publish these findings so that others could start looking for AAV2. Investigate this in more detail.”
The findings are interesting but preliminary, said Dr. Sole Carpen, a pediatric hepatologist at Emory University and Atlanta in pediatric medicine who was not involved in the study. “This is not a definitive study,” he said. “Thematically, it certainly makes sense, but it doesn’t fully support it.”
Cases of childhood hepatitis are very rare but can be severe. As of July 8 1,010 possible cases reported From 35 countries, according to the World Health Organization. Five percent of those children needed a liver transplant and two percent died.
Some early studies have found that many children are infected with adenovirus, one of the common groups of viruses that cause symptoms like the common cold and the flu. New studies suggest that if adenoviruses are involved in hepatitis cases, they may only be part of the story.
In one of the new studies, scientists compared nine Scottish children with unexplained hepatitis to 58 children in the control group. Researchers have used genomic sequencing to identify viruses that are present in blood, liver, and other samples from children.
Scientists have found adeno-associated virus 2 in the blood of all nine affected children and in the liver samples of all four children for whom such samples were available. They also found adenovirus in 6 children and a common herpes virus in 3 children.
Researchers, on the other hand, did not detect AAV2 in healthy children, children with adenovirus infection but normal liver function, or children with hepatitis of known cause.
These findings are consistent with the results of a second study led by a London researcher who examined samples from 28 children of unexplained hepatitis from across the United Kingdom. The science team also found high levels of AAV2 in the blood and liver of many children. Also, many had low levels of adenovirus or herpesvirus in their samples.
Scottish researchers also found that eight out of nine affected children, or 89%, share a relatively rare variant of a gene that encodes a key protein in the body’s immune response. discovered. This particular variant is present in only 16 percent of Scottish blood donors.
The London team found the same gene mutation in four of the five transplant recipients evaluated.
Sofia Morfopoulou, a computational statistician at the Great Ormond Street Child Health Institute at the University College of London and author of the second treatise, said in an email:
The idea is preliminary, but the recent resurgence of adenovirus after a diminished circulation during a coronavirus pandemic could explain why doctors noticed a sudden surge in these rare cases. There is a sex, the scientist said.
Dr. Emma Thomson, an infectious disease doctor and senior at the Center for Virus Research, said: Author of Scottish studies.
Researchers said additional larger studies are still needed, especially focusing on children in other countries.
