A pair of viruses and genetic mutation may be responsible for a string of acute hepatitis cases that's affected more than 1,000 children worldwide, according to early research cited by The Wall Street Journal.
The findings, which researchers say still need to be confirmed through larger studies, contradict the leading theory that an adenovirus and SARS-CoV-2, the virus that causes COVID-19, may be causing the hepatitis cases.
For the studies, published July 19 in the medical preprint server MedRxiv, researchers compared blood and tissue samples from kids with acute hepatitis to those from various control groups. Researchers at Great Ormond Street Hospital in London examined 28 samples from kids with severe hepatitis and 136 from controls, while researchers at the University of Glasgow in Scotland analyzed samples from nine kids with hepatitis and 58 controls in a second, separate study. Neither study has been peer-reviewed.
Both groups of researchers found high levels of adeno-associated virus 2, or AAV2, in nearly every child with unexplained hepatitis. AAV2 only replicates in the presence of a second virus, often an adenovirus, but the pair have never been associated with a human disease before, according to the Journal.
Researchers in Glasgow also found eight of nine children with acute hepatitis had the same genetic mutation associated with immune response.
"The AAV2, or adenovirus, or both may be triggering an immune response associated with this genetic susceptibility," study author Emma Thomson, PhD, a consultant in infectious diseases at the MRC-University of Glasgow Center for Virus Research, told the Journal. "And we really do need to nail down in much more detail as to the granularity of the mechanism."