Good morning. Please take your time to read this. It is important. I worry for my children and yours too. I waited for a while to tell you the story about this liver. I wanted to make sure it ended well. This is was the liver of a teenager we took out a month back. He was flown in from another State because of an unidentifiable jaundice + hepatitis that was making him sick. Hardly a few days in, he went into a coma because of liver failure and we put him on a ventilator. To help him survive, a parent donated part of the liver. This was the quickest emergency liver transplantation we ever did. Everything happened in less than 24 hours. On the outside the liver looks pretty normal, just a bit swollen from the hepatitis (liver inflammation). But when we looked at it under the microscope, there was nothing left. Almost all the liver cells were wiped out (a finding known as massive hepatocellular necrosis) with deep inflammation. The cause remained unknown. We call it indeterminate hepatitis - meaning, something we did not know, caused it. You may remember post Covid-19 era. There were multiple cases of unknown hepatitis among children which either led to them dying or receiving a transplant. At the time, scientists thought it was due to another virus - Adenovirus, that had changed the way it attacked us due to Covid-19 era restrictions and immune changes. But that theory fell apart because not every kid with indeterminate hepatitis had adenovirus positive. In the 1980s, some doctors in few hospitals across the world described a handful of single-center cases that first documented liver cell loss and inflammatory infiltrates in unexplained pediatric liver failure. And they kept seeing such cases, here and there, and forgot about it. Some died. Some lived after a liver transplant. In 1999, with the establishment of the Pediatric Acute Liver Failure (PALF) study group allowed for systematic tracking and larger-scale retrospective and prospective analysis of immune functionand dysfunction in such kids with unknown hepatitis. In 2022, medical scientists were armed with better technology and more impressive analysis methods. And global attention surged, in the post-Covid-19 era on outbreaks of severe acute hepatitis of unknown origin in children. who.int/news-room/questions-… They figured it out. Just like we did. A special stain and a technical advancement known as immunohistochemistry, a lab test that used antibodies to find specific proteins in a tissue sample was deployed. A special type of immune cell, supposed to defend us, was going crazy. Cytotoxic T cells act as the body's security guards to find and destroy cells infected by viruses or those that turned cancerous. There was no cancer in our teenager. And teenagers and children with this disease before him. The most likely culprit was a previous viral infection. pubmed.ncbi.nlm.nih.gov/3893… Covid-19 probably increased this. The little fcker wrecks havoc on the immune system like no other. It makes the body go wild and attack itself. It has done this before in other other organs too. It is called molecular mimicry. When you get infected with COVID-19, your immune system creates defenses—like antibodies—to target and destroy the virus. To do this, it memorizes the physical shapes and protein sequences of the virus. However, because some building blocks of the COVID-19 spike protein mimic the shapes of our own healthy human proteins, the immune system can experience "cross-reactivity". Your newly trained antibodies end up attacking both the invading virus and your own healthy organs because they cannot tell the difference. pmc.ncbi.nlm.nih.gov/article… Large numbers of children with indeterminate hepatitis have cytotoxic T-cell mediated hepatitis. And it can only be diagnosed through a liver biopsy before the kid got really sick or after a liver transplant when the kid was going to die. The liver that you see below, is far from normal. Deep within these tissues was a horde of cytotoxic T-cells that were picking of large areas of liver cells, pushing the child towards death. As a doctor, I was only able to give them a diagnosis, after the liver came out and because they were convinced about this hidden killer of children, we did it in the nick of time. The teenager survived and we found what nearly killed the patient. Any viral infection can lead to this. Not immediately, but even later on in life. It happens mostly in children, teenagers and young adults. Vaccines prevent/ reduce severity of various viral infections. Please make sure you and your children are vaccinated for age. I hope Governments everywhere promote annual vaccinations for Covid-19 too along with the flu-shot. Because there is a strong possibility that this is the one virus that can cause this type of damage on the liver, many months after the initial infection and we may never know - becuase Covid-19 can come and go silently.