The resurgence and exponential spread of Covid-19 has brought great challenges to our healthcare system. Most deaths are a result of respiratory failure due to significant injury to the lungs. We have also learnt that the virus may affect all parts of the digestive system including the food pipe, stomach, intestine, liver and pancreas. This has implications in the diagnosis, management, and transmission of the disease.
Here are a few facts on liver and the impact a Covid-19 infection can have on it:
Q: How does Covid-19 virus affect the liver?
A: The virus enters human cells by locking on to the angiotensin converting enzyme (ACE-2) receptor. Besides the lungs, these receptors are expressed in the cells of the intestine, liver, and bile duct, thus making these organs prone to injury by the virus.
Q: What are the gastrointestinal and liver manifestations in Covid-19?
A: Nausea, vomiting, diarrhoea, and pain in abdomen have been reported in up to 15 per cent patients with Covid-19 infection. Of note, up to 10 per cent of patients with Covid-19 may present with these symptoms before or without respiratory features. It has been found that patients presenting with initial gastrointestinal symptoms may have delay in hospital admission and a more severe course of illness as compared to those without. Injury to the liver injury may manifest as elevation of liver enzymes in liver function blood tests (LFT). Current data suggests that 19 per cent of Covid-19 patients have abnormal levels of liver enzymes Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST) during disease, with mostly mild elevation in serum bilirubin and Gamma-glutamyl transferase (GGT). In most patients the liver injury is mild and transient, although severe liver damage has been reported.
Q: How do patients with pre-exiting liver disease handle Covid-19 infection?
A: The common causes of chronic liver disease in our country include alcohol abuse, non-alcoholic fatty liver disease, Hepatitis B, Hepatitis C, and autoimmunity. The immune system of these patients is weak, and they must remain extra careful as there is an increased risk for severe illness due to the virus. Liver injury due to the virus in patients with pre-existing chronic liver disease who may lead to acute on chronic liver failure (ACLF). More severe the Covid infection, greater is the extent of liver injury. Most medications used for treatment of Covid-19 also tend to injure the liver and there is a need for close monitoring and dosage adjustment as required.
Q: What are the implications of Covid-19 in patients who have received a liver transplant? Is it safe to carry out liver transplant during these times?
A; There have been concerns that organ transplant recipients, who are on medications that reduce body immunity, may be more prone to infection with Covid-19 or have a more severe course of illness. It has now been consistently shown that use of majority of these medications is safe and may prevent severe Covid symptoms by blocking the cytokine storm. Outcome of Covid-19 infection is the same as healthy population in organ transplant recipients. It is no surprise that after initial apprehensions, transplant activity has resumed in the country, for those who need it most, as Covid-free pathways have been established.
Q: Should patients with chronic liver disease and liver transplant recipients take the vaccine against Covid-19 virus?
A: The safety of vaccination in this cohort has been well established now. All such individuals who are eligible must take the vaccine at the earliest. They should not pick or choose or wait for the perfect vaccine. It is felt that the efficacy of vaccine in patients on immunosuppression drugs may be a trifle less than the normal population, but there are no additional risks.
Q: What are the precautions that patients with liver disease should observe to prevent Covid-19 infection and poor outcomes?
A: As compared to healthy individuals, patients with underlying liver disease tend to do poorly with Covid-19. Hence, every attempt must be made to keep the liver as healthy as possible. Fatty liver disease provides an unhealthy environment on which the virus may flourish. Avoidance of fatty food, sweets and fast food coupled with regular exercise for 30 minutes a day at least 5 days a week are good for the liver. Excessive alcohol intake should be avoided. Patients who are suffering from Chronic Hepatitis due to Hepatitis B, Hepatitis C and auto-immunity must be regular with their medication. The availability of vaccine has brought hope that the pandemic may be controlled in a few months. Social distancing and prevention of transmission of virus will, however, continue to be of paramount importance as more and more vaccine-escape mutations in the virus are anticipated.
(Avnish Seth, Principal Director, Gastroenterology, Hepatobiliary Sciences and Transplant Hepatology, Fortis Memorial Research Institute, Gurugram)