27th June 2023

Biliary and pancreatic presentations

HIV causes inflammation of the liver parenchyma and biliary tree. HIV additionally causes biliary tree damage by opportunistic infections, resulting in the formation of biliary strictures, which is termed ‘AIDS cholangiopathy’ and tends to develop with a CD4+ T-cell count <100/μL. The most common organisms causing AIDS cholangiopathy are:

• Cryptosporidium parvum
• Cytomegalovirus
• Microsporidia (usually Enterocytozoon bieneusi)

The presentation of AIDS cholangiopathy includes:

• Right upper quadrant pain
• Fever
• Jaundice
• Nausea and vomiting

Abdominal tenderness and hepatomegaly may be seen on examination. Blood tests demonstrate raised liver function tests with obstructive pattern. Imaging is often useful for establishing the cause of biliary symptoms in HIV:

• Ultrasonography is abnormal in ~75%, showing dilated intrahepatic and extrahepatic ducts and/or dilated CBD
• CT is not the preferred imaging modality but may demonstrate intrahepatic and extrahepatic dilatation
• Magnetic resonance cholangiopancreatography (MRCP) is preferred to ERCP due to lower risk of perforation and pancreatitis

AIDS cholangiopathy management involves:

• Endoscopic sphincterotomy
• Analgesia, e.g. a CT-guided coeliac plexus block
• Ursodeoxycholic acid improves deranged liver function
• Screening for cholangiocarcinoma

The liver parenchymal cells are injured by numerous mechanisms, including:

• Oxidative stress
• Lipotoxicity
• Metabolite accumulation
• Translocation of the gut microbiota
• The accumulation of toxic metabolites

Additionally, there may be indirect mechanisms which result in HIV causing liver injury or a higher risk of liver injury. These include:

• Hepatitis co-infection
• HIV-associated neoplasm
• Hepatotoxic antiretroviral therapy

Overall, these mechanisms and confounding factors (e.g. non-alcoholic fatty liver disease) mean that people with HIV are ~10 times more likely to die from liver infection than the population as a whole.

Transient elastography can determine the degree of liver fibrosis. Patients with higher viral load usually have higher levels of fibrosis. Despite hepatotoxicity associated with some antiretroviral agents, better controlled HIV and higher antiretroviral use is associated with a lower risk of fibrosis overall.