HIV and Liver Function Tests

Diagnostic Tests Used to Measure Your Liver Health

Blood Test used under Creative Commons license
Photograph © Lori Greig

Liver function tests (LFTs) are a battery of routine blood tests which gives your doctor an idea of how well your liver is working. From these investigations, your doctor can identify underlying liver dysfunction, medication stresses affecting the liver, or diseases of the liver such as hepatitis B or hepatitis C. There are a number of different tests that comprise LFT monitoring, including:

Albumin (ALB)

Albumin is a protein produced by the liver that helps maintain osmotic pressure in blood vessels. By maintaining this pressure, the fluid stays in the vascular system instead of leaking out into the tissues and causing edema (swelling). Albumin also carries certain minerals in the bloodstream.

  • Normal values: 4 to 6
  • Elevated: Usually indicates dehydration
  • Below normal: Can indicate liver dysfunction or insufficient protein intake

Alkaline phosphatase (ALK PHOS)

Alkaline phosphatase is an enzyme found in many organs in the body, including the liver, digestive system, kidneys, and bones.

  • Normal values: 30 to 120
  • Elevated: Usually a warning sign that there is some type of liver problem resulting in liver damage or a bone disorder such as cancer or a healing fracture
  • Below normal: Usually not significant

Alanine aminotransferase (ALT or SGPT)

This protein is found primarily in the liver. It is released into the blood when there has been some sort of liver tissue damage.

  • Normal values: less than 35
  • Elevated: May indicate that liver damage has occurred as a result of infection, medications, cirrhosis, or traumatic injury to the liver
  • Below normal: Usually not a concern

Aspartate aminotransferase (AST or SGOT)

This protein is found primarily in the liver. It is released into the blood when there has been some sort of liver tissue damage.

  • Normal values: less than 35
  • Elevated: May indicate tissue damage as a result of such things as obstruction, hepatitis, or cirrhosis
  • Below normal: Usually not significant

Total bilirubin (TBIL)

Bilirubin is a normal component of red blood cells. When these cells break down free bilirubin is released into the blood. Bilirubin is then carried to the liver where it is broken down and excreted. When the liver is not functioning properly, bilirubin can build up in the body, causing jaundice (yellowing of the skin and eyes).

  • Normal values: less than 1.0
  • Elevated: Usually caused by a dysfunction of the system that breaks down bilirubin, including an obstruction or liver failure
  • Below normal: Usually not significant

Reasons for Elevated Liver Enzymes in HIV

When treating an HIV infection, liver enzymes can be elevated for a number of reasons, including HIV drugs, HIV-related coinfections, and, in some cases, HIV itself. Among these:

  • Viral hepatitis is commonly seen in people with HIV, with nearly 30 percent coinfected with hepatitis C alone. The disease can severely affect the liver, causing fibrosis (scarring) and cirrhosis (chronic degeneration).
  • Certain antiretroviral drugs can cause hepatoxicity (liver toxicity) including Viramune (nevirapine), and Aptivus (tipranavir) when boosted with Norvir (ritonavir).
  • Alcohol and certain over-the-counter medications have been known to cause liver problems and worsen treatment-related hepatotoxicity. Even dietary supplements like St. John's Wort area can increase the hepatotoxic effects of drugs like Viramune.
  • Non-alcoholic fatty liver disease (NAFLD) affects anywhere from& 17 percent to 33 percent of American and is often related to obesity. Nearly a third of people with HIV have NAFLD irrespective of hepatitis B or C infection.
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Article Sources
  • Centers for Disease Control and Prevention. "HIV and Viral Hepatitis." Atlanta, Georgia; accessed June 3, 2015.
  • Price, J. and Theo, C. "Liver Disease in the HIV-Infected Individual." Clin Gastroenterol Hepatol. 2010; 8(12):1002-21. DOI: 10.1016/j.cgh.2010.08.024.
  • U.S. Department of Health and Human Services. "Side Effects of HIV Medicines - HIV and Hepatoxicity." AIDSInfo. Washington, D.C.; accessed June 3, 2015.