Abnormal Liver Function Tests (or LFT’s)
Where is the liver located?
The liver is located in the right upper quadrant of your abdomen, just beneath your diaphragm, above your stomach, right kidney, and intestines. It weighs about 3 pounds and holds about 13% of your body's blood supply at any given moment.
The liver is made up of 2 main lobes: a right and a left lobe, which are divided into smaller lobes called lobules. These different areas are connected by ducts, which eventually join to form the common hepatic duct. This duct transports bile made by the liver to the gallbladder and small intestine. Bile helps to digest and absorb fats and fat-soluble vitamins (Vitamins A, D, E and K).
The liver is the largest solid organ in your body. It carries out over 500 functions and is a part of your digestive system. Its main function is to filter blood coming from your digestive tract, before it passes to the rest of your body. The liver detoxifies chemicals and breaks down drugs into simpler and less toxic forms.
What are the functions of the liver?
The liver has 100’s of vital functions. Some of these include:
- Regulating most chemical levels in your blood.
- Producing and excreting bile
- Processing and “cleaning” your blood
- Converting excess glucose (or sugar) into glycogen (for storage and later use). This helps to regulate our blood sugar levels.
- Breaking down or metabolizing drugs into simpler forms that are easier for our bodies to use and that are nontoxic.
- Producing proteins such as albumins and globulins. These proteins help with fluid balance, fighting infection, and they carry various substances throughout our bodies, like hormones, vitamins, and other enzymes.
- Producing cholesterol and proteins that help carry fats throughout our bodies.
- It plays a major role in red blood cell production by breaking down and recycling hemoglobin, a component of our red blood cells that carries oxygen to our cells.
- It stores iron as ferritin for later use to make new red blood cells.
- It processes and converts poisonous ammonia (a byproduct of protein metabolism) into urea, which is excreted in our urine.
- It plays a major role in blood clotting
- It disposes of bilirubin, made during the normal break down of red blood cells.
- It makes immune factors and removes bacteria from your blood
What are “Liver Function Tests”?
Liver function tests are blood tests that measure different enzymes, proteins, and other substances made in the liver. These substances are often tested together on a single blood sample, and may include:
- ALT (alanine aminotransferase) and AST (aspartate aminotransferase): These tests measure enzymes your liver releases in response to damage or disease.
- These enzymes normally live inside your liver cells, but when cells are damaged these enzymes can leak out and cause blood levels to increase.
- ALT is an enzyme specifically found in the liver. It helps convert proteins into energy for your liver cells.
- ALT is more specific to liver cells than AST, as AST can also be found in your heart, skeletal muscles, and red blood cells.
- AST is an enzyme that helps metabolize amino acids from proteins.
- Albumin is one of several proteins produced by the liver. This test measures how well your liver produces albumin.
- Albumin helps to maintain fluid balance in your body, and helps to keep fluid from leaking out of your blood vessels. It also carries things like hormones and vitamins throughout your body.
- Total Protein is a measure of the total amount of protein (both albumins and globulins) present in your blood.
- Proteins are important building blocks for all of your cells and tissues.
- Albumin to Globulin (or A/G) ratio: This is the ratio of albumin to globulin in your blood.
- Globulins are proteins that play an important role in your immune health.
- Alkaline phosphatase is an enzyme found in your liver and bones. It is important in breaking down proteins.
- This test is especially useful in diagnosing diseases of the bile duct system; however, it can be elevated in conditions unrelated to the liver so we may need to order “isoenzymes” to help differentiate the source of your abnormal labs: liver vs. bone.
- *Alk Phos is also normally elevated during adolescence and in the third trimester of pregnancy. This is largely due to bone growth during adolescence. Additionally, the placenta produces Alk phos during the 3rd trimester of pregnancy normally.
- GGT or gamma-glutamyl transpeptidase is an enzyme found in many organs throughout the body, with its highest concentrations in the liver. It is elevated in most diseases of the liver or bile ducts.
- Bilirubin is a test that measures how well your liver disposes of bilirubin.
- Bilirubin is a substance produced by the liver during the normal breakdown of red blood cells.
- L-lactate dehydrogenase (LD) is another enzyme found in your liver. Elevated levels may indicate liver damage but LD can be elevated in other disorders too.
- Prothrombin Time (or PT) is the time it takes your blood to clot.
- Increased PT levels may indicate liver damage but can also be seen if you're taking certain blood-thinning drugs, such as warfarin, or have other conditions.
- PT is often ordered in conjunction with INR, another test that assesses how well your blood clots. Your liver plays a major role in your body’s ability to clot blood by producing a number of clotting factors necessary for proper blood clotting.
What are some of the symptoms of liver disease?
Symptoms can be vague but may include:
- Weakness, fatigue, or lack of energy
- Weight loss or gain
- Shortness of breath
- New anemia
- Jaundice or yellowing of the skin or eyes
- Fluid collection in the abdomen or lower extremities
- Very dark urine
- Light colored, clay-colored, or white stools
- Change in bowel habits
- Abdominal pain
- Abnormal bruising
- Easy or excessive bleeding
- Itchy skin and other skin changes
Why are LFTs ordered?
LFTs are ordered for any variety of reasons. They may be ordered as a part of your routine annual physical exam with your family physician to screen for disease, or they may be ordered if certain diseases are suspected, or to monitor a known disease state.
What can liver function tests tell you?
Liver function tests can be used to:
- Screen for liver infections, such as hepatitis A, B, or C.
- They can help to monitor the progression and severity of certain diseases, such as viral or alcoholic hepatitis, fatty liver, NASH (Nonalcoholic steatohepatitis), NAFLD (Nonalcoholic Fatty Liver Disease), and cirrhosis of the liver,
- They can help to evaluate how effective your current treatment approach is.
- They can help to monitor for possible medication side effects. Many medications are metabolized (or broken down) via the liver and can affect how your liver is functioning.
- They can also measure how well your liver is performing its normal functions.
What are some of the causes of Abnormal Liver Function Tests?
LFT’s may be elevated for a variety of reasons.
- Infections like Acute Hepatitis A, Acute or Chronic Hepatitis B and C, infectious mononucleosis, cytomegalovirus (CMV), parvovirus, and even the novel coronavirus (COVID-19) can all causes elevated LFT’s.
- Alcohol (both long-term use, and acute alcoholic hepatitis)
- Certain prescription, herbal, and OTC medications. Tylenol, antidepressants, birth control pills, certain antibiotics, and certain anti-hypertensive’s are common culprits.
- Fatty liver disease, NAFLD (Nonalcoholic Fatty Liver Disease) and NASH (Nonalcoholic steatohepatitis)
- Certain autoimmune diseases
- Celiac disease
- Certain types of cancers, both primary and secondary neoplasms
- Genetic disorders such as Wilson’s Disease, Gilbert’s Disease, Alpha-1-Antitrypsin Deficiency, Hemochromatosis, and other metabolic glycogen storage disorders
- Cirrhosis of the liver
- Gallstones and other disease of the gallbladder and biliary ducts
- Tumors of the pancreas
- Heart failure
- Primary sclerosis cholangitis
- Paget’s disease
- Bone fractures
- Multiple myeloma, and
- Ischemic liver injury as seen in severely low blood pressure or shock
Diseases of the liver, pancreas, gallbladder, infections, autoimmune diseases, and blood diseases can ALL cause abnormal liver function tests. Just because your liver function tests are abnormal doesn’t necessarily mean you have liver disease. There are many reasons why your tests might be abnormal.
Liver disease is frequently asymptomatic, so ALL abnormal LFT’s should be investigated thoroughly, promptly, and properly by a trained medical professional like Dr. Sinha to avoid missed diagnoses and/or delayed diagnoses and delayed care. We interpret abnormal LFT’s and diagnose underlying liver disease every day in our practice.
The pattern of your test abnormality will help us determine the origin of your issue. A comprehensive clinical history, including family history and medication history, and the presence of any current or recent symptoms, will help us determine why your LFT’s are elevated and allow us to help create a treatment plan specific to your needs.
What are the risk factors for having elevated LFT’s?
- Having a known history of Hepatitis.
- Having a Family History of inherited liver disease or certain autoimmune conditions.
- Having a personal history of certain autoimmune conditions.
- Taking certain medications metabolized by the liver.
- Having certain infections like mono or Epstein-Barr Virus.
- Having a history of gallbladder disease.
- Having a history of cancer.
- Drinking alcohol.
- Being overweight.
- Having a history of diabetes, pre-diabetes, or high cholesterol.
I’m being worked up for elevated LFT’s. What can I expect?
When basic LFT’s are abnormal, we will conduct a comprehensive history and physical exam to help us understand what might be causing your abnormal lab results. This history may include questions about your:
- Personal Medical History, including history of Diabetes, Obesity, High Cholesterol, High Blood Pressure and Heart Disease.
- Family History and any known history of inherited genetic disorders
- Travel history
- History of blood transfusions
- Medication history
- Substance abuse history
- Alcohol use history
- Social history including your occupation and upbringing (where you were born)
A full Physical Exam will be conducted to evaluate for signs and symptoms of liver disease.
We’ll recheck your labs tests, order additional lab tests if appropriate, and consider imaging studies. These additional tests may include:
- Viral panels for hepatitis A, B, and C, cytomegalovirus (CMV), Epstein-Barr Virus (EBV), parvovirus, and possibly HIV.
- An autoantibody screen including antimitochondrial antibody, anti-smooth muscle antibody, and antinuclear antibody to assess for certain autoimmune disorders.
- A complete blood count and iron studies to assess for anemia and other disorders or iron absorption and storage.
- Elevated ferritin levels can be seen in Hemochromatosis, a genetic disorder of iron overload.
- Alpha-fetoprotein (AFP): a protein produced by certain cancers, such as liver cancer.
- It is often used as a tumor marker to evaluate for cancer concern or risk.
- Copper/ceruloplasmin to evaluate for Wilson's disease, a genetic disorder of copper overload.
- Alpha-1 antitrypsin (A1AT) to evaluate for Alpha 1 antitrypsin deficiency.
- A1AT is a protein the liver produces that protects the lungs. In this disorder the liver doesn’t produce this protein. The result can be lung and liver disease.
- Fibroscore. A blood test that helps measure the level of scarring or hardening in your liver and helps to evaluate for fibrosis and cirrhosis.
- Imaging studies such as ultrasound or MRI to help detect structural abnormalities, fatty liver, fibrosis and cirrhosis.