Liver Function Tests: An Overview

The liver has TONS of functions and plays a role in so many key processes within the body-

  • Make coagulation factors & other hematopoietic cells (in extra-medullary hematopoiesis)

  • Remove "bad stuff" in the bloodstream or ingested toxins

  • Maintain a "backup" of sugars, fat, and iron within the body

  • Regulate calcium & phosphate levels through activation of Vitamin D

  • Maintain blood pressure (& indirectly pH) via its role in the Renin-Angiotensin-Aldosterone System (RAAS)

  • Production of Bile

  • Protein production- Albumin, immunoglobulins

  • Many others...

As you can guess with all of these roles that the liver plays a role in, there are many tests available to assess its function. Keep in mind that some of these may be more specific to the "biliary tree" injury, but still can provide an idea of how "well" the liver is functioning. To see "the big picture", you must fit all of these pieces of the puzzle together to determine if (and where) there is damage.


"Liver function tests"


These posts will touch on just the most high yield aspects on how each test specifically relates to the liver. I have tried to include the most "board-relevant" points in the discussion and may intentionally be leaving out some (important) details regarding the test in a different clinical context. A more detailed review of each individual test will be discussed in separate posts. Please be sure to check them out for a deeper understanding of each test & keep this in mind as you continue reading...


Click on a (bolded) LFT test below to open in a new window & learn more about its use during the workup of liver (dys)function.



LIVER FUNCTION TESTS

Aspartate aminotransferase (AST)

& Alanine aminotransferase (ALT)

Lactate Dehydrogenase (LD or LDH)

Alkaline phosphatase (Alk Phos)





CURRENTLY IN PROGRESS... CHECK BACK LATER!


Gamma-Glutamyl Transferase (GGT)

5' Nucleotidase

Ammonia

Bilirubin

Prothrombin Time (PT)

Gamma globulins

Albumin & Pre-Albumin

Don't forget to check out the separate posts on each test to see how it can be used to evaluate other diseases & explore any pitfalls to the diagnosis/testing process!


As always, be aware of pre-analytic, analytic, and post-analytic errors when interpreting any test result.


*Typical disclaimer: This post does NOT provide medical advice. Talk with your physician before making any decisions.


Reference: Daniel D. Mais, MD. "Practical Clinical Pathology". pg 1- 5. Amer Soc for Clin Path. 2014.

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DISCLAIMER: THIS WEBSITE DOES NOT PROVIDE MEDICAL ADVICE

These posts contain high yield information collected from various educational resources including textbooks, journal articles, educational websites and more. They are intended for educational use only and should NOT be taken as medical advice. I strongly believe the spreading of knowledge and depth of learned information should be encouraged in today's society rather than coveted. Membership is required to view these posts  and should be used solely for educational purposes only.