Also Known As
Liver Kidney Microsomal Type 1 Antibodies
LKM1 Antibodies
Anti-Liver/Kidney Microsomal Antibodies Type 1
Anti-P450 2D6 Antibody
Formal Name
Liver Kidney Microsome Type 1 Antibodies (Cytochrome P450 2D6 Antibodies)
This article was last reviewed on
This article waslast modified on
March 20, 2018.
At a Glance
Why Get Tested?

To help diagnose autoimmune hepatitis and distinguish it from other causes of liver injury

When To Get Tested?

When you have hepatitis that your healthcare practitioner suspects may be due to an autoimmune-related process

Sample Required?

A blood sample drawn from a vein in your arm

Test Preparation Needed?


You may be able to find your test results on your laboratory's website or patient portal. However, you are currently at Lab Tests Online. You may have been directed here by your lab's website in order to provide you with background information about the test(s) you had performed. You will need to return to your lab's website or portal, or contact your healthcare practitioner in order to obtain your test results.

Lab Tests Online is an award-winning patient education website offering information on laboratory tests. The content on the site, which has been reviewed by laboratory scientists and other medical professionals, provides general explanations of what results might mean for each test listed on the site, such as what a high or low value might suggest to your healthcare practitioner about your health or medical condition.

The reference ranges for your tests can be found on your laboratory report. They are typically found to the right of your results.

If you do not have your lab report, consult your healthcare provider or the laboratory that performed the test(s) to obtain the reference range.

Laboratory test results are not meaningful by themselves. Their meaning comes from comparison to reference ranges. Reference ranges are the values expected for a healthy person. They are sometimes called "normal" values. By comparing your test results with reference values, you and your healthcare provider can see if any of your test results fall outside the range of expected values. Values that are outside expected ranges can provide clues to help identify possible conditions or diseases.

While accuracy of laboratory testing has significantly evolved over the past few decades, some lab-to-lab variability can occur due to differences in testing equipment, chemical reagents, and techniques. This is a reason why so few reference ranges are provided on this site. It is important to know that you must use the range supplied by the laboratory that performed your test to evaluate whether your results are "within normal limits."

For more information, please read the article Reference Ranges and What They Mean.

What is being tested?

Liver kidney microsome type 1 (anti-LKM-1) antibodies are autoantibodies, proteins produced by the body's immune system that recognize and target its own enzyme called cytochrome P450 2D6 (CYP2D6), a protein found primarily in liver cells. The development of anti-LKM-1 antibodies is strongly associated with type 2 autoimmune hepatitis. This test detects and measures the amount (titer) of anti-LKM-1 (or antibody against CYP2D6) in the blood.

Autoimmune hepatitis is an acute or chronic inflammation of the liver that can lead to liver cirrhosis and, in some cases, to liver failure. It is hepatitis that is not due to another identifiable cause, such as a viral infection, exposure to a drug or toxin, a hereditary disorder, or alcohol abuse. Anyone can develop the disorder, but the majority of those affected are women.

There is general agreement that there are two main types of autoimmune hepatitis (debate continues as to whether there is a distinct third type). Type 1 is the most common form of autoimmune hepatitis in the United States and is associated with the presence of smooth muscle antibodies (SMA) in the blood. Type 2 is less common and tends to be more severe. It is associated with anti-LKM-1 antibodies and primarily affects young girls and is more common in Europe than in the United States.

How is the sample collected for testing?

A blood sample is obtained by inserting a needle into a vein in the arm.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

Accordion Title
Common Questions
View Sources

Sources Used in Current Review

2017 review performed by Rose Romeo, PhD, DABCC, FACB.

Bogdanos, DP, Invernizzi, P, Mackay, IR and D vergani (2008). Autoimmune liver serology: Current diagnostic and clinical challenges. World Journal of Gastroenterology, vol 14: 3374-3387.

European Association for the Study of the Liver (EASL) Clinical Practice Guidelines: Autoimmune hepatitis (2015). Journal of Hepatology, vol 63: 971-1004.

Czaja, AJ (2016). Diagnosis and Management of Autoimmune Hepatitis: Current Status and Future Directions. Gut and Liver, vol 10: 177-203.

Narciso-Schiavon, JL and LL Schiavon (2017). To screen or not to screen? Celiac antibodies in liver diseases. World Journal of Gastroenterology, vol. 23: 776-791.

Himoto, T & M Nishioka (2013) Autoantibodies in liver disease: important clues for the diagnosis, disease activity and prognosis. Autoimmune Highlights. Vol 4: 39-53.

Wolf, D (2016). Medscape Article: Autoimmune hepatitis. Available online at Accessed April 28th, 2017.

ARUP. Liver-Kidney Microsome Antibody, IgG (2017). Available online at Accessed on April 29th 2017.

Sources Used in Previous Reviews

(Updated 2012 February 16). Autoimmune Hepatitis. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) [On-line information]. Available online at Accessed August 2013.

Longstreth, G. (Updated 2012 October 8) Autoimmune hepatitis. MedlinePlus Medical Encyclopedia [On-line information]. Available online at Accessed August 2013.

Slev, P. and Tebo, A. (Updated 2013 February). Hepatitis, Autoimmune – AIH. ARUP Consult [On-line information]. Available online at Accessed August 2013.

((©) 1995 – 2013). Liver/Kidney Microsome Type 1 Antibodies, Serum. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online at Accessed August 2013

Wolf, D. and Raghuraman, U. (Updated 2013 July 29). Autoimmune Hepatitis. Medscape Reference [On-line information]. Available online at Accessed August 2013.

Shaffer, E. (Revised 2009 June). Laboratory Tests of the Liver and Gallbladder. Merck Manual for Healthcare Professionals [On-line information]. Available online through Accessed August 2013.

Mayo Clinic Staff (2012 April 18). Autoimmune hepatitis. [On-line information]. Available online at Accessed August 2013.

Mieli-Vergani, G. (2009 August). Autoimmune Hepatitis. J Pediatr Gastroenterol Nutr, v 49 (2) [On-line information]. Available online at Accessed August 2013.

Trivedi, P. and Hirschfield, G. (2012). Review Article: Overlap Syndromes and Autoimmune Liver Disease. Medscape Today News from Aliment Pharmacol Ther. 2012;36(6):517-533. [On-line information]. Available online at Accessed August 2013.

Stephen Kriese, S. and Heneghan, M. (2013). Current Concepts in the Diagnosis and Management of Autoimmune Hepatitis. Medscape Multispecialty from Frontline Gastroenterol. 2013;4(1):2-11. Accessed September 2013.

Clarke, W., Editor (© 2011). Contemporary Practice in Clinical Chemistry 2nd Edition: AACC Press, Washington, DC. Pp 314.

Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 682-683.

Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. McPherson R, Pincus M, eds. Philadelphia, PA: Saunders Elsevier: 2007, pg 951.

Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Burtis CA, Ashwood ER, Bruns DE, eds. 4th edition, St. Louis: Elsevier Saunders; 2006, pp 1812-1814.

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