Test Id : LKM
Liver/Kidney Microsome Type 1 Antibodies, Serum
Useful For
Suggests clinical disorders or settings where the test may be helpful
Evaluation of patients with liver disease of unknown etiology
Evaluation of patients with suspected autoimmune hepatitis
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
For information see First-Line Screening for Autoimmune Liver Disease Algorithm.
Method Name
A short description of the method used to perform the test
Enzyme-Linked Immunosorbent Assay (ELISA)
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
Antibodies to Liver\Kidney Microsome Type 1, Serum
LKM1 (liver/kidney microsome type 1) antibodies
Microsomal (Liver/Kidney) Type 1 Antibodies
aLKM 1
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
For information see First-Line Screening for Autoimmune Liver Disease Algorithm.
Specimen Type
Describes the specimen type validated for testing
Serum
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL Serum
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Forms
If not ordering electronically, complete, print, and send 1 of the following with the specimen:
-Gastroenterology and Hepatology Test Request (T728)
-General Request (T239)
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
Serum: 0.4 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | OK |
| Heat treated | Reject |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 21 days | |
| Frozen | 21 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Evaluation of patients with liver disease of unknown etiology
Evaluation of patients with suspected autoimmune hepatitis
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
For information see First-Line Screening for Autoimmune Liver Disease Algorithm.
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Autoimmune hepatitis (AIH) is chronic liver disease characterized by immune-mediated destruction of hepatocytes, leading to inflammation and fibrosis.(1) The diagnosis of AIH in children and adults is based on a combination of clinical, laboratory, and histological findings in patients with unexplained acute or chronic hepatitis following the exclusion of the commonly encountered etiologies of hepatitis.(2,3) Based on these features and others, a revised diagnostic scoring system in AIH research studies was published in 2008.(2) AIH predominantly affects women with clinical presentation that varies significantly from asymptomatic liver dysfunction to acute liver failure. The laboratory profile for AIH is characterized by abnormalities of specific liver enzyme, diverse autoantibodies, and in some cases elevated total IgG levels.(1-3) Evidence of liver dysfunction includes elevated aspartate aminotransferase, alanine aminotransferase, and gamma glutaryl transferase in the context of normal alkaline phosphatase.(2,3) AIH can be stratified into two main subtypes based on the presence of specific autoantibodies and patient’s age, these include AIH-type1 (AIH-1) or AIH-type 2 (AIH-2).(2-5) Patients with AIH-1 are positive for antinuclear autoantibodies, smooth muscles antibodies associated with anti-filamentous-actin IgG antibody, or both, while patients with AIH-2 have detectable anti-liver kidney microsomal type-1 (anti-LKM1), or rarely, anti–liver kidney microsomal type-3, or anti–liver cytosol type-1 antibodies. Antibodies against soluble liver antigens/liver pancreas autoantigen can also be detected in AIH-1 patients.(5) Compared to AIH-2, which generally occurs in children with a more moderate or severe disease course, AIH-1 occurs in all age groups, has a relatively mild course that is responsive to timely treatment with steroids and azathioprine.(3)
Anti-LKM-1 antibodies were originally described by immunofluorescence exhibiting a typical cytoplasmic staining of hepatocytes and proximal renal tubular epithelia, using rodent tissue.(6) Subsequently, Mann and colleagues identified the cytochrome P450 2D6 (CYP2D6) as the major target for anti-LKM-1 antibodies.(7) Following the identification of cytochrome CYP2D6 antigen, solid-phase immunoassays have been developed and implemented for use in the differential evaluation of autoimmune liver disease or AIH-2 in children and young adults.(2,3) Very limited clinical or laboratory studies have been performed to investigate the performance characteristics of anti-LKM-1 antibodies in unbiased patient cohorts. In a recent study using the line immunoassay and digital liquid chip method, in patients with autoimmune liver disease, the agreement both assays not optimal probably due to low prevalence.(8)
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Negative: < or =20.0 Units
Equivocal: 20.1-24.9 Units
Positive: > or =25.0 Units
Reference values apply to all ages.
Interpretation
Provides information to assist in interpretation of the test results
Seropositivity for anti-liver/kidney microsomal antibodies type 1 antibodies is consistent with a diagnosis of autoimmune hepatitis type 2, in patients with compatible clinical symptoms and histopathology.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Serologic tests for autoantibodies, including anti-liver/kidney microsomal antibodies type 1 (anti-LKM-1), should not be relied upon exclusively to diagnose autoimmune hepatitis (AIH) or predict the development of disease.
Anti-LKM-1 antibodies are not the only serological marker for AIH and should be evaluated in the context of other AIH-associated autoantibodies, including antinuclear antibodies, smooth muscle antibodies, or filamentous-actin antibodies.
Anti-LKM-1 antibodies may occur in some patients with chronic hepatitis caused by hepatitis C virus (HCV) infection. Although the epitopes recognized by anti-LKM-1 antibodies in HCV infection are different than in patients with AIH type 2, physicians must use caution in interpreting the results of tests for anti-LKM-1 antibodies in such patients.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Mieli-Vergani G, Vergani D, Czaja AJ, et al. Autoimmune hepatitis. Nat Rev Dis Primers. 2018;4:18017. doi:10.1038/nrdp.2018.17
2. Hennes EM, Zeniya M, Czaja AJ, et al. Simplified criteria for the diagnosis of autoimmune hepatitis. Hepatology. 2008;48(1):169-176
3. Mack CL, Adams D, Assis DN, et al. Diagnosis and management of autoimmune hepatitis in adults and children: 2019 Practice Guidance and Guidelines From the American Association for the Study of Liver Diseases. Hepatology. 2020;72(2):671-722
4. Beretta-Piccoli BT, Mieli-Vergani G, Vergani D. Serology in autoimmune hepatitis: A clinical-practice approach. Eur J Intern Med. 2018;48:35-43
5. Dalekos GN, Gatselis NK. Autoimmune serology testing in clinical practice: An updated roadmap for the diagnosis of autoimmune hepatitis. Eur J Intern Med. 2023;108:9-17
6. Rizzetto M, Swana G, Doniach D. Microsomal antibodies in active chronic hepatitis and other disorders. Clin Exp Immunol. 1973;15(3):331-344
7. Manns MP, Johnson EF, Griffin KJ, Tan EM, Sullivan KF. Major antigen of liver kidney microsomal autoantibodies in idiopathic autoimmune hepatitis is cytochrome P450db1. J Clin Invest. 1989;83(3):1066-1072
8. Lv H, Deng A, Chen Y, Su Z. Clinical performance of the line immunoassay and digital liquid chip method for detecting autoimmune liver disease autoantibodies. Arch Pathol Lab Med. 2025;149(3):271-275
Method Description
Describes how the test is performed and provides a method-specific reference
Purified full-length recombinant human cytochrome P450 2D6 antigen is bound to the wells of a polystyrene microwell plate under conditions that will preserve the antigen in its native state. Pre-diluted controls and diluted patient sera are added to separate wells, allowing any liver/kidney microsomal antibodies type 1 present to bind to the immobilized antigen. Unbound sample is washed away, and an enzyme labeled anti-human IgG antibody (conjugate) is added to each well. A second incubation allows the enzyme labeled anti-human IgG antibody to bind any patient antibodies, which have become attached to the microwells. After washing away any unbound enzyme labeled anti-human IgG antibody, the remaining enzyme activity is measured by adding a chromogenic substrate and measuring the intensity of the color that develops. The assay is evaluated by spectrophotometrically measuring and comparing the color intensity that develops in the patient wells with the color in the calibrator wells.(Package insert: INOVA Diagnostics, Inc.; Revision 13; 10/2018)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday, Wednesday, Friday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
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- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
86376
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| LKM | Liver/Kidney Microsome Type 1 Ab, S | 32220-6 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| LKM | Liver/Kidney Microsome Type 1 Ab, S | 32220-6 |