Anti-LKM-1 (liver-kidney microsomal antibody)
An autoantibody targeting an enzyme found in liver and kidney cells. Its defining use is in type 2 autoimmune hepatitis — a less common form of the disease seen especially in children and young adults — where it is the characteristic marker, read with the liver enzymes and IgG.
What it measures
Anti-LKM-1 (anti-liver-kidney microsomal antibody type 1) is an autoantibody directed against a specific liver enzyme (cytochrome P450 2D6) found in liver and kidney cells. Its clinical value lies almost entirely in one place: it defines type 2 autoimmune hepatitis. Autoimmune hepatitis, in which the immune system attacks the liver, is split into two types by the autoantibodies present. Type 1 (the commoner form) carries the anti-smooth muscle antibody and antinuclear antibody; type 2 is defined instead by anti-LKM-1. Type 2 is less common overall and tends to affect children and young adults, sometimes presenting acutely and severely. The test is requested as part of an autoantibody panel when autoimmune liver disease is suspected — particularly in a young person with unexplained raised liver enzymes — and a positive result, together with a raised IgG and the liver enzyme pattern, strongly supports the diagnosis. As with all these antibodies, the diagnosis is made from the whole picture (autoantibodies, IgG, liver enzymes and usually a biopsy), not from anti-LKM-1 alone, but a positive result is a specific and important pointer.
What a high value can mean
- Type 2 autoimmune hepatitis — the defining use; the characteristic autoantibody, especially in children and young adults.
- Read with a raised IgG and the liver enzyme pattern — supporting the diagnosis.
- A subset of chronic hepatitis C — can carry anti-LKM antibodies, so the viral hepatitis status is checked.
- Rarely, drug-induced liver injury — some drug reactions can trigger LKM antibodies.
High Anti-LKM-1 (liver-kidney microsomal antibody): full guide
What a low value can mean
- Negative — the expected result; makes type 2 autoimmune hepatitis unlikely, though type 1 (with different antibodies) remains possible.
- Not used for monitoring — treatment response is followed by liver enzymes and IgG, not the antibody titre.
Low Anti-LKM-1 (liver-kidney microsomal antibody): full guide
When to discuss with a doctor
Anti-LKM-1 is a specialist autoantibody test, used when autoimmune liver disease is being considered, particularly in a child or young adult with unexplained raised liver enzymes. A positive result, alongside a raised IgG and a matching liver enzyme pattern, points strongly to type 2 autoimmune hepatitis — important to identify because it is treatable and, untreated, can progress to cirrhosis or present as acute liver failure. Because a subset of hepatitis C can also carry LKM antibodies, viral hepatitis is checked as part of the work-up. The diagnosis is made by a specialist from the full picture, usually with a liver biopsy. Mediora.AI shows anti-LKM-1 alongside the liver enzymes, IgG and other autoantibodies so the pattern is read in context; the diagnosis and treatment belong with your doctor.