Liver-Kidney Microsome-1 Ab (LKM 1)

Liver kidney microsomal type 1 antibody (anti‑LKM‑1) is an autoantibody against the liver microsomal enzyme cytochrome P450 2D6. It’s a diagnostic marker for autoimmune hepatitis type 2, more common in children and young adults, and may signal severe or drug‑induced liver injury. Anti‑LKM‑1 can also appear in some viral hepatitis cases; diagnosis requires clinical, serological and often biopsy correlation.

Normal result for liver–kidney microsomal (LKM) antibodies is negative or undetectable. Labs usually report titers by immunofluorescence; values below the lab’s cutoff (commonly <1:40, though some use <1:20) are considered negative. Titers at or above the lab-specific positive threshold (for example ≥1:40) indicate LKM positivity and should be interpreted by a clinician in the clinical context.

A positive LKM (liver–kidney microsomal) antibody test indicates an autoimmune reaction targeting liver cells, most often linked with autoimmune hepatitis (especially type 2). It suggests immune‑mediated liver injury and often accompanies abnormal liver enzymes. It’s not diagnostic alone — further evaluation (repeat blood tests, liver function tests, imaging, and sometimes biopsy) and specialist referral are needed to confirm diagnosis and start immunosuppressive treatment.

Costs for the LKM (anti‑LKM) antibody test vary by country and lab. In the UK it’s generally provided free through the NHS; in India private testing commonly costs around INR 700–2,500. In the US and Canada private laboratory charges typically range from about $50–300, and can be higher if included in a broader autoimmune panel. Check local labs or insurers for exact pricing.

Type 1 autoimmune hepatitis is the commonest autoimmune liver disease in teens and adults, where the immune system attacks hepatocytes causing chronic inflammation. Symptoms include fatigue, jaundice, abdominal pain and raised liver enzymes. Diagnosis uses blood tests for autoantibodies (ANA, SMA), liver function tests and often biopsy. Treatment is immunosuppression (corticosteroids with azathioprine) to control inflammation and prevent cirrhosis.

LKM disease (Liver–Kidney Microsomal antibody–associated autoimmune hepatitis, type 2) is an autoimmune liver disorder in which antibodies—often against cytochrome P450 enzymes—attack hepatocytes, causing inflammation. It commonly affects children and young adults, causing jaundice, fatigue, and raised liver enzymes. Diagnosis uses serology and liver biopsy. Treatment is immunosuppression (corticosteroids ± azathioprine) to prevent progression to cirrhosis.