Antibodies to microsomal antigen of the liver and kidneys in the blood
Last reviewed: 23.04.2024
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Normally, the concentration of antibodies to the microsomal antigen of the liver and kidneys in the serum is less than 20 IU / ml; 20-25 IU / ml - boundary values.
Antibodies to microsomal liver and kidney antigen (LKM) are a heterogeneous group of autoantibodies, which are divided into three subtypes based on their Ag targets. The cytochrome P-450IID6 component with a molecular weight of 50,000 was identified as the main LKM-I antigen (LKM-1), LKM-2 was directed to cytochrome P-450IIC9 and was detected in patients taking ticrinaphene (diuretic, currently not used) , LKM-3 were detected in the serum of patients with chronic viral hepatitis D (found in 5-13% of cases), but the antigen for them has not yet been identified. They can be present in patients with autoimmune hepatitis type II (in 10% of patients).
The ELISA method is based on the definition of antibodies to liver and kidney microsomes (LKM-1). This study is in addition to the already existing methods of diagnosing autoimmune hepatitis.
There are 4 types of autoimmune hepatitis. However, this separation of chronic autoimmune hepatitis is not of great clinical significance in terms of treatment tactics, since the main part of patients regardless of the type of disease, effective immunosuppressive therapy.
The diagnosis of chronic autoimmune hepatitis is considered accurately established if:
- titres of antinuclear antibodies, antibodies to smooth muscles, antibodies to microsomal antigen of the liver and kidneys (more than 1:80) in the blood serum;
- the concentration of IgG in the blood serum exceeds the upper limit of the norm by 1.5 times.
- in the anamnesis there are no instructions on reception of hepatoxic preparations and alcohol abuse;
- there are no markers of viral hepatitis.
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