Histone autoantibodies IgG

General Information

Histones are proteins that play an important role in the organization of DNA and the formation of cellular chromatin. Histones are rich in the amino acids arginine and lysine.

There are five classes of histones: H1, H2A, H2B, H3, H4. All five classes of histones, as well as the DNA-histone complex, are sometimes targets for the production of autoantibodies by the immune system.

Anti-histone autoantibodies are found in 95% of drug-induced lupus erythematosus cases and are an important diagnostic criterion.

Drug-induced lupus erythematosus is similar in course to systemic lupus erythematosus, but does not cause kidney or nervous system damage and is not associated with autoantibodies against double-stranded DNA.

Drug-induced lupus is caused by the following groups of medications: procainamide, hydralazine, isoniazid, carbamazepine, penicillamine, chlorpromazine, alpha-methyldopa, quinidine, sulfasalazine, minocycline.

Antihistone antibodies are also found in 30-60% of systemic lupus erythematosus cases, often in conjunction with autoantibodies against double-stranded DNA.

It is sometimes not possible to differentiate between systemic lupus erythematosus and drug-induced lupus based on antihistone autoantibodies. However, in drug-induced lupus, antihistone antibodies are present in isolation, without autoantibodies against double-stranded DNA.

Preparation of the patient: It's not necessary.

Material for examination: Venous blood

Interpretation of results

A positive result for anti-histone antibodies, in the context of a negative result for double-stranded DNA antibodies, is suggestive of drug-induced lupus.

Positive levels of anti-histone antibodies and double-stranded DNA antibodies are characteristic of systemic lupus erythematosus.

Antihistone antibodies may also be present in pathologies such as:

• Rheumatoid arthritis:
• Systemic sclerosis
• Juvenile arthritis
• Autoimmune liver diseases: primary biliary cirrhosis and autoimmune hepatitis

In rare cases, anti-histone antibodies are found in patients without symptoms of systemic lupus erythematosus or drug-induced lupus.