The measurement of anti-histone antibodies is used in the evaluation of patients with drug-induced lupus.
Histones are essential protein components of chromatin and their structures are largely conserved in different types of organisms. Five classes of histones have been described, namely H1, H2, H2b, H3, and H4, characterized by their molecular weights ranging from 11 to 23 kD and their contents of basic amino acids lysine and arginine.
Histone autoantibodies can react with any of the 5 histone classes. Such autoantibodies are caused by unknown mechanisms in patients treated with certain drugs, in particular protamine, hydralazine, quinidine, methyldopa, penicillamine, and isoniazid. These patients may have signs and symptoms that resemble systemic lupus erythematosus (SLE). This disorder is called drug-induced lupus.
Screening for anti-histone antibodies is useful for the evaluation of patients with suspected drug-induced lupus. These patients usually have a positive test for anti-histone antibodies and a negative test for autoantibodies against double-stranded DNA (dsDNA). In contrast, patients with SLE have positive tests for both types of autoantibodies.
Laboratory test results are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70%-80% of diagnostic decisions are based on laboratory tests. Correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased".
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be interpreted in relation to each individual case and family history, clinical findings, and the results of other laboratory tests and information. Your personal physician should explain the importance of your test results.
At Diagnostiki Athinon we answer any questions you may have about the test you perform in our laboratory and we contact your doctor to get the best possible medical care.