[2][3] Today, anti-histone antibodies are still used as a marker for systemic lupus erythematosus, but are also implicated in other autoimmune diseases like Sjögren syndrome, dermatomyositis, or rheumatoid arthritis.
There is evidence that IgG and IgM anti-histone antibodies produced as a result of different drug exposures are specific to epitopes of different histone complexes.
Homogeneous, diffuse staining indicates the presence of anti-histone antibodies, chromatin, and some double-stranded DNA.
[4] Ninety-six percent of patients with lupus induced by procainamide will have a positive test for anti-histone antibodies, and 100% of patients whose lupus was induced by penicillamine, isoniazid, or methyldopa will have a positive test for anti-histone antibodies.
[6] A value of greater than 1.5 units relative to a control serum is considered a positive ELISA test for the anti-histone antibodies.