Anti-histone antibodies

SARDs are a heterogeneous group of disorders characterized by dysregulation of the immune system, that starts to turn against the body’s own tissues. Major SARDs include systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis and Sjögren’s syndrome. These diseases can affect multiple organs and share common symptoms such as fatigue, fever, joint pain and skin rash. Diagnosis relies on a combination of clinical assessment and specific autoantibody tests. Early diagnosis is crucial to initiate appropriate therapy and slow down disease progression.

Histones are essential nuclear proteins found in almost all eukaryotic cells, enabling DNA compaction into structural units called nucleosomes. Anti-histone autoantibodies are not specific to a single disease but can be detected in various autoimmune conditions, particularly rheumatic disorders. High anti-histone antibody titres are most commonly observed in systemic lupus erythematosus (SLE) and, even more characteristically, in drug-induced lupus erythematosus (DILE). In the latter, a distinctive diagnostic feature is the presence of high anti-histone antibody levels and the absence of main autoantibodies typically associated with SLE (anti-dsDNA and anti-Sm).