Anti-histone antibodies in SLE and other autoimmune diseases

The frequency of IgG and IgM anti-total histones and anti-histone subfractions were studied in 63 patients with SLE and 257 patients with other autoimmune conditions employing the ELISA. IgG anti-histone antibodies were found in 17 of 63 (25%) sera of lupus patients and in only 16 of 257 (6%) sera of patients with other autoimmune conditions. The latter incidence did not differ statistically from that of 115 healthy control subjects. Furthermore, the concomitant appearance of both IgG and IgM anti-histone antibodies was observed only in SLE patients. Anti-histone subfraction (H1, H2A, H2B, H3, H4) activity was determined in sera containing anti-total histone antibodies. There was a higher preponderance for antibodies to H1, H2A, H2B in SLE. We conclude that anti-histone antibodies seem to be a marker for lupus and its variants (e.g. drug induced lupus) and should be routinely looked for in SLE patients.