Anti-interleukin-6 autoantibodies in rheumatic diseases. Increased frequency in the sera of patients with systemic sclerosis.
OBJECTIVE
To investigate the presence and the roles of anti-interleukin-6 (anti-IL-6) autoantibodies in rheumatic diseases, and to further elucidate clinical and pathophysiologic significance of anticytokine autoantibodies.


METHODS
Anti-IL-6 IgG autoantibodies were measured by the 125I-IL-6 binding activity of IgG, which was isolated from serum by protein A-Sepharose.


RESULTS
Nine of 52 sera (17.3%) from patients with systemic sclerosis (SSc) contained anti-IL-6 antibodies, whereas only 1.9% of sera from normal subjects and 0-5% of sera from patients with other rheumatic diseases were positive for the antibodies. Moreover, anti-IL-6 autoantibodies were found predominantly among patients with the limited form of SSc (42.9%), compared with those with the diffuse form (7.9%).


CONCLUSIONS
Anti-IL-6 IgG autoantibodies were detected in patients with SSc, particularly those with the limited form of the disease, at a significantly increased frequency compared with normal subjects and patients with other rheumatic diseases. These results suggest that the development of anti-IL-6 autoantibodies and IL-6 may have a role in the pathophysiology of SSc.
Takemura
H
H
Department of Rheumatology, University of Tsukuba, Japan.
Suzuki
H
H
Yoshizaki
K
K
Ogata
A
A
Yuhara
T
T
Akama
T
T
Yamane
K
K
Kashiwagi
H
H
D000328:Adult; D001323:Autoantibodies / Q000032:analysis* / Q000276:immunology / Q000502:physiology; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000276:immunology*; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D012216:Rheumatic Diseases / Q000097:blood / Q000276:immunology* / Q000503:physiopathology; D012595:Scleroderma, Systemic / Q000097:blood / Q000276:immunology* / Q000503:physiopathology
D001323:Autoantibodies; D015850:Interleukin-6; D007457:Iodine Radioisotopes