Myositis autoantibodies in Korean patients with inflammatory myositis: anti-140-kDa polypeptide antibody is primarily associated with rapidly progressive interstitial lung disease independent of clinically amyopathic dermatomyositis.
BACKGROUND
To investigate the association between myositis autoantibodies and clinical subsets of inflammatory myositis in Korean patients.


METHODS
Immunoprecipitation was performed using the sera of classic polymyositis (PM) (n = 11) and dermatomyositis (DM) (n = 38) patients who met the Bohan and Peter criteria for definite inflammatory myositis. A panel of defined myositis autoantibodies was surveyed to investigate the association between each autoantibody and clinical subsets of inflammatory myositis.


RESULTS
Either MSAs, anti-p140, or anti-p155/140 antibodies were found in 63.3% (31/49) of the study subjects. Anti-140-kDa-polypeptide (anti-p140) (18.4%, 9/49) and anti-155/140-kDa polypeptide (anti-p155/140) (16.3%, 8/49) antibodies were the most common, followed by anti-Mi2 (14.3%, 7/49), anti-ARS (12.2%, 6/49) and anti-SRP (2.0%, 1/49) antibodies. All MSAs and anti-p140 and anti-p155/140 antibodies were mutually exclusive. Anti-p140 (23.7%, 9/38), anti-p155/140 (21.1%, 8/38), and anti-Mi2 (18.4%, 3/38) antibodies were found exclusively in DM patients. Anti-p140 antibody was associated with rapidly progressive interstitial lung disease (ILD) (p = 0.001), with a sensitivity of 100.0% (4/4) and a specificity of 85.3% (29/34) in DM patients. Anti-p155/140 antibody was associated with cancer-associated DM (p = 0.009), with a sensitivity of 55.6% (5/9) and a specificity of 89.7% (26/29). Cancer-associated survival was significantly worse when anti-p155/140 antibody was present (19.2 ± 7.6 vs. 65.0 ± 3.5 months, p = 0.032). Finally, anti-ARS antibodies were associated with stable or slowly progressive ILD in PM and DM patients (p = 0.005).


CONCLUSIONS
Anti-p140 and anti-p155/140 antibodies were commonly found autoantibodies in Korean patients with inflammatory myositis. Despite the lack of clinically amyopathic DM patients in the study subjects, a strong association was observed between anti-p140 antibody and rapidly progressive ILD. Anti-p155/140 antibody was associated with cancer-associated myositis and poor survival.
Kang
Eun Ha
EH
Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
Nakashima
Ran
R
Mimori
Tsuneyo
T
Kim
Jinhyun
J
Lee
Yun Jong
YJ
Lee
Eun Bong
EB
Song
Yeong Wook
YW
D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D003882:Dermatomyositis / Q000150:complications / Q000276:immunology* / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000150:complications / Q000276:immunology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D009220:Myositis / Q000150:complications / Q000276:immunology* / Q000473:pathology*; D010455:Peptides / Q000097:blood; D056910:Republic of Korea / Q000453:epidemiology / Q000208:ethnology
D001323:Autoantibodies; D010455:Peptides