Immunogenetic features in 120 Japanese patients with idiopathic inflammatory myopathy.
OBJECTIVE
To examine the role of HLA-DRB1 and tumor necrosis factor (TNF) promoter genotypes in the development and the autoantibody profiles of idiopathic inflammatory myopathy (IIM) in Japanese patients.


METHODS
HLA-DRB1 and TNF promoter genotypes were determined, and serum antinuclear autoantibodies were identified in 120 adult Japanese patients with IIM [72 with dermatomyositis (DM), 30 with polymyositis (PM), 18 with myositis overlapping with other collagen vascular diseases], as well as in 265 controls.


RESULTS
Forty-two patients (35%) were positive for myositis-specific autoantibodies (MSA), including 37 (31%) for anti-aminoacyl-tRNA synthetase (ARS) autoantibodies. Allele carrier frequency of HLA-DRB1*0803 was increased in the patients with IIM [p = 0.02, corrected p (pc) NS, 23% vs 14%, odds ratio (OR) = 1.9 (95% confidence interval, CI = 1.1-3.2)], with PM [p = 0.006, pc NS, 33%, OR 3.1 (95% CI 1.3-7.1)], and with anti-ARS autoantibodies [27%, p = 0.04, OR 2.3 (95% CI 1.0-5.1)] compared with controls. DRB1*0405 was increased in patients with anti-ARS autoantibodies compared with controls [41% vs 25%, p = 0.04, pc NS, OR 2.1 (95% CI 1.0-4.3)]. TNF promoter genotype was associated with the presence of interstitial lung disease (ILD). The carriage of a TNF-a haplotype formed by -1031C, -863A, and -857C was increased in the patients with ILD versus those without ILD [33% vs 18%, p = 0.05, pc NS, OR 2.3 (95% CI 0.94-5.5)].


CONCLUSIONS
HLA-DRB1 alleles were associated with development of IIM and MSA in a Japanese population.
Furuya
Takefumi
T
Institute of Rheumatology and Department of Neurology, Tokyo Women's Medical University, Tokyo, Japan. furuyat@ior.twmu.ac.jp
Hakoda
Masayuki
M
Tsuchiya
Naoyuki
N
Kotake
Shigeru
S
Ichikawa
Naomi
N
Nanke
Yuki
Y
Nakajima
Ayako
A
Takeuchi
Megumi
M
Nishinarita
Makoto
M
Kondo
Hirobumi
H
Kawasaki
Aya
A
Kobayashi
Shio
S
Mimori
Tsuneyo
T
Tokunaga
Katsushi
K
Kamatani
Naoyuki
N
D000328:Adult; D001323:Autoantibodies / Q000097:blood; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009220:Myositis / Q000235:genetics* / Q000276:immunology*; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D017678:Sex Distribution; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
D001323:Autoantibodies; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D014409:Tumor Necrosis Factor-alpha