SAT0451 The HLA Class II Profile in Korean Patients with Inflammatory Myositis
Authors: D.J. Ko, E.H. Kang, H.M. Kwon, J.W. Park, S.J. Lee, S.W. Chung, Y.-J. Ha, Y.J. Lee, E.Y. Lee, Y.W. Song
Journal: Annals of the Rheumatic Diseases (2015)

<h3>Background</h3> Polymyositis (PM) and dermatomyositis (DM) is known to be associated with certain HLA alleles in several ethnic groups including Caucasians, African-Americans, and the Japanese. <h3>Objectives</h3> To investigate the profile of HLA class II alleles in Korean patients with PM and DM <h3>Methods</h3> Sequencing based genotyping for HLA-DRB1 and -DPB1 was performed in 140 Korean patients with DM (n=104) or PM (n=36) and in 207 healthy controls. Associations of each HLA-DR or -DP allele with myositis or clinical subsets of myositis were examined. <h3>Results</h3> HLA-DRB1*14:54 (odds ratio [95% confidence interval] 1.05 [1.01-1.09]), -DRB1*15:02 (2.44 [1.03-5.81]), -DRB1*16:02 (1.04 [1.00-1.07], and -DPB1*09:01 (2.44 [1.03-5.81]) were found to be susceptibility alleles while HLA-DRB1*14:01 (0.93 [0.90-0.97]) and -DRB1*15:01 (0.38 [0.18-0.79]) to be protective alleles for inflammatory myositis (Table 1). In DM, HLA-DRB1*15:02 (3.14 [1.30-7.62]) and -DPB1*09:01 (2.87 [1.17-7.05]) carriers were more frequent while HLA-DRB1*14:01 (0.93 [0.90-0.97]), -DRB1*15:01 (0.30 [0.12-0.74]), and -DPB1*04:02 (0.44 [0.20-0.94]) carriers were less frequent than controls. In PM, HLA-DRB1*14:03 (6.52 [1.78-23.81]), and -DRB1*14:54 (1.13 [1.00-1.23]) carriers were more frequently observed. When PM and DM were compared, HLA-DRB1*14:03 carriers were more frequently observed in PM (5.43 [1.23-24.02]). When the association between each allele and clinical subsets was examined, patients with interstitial lung disease (ILD) carried HLA-DRβ1*04:03 (6.34 [1.35-29.76]), -DRβ1*07:01 (0.22 [0.08-0.64]), -DRβ1*09:01 (0.16 [0.05-0.60]) -DRβ1*12:02 (2.91 [1.16-8.01]) DRβ1*15:01 (0.10 [0.01-0.80]), -DPβ1*14:01 (8.90 [1.08-73.21]), and -DPβ1*17:01 (0.11 [0.01-0.92]) more frequently than patients without. DM patients with ILD showed higher frequency of HLA-DRβ1*04:05 than DM patients without ILD (4.68 [1.24-17.74]). Other associations included dysphagia with HLA-DRβ1*08:02 (6.73 [1.51-30.00]), -DRβ1*14:54 (5.19 [1.09-24.57]), and -DPβ1*03:01 (5.19 [1.09-24.57]), arthralgia with HLA-DRβ1*03:01 (4.79 [1.21-18.98]) and -DPβ1*02:01 (2.30 [1.10-4.82]), and mechanic9s hand with HLA-DRB1*08:03 (3.25 [1.12-9.45]) and -DRB1*12:02 (5.04 [1.66-15.29]). Regarding skin rashes, heliotrope rash was associated with HLA-DRβ1*09:01 (2.98 [1.05-8.46]) and -DPβ1*05:01 (0.41 [0.18-0.87]), Gottron9s papules with HLA-DRβ1*14:05 (8.77 [1.07-72.17]), -DPβ1*02:01 (2.29 [1.11-4.73]), -DPB1*02:02 (0.086 [0.01-0.67]), and -DPB1*05:01 (0.41 [0.20-0.85]), and shawl sign with HLA-DRB1*14:05 (4.67 [1.15-18.99]) and -DPB1*14:01 (4.67 [1.15-18.99]). Cancer development was associated with HLA-DRB1*12:01 (7.25 [1.65-31.89]) and -DRB1*13:02 (0.81 [0.74-0.88]). No HLA-DRB1 or -DPB1 allele was found to be associated with anti-Jo1 antibody. <h3>Conclusions</h3> Korean patients with inflammatory myositis showed a unique profile of HLA-DR and -DP alleles compared with other ethnic groups. Alleles associated with disease susceptibility were different between PM and DM. Clinical subsets, particularly ILD, showed different immunogenetic backgrounds. <h3>Disclosure of Interest</h3> None declared