Table 1.
Clinicopathologic and Autoantibody Groups of European American (EA) and African American (AA) Patients with Idiopathic Inflammatory Myopathies (IIM)*
| Clinical Composition N (%) |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| IIM N (%) | PM | DM | IBM | JIIM¶ | |||||||
| EA N=297 | AA N=73 | EA N=149 | AA N=43 | EA N=114 | AA N=27 | EA N=32 | AA N=3 | EA N=217 | AA N=50 | ||
| Myositis-Specific Autoantibodies (MSA) | |||||||||||
| All MSA | 91 (33.2) | 41 (59.4) | 52 (37.1) | 25 (62.5) | 39 (37.9) | 18 (66.7) | 0 (0.0) | 0 (0.0) | 7 (4.5) | 10 (31.2) | |
| Anti-Synthetases | 72 (26.2) | 26 (37.7) | 45 (32.1) | 13 (32.5) | 27 (26.2) | 15 (55.6) | 0 (0.0) | 0 (0.0) | 5 (3.2) | 4 (12.5) | |
| Anti-Jo-1 | 50 (18.2) | 15 (21.7) | 32 (22.8) | 7 (17.5) | 18 (17.5) | 8 (29.6) | 0 (0.0) | 0 (0.0) | 4 (2.3) | 3 (94) | |
| Anti-PL-7 | 7 (2.6) | 4 (5.8) | 5 (3.6) | 3 (7.5) | 2 (1.9) | 1 (3.7) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Anti-PL-12 | 4 (1.4) | 3 (4.3) | 3 (2.1) | 2 (5.0) | 4 (3.9) | 1 (3.7) | 0 (0.0) | 0 (0.0) | 1 (0.6) | 1 (3.1) | |
| Anti-OJ | 5 (1.8) | 1 (1.4) | 3 (2.1) | 0 (0.0) | 2 (1.9) | 1 (3.7) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Anti-EJ | 3 (1.1) | 3 (4.3) | 2 (1.4) | 1 (2.5) | 1 (1.0) | 2 (7.4) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Anti-Mi-2 | 13 (4.7) | 4 (5.8) | 1 (0.7) | 1 (2.5) | 12 (11.6) | 3 (11.1) | 0 (0.0) | 0 (0.0) | 1 (0.6) | 2 (6.3) | |
| Anti-SRP | 6 (2.2) | 11 (15.9) | 6 (4.3) | 11 (27.5) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (0.6) | 4 (12.5) | |
| Negative† | 183 (66.8) | 28 (40.6) | 88 (62.8) | 15 (37.5) | 64 (62.1) | 11 (40.7) | 29 (100.0) | 2 (100.0) | 147 (95.4) | 22 (68.8) | |
| Myositis-Associated Autoantibodies (MAA) | |||||||||||
| All MAA | 92 (33.6) | 26 (37.7) | 48 (34.3) | 14 (35.0) | 34 (33.0) | 12 (44.4) | 8 (27.6) | 0 (0.0) | 20 (13.0) | 12 (37.5) | |
| Anti-PM/Scl | 31 (11.3) | 2 (2.9) | 16 (11.4) | 2 (5.0) | 15 (14.6) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 10 (6.5) | 0 (0.0) | |
| Anti-Ro | 31 (11.3) | 11 (15.9) | 15 (10.7) | 7 (17.5) | 10 (9.7) | 4 (14.8) | 5 (17.2) | 0 (0.0) | 3 (1.9) | 4 (12.5) | |
| Anti-La | 13 (4.7) | 3 (4.3) | 5 (3.6) | 1 (2.5) | 4 (3.9) | 2 (7.4) | 3 (10.3) | 0 (0.0) | 1 (0.6) | 1 (3.1) | |
| Anti-U-RNP | 14 (5.1) | 10 (14.5) | 9 (6.4) | 4 (10.0) | 5 (4.8) | 6 (22.2) | 0 (0.0) | 0 (0.0) | 6 (3.9) | 7 (21.9) | |
| Anti-Ku | 3 (1.1) | 0 (0.0) | 3 (2.1) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0 | 0 (0.0) | 0 (0.0) | |
| Negative† | 198 (72.3) | 51 (73.9) | 99 (70.7) | 28 (70.0) | 75 (72.8) | 21 (77.8) | 23 (79.3) | 2 (100.0) | 138 (89.6) | 26 (81.2) | |
*
Abbreviations: PM, polymyositis; DM, dermatomyositis; IBM, inclusion body myositis; Anti-synthetases include anti-Jo-1 (anti-histidyl-tRNA synthetase), anti-PL-7 (anti-threonyl-tRNA synthetase), anti-PL-12 (anti-alanyl-tRNA synthetase), anti-OJ (anti-isoleucyl-tRNA synthetase) and anti-EJ (anti-glycyl-tRNA synthetase). Autoantibody data were available for EA: 152/168 PM, 245/312 DM, 29/32 IBM; AA: 49/57 PM, 50/63 DM, 2/3 IBM.
¶
JIIM (EA: 19 PM, 198 DM; AA: 14 PM, 36 DM)
†
Negative for serum autoantibodies evaluated in this study (see Methods).