Table 2.
Myositis-associated autoantibody (MAA) status, epidemiologic, and clinical features of anti-cortactin autoantibodies in adult and juvenile myositis patients.
| Adult myositis | Juvenile myositis | |||||||
|---|---|---|---|---|---|---|---|---|
| Anti-CTTN+ (n=74) |
Anti-CTTN− (n=596) |
Univariate p-value |
Multivariate p-value |
Anti-CTTN+ (n=8) |
Anti-CTTN− (n=335) |
Univariate p-value |
Multivariate p-value |
|
| Epidemiologic features and MAA | ||||||||
| Female sex | 72% (53) | 62% (369) | NS | NS | 62% (5/8) | 71% (238) | NS | NS |
| Race | ||||||||
| White | 59% (44) | 75% (447) | 0.004 | 0.02 | 75% (6) | 64% (215) | NS | NS |
| Black | 27% (20) | 17% (99) | 0.03 | NS | 13% (1) | 16% (53) | NS | NS |
| Other races | 14% (10) | 8% (50) | NS | NS | 13% (1) | 20% (67) | NS | NS |
| Age of onset (years) | 45.8 (14.6) | 50.5 (14.7) | 0.01 | NS | 10.8 (5.5) | 8.9 (4.2) | NS | NS |
| Time of follow-up (years) | 2.8 (3.3) | 2.8 (3.3) | NS | NS | 5.2 (4.8) | 6.1 (7.2) | NS | NS |
| Cancer associated myositis | 7% (5) | 12% (67) | NS | NS | 0% (0) | 0% (0) | NS | NS |
| Death during follow-up | 0% (0) | 5% (27) | NS | NS | 0% (0) | 4% (12) | NS | NS |
| Myositis-associated autoantibodies * | ||||||||
| Anti-Ro52 | 47% (35) | 26% (156) | < 0.001 | 0.001 | 0% (0) | 16% (50) | NS | NS |
| Anti-NT5c1a | 59% (10) | 33% (70) | 0.03 | 0.001 | 25% (2) | 28% (86) | NS | NS |
| Clinical features | (n=42) | (n=367) | (n=8) | (n=335) | ||||
| Muscle weakness | 95% (40) | 96% (354) | NS | NS | 100% (8) | 99% (333) | NS | NS |
| Skin involvement | ||||||||
| DM-specific skin involvement | 62% (26) | 38% (141) | 0.003 | 0.03 | 100% (8) | 91% (305) | NS | NS |
| Raynaud's phenomenon | 21% (9) | 14% (51) | NS | NS | 25% (2) | 14% (48) | NS | NS |
| Mechanic's hands | 19% (8) | 18% (66) | NS | NS | 25% (2) | 7% (24) | NS | 0.03 |
| Calcinosis | 12% (5) | 10% (36) | NS | NS | 50% (4) | 29% (98) | NS | NS |
| Interstitial lung disease | 24% (10) | 16% (58) | NS | NS | 12% (1) | 9% (30) | NS | NS |
| Esophageal involvement | ||||||||
| Dysphagia | 36% (15) | 17% (61) | 0.003 | 0.02 | 50% (4) | 41% (137) | NS | NS |
| Gastroesophageal reflux disease | 67% (28) | 47% (174) | 0.02 | 0.02 | 12% (1) | 22% (73) | NS | NS |
| Arthritis | 17% (7) | 16% (60) | NS | NS | 50% (4) | 52% (173) | NS | NS |
| Fever | 19% (8) | 9% (33) | 0.05 | NS | 14% (1) | 30% (101) | NS | NS |
Dichotomous variables were expressed as a percentage (count) and continuous variables as mean (SD). Univariate comparisons of continuous variables were made using Student’s t-test while dichotomous variables were compared either using the chi-squared test or Fisher’s exact test, as appropriate. Multivariate comparisons were performed using linear regression for continuous variables and logistic regression for dichotomous variables. All multivariate comparisons were adjusted by the patient group (IBM or autoantibody group) for the epidemiological comparisons and by time of follow-up, and patient group for the comparisons of clinical features. DM-specific skin involvement: either heliotrope, Gottron’s sign, or papules.
Anti-NT5c1a autoantibodies in adults were performed only in a subset of 227 patients (mostly IBM [n=139] and DM [n=50]). In children, both anti-Ro52 and anti-NT5c1a were performed in 314 of the total number of patients.