Table 2.
Immunogenetic differences between different clinicopathologic and autoantibody groups of European American (EA) and African American (AA) IIM patients and unrelated, ethnically-matched controls*
| EA | GM/KM Marker | Cases% (n/N†) | Controls% (n/N†) | P | Pc | OR | 95% CI |
|---|---|---|---|---|---|---|---|
| ALLOTYPES | |||||||
| Adults | PM | ||||||
| KM 1 | 41.6 (62/149) | 26.1 (60/230) | 0.0023 | 0.025 | 2.0 | 1.27–3.21 | |
| THR-IIM | |||||||
| GM 3 | 42.9 (3/7) | 89.6 (207/231) | 0.0043 | 0.047 | 0.1 | 0.01–0.56 | |
| RNP-IIM | |||||||
| GM 3 | 57.1 (8/14) | 89.6 (207/231) | 0.0031 | 0.034 | 0.2 | 0.04–0.60 | |
| Juveniles | JDM | ||||||
| GM 13 | 87.9 (174/198) | 65.2 (135/207) | <0.0001 | <0.0001 | 3.9 | 2.26–6.76 | |
| PHENOTYPES | |||||||
| Adults | DM | ||||||
| Gm 3 23 5,13 | 59.6 (68/114) | 40.7 (83/204) | 0.0015 | 0.020 | 2.2 | 1.32–3.54 | |
| JO1-IIM | |||||||
| GM 3 23 5,13 | 70.0 (35/50) | 40.7 (83/204) | 0.0002 | 0.0031 | 3.4 | 1.68–7.12 | |
| Juveniles | JDM | ||||||
| Gm 1,3,17 5,13,21 | 37.9 (75/198) | 22.0 (45/205) | 0.0005 | 0.0060 | 2.2 | 1.37–3.45 | |
| Gm 3 23 5,13 | 60.1 (119/198) | 40.7 (83/204) | 0.0001 | 0.0013 | 2.2 | 1.45–3.34 | |
|
| |||||||
| AA | Cases% (n/N†) | Controls% (n/N†) | P | Pc | OR | 95% CI | |
|
| |||||||
| ALLOTYPES | |||||||
| Adults | IIM | ||||||
| GM 5 | 98.6 (72/73) | 85.3 (93/109) | 0.0016 | 0.018 | 12.4 | 1.82–526.5 | |
| SRP-IIM | |||||||
| GM 6 | 54.5 (6/11) | 13.8 (15/109) | 0.0037 | 0.041 | 7.5 | 1.64–34.6 | |
| Juveniles | JDM | ||||||
| GM 13 | 88.9 (32/36) | 62.6 (62/99) | 0.0030 | 0.033 | 4.8 | 1.50–19.9 | |
| PHENOTYPES | |||||||
| Juveniles | JDM | ||||||
| KM 1,1 | 27.8 (10/36) | 7.3 (8/109) | 0.0028 | 0.037 | 4.8 | 1.53–15.5 | |
| RO-IIM | |||||||
| KM 1,1 | 75.0 (3/4) | 7.3 (8/109) | 0.0027 | 0.032 | 37.9 | 2.5–2005.7 | |
Abbreviations: PM, polymyositis; (J)DM, (juvenile)dermatomyositis; MSA, myositis-specific autoantibody; MAA, myositis-associated autoantibody; THR, anti-threonyl tRNA synthetase autoantibodies; RNP, anti-ribonucleoprotein autoantibodies; JO1, anti-histidyl tRNA synthetase autoantibodies; SRP, anti-signal recognition particle autoantibodies; P, P values; Pc, corrected P values; OR, odds ratio; 95% CI, confidence interval. Other abbreviations per Table 1. Markers identified as protective factors are listed in italics.
The number (n) of sero-marker positive subjects/the total number of subjects (N) for which complete sero-typing data were available for a given marker.
Fisher’s Exact P values were adjusted for multiple testing within race and age group for each set of comparisons using the sequential Holm procedure as described in Methods. The size of the family (k value) within which the Holm procedure was applied varied by the number of testable factors in each group of comparisons (k family values for multiple GM and KM allotype and phenotype testing were 11 and 13, respectively).