Correlation between specific SSc autoantibodies and clinical subsets within race. Results for patients with a defined subset of SSc are shown. Of the 1000 patients with SSc, 10 were unspecified for dsSSc or lcSSc (4 African American, 3 white, and 3 Hispanic patients). ANA+ samples negative for ACA, Scl-70, RNAP III, U3-RNP, Th/To, and PM/Scl were classified as undefined. Values are % (n) unless otherwise specified.
| Race | Autoantibody | Disease Subsets | p | |
|---|---|---|---|---|
| African American, n = 224 | dcSSc, n = 151 | lcSSc, n = 73 | ||
| ACA, n = 13 | 2.6 (4) | 12.3 (9) | 0.011 | |
| Scl-70, n = 58 | 29.8 (45) | 17.8 (13) | NS | |
| RNAP III, n = 32 | 15.9 (24) | 11.0 (8) | NS | |
| U3-RNP, n = 52 | 24.5 (37) | 20.5 (15) | NS | |
| Th/To, n = 4 | 0.7 (1) | 4.1 (3) | NS | |
| PM/Scl, n = 2 | 1.3 (2) | 0.0 (0) | NS | |
| More than 1, n = 2 | 1.3 (2) | 0.0 (0) | NS | |
| Undefined, n = 51 | 18.5 (28) | 31.5 (23) | 0.041 | |
| ANA−, n = 13* | 7.3 (11)* | 2.7 (2) | NS | |
| White, n = 552 | dcSSc, n = 210 | lcSSc, n = 342 | ||
| ACA, n = 162 | 6.7 (14) | 43.2 (148) | < 0.0001 | |
| Scl-70, n = 99 | 25.7 (54) | 13.2 (45) | 0.0002 | |
| RNAP III, n = 91 | 31.4 (66) | 7.3 (25) | < 0.0001 | |
| U3-RNP, n = 10 | 4.8 (10) | 0.0 (0) | < 0.0001 | |
| Th/To, n = 25 | 1.4 (3) | 6.4 (22) | 0.005 | |
| PM/Scl, n = 16 | 2.9 (6) | 2.9 (10) | NS | |
| More than 1, n = 6 | 1.4 (3) | 0.9 (3) | NS | |
| Undefined, n = 110 | 20.0 (42) | 19.9 (68) | NS | |
| ANA−, n = 37* | 6.7 (14)* | 6.7 (23)* | NS | |
| Hispanic, n = 193 | dcSSc, n = 112 | lcSSc, n = 81 | ||
| ACA, n = 37 | 4.5 (5) | 39.5 (32) | < 0.0001 | |
| Scl-70, n = 47 | 30.4 (34) | 16.0 (13) | 0.0271 | |
| RNAP III, n = 41 | 33.9 (38) | 3.7 (3) | < 0.0001 | |
| U3-RNP, n = 12 | 8.9 (10) | 2.5 (2) | NS | |
| Th/To, n = 8 | 1.8 (2) | 7.5 (6) | NS | |
| PM/Scl, n = 3 | 1.8 (2) | 1.2 (1) | NS | |
| More than 1, n = 3 | 1.8 (2) | 1.2 (1) | NS | |
| Undefined, n = 35 | 14.3 (16) | 23.5 (19) | NS | |
| ANA−, n = 10* | 5.4 (6)* | 4.9 (4) | NS | |
| Other, n = 21 | dcSSc, n = 9 | lcSSc, n = 12 | ||
| ACA, n = 5 | 0.0 (0) | 41.7 (5) | 0.045 | |
| Scl-70, n = 5 | 11.1 (1) | 33.3 (4) | NS | |
| RNAP III, n = 3 | 33.3 (3) | 0 (0) | NS | |
| U3-RNP, n = 4 | 44.4 (4) | 0 (0) | 0.021 | |
| Th/To, n = 2 | 0.0 (0) | 16.7 (2) | NS | |
| PM/Scl, n = 0 | 0.0 (0) | 0 (0) | NA | |
| More than 1, n = 0 | 0.0 (0) | 0 (0) | NA | |
| Undefined, n = 1 | 0.0 (0) | 8.33 (1) | NS | |
| ANA−, n = 1 | 11.1 (1) | 0 (0) | NS | |
↵* There are 10 overlapping RNAP III and ANA− samples (3 African Americans with dcSSc, 2 whites with dcSSc, 2 whites with lcSSc, and 3 Hispanics with dcSSc). SSc: systemic sclerosis; dcSSc: diffuse cutaneous SSc; lcSSc: limited cutaneous SSc; ANA: antinuclear antibodies; ACA: anticentromere antibodies; RNAP III: RNA polymerase III antibodies; NS: not significant; NA: not applicable.