Table 3.
Highest magnitude component loadings from PCA (PC2, PC3) for JDM/MSA subgroups versus other conditions
| Gene | PCA-A with JDM | PCA-B with anti-MDA5 Ab | PCA-C with anti-NXP2 Ab | PCA-D with anti-TIF1 Ab | PCA-E with MSA-neg | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| PC2 | PC3 | PC2 | PC3 | PC2 | PC3 | PC2 | PC3 | PC2 | PC3 | |
| CXCL10 | − 0.102 | − 0.667 | − 0.267 | − 0.666 | −0.321 | − 0.685 | − 0.659 | 0.336 | − 0.259 | − 0.686 |
| GBP1 | − 0.506 | 0.215 | − 0.562 | 0.167 | − 0.448 | 0.216 | − 0.200 | − 0.473 | 0.517 | − 0.076 |
| IFI27 | − 0.510 | − 0.345 | − 0.218 | − 0.467 | − 0.444 | − 0.250 | − 0.579 | 0.062 | 0.145 | − 0.546 |
| LAMP3 | − 0.216 | 0.059 | − 0.444 | 0.049 | − 0.325 | − 0.021 | − 0.066 | − 0.311 | 0.349 | − 0.177 |
| SIGLEC1 | 0.132 | − 0.424 | 0.338 | − 0.330 | 0.017 | − 0.348 | − 0.204 | 0.315 | − 0.343 | − 0.224 |
| SOCS1 | − 0.428 | 0.300 | − 0.437 | 0.155 | − 0.413 | 0.323 | − 0.085 | − 0.503 | 0.486 | 0.061 |
Bold indicates an absolute value of component loading > 0.4 (high magnitude)
Italic and underline indicates an absolute value of component loading between 0.2 to 0.4
PCA-A: PCA of JDM, CANDLE, SAVI, NOMID, and HC
PCA-B: PCA of Anti-MDA5 Ab, CANDLE, SAVI, NOMID, and HC
PCA-C: PCA of Anti-NXP2 Ab, CANDLE, SAVI, NOMID, and HC
PCA-D: PCA of Anti-TIF1 Ab, CANDLE, SAVI, NOMID, and HC
PCA-E: PCA of MSA-neg, CANDLE, SAVI, NOMID, and HC
The component loadings are the correlations of the individual gene normalized Z-scores with the given principal component. A stronger loading (e.g., greater than 0.40 or less than − 0.40) indicates a stronger relationship or contribution of that gene with that principal component. As with correlations, these can be negative or positive. The highest magnitude component loading interferon-regulated genes are listed on the left. The sign or direction of the component loading is arbitrary and can be reversed with the same interpretation, so the focus should be on the weight or magnitude
Abbreviations: PCA principal component analysis, PC principal component, JDM includes all juvenile dermatomyositis patients, MSA myositis-specific autoantibody group, anti-TIF1 Ab includes subgroup of JDM patients with anti-TIF1 autoantibodies, anti-NXP2 Ab subgroup of JDM patients with anti-NXP2 autoantibodies, anti-MDA5 Ab includes subgroup of JDM patients with anti-MDA5 autoantibodies, MSA-neg includes subgroup of JDM that is negative for myositis-specific autoantibodies, CANDLE Chronic Atypical Neutrophilic Dermatosis with Lipodystrophy and Elevated temperature, SAVI STING-Associated Vasculopathy with onset during Infancy, NOMID neonatal-onset multisystem inflammatory disease