Table 6.
Cutoff points of serum biomarkers and relevant sensitivity, specificity, PPV, and NPV when predicting ACR and PASI improvement at weeks 12 and 24.
| Item | Youden index | Cutoff | Sen | Spe | PPV | NPV |
|---|---|---|---|---|---|---|
| Week 12 | ||||||
| b-MPO–DNA | 0.525 | 0.416 | 0.875 | 0.65 | 0.5 | 0.92 |
| b-ESR | 0.45 | 16.5 | 0.75 | 0.7 | 0.5 | 0.875 |
| b-CRP | 0.45 | 4.44 | 0.75 | 0.7 | 0.5 | 0.875 |
| Week 24 | ||||||
| b-MPO–DNA | 0.618 | 0.824 | 0.8 | 0.818 | 0.5 | 0.95 |
| ΔMPO–DNA | 0.618 | 0.34 | 0.8 | 0.818 | 0.44 | 0.95 |
| ΔMPO–DNA% | 0.618 | 56.3% | 0.8 | 0.818 | 0.4 | 0.94 |
| b-ESR | 0.482 | 18.5 | 0.8 | 0.318 | 0.36 | 0.94 |
| ΔESR | 0.418 | 6.5 | 0.6 | 0.818 | 0.42 | 0.9 |
| ΔESR% | 0.191 | 30.1% | 0.6 | 0.591 | 0.25 | 0.87 |
| b-CRP | 0.573 | 9.3 | 0.8 | 0.773 | 0.57 | 0.94 |
| ΔCRP | 0.573 | 3.7 | 0.8 | 0.773 | 0.44 | 0.94 |
| ΔCRP% | 0.436 | 47.3% | 0.8 | 0.636 | 0.31 | 0.93 |
Sen, sensitivity; Spe, specificity; PPV, positive predictive value; NPV, negative predictive value; b-MPO–DNA/ESR/CRP, serum MPO–DNA complex/ESR/CRP at baseline; ΔMPO–DNA/ESR/CRP, reduction of serum MPO–DNA/ESR/CRP at 12 week in absolute value; ΔMPO–DNA/ESR/CRP%, reduction of serum MPO–DNA/ESR/CRP at 12 weeks in percentage.