Table 4.
Diagnostic accuracy of haptoglobin gene expression and serological CRP, ESR, platelet counts, and HP protein for the detection of endoscopically active disease in ulcerative colitis. For each variable, the AUC is given and the sensitivity [Se], specificity [Sp], positive predictive value [PPV], negative predictive value [NPV], and accuracy were calculated and are shown as percentages based on the defined cut-off points. The CRP [normally < 1 mg/dL], ESR [normally < 20 mm/h], and platelet count [normally < 400· 10^9/L] cut-offs were defined according to the normal levels.
| Biomarker | AUC | Cut-off | Se | Sp | PPV | NPV | Accuracy |
|---|---|---|---|---|---|---|---|
| HP transcript [DCt] | 0.75 | -2.9 DCta | 63.5 | 80.0 | 91.5 | 39.2 | 67.3 |
| HP transcript [DCt] | 0.73 | -2.5 DCtb | 60.7 | 81.6 | 80.4 | 62.5 | 70.0 |
| CRP [mg/dL] | 0.72 | 1 mg/dL | 43.2 | 83.3 | 89.7 | 30.3 | 52.4 |
| ESR [mm/h] | 0.60 | 20 mm/h | 34.5 | 86.7 | 90.9 | 25.5 | 45.2 |
| Platelet count [10^9/L] | 0.66 | 400·10^9/L | 12.7 | 100 | 100 | 22.5 | 30.3 |
| HP protein[g/L] | 0.70 | 1.32 g/La | 48.7 | 90.9 | 94.9 | 33.9 | 58.2 |
CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; AUC, area under the curve.
aCut-off point resulted from the regression model with binary response defined as inactive [Endoscopic Mayo score 0] versus active [Endoscopic Mayo score 1–3].
bCut-off point resulted from the regression model with binary response defined as inactive [Endoscopic Mayo score 0–1] versus active [Endoscopic Mayo score 2–3].