Table 4.
Diagnostic indices of various plasma acute phase proteins for prediction of intra-amniotic inflammation and/or microbial invasion of the amniotic cavity, acute histologic chorioamnionitis, and funisitis.
| Variables | Area (±SE) under the ROC curve | 95% CI | Cut-off valuea | Sensitivityb (95% CI) | Specificityb (95% CI) | PPV | NPV |
|---|---|---|---|---|---|---|---|
| Intra-amniotic inflammation and/or microbial invasion of the amniotic cavity | |||||||
| Plasma hepcidin (ng/mL) | 0.57 ± 0.04 f | 0.49–0.65 | ≥ 1.023 | 60.9 (50.1–70.8) | 45.1 (35.2–55.2) | 50.0 | 56.1 |
| Plasma RBP4 (µg/mL) | 0.65 ± 0.04 f | 0.57–0.72 | ≤ 16.953 | 62.0 (51.2–71.9) | 53.9 (43.8–63.8) | 54.8 | 61.1 |
| Plasma SAA1 (µg/mL) | 0.66 ± 0.04 f | 0.58–0.73 | ≥ 2.045 | 58.1 (47.4–68.2) | 67.6 (57.7–76.6) | 62.1 | 63.9 |
| Serum CRP (mg/dL) | 0.65 ± 0.04 f | 0.57–0.72 | ≥ 0.335 | 61.3 (50.6–71.2) | 55.0 (44.7–65.0) | 55.9 | 60.4 |
| Maternal blood NLR | 0.72 ± 0.04f | 0.64–0.79 | ≥ 5.196 | 76.7 (66.6–84.9) | 61.9 (51.4–71.5) | 65.1 | 74.1 |
| Combined model A c | 0.80 ± 0.03 | 0.74–0.87 | ≥ 0.383 | 85.5 (76.1–92.3) | 63.4 (52.8–73.2) | 67.6 | 83.1 |
| Acute histologic chorioamnionitis | |||||||
| Serum CRP (mg/dL) | 0.61 ± 0.04g | 0.53–0.69 | ≥ 0.305 | 60.2 (49.2–70.5) | 48.8 (37.6–60.1) | 55.8 | 53.3 |
| Maternal blood NLR | 0.62 ± 0.04g | 0.53–0.70 | ≥ 5.196 | 65.9 (54.8–75.8) | 51.9 (40.4–63.3) | 59.6 | 58.6 |
| Combined model B d | 0.75 ± 0.04 | 0.68–0.83 | ≥ 0.402 | 77.3 (67.1–85.5) | 62.2 (50.8–72.7) | 68.7 | 71.8 |
| Funisitis | |||||||
| Plasma RBP4 (µg/mL) | 0.65 ± 0.05h | 0.56–0.74 | ≤ 16.619 | 64.3 (48.0–78.5) | 51.2 (42.2–60.1) | 30.0 | 81.5 |
| Combined model C e | 0.72 ± 0.04 | 0.64–0.81 | ≥ 0.226 | 71.4 (55.4–84.3) | 62.8 (53.8–71.1) | 38.5 | 87.1 |
SE, standard error; ROC, receiver-operating characteristic; CI, confidence interval; PPV, positive predictive value; NPV, negative predictive value; RBP4, retinol-binding protein 4; SAA1, serum amyloid A1; CRP, C-reactive protein.
Cut-off values corresponding to the highest sum of sensitivity and specificity or the point on the ROC curve closest to (0, 1).
Values are given as % (95% CI).
Combined model A consists of plasma RBP4 levels, cervical length, maternal blood NLR (≥5.19), gestational age at sampling, and parity.
Combined model B consists of gestational age at sampling and serum CRP levels.
Combined model C consists of gestational age at sampling and plasma RBP4 levels.
P < 0.05 compared with combined model A by the method of DeLong et al.
P < 0.05 compared with combined model B by the method of DeLong et al.
P < 0.05 compared with combined model C by the method of DeLong et al.