Table 3.
Agreement between three immunoassays measuring antibody responses against the CT antigen Pgp3
| MBA-positive (N = 237) | MBA-negative (N = 332) | ||||
|---|---|---|---|---|---|
| LFA positive (% [95% CI]) | LFA negative (% [95% CI]) | LFA positive (% [95% CI]) | LFA negative (% [95% CI]) | ||
| ELISA-fresh-ROC | Positive | 86.1 (80.9–90.1) | 0.8 (0.14–3.3) | 1.8 (0.7–4.1) | 2.1 (0.9–4.5) |
| Negative | 10.5 (7.1–15.3) | 2.5 (1.0–5.7) | 3.3 (1.7–6.0) | 92.8 (89.3–95.2) | |
| ELISA-fresh-MM | Positive | 96.2 (92.7–98.1) | 1.7 (0.5–4.6) | 3.6 (2.0–6.4) | 7.5 (5.0–11.0) |
| Negative | 0.4 (0.02–2.7) | 1.7 (0.5–4.6) | 1.5 (0.6–3.7) | 87.3 (83.2–90.6) | |
| ELISA-precoated-ROC | Positive | 82.7 (77.1–87.1) | 0.8 (0.14–3.3) | 1.2 (0.4–3.3) | 1.8 (0.7–4.1) |
| Negative | 13.9 (9.9–19.1) | 2.5 (1.0–5.7) | 3.9 (2.2–6.8) | 93.1 (89.6–95.5) | |
| ELISA-precoated-MM | Positive | 96.2 (92.7–98.1) | 1.3 (0.3–4.0) | 3.3 (1.7–6.0) | 3.9 (2.2–6.8) |
| Negative | 0.4 (0.02–2.7) | 2.1 (0.8–5.1) | 1.8 (0.7–4.1) | 91.0 (87.2–93.7) | |
CI = confidence interval; CT = Chlamydia trachomatis; ELISA = enzyme-linked immunosorbent assay; LFA = lateral flow assay; MBA = multiplex bead array; MM = fixed mixture model; Pgp3 = protein plasmid gene product 3; ROC = receiver operator characteristic. A set of 579 samples (provenance of samples detailed in Table 1) were tested for antibody responses using MBA, ELISA, and LFA. Ten samples were inconclusive on LFA and those data were excluded from analysis (final N = 569). Data shown are percentage of samples that fall into the indicated classification with 95% CIs shown in parentheses.