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Table 3 Diagnostic performance of CFP-10pep assay for TB

From: Evaluation of a serum-based antigen test for tuberculosis in HIV-exposed infants: a diagnostic accuracy study

  Confirmed TBα Unconfirmed TBβ Unlikely TBγ
MTB infectiona No MTB infectionb Total MTB infection No MTB infectionc Total
All participants (N = 471)
 CFP-10pep +, no. (%) 6 (100.0) 34 (79.1) 17 (85.0) 51 (81.0) 6 (11.3) 16 (4.6) 22 (5.5)
 CFP-10pep −, no. (%) 9 (20.9) 3 (15.0) 12 (19.0) 47 (88.7) 333 (95.4) 380 (94.5)
 Sensitivity—% (95% CI) 100 (54.1–100.0) 79.1 (64.0–90.0) 85.0 (62.1–96.8) 81.0 (69.1–89.8)
 Specificity—% (95% CI) 88.7 (77.0–95.7) 95.4 (92.7–97.4) 94.5 (91.8–96.5)
HIV-infected participants (N = 266)
 CFP-10pep +, no. (%) 5 (100.0) 24 (80.0) 12 (92.3) 36 (83.7) 3 (9.4) 12 (6.4) 15 (7.7)
 CFP-10pep −, no. (%) 6 (20.0) 1 (7.7) 7 (16.3) 29 (90.6) 174 (93.6) 203 (92.3)
 Sensitivity—% (95% CI) 100 (47.8–100.0) 80.0 (61.4–92.3) 92.3 (64.0–99.8) 83.7 (69.3–93.2)
 Specificity—% (95% CI) 90.6 (75.0–98.0) 93.6 (89.0–96.6) 93.1 (88.9–96.1)
HIV-uninfected participants (N = 205)
 CFP-10pep +, no. (%) 1 (100.0) 10 (76.9) 5 (71.4) 15 (75.0) 3 (14.3) 4 (2.4) 7 (4.3)
 CFP-10pep −, no. (%) 3 (23.1) 2 (28.6) 5 (25.0) 18 (85.7) 159 (97.6) 177 (96.2)
 Sensitivity—% (95% CI) 100 (2.5–100.0) 76.9 (46.2–95.0) 71.4 (29.0–96.3) 75.0 (50.9–91.3)
 Specificity—% (95% CI) 85.7 (63.7–97.0) 97.6 (93.8–99.3) 96.2 (92.3–98.5)
  1. CI confidence interval
  2. αConfirmed TB: Mtb culture-positive
  3. βUnconfirmed TB: ≥ 2 types of non-bacteriological TB evidence within 12 weeks
  4. γUnlikely TB: no or insufficient evidence of TB or a confirmed alternative diagnosis (did not have active TB)
  5. aTST positive (induration of ≥ 5 mm for HIV-infected children and ≥ 10 mm for HIV-uninfected children)
  6. bTST negative (induration of < 5 mm for HIV-infected children and < 10 mm for HIV-uninfected children)
  7. cTST-negative or no TST result available for children not suspected of TB who did not reach a protocol-designated visit for TST performance (parent study weeks 96, 144, 196)
  8. CFP-10pep diagnostic sensitivity was calculated using the sample drawn closest (± 24 weeks; ± 1 study visit for the HIV-uninfected cohort following INH/placebo treatment) to the time of their retrospective diagnosis by 2015 NIH criteria