Table 2.
Studies evaluating mycobacterial antigens with in-house Ab detection assays for serodiagnostic value in childhood TBa
| Antigen | Isotype | Age (yr) | Subject group (no. of subjects) | Sensitivity | Specificity | Comments | Reference |
|---|---|---|---|---|---|---|---|
| PPD | IgG, IgM | 0–14 | TB (163) (49 culture+), healthy/not TST tested (17), healthy/TST+ (38), healthy/TST− (20), other diseases (38) | IgG, 51% for culture+ TB (63% for smear+ TB, 36% for smear− TB); 28% for culture− TB; lower sensitivities with similar high specificity of IgM | IgG, 98% in diseases other than TB and 88% in TST+ and 90% in TST− household contacts | No categorization and comparison of results according to more-narrow age ranges | 4 |
| Ag5 | IgG | 1–14 | TB (21) (all smear+ and culture+), healthy TB contacts (19) (all controls BCG vaccinated) | 86% | 100% | No categorization and comparison of results according to more-narrow age ranges; high sensitivity likely due to evaluating only smear+ cases | 2 |
| Mycobacterial sonicates | IgG | <5 yrs | TB (31), healthy (129) | 21% | 40% | No description of ELISA method | 48 |
| Old tuberculin, PPD; 30 kDa | IgG | 0–12 | TB (72) (no info on culture results), healthy (188) (83 BCG vaccinated and 0–5 yrs old, 104 BCG revaccinated and 6–12 yrs old) | IgG (PPD), 50%; IgG (30 kDa), 36% | IgG (PPD), 97% | No comment on how TB cases were diagnosed | 74 |
| LOS, DAT, PGLTb1 | IgG | 0–18 | TB (12) (7 pulmonary, 5 lymphadenitis), healthy TST+ (8), TB contacts (7), other diseases (26) | 34% for culture+ TB, 33% for culture− TB | 86% | No description of ELISA method; small sample size | 58 |
| 16 kDa | IgG, IgM, IgA | 0–14 | TB (74) (29 culture+, 70 pulmonary, 4 extrapulmonary), healthy TB contacts (49), other diseases (149) | IgG, 34% for culture+ and culture− TB; IgA, 19%; IgM, 3%; IgG and/or IgA, 43% | For all isotypes, 95% for subjects with other diseases | 30 | |
| 16 kDa, 30 kDa | IgG, IgM, IgA | <15 | TB (26) (9 smear+ and/or culture+, 3 lymphadenitis, 14 other extrapulmonary TB), healthy TST− (61) | IgG and/or IgM and/or IgA (30 kDa), 85%; IgG and/or IgM and/or IgA (16 kDa), 73% | For all isotypes and both proteins, 98% | Graphs appear to be not consistent, with specificity claimed for all isotypes combined; no information given on age distribution | 47 |
| ES-31 | IgG | No age information | TB (70) (no information on how TB was diagnosed; 30 pulmonary, 20 meningitis, 10 pleural, 10 lymphadenitis), healthy (50), other diseases (105) | 81% | 93% | Poor description of ELISA method; no age information; no information on how TB was diagnosed | 6 |
| PPD, 38 kDa | Salivary IgA | 0–15 | TB (31) (TB cases poorly defined), healthy/TST+ (53), healthy/TST− (43) | Salivary IgA (38 kDa), 26%; salivary IgA (PPD), 8% | Salivary IgA (38 kDa), 88% for TST+ and 93% for TST−; salivary IgA (PPD), 94% for TST+ and 95% for TST− | TB cases poorly defined | 23 |
| ESAT6, PGLTb1 | IgG | <18 | Two separate studies described; for anti-PGLTB1 Abs, TB (65) (10 culture+, 32 pulmonary, 13 lymphadenitis, 16 meningitis, 4 GI), controls (27) (not specified); for anti-ESAT6 Abs, TB (83) (29 culture+, 37 pulmonary, 19 lymphatic, 16 CNS, 11 GI), controls (27) (not specified) | IgG (ESAT6), 49%; IgG (PGLTb1), 53% | IgG (ESAT6), 96%; IgG (PGLTb1), 91% | No description of ELISA method; no information on controls; no information on age distribution | 21 |
| Ag85 complex | IgG | 0–18 | Suspected TB (83) (64 pulmonary [17 culture+], 19 meningitis [3 culture+]); healthy, mostly BCG vaccinated (32) | 59% | 72% | No description of ELISA method; TB cases poorly defined; no information on age distribution | 20 |
| Ag85 complex, Ag85A, Ag85B, Ag85C, ESAT-6, CFP10 | IgG | <18 | TB (88) (36 pulmonary, 20 lymphadenitis, 11 abdominal, 20 meningitis, 1 military), healthy (25), other diseases (17) | IgG (Ag85 complex), 56%; IgG (85A), 32%; IgG (85B), 65%; IgG (85C), 90%; IgG (CFP10), 30%; IgG (all Ags and ESAT 6), 67% | IgG (Ag85 complex), 72%; IgG (85A), 24%; IgG (85B), 64%; IgG (85C), 92%; IgG (CFP10), 80%; IgG (all Ags and ESAT 6), 80% | No information on age distribution | 31 |
a
PPD, purified protein derivative; Ag5, antigen 5, 38-kDa culture filtrate protein (also known as 38 kDa); 30 kDa, 30-kDa culture filtrate protein, more commonly known as antigen 85B; LOS, fractions 4 and 5 of polar lipids belonging to the lipo-oligosaccharide family; DAT, 2,3-diacyl trehalose, formerly also referred to as 2,3-diacyl-trehalose-2'-sulfate (SLIV) antigen; PGLTb1, glycolipid triglycosyl phenol phthiocerol dimycocerosate glycolipid antigen; HSP60, 60-kDa heat shock protein 60; ES-31, excretory-secretory antigen; ESAT6, early secretory antigen 6; Ag85 complex, antigen 85 complex consisting of the proteins Ag85A, 85B, and 85C; CFP10, culture filtrate protein 10; ATT, antituberculous therapy; TST, tuberculin skin test; smear+, smear positive; smear−, smear negative.