Table 2

Studies evaluating mycobacterial antigens with in-house Ab detection assays for serodiagnostic value in childhood TBa

AntigenIsotypeAge (yr)Subject group (no. of subjects)SensitivitySpecificityCommentsReference
PPDIgG, IgM0–14TB (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 IgMIgG, 98% in diseases other than TB and 88% in TST+ and 90% in TST− household contactsNo categorization and comparison of results according to more-narrow age ranges4
Ag5IgG1–14TB (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+ cases2
Mycobacterial sonicatesIgG<5 yrsTB (31), healthy (129)21%40%No description of ELISA method48
Old tuberculin, PPD; 30 kDaIgG0–12TB (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 diagnosed74
LOS, DAT, PGLTb1IgG0–18TB (12) (7 pulmonary, 5 lymphadenitis), healthy TST+ (8), TB contacts (7), other diseases (26)34% for culture+ TB, 33% for culture− TB86%No description of ELISA method; small sample size58
16 kDaIgG, IgM, IgA0–14TB (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 diseases30
16 kDa, 30 kDaIgG, IgM, IgA<15TB (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 distribution47
ES-31IgGNo age informationTB (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 diagnosed6
PPD, 38 kDaSalivary IgA0–15TB (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 defined23
ESAT6, PGLTb1IgG<18Two 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 distribution21
Ag85 complexIgG0–18Suspected 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 distribution20
Ag85 complex, Ag85A, Ag85B, Ag85C, ESAT-6, CFP10IgG<18TB (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 distribution31
  • 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.