Elevated anti-tuberculous glycolipid antibody titres in healthy adults and tuberculosis patients in Thailand.
OBJECTIVE
To evaluate immunoglobulin G (IgG) and immunoglobulin A (IgA) responses to tuberculous-glycolipid antigen (TBGL-IgG and -IgA) in pulmonary tuberculosis (TB) patients and healthy controls in Thailand.


METHODS
Anti-TBGL antibody titres and other TB related markers were measured  in the serum samples of 24 adults with pulmonary TB (PTB), 28 healthy adults (HA), 23 children with TB (CTB) and 24 healthy children (HC).


RESULTS
Both TBGL-IgG and -IgA titres were significantly higher only in adult PTB cases compared to controls (P < 0.001 for all). TBGL-IgG  was highly sensitive (92%) in PTB patients, but frequent positive proportions of TBGL-IgG (46%) and -IgA (36%) in HAs were the cause of low specificities of TBGL-IgG (54%) and -IgA (64%); that of TBGL-IgG+IgA (75%) was the highest. Antibody titres were positively correlated in TBGL-IgG+IgA  double-positive HAs (HA+, 7/28, P < 0.01), but not in HA- (P > 0.05). Serum IgG and IgA levels were not correlated with TBGL-IgG or -IgA levels (P > 0.05). KL-6 and leptin levels were normal and were not different between HA+ and HA-, indicating absence  of active TB in HAs.


CONCLUSIONS
Enhanced TBGL-IgG+IgA responses in HAs could indicate latent TB infection. Careful follow-up studies in HAs could clarify the significance of elevated TBGL antibodies as early disease markers.
Division of Emerging Infectious Diseases, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan.
U R
UR
Siddiqi
W
W
Punpunich
C
C
Chuchottaworn
S
S
Jindakul
Y
Y
Ashino
H
H
Saitoh
M
M
Okada
T
T
Chotpittayasunondh
T
T
Hattori
D000328:Adult; D000367:Age Factors; D000907:Antibodies, Bacterial / Q000097:blood*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006017:Glycolipids / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology*; D007223:Infant; D055985:Latent Tuberculosis / Q000175:diagnosis / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology; D013785:Thailand; D014397:Tuberculosis, Pulmonary / Q000276:immunology*; D055815:Young Adult
D000907:Antibodies, Bacterial; D006017:Glycolipids; D007070:Immunoglobulin A; D007074:Immunoglobulin G