Use of antibodies in lymphocyte secretions for detection of subclinical tuberculosis infection in asymptomatic contacts.
We have previously demonstrated that Mycobacterium bovis BCG-specific immunoglobulin G antibodies in lymphocyte secretions (ALS) can be employed as a marker for active tuberculosis (TB). We aimed to determine whether the ALS method allows detection of subclinical TB infection in asymptomatic individuals. A prospective study of family contacts (FCs) of patients with active TB and healthy controls was performed. Thirteen of 42 FCs had high ALS responses, including 6 FCs who subsequently developed active TB. No correlation was observed between the tuberculin skin test and the ALS responses in the FCs (r = 0.1, P = 0.23). Among patients with active TB, BCG-specific ALS responses steadily declined from the time of diagnosis through 6 months following antimycobacterial chemotherapy (P = 0.001). The ALS assay enabled detection of infection in exposed symptom-free contacts, who are at greater risk for developing active TB. The method may also allow discrimination between effective treatment of active infection and suboptimal response to therapy.
Raqib
Rubhana
R
ICDDR,B-Centre for Health and Population Research, National Institute of Diseases of the Chest and Hospital, Dhaka, Bangladesh. rubhana@icddrb.org
Kamal
S M Mostafa
SM
Rahman
M Jubayer
MJ
Rahim
Zeaur
Z
Banu
Sayera
S
Bardhan
Pradip K
PK
Chowdhury
Fahima
F
Ara
Gul
G
Zaman
K
K
Breiman
Robert F
RF
Andersson
Jan
J
Sack
David A
DA
D000907:Antibodies, Bacterial / Q000032:analysis* / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology*; D002478:Cells, Cultured; D007074:Immunoglobulin G / Q000032:analysis* / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D009163:Mycobacterium bovis / Q000276:immunology*; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D011237:Predictive Value of Tests; D013183:Sputum / Q000166:cytology / Q000276:immunology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000473:pathology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007074:Immunoglobulin G