Rapid detection of Mycobacterium tuberculosis biomarkers in a sandwich immunoassay format using a waveguide-based optical biosensor.
Early diagnosis of active tuberculosis (TB) remains an elusive challenge, especially in individuals with disseminated TB and HIV co-infection. Recent studies have shown a promise for the direct detection of pathogen-specific biomarkers such as lipoarabinomannan (LAM) for the diagnosis of TB in HIV-positive individuals. Currently, traditional immunoassay platforms that suffer from poor sensitivity and high non-specific interactions are used for the detection of such biomarkers. In this manuscript, we demonstrate the development of sandwich immunoassays for the direct detection of three TB-specific biomarkers, namely LAM, early secretory antigenic target 6 (ESAT6) and antigen 85 complex (Ag85), using a waveguide-based optical biosensor platform. Combining detection within the evanescent field of a planar optical waveguide with functional surfaces that reduce non-specific interactions allows for the ultra-sensitive and quantitative detection of biomarkers (an order of magnitude enhanced sensitivity, as compared to plate-based ELISA) in complex patient samples (urine, serum) within a short time. We also demonstrate the detection of LAM in urine from a small sample of subjects being treated for TB using this approach with excellent sensitivity and 100% corroboration with disease status. These results suggest that pathogen-specific biomarkers can be applied for the rapid and effective diagnosis of disease. It is likely that detection of a combination of biomarkers offers greater reliability of diagnosis, rather than detection of any single pathogen biomarker. NCT00341601.
Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA. Harshini@lanl.gov
Harshini
H
Mukundan
Sandeep
S
Kumar
Dominique N
DN
Price
Sonja M
SM
Ray
Ye-Jin
YJ
Lee
Seonyeong
S
Min
Seokyong
S
Eum
Jessica
J
Kubicek-Sutherland
Jesse M
JM
Resnick
W Kevin
WK
Grace
Aaron S
AS
Anderson
Soo Hee
SH
Hwang
Sang Nae
SN
Cho
Laura E
LE
Via
Clifton
C
Barry
Ramamurthy
R
Sakamuri
Basil I
BI
Swanson
D000217:Acyltransferases / Q000378:metabolism*; D000942:Antigens, Bacterial / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D015374:Biosensing Techniques; D060085:Coinfection; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006679:HIV Seropositivity / Q000453:epidemiology / Q000378:metabolism*; D006801:Humans; D007118:Immunoassay; D008070:Lipopolysaccharides / Q000378:metabolism*; D008297:Male; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification* / Q000472:pathogenicity; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000453:epidemiology / Q000378:metabolism*
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D015415:Biomarkers; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D008070:Lipopolysaccharides; D011933:Reagent Kits, Diagnostic; C050016:lipoarabinomannan; D000217:Acyltransferases; C112580:antigen 85A, Mycobacterium tuberculosis