title: Development of a POC test for TB based on multiple immunodominant epitopes of M. tuberculosis specific cell-wall proteins.
abstract: The need for an accurate, rapid, simple and affordable point-of-care (POC) test for Tuberculosis (TB) that can be implemented in microscopy centers and other peripheral health-care settings in the TB-endemic countries remains unmet. This manuscript describes preliminary results of a new prototype rapid lateral flow TB test based on detection of antibodies to immunodominant epitopes (peptides) derived from carefully selected, highly immunogenic M. tuberculosis cell-wall proteins. Peptide selection was initially based on recognition by antibodies in sera from TB patients but not in PPD-/PPD+/BCG-vaccinated individuals from TB-endemic settings. The peptides were conjugated to BSA; the purified peptide-BSA conjugates striped onto nitrocellulose membrane and adsorbed onto colloidal gold particles to devise the prototype test, and evaluated for reactivity with sera from 3 PPD-, 29 PPD+, 15 PPD-unknown healthy subjects, 10 patients with non-TB lung disease and 124 smear-positive TB patients. The assay parameters were adjusted to determine positive/negative status within 15 minutes via visual or instrumented assessment. There was minimal or no reactivity of sera from non-TB subjects with the striped BSA-peptides demonstrating the lack of anti-peptide antibodies in subjects with latent TB and/or BCG vaccination. Sera from most TB patients demonstrated reactivity with one or more peptides. The sensitivity of antibody detection ranged from 28-85% with the 9 BSA-peptides. Three peptides were further evaluated with sera from 400 subjects, including additional PPD-/PPD+/PPD-unknown healthy contacts, close hospital contacts and household contacts of untreated TB patients, patients with non-TB lung disease, and HIV+TB- patients. Combination of the 3 peptides provided sensitivity and specificity>90%. While the final fully optimized lateral flow POC test for TB is under development, these preliminary results demonstrate that an antibody-detection based rapid POC lateral flow test based on select combinations of immunodominant M. tb-specific epitopes may potentially replace microscopy for TB diagnosis in TB-endemic settings.
authors.affiliation: Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania, United States of America.
authors.forename: Jesus M
authors.initials: JM
authors.lastname: Gonzalez
authors.affiliation: TB Biosciences, Bethlehem, Pennsylvania, United States of America.
authors.forename: Bryan
authors.initials: B
authors.lastname: Francis
authors.affiliation: Department of Pathology, New York University Langone Medical Center, New York, NewYork, United States of America.
authors.forename: Sherri
authors.initials: S
authors.lastname: Burda
authors.affiliation: Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania, United States of America.
authors.forename: Kaitlyn
authors.initials: K
authors.lastname: Hess
authors.affiliation: Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Digamber
authors.initials: D
authors.lastname: Behera
authors.affiliation: Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Dheeraj
authors.initials: D
authors.lastname: Gupta
authors.affiliation: Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Ashutosh Nath
authors.initials: AN
authors.lastname: Agarwal
authors.affiliation: Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Indu
authors.initials: I
authors.lastname: Verma
authors.affiliation: National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India.
authors.forename: Ajoy
authors.initials: A
authors.lastname: Verma
authors.affiliation: National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India.
authors.forename: Vithal Prasad
authors.initials: VP
authors.lastname: Myneedu
authors.affiliation: Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania, United States of America; TB Biosciences, Bethlehem, Pennsylvania, United States of America.
authors.forename: Sam
authors.initials: S
authors.lastname: Niedbala
authors.affiliation: Department of Pathology, New York University Langone Medical Center, New York, NewYork, United States of America; Veterans Affairs New York Harbor Healthcare System, New York, New York, United States of America.
authors.forename: Suman
authors.initials: S
authors.lastname: Laal
mesh_terms: D001426:Bacterial Proteins / Q000276:immunology*; D002473:Cell Wall / Q000276:immunology; D019353:Endemic Diseases / Q000517:prevention & control; D006801:Humans; D016056:Immunodominant Epitopes / Q000737:chemistry / Q000302:isolation & purification*; D009169:Mycobacterium tuberculosis / Q000276:immunology / Q000378:metabolism*; D019095:Point-of-Care Systems; D012680:Sensitivity and Specificity; D012710:Serum Albumin, Bovine / Q000737:chemistry; D014374:Tuberculin Test / Q000191:economics / Q000379:methods*; D014397:Tuberculosis, Pulmonary / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins; D016056:Immunodominant Epitopes; D012710:Serum Albumin, Bovine