Immunologic evaluation and validation of methods using synthetic peptides derived from Mycobacterium tuberculosis for the diagnosis of tuberculosis infection

• Published in: Memórias do Instituto Oswaldo Cruz 2013-04, Vol.108 (2), p.131-139
• Main Authors: Araujo, Zaida, Giampietro, Francesca, Bochichio, María de los Angeles, Palacios, Andrea, Dinis, Jenifer, Isern, Jaime, Waard, Jacobus Henry de, Rada, Elsa, Borges, Rafael, Fernández de Larrea, Carlos, Villasmil, Angel, Vanegas, Magnolia, Enciso-Moreno, Jose Antonio, Patarroyo, Manuel Alfonso
• Format: Article
• Language: English
• Subjects: Adult; Ag85A antigen; Antigens, Bacterial - immunology; Case-Control Studies; Enzyme-Linked Immunosorbent Assay; ESAT-6 antigen; extrapulmonary tuberculosis; Female; Humans; Male; Middle Aged; Mycobacterium tuberculosis; Mycobacterium tuberculosis - immunology; PARASITOLOGY; Peptides - immunology; pulmonary tuberculosis; Sensitivity and Specificity; synthetic peptide; TROPICAL MEDICINE; Tuberculosis - diagnosis; Tuberculosis - immunology; Tuberculosis, Pulmonary - diagnosis; Tuberculosis, Pulmonary - immunology
• ISSN: 0074-0276; 1678-8060; 1678-8060; 0074-0276
• DOI: 10.1590/0074-0276108022013001

The goal of this study was to demonstrate the usefulness of an enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of pulmonary tuberculosis (PTB) and extrapulmonary TB (EPTB). This assay used 20 amino acid-long, non-overlapped synthetic peptides that spanned the complete Mycobacterium tuberculosis ESAT-6 and Ag85A sequences. The validation cohort consisted of 1,102 individuals who were grouped into the following five diagnostic groups: 455 patients with PTB, 60 patients with EPTB, 40 individuals with non-EPTB, 33 individuals with leprosy and 514 healthy controls. For the PTB group, two ESAT-6 peptides (12033 and 12034) had the highest sensitivity levels of 96.9% and 96.2%, respectively, and an Ag85A-peptide (29878) was the most specific (97.4%) in the PTB groups. For the EPTB group, two Ag85A peptides (11005 and 11006) were observed to have a sensitivity of 98.3% and an Ag85A-peptide (29878) was also the most specific (96.4%). When combinations of peptides were used, such as 12033 and 12034 or 11005 and 11006, 99.5% and 100% sensitivities in the PTB and EPTB groups were observed, respectively. In conclusion, for a cohort that consists entirely of individuals from Venezuela, a multi-antigen immunoassay using highly sensitive ESAT-6 and Ag85A peptides alone and in combination could be used to more rapidly diagnose PTB and EPTB infection.