ESAT-6 and Ag85A Synthetic Peptides as Candidates for an Immunodiagnostic Test in Children with a Clinical Suspicion of Tuberculosis

Abstract

Background. Tuberculosis (TB) is being underdetected in children as most are smear-negative. This work was aimed at evaluating ESAT-6 and Ag85A synthetic peptides’ serodiagnostic potential for diagnosing children having a clinical suspicion of TB. Methods. The study involved 438 children: 77 Creole nonindigenous (13 suspected of having TB and 64 healthy ones) and 361 Warao indigenous children (39 suspected of TB and 322 healthy children). The approach’s diagnostic information was compared using operational characteristics and receiver-operating characteristic (ROC) curves. Results. Ag85A P-29879 had 94.6% sensitivity ( AUC = 0.741 : 0.651 to 0.819 95% CI) in indigenous children. ESAT-6 P-12036 and P-12037 had 100% and 92.3% of sensitivity ( AUC = 0.929 : 0.929: 0.846 to 0.975 95% CI and 0.791: 63.9 to 98.7 95% CI, respectively) in Creole children. ESAT-6 peptides also allowed a differentiation between children with TB and healthy ones. Conclusions. Further validation of this approach could lead to developing a complementary tool for rapid TB diagnosis in children.

ESAT-6 a Major Virulence Factor of Mycobacterium tuberculosis

“…This combination of antigens includes proteins that are associated with the different stages of disease progression [ 156 ] and has been shown to significantly improve sensitivity. Recently, another cocktail using biosynthetically derived peptides of ESAT-6 and Ag-85 allowed the detection of irrespectively specific IgG in patients’ sera, providing a reliable diagnosis of active TB in children [ 157 ].…”