Evaluation of a multi-antigen test based on B-cell epitope peptides for the serodiagnosis of pulmonary tuberculosis

SETTING: Two sample panels: 1) 20 pulmonary tuberculosis (PTB) patients and 10 healthy subjects from a country with a low incidence of TB (Italy); and 2) 47 PTB patients and 26 healthy subjects from a country with a high incidence of TB (Morocco). OBJECTIVE: To identify a combination of Mycobacterium tuberculosis peptides useful for the serodiagnosis of active PTB. METHODS: Fifty-seven B-cell epitope peptides of M. tuberculosis were evaluated by immunoenzymatic assay and the data were analysed using logistic regression analysis and the random forest method. RESULTS: The best discriminating peptide between PTB patients and healthy subjects from the sample of the low TB incidence country was the 23 amino acid peptide of the Rv3878 protein. The sensitivity and specificity were respectively 65% and 100%. The same peptide had a sensitivity and specificity of respectively 47% and 100% for the sample from the high TB incidence country. The best combination of peptides was a pool of nine peptides which had a sensitivity of 70.2% and a specificity of 100% in the high TB incidence country. CONCLUSIONS: The 9-peptide pool can be useful in identifying patients with active PTB.