Assessment of the diagnostic value of the native PGLTB1, its synthetic neoglycoconjugate PGLTB0 and the sulfolipid IV antigens for the serodiagnosis of tuberculosis.

A major phenolic glycolipid (PGLTB1) from Mycobacterium tuberculosis, that resembles the phenolic glycolipid-I (PGL-I) from M. leprae, and its synthetic terminal diglycosyl conjugate (PGLTB0) were reported and raised the prospects of a specific serodiagnostic test for tuberculosis (TB). The diagnostic use of a sulfolipid, namely the SLIV, was also reported. The objective of this investigation was to assess the relative sensitivity, specificity, and predictive values of three ELISAs using the PGLTB1, the PGLTB0, and the SLIV as antigens for the serodiagnosis of TB. Similarly to leprosy patients for the PGL-I antigen, the TB patients responded preferentially in IgM against the phenolic glycolipid. We screened the sera from 191 active tuberculous patients, 29 healthy subjects living in France, 102 healthy Polynesian blood donors, 82 contacts of new TB patients, and 20 leprosy patients before treatment for IgG anti-SLIV, and for IgM anti-PGLTB1 and IgM anti-PGLTB0. TB patients showed significantly higher activity than did healthy Polynesians when tested against SLIV and PGLTB0, and the smear-positive group gave higher activity than did the smear-negative but culture-positive group, especially for IgG anti-SLIV. The leprosy patients did not show higher activity than the Polynesian controls. Respectively, for SLIV, PGLTB1 and PGLTB0 antigens, the specificities were of 95%, 85%, and 89%; the sensitivities of 36%, 16% and 15%; the efficiencies of 58%, 40% and 39%; the predictive values for a positive result, assuming a prevalence of 15% among patients with respiratory symptoms, were of 30%, 16% and 19%.