Added Value of IP-10 as a Read-Out of Mycobacterium tuberculosis: Specific Immunity in Young Children

Abstract

We have explored the added value of interferon-γ (IFNγ)-inducible protein 10 as a read-out of Mycobacterium tuberculosis-specific immunity in young Indian children, where the sensitivity of the IFNγ release assays for tuberculosis is poor. Reduced frequency of indeterminate results and an increased sensitivity for tuberculosis suggest a potential for fewer missed cases with a combined IFNγ/inducible protein 10 read-out in a 4th generation IFNγ release assays.

FIGURE 1.

Comparison of the concentration of IFNγ and IP10 in 2-plex and single-plex set-ups in response to A: Mitogen and B: TB-antigen. The concentration of the analytes within the MTB infection categories in response to tuberculosis (TB) antigen [C: interferon-γ (IFNγ) and D: IFNγ-inducible protein 10 (IP-10)] and mitogen (H: IFNγ and I: IP-10). IP-10:IFNγ ratio for the MTB infection categories are depicted in response to TB antigen (E) and mitogen (J). Discriminatory capacity between children with active TB versus MTB infection is shown for IFNγ (F) and IP-10 (G) concentrations, respectively. The P values <0.05 (*), <0.01 (**), <0.001 (***) were considered to be significant. AUC indicates area under curve; ROC, receiver operating characteristic.