Rapid decrease in IL-1Ra and IP-10 plasma levels following tuberculosis treatment initiation

Monitoring tools that could provide quick predictions of tuberculosis (TB) treatment outcomes are urgently needed. Here, we assessed whether the evolution of selected biomarkers of innate immunity may help monitoring TB treatment response within 2 weeks of treatment initiation.

ANRS12394-LILAC-TB was a proof-of-concept prospective study: adults with a rifampicin-susceptible TB who are HIV-negative and HIV-infected documented by a positive Xpert MTB/RIF test were enrolled in Cambodia and Côte d'Ivoire. Plasma concentrations of interleukin-1 receptor antagonist (IL-1Ra), interferon-γ-induced protein-10 and clusters of differentiation (CD) (scavenging CD163) were measured by commercial enzyme-linked immunosorbent assay kits. A Wilcoxon test for paired data was used for longitudinal comparisons.

A total of 55 patients were enrolled (women: 31%, median age: 37 years; median CD4 count in the 10 of 13 participants with HIV: 53 cells/mm³). Overall, 83% were considered in TB treatment success. Compared with baseline, the IL-1Ra plasma levels significantly decreased as soon as week (W) 1, independent of HIV status (-71% in HIV-positive vs -33% in HIV-negative; P <0.001). The IP-10 plasma levels significantly decreased at W1 and W2 compared with baseline (P <0.0001); however, that decrease was less marked in participants with HIV.

Our findings suggest that measuring IL-1Ra plasma levels with a standard enzyme-linked immunosorbent assay technique at baseline and then 1 week after TB treatment onset could help clinicians to quickly assess TB treatment response.