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

Objectives 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. Methods ANRS12394-LILAC-TB was a proof-of concept prospective study: HIV-negative and HIV-infected adults with a rifampicin-susceptible TB, documented by a positive Xpert MTB/RIF test, were enrolled in Cambodia and Côte d'Ivoire. Plasma concentrations of IL-1Ra, IP-10 and sCD163 were measured by commercial ELISA kits. A Wilcoxon test for paired data was used for longitudinal comparisons. Results 55 patients were enrolled (women: 31%, median age: 37 years; median CD4 count in the 10/13 HIV-infected participants: 53 cells/mm3). Overall, 83% were considered in TB treatment success. Compared to baseline, IL-1Ra plasma levels significantly decreased as soon as Week (W)1, independently of HIV status (-71% in HIV-positive vs. -33% in HIV-negative; p<0.001). IP-10 plasma levels significantly decreased at W1 and W2 compared to baseline (p<0.0001), but that decrease was less marked in HIV-infected participants. Conclusion Our findings suggest that measuring IL-1Ra plasma levels with a standard ELISA technique at baseline then one week after TB treatment onset could help clinicians to quickly assess TB treatment response.