Inflammation predicts lingering lung damage after drug-resistant TB

Drug-resistant tuberculosis poses a double challenge: even when the bacteria are cleared, many people are left with lasting lung damage and reduced daily functioning. The study led by Cristina Vilaplana set out to look beyond standard bacteriology to understand why some patients fail to recover structurally and functionally after treatment. Using stored samples and data from a small, prospective, open-label pilot study of adjunctive ibuprofen in XDR-TB (NCT02781909), the team tracked multiple kinds of recovery at and after the start of treatment. Rather than focusing only on sputum and cultures for Mycobacterium tuberculosis, they compared microbiological tests with chest radiography, patient-reported health using the SGRQ, and a range of blood-based measures. These included routine blood cell indices, plasma cytokines, and whole-blood transcriptomic profiling. The goal was to define a multidomain treatment response and to identify inflammatory and transcriptional patterns at baseline that were associated with incomplete structural (radiological) and functional (symptom and quality-of-life) recovery months later.

In this ancillary analysis the researchers measured TBS, chest radiography, sputum culture, SGRQ scores, blood cell indices, plasma cytokines, and whole-blood transcriptomic profiling at baseline and during treatment. Clinical and laboratory measures were compared across outcome groups, and blood transcriptional profiles were analyzed in relation to treatment outcomes. The results showed that microbiological clearance and symptom improvement tended to occur earlier than radiological and functional recovery. Higher baseline systemic inflammation — signaled by elevated NLR, SII, and IL-6 — was linked to worse radiological and SGRQ outcomes at six months. Increased expression of interferon-related genes, including CD274 and GBP5, was also associated with poorer structural and functional recovery. By contrast, transient rises in IL-8 and IL-4 were associated with earlier bacteriological clearance. Notably, IL-8 emerged as the only plasma biomarker consistently correlated with symptom severity, radiological findings, and functional health across assessments.

These findings underline that treatment response in drug-resistant TB is asynchronous across biological domains: clearing the bacteria does not guarantee the lungs and a person’s everyday life recover on the same timeline. By integrating blood-based inflammatory markers and gene-expression profiles with clinical and radiological measures, the study identifies host features present before treatment that are associated with ongoing structural lung changes and poorer quality of life. This supports the idea that TB care and trials should use multidimensional endpoints — combining microbiology, imaging, symptom scores like the SGRQ, and host biomarkers such as NLR, SII, IL-6, IL-8, IL-4, and transcriptional signals like CD274 and GBP5 — to better capture long-term outcomes. For clinicians and researchers, these results point to the potential value of monitoring inflammation and host response, not just bacterial clearance, when planning follow-up and tailored interventions for people with XDR-TB or pre–extensively drug-resistant TB.