A new study published inScientific Reports(1) offers insights into howdexamethasone, a commonly used steroid, could support immune cells in fightingtuberculosis(TB). (2) Researchers from Trinity College Dublin have demonstrated that dexamethasone can enhance macrophage function, boosting the immune system’s ability to kill TB bacteria, while also limiting harmful inflammation. Tuberculosis remains one of the world’s deadliest infectious diseases, with over 10 million people infected each year and 1.25 million deaths globally. (3) While steroids like dexamethasone are already used in some TB cases, especially in TB meningitis, their effects on the immune system have not been fully understood. With the renewed focus on dexamethasone during theCOVID-19pandemic, the research team aimed to explore how the drug impacts the innate immune response, particularly macrophages, which are key to fighting TB in the lungs. To investigate, Scientists treated and infected macrophages, immune cells derived from healthy blood donors and lung fluid with Mycobacterium tuberculosis (Mtb), the bacteria responsible for TB. (4) They then examined how dexamethasone affected the cells. The results revealed that Dexamethasone reduces glycolysis in macrophages, decreasing cellular energy use, and dampens the production of inflammatory cytokines such as IL-1β, TNF, IL-6, IL-8, and IL-10. While these cytokines aid immunity, reducing them can prevent tissue damage from excessive inflammation. Crucially, the study found that dexamethasone-treated, Mtb-infected macrophages survived better (5) and had a lower bacterial burden. The Steroid’s effect appeared to be linked to enhanced autophagy and phagosomal acidification, mechanisms that help cells degrade and clear bacteria The research suggests that steroids, when used alongside antibiotics, could speed recovery in TB patients and potentially prevent progression from latent to active disease. Reference:Lorraine Thong et al, Dexamethasone inhibits Mycobacterium tuberculosis-induced glycolysis but preserves antimicrobial function in primary human macrophages, Scientific Reports (2025). DOI: 10.1038/s41598-025-20188-2