A widely used steroid may be able to tame the harmful inflammation of a chronic lung infection without the usual downside of weakening the immune system’s ability to fight the bug, new lab research suggests.
Researchers at Trinity College Dublin and St. James’s Hospital studied dexamethasone in the context of nontuberculous mycobacterial (NTM) infection — specifically Mycobacterium avium, a hard-to-treat cause of chronic lung inflammation. Using human immune cells (macrophages) infected in the lab, they found that dexamethasone reduced inflammatory signaling — lowering cytokines like TNF, IL-6 and IL-1β — while preserving the cells’ antimicrobial functions. The steroid did not increase the bacterial burden over 120 hours. The work was published August 11, 2026 in The Journal of Infectious Diseases.
The balancing act
Steroids are powerful anti-inflammatories, but doctors often hesitate to use them in infections for fear of blunting immune defenses. The study suggests the two effects can be separated: dexamethasone throttled the cells’ inflammatory metabolism (glycolysis) while keeping their bacteria-killing machinery intact. “It may be possible to fine-tune this response by reducing damaging inflammation while still preserving the immune defenses that help control infection,” said researcher Donal Cox.
Why it matters
NTM lung infections are rising and notoriously difficult to treat, and much of the lung damage comes from the body’s own inflammatory response. A way to calm that inflammation safely could help — but this is early, cell-based research, and clinical studies would be needed before changing how these infections are managed.