Researchers from Trinity College Dublin and St. James’s Hospital have shown that dexamethasone, a commonly prescribed anti-inflammatory steroid, can reduce harmful inflammation triggered by Mycobacterium avium without weakening the ability of human immune cells to control the infection. The findings suggest dexamethasone may thus offer a new adjuvant approach for better managing nontuberculous mycobacterial (NTM) disease. 

NTM infections present a growing global health challenge, particularly among people with chronic lung disease. Treatment often requires prolonged courses of multiple antibiotics, yet many patients continue to experience symptoms driven by persistent inflammation. Steroids are not routinely used in NTM disease because clinicians have traditionally been cautious about suppressing T cell immune responses during infection.

Here, the research team, based in the Trinity Translational Medicine Institute, investigated how human macrophages, specialised immune cells that act as a first line of defence against infection, respond to Mycobacterium avium. 

They found that treatment with dexamethasone significantly reduced infection-driven macrophage metabolic activity while also lowering the production of inflammatory signals. Importantly, the steroid reduced the inflammatory response but did not increase bacterial growth within these key immune cells. 

Researchers at the Icahn School of Medicine at Mount Sinai are among the Milestone 2 Awardee teams in XPRIZE Healthspan, a $101 million global competition that challenges researchers to develop new approaches that help people live healthier, longer lives.  XPRIZE Healthspan is a 7-year global competition incentivizing teams to develop and test therapeutics that restore muscle, cognition, and immune function in adults aged 50 to 90 by a minimum of 10 years, with an ambitious goal of 20 years, to extend healthy life within one year or less of treatment. After emerging from an international field of semifinalists announced in May 2025, Mount Sinai’s NYC-Vita clinical trial team was selected as a Milestone 2 Award recipient, advancing to the XPRIZE Healthspan Finals and receiving $1 million for its evidence-based approach to extending healthy aging.