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.
“Our study suggests that it may be possible to fine-tune this response by reducing damaging inflammation while still preserving the immune defenses that help control infection,” said Dr Donal Cox, senior author of the research, which has just been published in the Journal of Infectious Diseases.
Dr Cox and the research team, based in the Trinity Translational Medicine Institute, investigated how human macrophages, specialised immune cells that act as a first line of defense 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.
Why did the team undertake this research?
Advances in immunometabolism research have shown that immune cell metabolism plays an important role in determining how macrophages respond to infection. While this has been well studied in infectious diseases such as tuberculosis, very little is known about how metabolism influences immune responses to NTM.
The Trinity research group has previously demonstrated that dexamethasone alters the metabolism of macrophages infected with Mycobacterium tuberculosis. They therefore wanted to determine whether similar pathways could be targeted during Mycobacterium avium infection and whether inflammation could be reduced without compromising the body’s natural ability to control infection.
Source : www.news-medical.net
