Targeted Steroid Use in TB: A Potential Complement to Antimicrobial Therapy
Tuberculosis (TB) remains a global health challenge, affecting more than 10 million people each year. A recent study published in Scientific Reports explores a promising strategy: targeted use of steroids as an adjunct to standard antimicrobial therapy. The goal is not to replace antibiotics but to enhance the immune system’s ability to fight Mycobacterium tuberculosis (Mtb) while limiting inflammation that can cause tissue damage.
How steroids influence the TB-fighting immune response
Steroids such as dexamethasone are known to modulate inflammation, but their precise effects on the immune cells that battle Mtb were less clear until now. The study focused on macrophages, a type of immune cell that engulfs and attempts to digest the bacteria. By examining macrophages derived from blood and lung fluid, researchers treated these cells with dexamethasone and infected them with Mtb to observe changes in antimicrobial activity and inflammatory signaling.
Enhanced antimicrobial activity and controlled inflammation
The findings indicate that dexamethasone can both temper inflammatory pathways and support mechanisms that kill the bacteria. In dexamethasone-treated macrophages infected with Mtb, bacterial burden decreased, and macrophages showed increased survival in the face of infection. This suggests that steroid treatment may help macrophages resist the harmful effects of bacteria and excessive inflammatory responses.
Energy metabolism and cytokine production
Another key observation was that dexamethasone reduced glycolysis in macrophages, lowering the energy available to these cells. This metabolic shift can influence how macrophages respond to infection. The study also found a reduction in the production of both pro- and anti-inflammatory cytokines, highlighting the dual role of steroids in balancing immune defense with protection from inflammatory damage. The researchers argue that striking this balance could prevent tissue injury while preserving antimicrobial effectiveness.
Clinical implications and expert perspectives
In clinical practice, steroids are frequently used to manage inflammation in severe TB cases, including TB meningitis. However, their broader role as an adjunctive therapy has been underused. Prof. Joseph Keane of Trinity College Dublin notes that dexamethasone may do more than dampen inflammation—it could also bolster the macrophage’s capacity to control infection. This study provides a pathway to redefine steroid use in TB care, focusing on targeting inflammation without compromising antimicrobial defenses.
From the lab to patient care: next steps
The researchers derived macrophages from healthy volunteers and patients undergoing bronchoscopy, then exposed them to Mtb in controlled laboratory conditions. These experiments were designed to reveal how dexamethasone influences the delicate balance between killing bacteria and limiting collateral lung damage. While encouraging, translating these findings into standardized treatment protocols will require careful clinical trials to determine optimal dosing, timing, and patient selection.
Conclusion: a potential adjunct, not a replacement
Overall, the study supports using steroids as a complementary therapy for TB, particularly in cases characterized by excessive inflammation. Targeted steroid use could enhance macrophage antimicrobial responses while reducing inflammatory injury, working in concert with conventional antibiotics. If validated in clinical settings, this approach might help improve outcomes for millions affected by TB and offer a more nuanced, inflammation-aware strategy for TB care.
