Immune cells gone rogue: Why diabetic wounds won't heal — and what could fix them

Chronic diabetic ulcers are a massive global problem — affecting over 131 million people and costing roughly $755 billion in healthcare annually — yet the biological reasons behind their stubborn resistance to healing have remained murky. A comprehensive new review by Yi Ru and colleagues sheds light on the culprit: a breakdown in immune cell behavior that keeps wounds locked in a damaging inflammatory state instead of progressing toward repair.

Under normal conditions, immune cells like macrophages shift from pro-inflammatory (M1) to pro-reparative (M2) states as healing progresses. In diabetic wounds, that transition stalls. Neutrophils form poorly regulated extracellular traps, mast cells over-activate, dendritic cells lose their ability to clear dead cellular debris, and regulatory T cells decline in both number and function — all of which sustain chronic inflammation and block tissue repair.

By the Numbers:

• 131 million+ people worldwide affected by chronic diabetic ulcers
• ~$755 billion in annual global healthcare costs tied to diabetic wounds
• Multiple immune cell types implicated: macrophages, neutrophils, mast cells, dendritic cells, T cells, B cells, and natural killer cells

Why it matters: Pinpointing the immune dysfunction behind diabetic wounds opens the door to targeted therapies — from macrophage-reprogramming drugs and IL-15 superagonists to smart wound dressings and mesenchymal stem cell therapies — that could dramatically improve outcomes for millions of patients facing amputation or worse.