Emerging mechanisms and targetable pathways in immune checkpoint inhibitor‑associated thyroid dysfunction: From...

Immune checkpoint inhibitors (ICIs) improve cancer outcomes but frequently cause immune-related thyroid dysfunction (ICI-TD), a critical clinical issue. The clinical manifestations of ICI-TD are diverse and can progress from subclinical abnormalities to thyroid storm. ICI-TD arises from immune tolerance breakdown, triggering autoreactive T-cell attack, cytokine storms, and epitope spreading. Different types of ICIs have different toxicity characteristics: anti-PD-1/PD-L1 drugs can easily induce thyroiditis directly, while anti-CTLA-4 drugs often indirectly affect thyroid function through hypophysitis. Combination therapy can produce synergistic toxic effects and shorten the time of occurrence. Emerging therapies such as LAG-3 inhibitors pose related risks. Current management relies on periodic monitoring and hormone replacement, with intervention often delayed. This review constructs a "mechanism-prediction-intervention" framework for ICI-TD by systematically exploring emerging mechanisms (immune cell interactions, epigenetic regulation, gut‑thyroid axis) and reviewing targeted strategies (conditionally activated antibodies, Fc engineering, chemokine receptor targeting, cytokine neutralization). In the future, by integrating multi-omics technologies to build a dynamic prediction model and establishing an interdisciplinary full-process management system, it is expected to enable early warning and hierarchical intervention for ICI-TD within the "mechanism-prediction-intervention" framework, thereby optimizing the risk-benefit balance of immunotherapy and improving treatment safety.