Nurse-coordinated biomarker and symptom monitoring for immune checkpoint inhibitor toxicity.

Immune checkpoint inhibitors have transformed cancer treatment, but immune-related adverse events (irAEs) may affect almost any organ and can progress rapidly when early manifestations are overlooked. Because nurses perform repeated assessment, laboratory review, symptom triage, patient education, and coordination across treatment cycles, nurse-coordinated monitoring is a clinically relevant component of ICI safety. This targeted narrative Mini Review distinguishes four biomarker functions: pretreatment prediction of future irAE risk, longitudinal surveillance, diagnostic support after symptoms or laboratory abnormalities emerge, and severity or outcome prognostication. Complete blood count-derived indices, C-reactive protein, albumin, lactate dehydrogenase, ferritin, cytokines, autoantibodies, and immune-cell subsets provide non-interchangeable signals, while organ-directed tests may identify thyroid, adrenal, hepatic, renal, pancreatic, cardiac, neuromuscular, or pulmonary injury. We discuss the immunobiological links between checkpoint blockade, loss of peripheral tolerance, autoreactive lymphocytes, cytokine amplification, and measurable laboratory changes. We further propose an implementation framework based on baseline assessment, standardized serial testing, trend interpretation, symptom correlation, electronic patient-reported outcomes, and predefined escalation pathways. Here, "early warning" means recognition of a reproducible symptom or biomarker trajectory that prompts evaluation before Common Terminology Criteria for Adverse Events grade progression or hospitalization; it does not imply universally presymptomatic detection. No single biomarker currently provides sufficient sensitivity or specificity for routine prediction or diagnosis. Biomarker trends should therefore complement, not replace, clinical assessment and responsible medical decision-making.