A multidimensional immunology study of early-stage Parkinson’s disease identified a hyperinflammatory, hypermetabolic blood signature that separates patients with Alzheimer’s co-pathology from those without. The work points to a potential biomarker route that could help stratify mixed disease biology earlier than current clinical or imaging approaches. By focusing on blood-based immune and metabolic state rather than single markers, the study emphasizes how co-pathology may shape systemic signals relevant to diagnosis and targeted intervention planning. For developers, the immediate implication is patient selection and endpoint refinement—especially in trials where co-pathology could otherwise dilute treatment effects.