Advances in nanotechnology for the diagnosis and management of autoimmune diseases

Autoimmune diseases (AIDs) are chronic, heterogeneous disorders that are often diagnosed after irreversible tissue damage and treated with broad immunosuppression that fails to deliver durable remission. Nanotechnology offers opportunities to sense early immune perturbations and to deliver interventions with molecular, cellular and organ-level precision. Here we synthesize advances from 2015 to 2025 in nano-enabled diagnosis and therapy for rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, inflammatory bowel disease, type 1 diabetes, psoriasis and selected rare AIDs. On the diagnostic side, nano-optical and electrochemical biosensors, nano-enhanced imaging probes, and liquid-biopsy platforms for extracellular vesicles and cell-free nucleic acids improve sensitivity, stratification and longitudinal monitoring, while wearable and point-of-care devices extend assessment into home and community settings. We relate these technologies to concrete clinical scenarios and highlight performance metrics such as limit of detection, sample volume, and clinical sensitivity/specificity. Therapeutically, we review stimuli-responsive and ligand-targeted nanocarriers for small molecules and biologics, tolerogenic nanoparticles and exosomes, mRNA-lipid nanoparticle "inverse vaccines", and microneedles or tissue-nanotransporter systems for local gene and cytokine modulation. We summarize emerging clinical trial data and currently marketed nanomedicines for autoimmune indications, linking formulation design to efficacy and safety readouts. Across platforms, we outline design principles connecting physicochemical properties to biodistribution and immune interactions, and we discuss manufacturability, long-term safety and regulatory hurdles that govern translation. Collectively, these advances, together with emerging AI and digital twin frameworks, illustrate how nanotechnology can support earlier diagnosis, more precise and tolerogenic interventions, and progress toward durable, personalized remission in AIDs.