Immune system ↗Strong self-reactivity is edited or removed
Developing B cells in marrow can change receptors, die, or become unresponsive when they strongly recognize accessible self antigen.
IMMUNE / 11
Recognition turns
against self.
Autoimmune diseases are not one pathway. Different combinations of genes, environment, tolerance failure, T cells, autoantibodies, complement, organs, repair, and treatment create distinct diseases and clinical patterns.
Thymus narrows the repertoire
T cells must recognize self MHC while those with excessive self-reactivity are deleted or diverted toward regulatory programs.
Antigen without permission can silence
Recognition without suitable costimulation or inflammatory context may produce a durable hyporesponsive state.
Regulatory cells actively restrain effectors
Regulatory T cells use cell contact, inhibitory molecules, cytokines, and metabolic competition to limit activation.
Inhibitory receptors limit tissue damage
CTLA-4, PD-1, and other checkpoints raise activation thresholds and shorten responses after antigen encounter.
Many variants alter thresholds
HLA alleles and genes affecting signaling, clearance, cytokines, barriers, and tolerance can raise susceptibility without determining destiny.
Triggers differ across diseases
Infections, smoking, ultraviolet light, silica, medicines, microbiome context, hormones, tissue injury, and chance may contribute differently.
Damage reveals new targets
Cell death, altered proteins, post-translational modification, or normally secluded antigens can broaden self-recognition.
Inflammatory context supplies costimulation
Dendritic cells presenting self-derived peptide during tissue alarm may activate clones that were previously silent.
Damage can expand the target list
Continued injury releases additional antigens, allowing new T- and B-cell specificities to join the response.
Self-reactive effectors attack tissue
CD4 programs recruit macrophages and other cells, while CD8 cells can kill self cells presenting matching peptide–MHC I.
Antibodies have different pathogenic roles
They may block or stimulate receptors, damage cells, form immune complexes, recruit complement, or serve mainly as markers.
Deposited antigen–antibody can inflame vessels
Complex size, clearance, complement, Fc receptors, pressure, and filtration affect deposition in kidney, skin, joints, and other tissues.
Local and systemic diseases diverge
Autoimmunity can target one organ or involve joints, skin, blood, vessels, kidneys, lungs, heart, brain, and glands in combinations.
Activity changes over time
Trigger exposure, tissue damage, regulatory recovery, treatment, hormones, infection, and stochastic changes can alter disease activity.
Targets trade inflammation for defense risk
Corticosteroids, conventional immunomodulators, biologics, small molecules, antibody depletion, and organ support act at different nodes and require monitoring.