Immunology of amyloid disease: a review

Amyloids in Site-Specific Autoimmune Reactions and Inflammatory Responses

Amyloid deposition is a histological hallmark of common human disorders including Alzheimer's disease (AD) and type 2 diabetes. Although some reports highlight that amyloid fibrils might activate the innate immunity system via pattern recognition receptors, here, we provide multiple lines of evidence for the protection by site-specific amyloid protein analogs and fibrils against autoimmune attacks: (1) strategies targeting clearance of the AD-related brain amyloid plaque induce high risk of deadly autoimmune destructions in subjects with cognitive dysfunction; (2) administration of amyloidogenic peptides with either full length or core hexapeptide structure consistently ameliorates signs of experimental autoimmune encephalomyelitis; (3) experimental autoimmune encephalomyelitis is exacerbated following genetic deletion of amyloid precursor proteins; (4) absence of islet amyloid coexists with T-cell-mediated insulitis in autoimmune diabetes and autoimmune polyendocrine syndrome; (5) use of islet amyloid polypeptide agonists rather than antagonists improves diabetes care; and (6) common suppressive signaling pathways by regulatory T cells are activated in both local and systemic amyloidosis. These findings indicate dual modulation activity mediated by amyloid protein monomers, oligomers, and fibrils to maintain immune homeostasis. The protection from autoimmune destruction by amyloid proteins offers a novel therapeutic approach to regenerative medicine for common degenerative diseases.

Serum amyloid protein levels in south american children with rheumatoid arthritis: a co-operative study

Serum amyloid protein (SAA) levels were determined by radioimmunoassay in 90 children with juvenile rheumatoid arthritis (JRA). Significantly higher levels of SAA were present in children with the polyarticular and systemic forms of the disease. SAA levels correlate with disease activity, increasing during acute exacerbations, decreasing during remission and in patients having prednisone therapy. High serum SAA concentrations in children with JRA did not correlate with the presence of secondary amyloidosis and may be useful as a disease monitor.

The effect of levamisole in experimental murine amyloidosis

In casein-induced murine amyloidosis various lines of investigation have implicated immunodeficiency as playing a role in amyloid formation. In this study, the immunopotentiating agent levamisole failed to prevent amyloidogenesis or to accelerate resolution of preformed amyloid deposits in the mouse model. The serum precursor of amyloid, serum amyloid protein A (SAA), was increased by levamisole in both normal and amyloidotic mice.