The thymus in myasthenia gravis: Site of "innate autoimmunity"?

• Published in: Muscle & nerve Vol. 44; no. 4; pp. 467 - 484
• Main Authors: Cavalcante, Paola, Le Panse, Rozen, Berrih-aknin, Sonia, Maggi, Lorenzo, Antozzi, Carlo, Baggi, Fulvio, Bernasconi, Pia, Mantegazza, Renato
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.10.2011; Wiley
• Subjects: Autoantibodies - immunology; Autoimmune Diseases - immunology; Autoimmune Diseases - metabolism; Autoimmune Diseases - pathology; Biological and medical sciences; Diseases of striated muscles. Neuromuscular diseases; Humans; Immunity, Innate - physiology; inflammation; innate immunity; Medical sciences; Muscle; myasthenia gravis; Myasthenia Gravis - immunology; Myasthenia Gravis - pathology; Myasthenia Gravis - therapy; Neurology; Pharmacology. Drug treatments; thymus; Thymus Gland - abnormalities; Thymus Gland - immunology; Thymus Gland - metabolism; viral infection; Autoimmunity; Human; Immunopathology; Nervous system diseases; Neuromuscular diseases; thymus; viral infection; Pathogenesis; Autoantibody; Autoimmune disease; Neuromuscular junction; Infection; Chronic; Cholinergic receptor; Myasthenia gravis; innate immunity; inflammation; Viral disease; Tumor; Muscle; Biological receptor
• ISSN: 0148-639X; 1097-4598; 1097-4598
• DOI: 10.1002/mus.22103

Myasthenia gravis (MG) is an autoimmune disorder caused, in most cases, by autoantibodies against components of the neuromuscular junction, frequently the acetylcholine receptor (AChR), and less often the muscle‐specific kinase receptor. The thymus plays a major role in the pathogenesis of MG with anti‐AChR antibodies: it shows marked pathologic alterations (hyperplastic or tumoral) in most AChR‐positive patients and contains the elements required to initiate and sustain an autoimmune reaction (AChR autoantigen, AChR‐specific T cells, and autoantibody‐secreting plasma cells). In this study we review early and more recent findings implicating the thymus as site of AChR autosensitization in MG and briefly discuss the therapeutic role of thymectomy. We also summarize data showing that the MG thymus is in a state of chronic inflammation, and we review emerging evidence of a viral contribution to the onset and maintenance of the thymic autoimmune response. Muscle Nerve, 2011