Thymectomy in myasthenia gravis: removal of the defective 'sick' organ?

As evidenced by this randomized trial, thymectomy clearly improved clinical status of patients with nonthymomatous myasthenia gravis (MG) and this study ends a very long controversy about the interest of this surgical procedure mainly based on previous empirical observations. Although they are not discussed in this important paper, a series of experimental arguments reviewed in joint references argue for the idea that the clinical benefit of thymectomy is primarily due to the removal of the organ primarily implicated in MG pathophysiology. The thymus plays a central role in programming central immunological self-tolerance [1,2], and a thymus dysfunction is a primary event in the development of organ-specific autoimmunity [3,4]. It is therefore not surprising that the surgical removal of the primary 'sick' organ contributes to improve clinical outcomes and to reduce immunosuppressive therapy in MG patients. References: 1. Kamradt T, Mitchison NA. N Engl J Med 2001; 344:655-64. 2. Kyewski B, Klein L. Annu Rev Immunol 2006; 24:571-606. 3. Giraud M, Taubert R, Vandiedonck C, et al. Nature 2007; 448:934-7. 4. Geenen V, Bodart G, Henry S, et al. Front Neurosc 2013; 7:art 187.