Thymectomy and Systemic Lupus Erythematosus (SLE)

UNLABELLED: Dear Sir The thymus plays a crucial role in the context of cellmediated immunity in the differentiation of T lymphocytes, not only during the embryogenesis and fetal period but also during the adulthood, even after its involution 1,2,3. It has been proved, indeed, that thymectomy in adult rat entails a decrease of the T-lymphocite response to mitogens and eventually its abolition 4,5,6. The removal of the thymus can decrease the activity of T-helper cells but in the same time it might enhance the activity of T-suppressor whose function is depressed in autoimmune diseases 7. The therapeutic role of thymectomy is proved in Myasthenia Gravis even if the exact mechanism underlying its effect remains largely unknown. The role of thymectomy as a treatment of autoimmune diseases other than Myasthenia Gravis (i.e. sistemic lupus erythematosus, rheumatoid arthritis, autoimmune hemolytic anemia, multiple sclerosis) has been investigated but the results of these studies are questionable 7. Our aim is to evaluate the role of thymectomy in order to clarify whether it may be regarded not just as therapeuytic, but, on the contrary, as a factor paving the way to the onset of autoimmune diseases. Therefore, the relevant literature has been taken into account along our study. Thymus has an important role in regulating immune reaction through its control on T-cell differentiation of both T-helper and T-suppressor/cytotoxic cells. That is the reason why thymectomy produces a shift in autoimmune diseases with disregulation of the immune networks2. After thymectomy, indeed, an induction and an acceleration of autoimmune processes has been observed. A relevant work focusing on those mechanisms was written by Gerli et al1 . In their work, the authors consider the long term immunologic effects of therapeutic thymectomy in patients with Myasthenia Gravis comparing 16 patients with Myasthenia Gravis and previous Thymectomy (at least 8 years before), 6 patients with Myasthenia Gravis and recent Thymectomy ([removed] CONCLUSIONS: Thymectomy may thus be a precipitating factor for the development of SLE due to the loss of central tolerance and the overproduction of antibodies. Therefore, after a thymectomy, it is important to perform a timely follow up of the patient