Thymus and Myasthenia Gravis

Association between Myasthenia Gravis and Malignant Lymphoma

“…Thymic pathology is found in 80% of myasthenic patients [3,5,22] 8-15°/o of whom have a thymoma [3,5,9,22,32], According to G old stein [9] the underlying pathology in MG is an autoimmune disease of the thymus (thymitis). The affected thymus secretes abnormal amounts of a humoral substance (thymin) which causes the neuromuscular block and thus is responsible for the myasthenic symptoms.…”

“…The affected thymus secretes abnormal amounts of a humoral substance (thymin) which causes the neuromuscular block and thus is responsible for the myasthenic symptoms. Thymectomy im proves the clinical state of most myasthenic patients [3,9,19,22,27,32], Many experimental studies in animals show that thymectomy increas es the occurrence of malignant tumors [9,10,33,34] and that animals can be protected by reimplantation of the thymus or even by injecting a thymic humoral factor [34]. However, other experimental evidence points to the opposite effect [2,10,20].…”

“…It is mainly responsible for cellular immunity but has a definite effect on humoral immunity as well [10,11,13,25,34], Abnormal function of the thymus may cause immune deficiency states or cellular-humoral im munologic imbalance. These conditions are thought to influence the ap pearance of both malignancy and autoimmune diseases [8,10,12,23,[30][31][32], G atti and G ood [8| demonstrated that the occurrence of malig nancy, especially of the lymphoreticular system, is 10,000 times higher in patients with immune deficiency than in an age and sex-matched con trol group. Lymphomas occur in a very high rate in patients with renal transplants while on immunosuppressive therapy [12].…”

“…MG is associated with autoimmune diseases [3,6,16,17,19,22,[28][29][30][31][32] and is considered by many investigators to be part of the spec trum of autoimmune disorders. In many myasthenic patients humoral and cellular immune reactions directed against muscle antigens and well correlated with disease severity can be detected [3,4,9,14,15,31].…”

“…Myasthenia gravis (MG) may well represent one of the manifestations of the spectrum of autoimmune diseases [31]. This disease is commonly associated with thymic pathology which could lead to an altered immune state [32]. The fact that lately significant cor relation between MG and malignancy, especially of the lymphoreticular type, has been reported [24] is in accordance with this concept.…”