RESUMO
The expression of IL-1 beta mRNA and IL-2 mRNA was analyzed in seven thymuses from patients with myasthenia gravis (MG) and in three normal thymuses using in situ hybridization techniques. Cells containing IL-beta mRNA were detected in all seven cases. These IL-1 beta producing cells were mainly located and clustered in the connective structures of thymic septae and peri-lobuler area like anti-keratin AE3 positive cells. The distribution of anti-CD68 positive cells was different from that of IL-1 beta producing cells in thymus of myasthenia gravis patients. IL-2 producing cells were also found in all seven cases, and their frequency (number of cells/mm2) had a tendency to correlate with the severity of the disease. On the other hand, we could not find both IL-1 beta mRNA and IL-2 mRNA in three normal thymuses. These results suggested a possible role of high IL-1 beta and IL-2 production to activate T cells in myasthenia gravis thymus. Furthermore, in situ production of IL-2 might be reflected in the severity of the disease.
