Cellular immunity in myasthenia gravis after thymectomy and corticosteroid therapy.

Abstract

Clinical and immunological changes in patients with myasthenia gravis (MG) who had extended thymectomy (Tx) and/or corticosteroid therapy were examined to elucidate the mechanisms of improvement following the treatments. The changes found were: 1) After Tx and steroid therapy, in patients with MG whoshowed clinical improvement, the CD4/CD8 ratio and B lymphocyte subpopulations were markedly decreased. 2) Linear correlations between two T-cell subsets were evident in CD3against CD4 and CD4/CD8 against CD4after both Tx and steroid therapy. 3) T lymphocytes-CD8 decreased immediately after Tx and returned to pre-treatment levels within three weeks. 4) Cellular sensitization against a nicotinic acetylcholine receptor(AChR)-like protein isolated from fetal calf thymus decreased after steroid therapy. These results indicate that clinical improvement in MGafter the treatments was accompanied by a decrease in helper/ inducer T lymphocytes, B lymphocytes and specific lymphocyte sensitization against nicotinic AChR.

B cells produce less IL-10, IL-6 and TNF-αin myasthenia gravis

“…Previous data on corticosteroid therapy in MG showed a general decrease of B cells in MG which was not observed in this study [29]. Similar to the present study, higher frequency of CD27 + memory and lower frequency of CD27 À naïve B cell subsets have recently been demonstrated in AChR-MG patients treated with IS or longterm disease [30].…”

Colon Carcinoma After Thymectomy for Myasthenia Gravis: Report of a Case

“…Immunosuppressed individuals, such as transplant patients, are known to have an increased risk of malignancies; 9 however, several series have indicated that thymectomy dose not influence immunoparameters in patients with thymoma and myasthenia gravis. 10,11 Moreover, the extrathymic malignancies were often diagnosed before or at the same time as thymoma. Therefore, the precise mechanism of these types of malignancies remains unclear.…”