T-cell tumor necrosis factor-alpha receptor binding in myasthenic patients

Myasthenia gravis (MG) is a T-cell-dependent and antibody-mediated autoimmu ne disease of the neuromuscular junction, in which the cytokine network may be deranged. Specific receptors for tumor necrosis factor (TNF)-alpha, a c ytokine with several effects on the neuroimmune system, were found on human lymphocytes. In the present study, we assayed TNF-alpha binding on periphe ral blood T-cells from MG patients, finding that T-cells from patients have significantly more TNF-alpha receptors than those from controls (B-max: 65 4 +/- 12 vs. 133 +/- 4 (mean +/- SEM) receptors/cell). Such TNF-alpha bindi ng sites are of the same type in patients and healthy subjects (K-d: 68.7 /- 4.3 vs. 70.1 +/- 4.8 (mean +/- SEM) pM). The enhanced T-cell TNF-alpha b inding is due to an increased number of TNF-alpha receptors on T-helper lym phocytes. These results are discussed in terms of MG immunopathogenesis, si nce it has been reported that activated T-cells have increased amounts of T NF-alpha receptors. (C) 1999 Elsevier Science B.V. All rights reserved.