Cellular aspects of myasthenia gravis.
Several cellular aspects were investigated in a large series of patients with MG. First, non-Ag-specific proliferation was tested by measuring the response to r-IL2. Thymocytes from most MG patients showed hyperactivity to r-IL2. Peripheral blood lymphocytes (PBL) from some patients also showed a high response to r-IL2. These responding patients were generally those tested before thymectomy, presenting a high anti-AChR Ab titer and a severe form of the disease. Second, Ag-specific proliferation of MG PBL was assayed using 8 synthetic peptides corresponding to selected domains of torpedo or human AChR. Only 2 peptides gave a positive response in a significant number of patients, essentially in those presenting high anti-AChR Ab titer. The first is located near the alpha-bungarotoxin binding site and the second is in a cytoplasmic domain, according to models predicting the AChR transmembrane orientation. The positive results were essentially obtained with the human peptides; the corresponding torpedo peptides were positive in very few patients. Both human and torpedo peptides which include a part of the alpha-bungarotoxin binding site were negative. Finally, although morphological abnormalities were clearly visible in thymic hyperplasia, no correlation could be established between the thymus type and the cellular proliferation either to r-IL2, or to the peptides. Overall, our data indicate that cell-dependent mechanisms participate in the pathogenesis of MG, but the level of their involvement deserves further investigation.
Berrih-Aknin
S
S
Centre Chirurgical Marie-Lannelongue, CNRS UA 1159, Le Plessis-Robinson, France.
Cohen-Kaminsky
S
S
Neumann
D
D
Safar
D
D
Eymard
B
B
Gaud
C
C
Levasseur
P
P
Fuchs
S
S
Bach
J F
JF
D006801:Humans; D007111:Immunity, Cellular; D007150:Immunohistochemistry; D008213:Lymphocyte Activation; D009157:Myasthenia Gravis / Q000276:immunology* / Q000473:pathology; D010449:Peptide Mapping; D011950:Receptors, Cholinergic / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000473:pathology; D013952:Thymus Hyperplasia / Q000276:immunology / Q000473:pathology
D011950:Receptors, Cholinergic