title: [HLA and myasthenia. Subdivision in 3 categories].
abstract: Genetic susceptibility (HLA types), clinical and pathological findings, amount of acetylcholine receptor antibodies and T lymphocyte subpopulations were studied in 63 patients with Myasthenia Gravis (MG). The frequency of HLA-DR5 was increased among patients (0.50 versus 0.23 in controls, pc less than 0.01, relative risk 3.3) and that of HLA-DR3 previously described as associated with MG was slightly increased (0.31 versus 0.20 in controls). The relative frequencies of two T cell subpopulations (T4 helper and T8 suppressor/cytotoxic lymphocytes) were normal in HLA-DR5 positive patients while the ratio T4/T8 was increased in other MG patients, who were HLA-DR3 (p less than 0.005). The high rate was due to an increase in the absolute number of T4 lymphocytes (p less than 0.001). HLA-DR3 patients were mostly women with early onset of a severe form of the disease, marked by the presence of thymic follicular lymphoid hyperplasia. A third genetic susceptibility to this disease was recently described in patients treated with D-penicillamine, the antigenic frequency of HLA-Bw35, DR1 is significantly increased. These 3 types of association between HLA and myasthenia gravis can be related to three different physiopathological mechanisms: the first two are probably linked to individual immunity (inductor/suppressor disequilibrium), in the third association, the mechanism is immunopharmacological.
mesh_terms: D000328:Adult; D004198:Disease Susceptibility; D005260:Female; D006680:HLA Antigens / Q000032:analysis* / Q000276:immunology; D015795:HLA-B8 Antigen; D015236:HLA-C Antigens; D015805:HLA-DR5 Antigen; D015809:HLA-DR7 Antigen; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006801:Humans; D008297:Male; D009157:Myasthenia Gravis / Q000235:genetics / Q000276:immunology*; D013601:T-Lymphocytes / Q000145:classification
chemical_list: D006680:HLA Antigens; D015795:HLA-B8 Antigen; D015236:HLA-C Antigens; D015805:HLA-DR5 Antigen; D015809:HLA-DR7 Antigen; D000949:Histocompatibility Antigens Class II
vernacular_title: HLA et myasthéne. Subdivision en trois catégories.