[Immunogenetics of the Sjogren's syndrome in southern Spain]. / Inmunogenética del síndrome de Sjögren en el sur de España.

ABSTRACT

To establish the relation between HLA antigens, Primary Sjögren Syndrome (PSS) and autoantibodies production, in our geographical area, we undertook a case-control study with a consecutive sample of 30 patients with PSS (Fox's criteria) attending in a reference hospital. Two hundred and sixty-four local controls with no apparent pathology were included for comparison. In patients we evaluated clinical and analytical aspects about multisystem autoimmune disease. Anti-SSA/Ro and -SSB/La autoantibodies were determined by double immunodiffusion. HLA typing was serologically determined. In logistic regression multivariate analysis, there were significant association between PSS and specificities HLA-Cw7 (73% in cases, versus 35% in controls; RR = 8.0; 95% CI 23.2-2.7), HLA-DR3 (63% vs 20%; RR = 3.4; 95% CI 9.5-1.4) and HL-DR11 (43% vs 13%; RR = 4.1; 95% CI 12.0-1.4). In patients, the anti-SSA/Ro autoantibodies production were associated with HLA-DR3 antigen (83% vs 25%; RR = 6./; 95% CI 1.3-34.2). All HLA-DQ2/DQ6 heterozygotes patients (8 cases) had anti-SSA/Ro autoantibodies, versus only one half of the remainder (p = 0.029; RR = 6.3). In anti-SSA/Ro negative patients there weren't association with HLA-DR3 antigen (33% vs 20%). HLA-DR3 were associated with the presence of anti-SSB/La autoantibodies, but there wasn't signification (p = 0.081). We conclude that our patients with PSS present association with HLA-DR11 specificity, that it's a risk factor for the disease development. HLA-DR3 would determined the anti-SSA/Ro autoantibodies, and maybe also anti-SSB/La autoantibodies, production. Furthermore, HLA-DQ2/DQ6 heterozygosity would determined immune response to SSA/Ro autoantigen.