RESUMO
We have described suggestive linkage between microsatellite markers within the cytogenetic region 18q21-23 and SLE, a region where linkage with other autoimmune diseases has also been detected. The Bcl-2 gene located within this region, is a candidate gene because of its role in apoptosis, a physiological mechanism that could be deregulated in autoimmune disease. Furthermore, several studies have found abnormalities of Bcl-2 expression in SLE patients. We therefore sought to determine if the Bcl-2 gene is involved in SLE by studying members of a large cohort of Mexican SLE patients (n = 378) and 112 Swedish simplex families. Using a microsatellite marker and two single nucleotide polymorphisms located within the gene, we were unable to detect association between Bcl-2 and SLE in either population. We also tested whether combinations of alleles of the Bcl-2 and IL-10.G microsatellites would increase the risk for SLE. Our results do not support such hypothesis. Our findings suggest that linkage between SLE and the 18q21-23 region is due to a gene other than Bcl-2.
Assuntos
Genes bcl-2 , Lúpus Eritematoso Sistêmico/genética , Alelos , Sequência de Bases , Estudos de Casos e Controles , Estudos de Coortes , Primers do DNA/genética , Feminino , Frequência do Gene , Ligação Genética , Genótipo , Humanos , Interleucina-10/genética , Lúpus Eritematoso Sistêmico/imunologia , Masculino , México , Repetições de Microssatélites , Polimorfismo de Nucleotídeo Único , SuéciaRESUMO
OBJECTIVE: To study the contribution of the IL10 gene to the susceptibility to systemic lupus erythematosus (SLE). METHODS: Analysis by fluorescent-semiautomated genotyping of a dinucleotide repeat located in the promoter region of the IL10 locus (microsatellite G). RESULTS: No significant difference was found in the frequencies of the microsatellite alleles of 330 Mexican patients with SLE compared to 368 controls from the same population. Two-point linkage analyses were carried out using 13 Mexican, 13 Swedish, and 8 Icelandic families with 2 or more cases with SLE. No linkage was revealed between IL10 and SLE, using a variety of parameter settings. CONCLUSION: Our results do not support that the IL10 gene contributes to the susceptibility to SLE in the populations we studied.
Assuntos
Interleucina-10/genética , Lúpus Eritematoso Sistêmico/genética , Repetições de Dinucleotídeos/genética , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Lúpus Eritematoso Sistêmico/imunologia , Masculino , México , Repetições de Microssatélites , Regiões Promotoras Genéticas/genéticaRESUMO
Systemic lupus erythematosus is a disease of unknown etiology. Multiple genetic factors are believed to be involved in its pathogenesis. In addition, and due to genetic heterogeneity, these factors and/or their combinations may be different in different ethnic groups, while some might be shared between populations. We have performed genome scans in multicase families from three different population groups, two from Northern Europe, with a high degree of homogeneity, and the third from a recently admixed population of Mexican Mestizos. Although our family material is relatively small, the results presented here show that using family sets from well defined populations are sufficient to detect susceptibility loci for SLE. Our results also reveal the chromosomal regions most likely to contain susceptibility genes for SLE.
Assuntos
Genoma Humano , Lúpus Eritematoso Sistêmico/genética , Etnicidade/genética , Feminino , Técnicas Genéticas , Genética Populacional , Humanos , Islândia/epidemiologia , Indígenas Norte-Americanos/genética , Escore Lod , Lúpus Eritematoso Sistêmico/epidemiologia , Masculino , México/epidemiologia , Suécia/epidemiologia , Estados Unidos/epidemiologia , População Branca/genéticaRESUMO
This study is a cross-sectional analysis of the differences between SLE outpatients seen in Rheumatology departments at University centres in England, Brazil and Sweden, using a standard protocol. The demographic characteristics, extent and activity of disease of 209 patients with SLE were studied; 112 patients were seen in England, 33 in Brazil and 64 in Sweden. The median age of disease onset of Brazilian and English patients was 25 years and of Swedish patients 31.5 years. Disease activity was measured by the BILAG index. In most systems Brazilian patients experienced more activity than English patients and English patients more activity than Swedish patients. Non-Caucasians experienced more active disease than Caucasians. No sex or occupational differences were observed in disease activity. English patients were the most likely to have experienced photosensitivity, oral ulcers and haematological disorders, Brazilian patients renal disorders and Swedish patients discoid rashes. Brazilian patients were the most likely to be prescribed only one drug for treatment of SLE and to be taking steroids and the highest dose of steroids, in contrast to the European patients who were often prescribed steroids and an antimalarial agent or azathioprine. The results of this cross-sectional assessment of disease activity using a standardized instrument indicate that there are real differences in the extent and degree of activity of SLE in different national groups. This reflects a combination of genetic, environmental and social influences on disease expression and has implications for treatment and monitoring of SLE patients.