Isotipos IgG e IgM anti-dsDNA em pacientes com lúpus eritematoso sistêmico

• Ano de defesa: 2012
• Autor(a) principal: Keiserman, Briele
• Orientador(a): Staub, Henrique Luiz
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Pontifícia Universidade Católica do Rio Grande do Sul
• Programa de Pós-Graduação: Programa de Pós-Graduação em Medicina e Ciências da Saúde
• Departamento: Faculdade de Medicina
• País: BR
• Palavras-chave em Português: MEDICINA; LUPUS ERITEMATOSO SISTÊMICO; NEFRITE LÚPICA; IMUNOGLOBULINAS; ANTICORPOS
• Área do conhecimento CNPq: CNPQ::CIENCIAS DA SAUDE::MEDICINA
• Link de acesso: http://tede2.pucrs.br/tede2/handle/tede/1686

IgG anti-dsDNA antibodies are associated to lupus nephritis. Recent data suggest that IgM isotype is nephroprotector. We evaluated the frequency of IgG anti-dsDNA in patients with Systemic lupus erythemathosus (SLE) and its relation between IgG/IgM proportion and clinical manifestations of the disease. This transversal study included 137 SLE patients according to traditional criteria (92.5% female, 79.5% Caucasian) and 58 SLE individual (93.1% female, 81% Caucasian) selected by positivity for IgG anti-dsDNA. IgG and IgM anti-dsDNA antibodies were detected by Chrithidiae luciliae indirect immunofluorescence with cut point 1/10 dilution. The presence of IgG anti-dsDNA was associated to the presence of hemolytic anemia, leukopenia/lymphopenia and Complement depletion (p<0.001). Of the 58 patients positive for IgG anti-dsDNA 15 were also positive for IgM anti-dsDNA. The group presenting both isotypes showed significant less frequency of active urinary sediment when compared to isolated IgG anti-dsDNA (6.7% versus 34.9%, p=0.046). IgG/IgM proportion distribution evidenced a trend of higher medians in the presence of arthritis and leukopenia/lymphopenia [4 (2-8) versus 1 (1-2), p=0.070 and 4 (3-8) versus 1 (1-4), p=0.066, respectively]. Summarizing, the frequency of IG anti-dsDNA was relevant in our casuistic. Positive subpopulation for both IgG/IgM isotypes anti-dsDNA was less willing to urinary sediment alterations than IgG anti-dsDNA isolated population. These data suggest a distinct biologic behavior for IgM anti-dsDNA.