Made available in DSpace on 2015-04-14T13:35:31Z (GMT). No. of bitstreams: 1 438287.pdf: 659033 bytes, checksum: 74536bb270173b92a486ff2c17575495 (MD5) Previous issue date: 2012-03-28 / 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. / Anticorpos IgG anti-dsDNA se associam ? ocorr?ncia de nefrite l?pica. Relatos recentes sugerem que o isotipo IgM anti-dsDNA seja nefroprotetor. Avaliamos frequ?ncia de IgG anti-dsDNA em pacientes com l?pus eritematoso sist?mico (LES), e averiguamos a rela??o entre propor??o IgG/IgM anti-dsDNA e manifesta??es cl?nicas da doen?a. O estudo, transversal, incluiu 137 pacientes com LES de acordo com os crit?rios tradicionais (92,5% mulheres, 79,5% ra?a branca) e uma popula??o de 58 casos de LES (93,1% mulheres, 81% ra?a branca) selecionados por positividade para IgG anti-dsDNA. Anticorpos IgG e IgM anti-dsDNA foram detectados por imunofluoresc?ncia indireta com Crithidia luciliae, com ponto de corte na dilui??o 1/10. A presen?a de IgG anti-dsDNA se associou ? presen?a de anemia hemol?tica, leucolinfopenia e deple??o de Complemento (p<0, 001). Dos 58 pacientes com teste positivo para IgG anti-dsDNA, 15 foram tamb?m positivos para o isotipo IgM. O grupo com ambos os isotipos teve frequ?ncia significativamente menor de sedimento urin?rio ativo quando comparado ao grupo com IgG anti-dsDNA isolado (6,7% versus 34,9%, p=0, 046). A distribui??o da propor??o IgG/IgM anti-dsDNA evidenciou tend?ncia de medianas mais elevadas na presen?a de artrite e leucolinfopenia [4 (2-8) versus 1 (1-2), p=0, 070 e 4 (3-8) versus 1 (1-4), p=0, 066, respectivamente]. Em suma, a frequ?ncia de IgG anti-dsDNA foi relevante em nossa casu?stica. A subpopula??o positiva para ambos IgG e IgM anti-dsDNA foi menos propensa a altera??es de sedimento urin?rio do que aquela com IgG anti-dsDNA isolado. Estes dados sugerem um comportamento biol?gico distinto para o isotipo IgM anti-dsDNA.