RESUMO
HLA-G alleles follow a different pattern of polymorphism generation that those of the HLA classical I alleles. However, this polymorphism maintenance could have an evolutionary specific pathways based on non coding regions as introns, 14 bp deletion/insertion (exon 8) or promoter regions. For this reason, a systematic sequencing study of HLA-G promoter region was done in 36 individuals with a total of 15 different alleles. From the 12 sequences obtained, 7 were new sequences and not previously described. Results show that the sequences have three different patterns of evolution confirming the results obtained in the rest of the sequence regions (exons, introns and 3'UTR) where three different lineages were established. Only one of these lineages includes the non-human primate promoter sequences suggesting the possibility of this lineage could come directly from non-human primates while the other two could be generated after the speciation. More non-human primates MHC-G promoter sequences must be obtained to confirm this hypothesis. Expression and functional assays could be done considering the differences obtained in the promoter regions involving the HLA-G function (mRNA expression, isoforms).
Assuntos
Evolução Molecular , Antígenos HLA-G/genética , Polimorfismo Genético , Regiões Promotoras Genéticas/genética , Regiões 3' não Traduzidas/genética , Alelos , Animais , Éxons/genética , Antígenos HLA-G/classificação , Humanos , Íntrons/genética , Dados de Sequência Molecular , Filogenia , Primatas/genética , Análise de Sequência de DNARESUMO
Seven patients with widespread proliferation of the capilar epithelium producting glomerular crescents in more than 80 percent of the glomeruli have been studied. Three patients had a systemic lupus erythematosus, two had primitive extracapillary glomerulonephritis, one had panarteritis nodosa, and another a Schönlein-Henoch syndrome. All patients presented severe renal failure when plasmapheresis was begun. Hemodialysis was needed in four cases. The remained three patients showed creatinine clearance values of 8, 20, and 30 ml/min, respectively. Search for immune complexes was negative in all cases. Plasmapheresis were applied within 1 to 7 months of the onset of the disease in alternate-day sessions. Duration of treatment varied between 1 to 5 months. Moreover, prednisone, cyclophosphamide and azathioprine were given to all patients. Values of creatinine clearance rised to 71, 49 and 18 ml/min in the two patients with primitive extracapillary glomerulonephritis and in the patient with panarteritis nodosa, respectively. Renal function improvement was not achieved in the three patients with systemic lupus erythematosus and in the patient with Henoch's purpura.
