title: Mannose-binding lectin gene polymorphisms in Brazilian patients with rheumatoid arthritis.
abstract: OBJECTIVE
  Rheumatoid arthritis (RA) is a disease with unknown etiology but it is probably multifactorial. RA susceptibility is related to genetic, hormonal, immunologic, and environmental factors. Mannose-binding lectin (MBL) is an important protein of the human innate immune system, encoded by the MBL2 gene. Polymorphisms in MBL2 were associated with several diseases, and may be an important factor in RA susceptibility. We analyzed 3 MBL2 gene polymorphisms in 322 Brazilian patients with RA and 345 ethnically matched healthy controls.
  
  
  METHODS
  MBL2 gene variants were analyzed through polymerase chain reaction sequencing.
  
  
  RESULTS
  Considering MBL2 B, C, and D alleles separately, a significant difference in both genotypic and allelic frequencies, particularly concerning frequency of the C allele, was observed comparing European-derived and African-derived individuals (European-derived patients 0.022 vs African-derived patients 0.205; European-derived controls 0.029 vs African-derived controls 0.144; both p < 0.001). We also analyzed MBL2 genotype in relation to extraarticular manifestations. Considering MBL2 variants together, we found an increased frequency of the OO genotype among patients with rheumatoid nodules (p = 0.031), although this association lost significance after Bonferroni correction.
  
  
  CONCLUSIONS
  Our findings suggest an association of MBL2 genotypes with some clinical manifestations of RA, but more studies are needed to clarify the actual role of MBL in RA.
authors: Av. Ipiranga, 6681-12C, Sala 172, Porto Alegre, 90619-900, RS, Brazil.
authors: Fernanda Leticia
authors: FL
authors: Martiny
authors: Tiago Degani
authors: TD
authors: Veit
authors: Claiton Viegas
authors: CV
authors: Brenol
authors: João Carlos Tavares
authors: JC
authors: Brenol
authors: Ricardo Machado
authors: RM
authors: Xavier
authors: Maurício Reis
authors: MR
authors: Bogo
authors: José Artur Bogo
authors: JA
authors: Chies
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000276:immunology / Q000503:physiopathology; D044383:Black People / Q000235:genetics; D001938:Brazil; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology; D037601:Mannose-Binding Lectin / Q000235:genetics*; D008875:Middle Aged; D011110:Polymorphism, Genetic; D044465:White People / Q000235:genetics
chemical_list: C445619:MBL2 protein, human; D037601:Mannose-Binding Lectin