title: Interleukin-1 receptor antagonist gene (IL1RN) polymorphism possibly associated to severity of rheumatic carditis in a Brazilian cohort.
abstract: OBJECTIVE
  To evaluate the IL1RN polymorphism as a possible marker for Rheumatic Fever (RF) susceptibility or disease severity.
  
  
  METHODS
  The genotypes of 84 RF patients (Jones criteria) and 84 normal race-matched controls were determined through the analysis of the number of 86-bp tandem repeats in the second intron of IL1RN. The DNA was extracted from peripheral-blood leukocytes and amplified with specific primers. Clinical manifestations of RF were obtained through a standardized questionnaire and an extensive chart review. Carditis was defined as new onset cardiac murmur that was perceived by a trained physician with corresponding valvae regurgitation or stenosis on echocardiogram. Carditis was classified as severe in the presence of congestive heart failure or upon the indication for cardiac surgery. The statistical association among the genotypes, RF and its clinical variations was determined.
  
  
  RESULTS
  The presence of allele 1 and the genotype A1/A1 were found less frequently among patients with severe carditis when compared to patients without this manifestation (OR=0.11, p=0.031; OR=0.092, p=0.017). Neither allele 1 nor allele 2 were associated with the presence of RF (p=0.188 and p=0.106), overall carditis (p=0.578 and p=0.767), polyarthritis (p=0.343 and p=0.313) and chorea (p=0.654 and p=0.633).
  
  
  CONCLUSIONS
  In the Brazilian population, the polymorphism of the IL-1ra gene is a relevant factor for rheumatic heart disease severity.
authors.affiliation: Rheumatology Division, Faculdade de Medicina da Universidade de Sao Paulo, CEP: 01246903 Sao Paulo, SP, Brazil.
authors.forename: Pedro Ming
authors.initials: PM
authors.lastname: Azevedo
authors.forename: Raquel
authors.initials: R
authors.lastname: Bauer
authors.forename: Valeria de Falco
authors.initials: Vde F
authors.lastname: Caparbo
authors.forename: Clovis Artur Almeida
authors.initials: CA
authors.lastname: Silva
authors.forename: Eloísa
authors.initials: E
authors.lastname: Bonfá
authors.forename: Rosa Maria Rodrigues
authors.initials: RM
authors.lastname: Pereira
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D001938:Brazil; D002648:Child; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein / Q000235:genetics*; D011110:Polymorphism, Genetic; D012214:Rheumatic Heart Disease / Q000235:genetics / Q000503:physiopathology; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D005819:Genetic Markers; D053590:Interleukin 1 Receptor Antagonist Protein