title: Association of PDCD1 with susceptibility to systemic lupus erythematosus: evidence of population-specific effects.
abstract: OBJECTIVE
  The A allele of the PD1.3 single-nucleotide polymorphism (SNP) on the programmed cell death gene PDCD1 was markedly more frequent in patients with systemic lupus erythematosus (SLE) than in unaffected controls in a recent study involving large sets of Swedish, European American, and Mexican families. This study sought to determine the role of PDCD1 in susceptibility to SLE in the Spanish population.
  
  
  METHODS
  Seven PDCD1 SNPs were studied in 518 SLE patients and 800 healthy control subjects who had been recruited in 5 distant towns spanning continental Spain. Patients and controls were of Spanish ancestry. The diagnosis of SLE was in accordance with the American College of Rheumatology updated classification criteria.
  
  
  RESULTS
  The A allele of the PD1.3 polymorphism was significantly less frequent in Spanish female patients with SLE than in Spanish female controls (9.0% versus 13.0%, odds ratio 0.67, 95% confidence interval 0.50-0.89). This difference was consistent across the 5 sets of samples grouped by town of recruitment. The other PDCD1 SNPs were not associated with SLE susceptibility. The haplotype structure of PDCD1 in the Spanish controls was different from that reported in other healthy control populations.
  
  
  CONCLUSIONS
  Our results confirm the association of PDCD1 with susceptibility to SLE, but the findings show a lack of involvement of the PD1.3 SNP, which is contrary to the role of the PD1.3 A allele observed previously. These contradictory results probably reflect population differences in the haplotype structure of the PDCD1 locus. More research focusing on new polymorphisms and identifying associations in other populations will be needed to clarify the role of PDCD1 in SLE susceptibility.
authors.affiliation: Hospital Clinico Universitario de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Ferreiros-Vidal
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Gomez-Reino
authors.forename: Francisco
authors.initials: F
authors.lastname: Barros
authors.forename: Angel
authors.initials: A
authors.lastname: Carracedo
authors.forename: Patricia
authors.initials: P
authors.lastname: Carreira
authors.forename: Francisca
authors.initials: F
authors.lastname: Gonzalez-Escribano
authors.forename: Myriam
authors.initials: M
authors.lastname: Liz
authors.forename: Javier
authors.initials: J
authors.lastname: Martin
authors.forename: Josep
authors.initials: J
authors.lastname: Ordi
authors.forename: Jose L
authors.initials: JL
authors.lastname: Vicario
authors.forename: Antonio
authors.initials: A
authors.lastname: Gonzalez
mesh_terms: D000483:Alleles; D015703:Antigens, CD; D000954:Antigens, Surface / Q000235:genetics*; D051017:Apoptosis Regulatory Proteins; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000235:genetics*; D008297:Male; D020641:Polymorphism, Single Nucleotide; D061026:Programmed Cell Death 1 Receptor; D013030:Spain; D044465:White People / Q000235:genetics
chemical_list: D015703:Antigens, CD; D000954:Antigens, Surface; D051017:Apoptosis Regulatory Proteins; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor