title: Association of complement C4 and HLA-DR alleles with systemic lupus erythematosus in Koreans.
abstract: OBJECTIVE
  To examine the association of complement C4 and HLA-DR to systemic lupus erythematosus (SLE) susceptibility in Korea.
  
  
  METHODS
  Complement C4 protein typing was carried out by immunofixation and immunoblotting methods using EDTA-plasma from 60 patients with SLE and 72 healthy controls. Restriction fragment length polymorphism analysis of C4 genes was also carried out using TaqI or HindIII for restriction enzymes. HLA-DR was determined by polymerase chain reaction amplification with sequence specific primers using genomic DNA from 67 patients with SLE and 72 healthy controls.
  
  
  RESULTS
  The frequency of the C4AQ0 allele was significantly higher in the patients with SLE than in controls (41.7 vs 25.0%, p < 0.05). The deletion of the C4A gene commonly found in Caucasian patients with SLE was not observed in any patients. For HLA-DR, a significant increase of the haplotype DRB1*1501 was observed in the patients (26.9 vs 12.5%, p < 0.05) and DR9 was also significantly increased (23.9 vs 11.1%, p < 0.05). An increase in each DR2 and DR9 was independent of an increase in C4AQ0. The frequencies of DR2 and DR9 were significantly decreased in patients with renal involvement and alopecia, respectively.
  
  
  CONCLUSIONS
  Our data suggested that the presence of C4AQ0 allele, DRB1*1501-DRB5*0101 haplotype and DR9 contributed to susceptibility to SLE in Koreans and that Korean SLE is based on a different genetic background from Caucasian patients.
authors.affiliation: Department of Biology, Sungshin Womens University, Seoul, Korea.
authors.forename: G H
authors.initials: GH
authors.lastname: Hong
authors.forename: H Y
authors.initials: HY
authors.lastname: Kim
authors.forename: F
authors.initials: F
authors.lastname: Takeuchi
authors.forename: K
authors.initials: K
authors.lastname: Nakano
authors.forename: H
authors.initials: H
authors.lastname: Yamada
authors.forename: K
authors.initials: K
authors.lastname: Matsuta
authors.forename: H
authors.initials: H
authors.lastname: Han
authors.forename: K
authors.initials: K
authors.lastname: Tokunaga
authors.forename: K
authors.initials: K
authors.lastname: Ito
authors.forename: K S
authors.initials: KS
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D044466:Asian People / Q000235:genetics; D001327:Autoimmune Diseases / Q000208:ethnology / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D003181:Complement C4 / Q000145:classification / Q000235:genetics*; D004198:Disease Susceptibility / Q000208:ethnology / Q000276:immunology; D005260:Female; D017353:Gene Deletion; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006684:HLA-DR Antigens / Q000145:classification / Q000235:genetics*; D006801:Humans; D007723:Korea; D008180:Lupus Erythematosus, Systemic / Q000208:ethnology / Q000235:genetics* / Q000276:immunology; D008285:Major Histocompatibility Complex; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D012150:Polymorphism, Restriction Fragment Length; D011446:Prospective Studies; D044465:White People / Q000235:genetics
chemical_list: D003181:Complement C4; D006684:HLA-DR Antigens