title: Lack of an association of PD-1 and its ligand genes with Behcet's disease in a Chinese Han population.
abstract: BACKGROUND
  Behcet's disease is a chronic, multi-systemic autoimmune disease. Programmed cell death 1 (PD-1) gene is one of non-human leucocyte antigen genes. It has been demonstrated to be associated with several autoimmune diseases. However, only a few studies have addressed the association of ligand genes of PD-1, PD-L1 and PD-L2 with autoimmune disease. The purpose of this study was to analyze the potential association of the PD-1 and its ligand genes with Behcet's disease in a Chinese Han population.
  
  
  RESULTS
  Four single-nucleotide polymorphism (SNPs) rs2227981 and rs10204525 of PD-1, rs1970000 of PD-L1 and rs7854303 of PD-L2 were genotyped in 405 Behcet's patients and 414 age-, sex-, ethnic-matched healthy controls using polymerase chain reaction-restriction fragment length polymorphism assay. The results revealed that there were no significant differences in the genotype and allele frequencies of PD-1 rs2227981 and rs10204525 between the Behcet's patients and controls. A similar result was found for PD-L1 rs1970000 versus healthy controls. Only the C allele and the CC genotype of PD-L2 rs7854303 were identified in patients and controls. Stratification analysis based on gender and clinical findings did not show any associations between PD-1 or its ligand polymorphisms and Behcet's disease.
  
  
  CONCLUSIONS
  None of the currently studied SNPs, PD-1 rs2227981 and rs10204525, PD-L1 rs1970000 and PD-L2 rs7854303, are associated with the susceptibility to Behcet's disease in a Chinese Han population. More studies are needed to confirm these findings in Behcet's patients with other ethnic backgrounds.
authors: Department of Ophthalmology, Guangdong Eye Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, People's Republic of China.
authors: Qianli
authors: Q
authors: Meng
authors: Haike
authors: H
authors: Guo
authors: Shengping
authors: S
authors: Hou
authors: Zhengxuan
authors: Z
authors: Jiang
authors: Aize
authors: A
authors: Kijlstra
authors: Peizeng
authors: P
authors: Yang
mesh_terms: D000328:Adult; D001528:Behcet Syndrome / Q000235:genetics*; D016022:Case-Control Studies; D002681:China; D005006:Ethnicity; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D008024:Ligands; D008297:Male; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D061026:Programmed Cell Death 1 Receptor / Q000235:genetics*
chemical_list: D008024:Ligands; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor