title: Association of an A/C single nucleotide polymorphism in programmed cell death-ligand 1 gene with Graves' disease in Japanese patients.
abstract: OBJECTIVE
  Programmed cell death-1 (PD-1) and its ligands (PD-L1 and PD-L2) inhibit T-cell proliferation and activation. This inhibition down-regulates the immune responses. The association of a PD-L1 polymorphism with Graves' disease (GD) was studied.
  
  
  METHODS
  The association of an A/C polymorphism at position 8923 in PD-L1 intron 4 with GD was studied.
  
  
  METHODS
  The study included 327 GD patients and 192 controls, of which 252 GD patients were followed over 5-10 years.
  
  
  METHODS
  PD-L1 intron 4 position 8923 A/C polymorphism was typed using the PCR-restriction fragment length polymorphism method.
  
  
  RESULTS
  The A/C genotype frequencies were significantly different between GD patients and controls. The A/C and C/C frequencies were higher in GD patients than in controls. The A/A frequencies were lower in GD patients than in controls. C-allele frequency was higher in GD patients than in controls. A total of 252 GD patients were followed over 5-10 years; 200 had discontinued antithyroid drugs (ATD) while 52 continued to take ATD. Of these 200, 176 continued to be in remission and 24 had relapsed into hyperthyroidism. Significant differences in the duration of positive TBII, positive thyroid-stimulating antibodies, and ATD treatment were noted between the patients in remission and those that had relapsed. Significant differences in the A- and C-allele frequencies were noted between the two. The C-allele frequency was higher in GD patients who did not achieve remission than in those who achieved remission.
  
  
  CONCLUSIONS
  An A/C polymorphism at position 8923 in PD-L1 is associated with GD. The PD-L1 polymorphism plays a role in GD development. GD patients with the C allele at position 8923 in PD-L1 gene had difficulty in achieving remission.
authors.affiliation: Department of Endocrinology and Metabolism, Internal Medicine, University of the Ryukyus, Uehara 207, Nishihara, Okinawa 903-0215, Japan.
authors.forename: Mina
authors.initials: M
authors.lastname: Hayashi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kouki
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Takasu
authors.forename: Sumito
authors.initials: S
authors.lastname: Sunagawa
authors.forename: Ichiro
authors.initials: I
authors.lastname: Komiya
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000235:genetics*; D044466:Asian People / Q000235:genetics*; D060890:B7-H1 Antigen; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006111:Graves Disease / Q000208:ethnology / Q000235:genetics*; D006801:Humans; D007438:Introns / Q000235:genetics; D007564:Japan; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide
chemical_list: D015703:Antigens, CD; D060890:B7-H1 Antigen; C423236:CD274 protein, human