Association of interleukin-18 gene promoter polymorphisms in type 1 diabetes and autoimmune thyroid disease.
Type 1 diabetes is a heterogeneous autoimmune disease and is often associated with other organ-specific autoimmune diseases, including autoimmune thyroid disease (AITD). IL-18 is a potent proinflammatory cytokine capable of inducing IFN-gamma production that is associated with the development of type 1 diabetes and AITD. The gene for IL-18 is located near Idd2 and has been reported to be associated with a susceptibility to type 1 diabetes. To test the putative involvement of IL-18 gene polymorphism in predisposition to type 1 diabetes and AITD, we conducted a case-control study in Japanese population. The SNPs at position -607 (C/A) and -137 (G/C) in the promoter region of the IL-18 gene were analyzed by sequence-specific PCR in 74 nondiabetic patients with AITD, 47 type 1 diabetic patients with AITD, and 114 normal controls. There was no significant increase in the genotype and allele frequencies not only in nondiabetic patients with AITD compared with normal controls, but also in type 1 diabetic patients with AITD compared with normal controls. The distribution of IL-18 gene haplotypes was also similar between both patient groups and normal controls. These results suggest that polymorphisms of the IL-18 gene are not associated with a susceptibility to AITD and type 1 diabetes coexistent with AITD in Japanese population.
Ide
Akane
A
First Department of Internal Medicine, Graduate School of Biochemical Sciences, Nagasaki University School of Medicine, Nagasaki, Japan.
Kawasaki
Eiji
E
Abiru
Norio
N
Sun
Fuyan
F
Fukushima
Tetsuya
T
Ishii
Reiko
R
Takahashi
Ryoko
R
Kuwahara
Hironaga
H
Fujita
Naruhiro
N
Kita
Atsushi
A
Imaizumi
Misa
M
Oshima
Katsuya
K
Usa
Toshiro
T
Uotani
Shigeo
S
Ejima
Eri
E
Yamasaki
Hironori
H
Ashizawa
Kiyoto
K
Yamaguchi
Yoshihiko
Y
Eguchi
Katsumi
K
D000328:Adult; D001327:Autoimmune Diseases / Q000235:genetics*; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D020382:Interleukin-18 / Q000097:blood / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D013959:Thyroid Diseases / Q000235:genetics*
D020382:Interleukin-18