Polymorphisms of IL4, IL13, and ADRB2 genes in COPD.
OBJECTIVE
Interleukin (IL)-4, IL-13, and beta(2)-adrenoceptor (ADRB2) are involved in airway hyperresponsiveness (AHR), and their coding genes are located on chromosome 5q31-q33. AHR is one of the risk factors for COPD. Investigating polymorphisms within these genes may help to pinpoint the genetic susceptibility to COPD.


METHODS
A case-control association study was conducted on two different ethnic groups: Japanese subjects (88 patients with COPD and 61 control subjects) and Egyptian subjects (106 patients with COPD and 72 control subjects). The following polymorphisms were genotyped: - 589 C/T, - 33 C/T, and variable number of tandem repeat (VNTR) in IL4, - 1111 C/T and + 2044 G/A in IL13, and + 46 A/G and + 79 C/G in ADRB2. Pairwise haplotype frequencies as well as genotype and allele frequencies were analyzed.


RESULTS
The distribution of the genotype frequencies of ADRB2 + 79 C/G was significantly different between the COPD and the control groups in the Egyptians (p = 0.002). The distributions of the haplotypes in the Japanese (IL4 - 589 C/T: IL4 VNTR; IL4 - 33 C/T: IL4 VNTR) [corrected p values < 0.001 and 0.022, respectively], and those in the Egyptians (IL4 - 589 C/T: ADRB2 + 79 C/G; IL4 VNTR: ADRB2 + 79 C/G) [corrected p values, 0.033 and 0.001, respectively] showed significant differences between the COPD and the control groups.


CONCLUSIONS
The ADRB2 + 79 C/G polymorphism and the haplotypes shown in this study may be involved in the pathogenesis of COPD.
Hegab
Ahmed E
AE
Department of Pulmonary Medicine, Institute of Clinical Medicine, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8575, Japan.
Sakamoto
Tohru
T
Saitoh
Wataru
W
Massoud
Hosam H
HH
Massoud
Hosny M
HM
Hassanein
Khalid M
KM
Sekizawa
Kiyohisa
K
D000368:Aged; D016022:Case-Control Studies; D002895:Chromosomes, Human, Pair 5; D004534:Egypt; D005260:Female; D005541:Forced Expiratory Volume; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D018793:Interleukin-13 / Q000235:genetics*; D015847:Interleukin-4 / Q000235:genetics*; D007564:Japan; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats; D011110:Polymorphism, Genetic; D029424:Pulmonary Disease, Chronic Obstructive / Q000235:genetics* / Q000503:physiopathology; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics*
D018793:Interleukin-13; D018343:Receptors, Adrenergic, beta-2; D015847:Interleukin-4