Association Of ICAM1 Gene K469E Polymorphism With COPD And Expression Of ICAM1

BACKGROUND AND OBJECTIVE:Intercellular adhesion molecule-1 (ICAM1) acts as ligand for beta2-integrin molecules and mediates leucocytes trafficking to the site of inflammation. Recently, K469E, the common ICAM1 polymorphism was found to have association with a number of diseases, including paediatric bronchial asthma. It was also found to have association with expression of ICAM-1 in few studies. Since that chronic obstructive pulmonary disease (COPD) shows some similarities to asthma, thus, we hypothesize that K469E may affect the genetic susceptibility or severity of COPD. The aim of this study was to test the common ICAM-1 polymorphism for association with COPD and expression of ICAM-1 in Han peoples of Central and South Region in CHINA.MATERIALS AND METHODS:A case-control study was done on 91 patients with COPD and 80 matched controls of Han peoples come from Central and South Region in CHINA, mainly from HUNAN Provence. Genomic DNA was extracted from white blood cells by phenol-chloroform extraction method. ICAM-1 sequences were amplified from genomic DNA by polymerase chain reaction (PCR). The PCR products were analyzed by agarose gel electrophoresis. Genotypes were defined by base sequencing. In addition, sICAM1 serum levels were measured in 86 peoples pick out randomly from the COPD and control group. Statistical analysis was done using SPSS program.RESULTS:There is no difference in the frequency of the genotype and allele between the case group and control, but comparing to those who are not very severe, the frequency of KE/EE genotypes and E allele in COPD patients of very severe stage is significantly higher. The level of sICAM-1 increases in COPD cases, with correlation to FEV1%. But in both cases and controls, it differs no significantly in different genotypes. CONCLUSION:The K469E polymorphism of ICAM-1 may not affect the susceptibility of COPD and the expression of ICAM-1 in Han peoples come from Central and South Region of CHINA in this study, but carriers of E Allele are at high risk of developing to very severe stage of COPD.