Assessment of association between interleukin 6 gene variant and its serum level in chronic obstructive pulmonary disease in a sample of Egyptian population

Abstract

Background
Researches in chronic obstructive pulmonary disease (COPD) had shown signs of inflammation with inflammatory markers that had pivotal role in COPD. some studies proposed that elevated serum interleukin-6 (IL-6) is associated with negative impact on lung functions but up to our knowledge, no studies were performed to correlate the genotypes of IL-6 with COPD patients in Egyptian and middle east populations.


Objectives
To study both the correlation of serum level of IL-6 as well as its gene variant (also known as G174C)) as possible genetic marker for COPD patients in Egyptian patients.


Materials and methods
This study is case-control that enrolled ninety participants; it consisted of two groups. Group I included 45 patients who were diagnosed as stable COPD; Group II included 45 healthy participants. After full clinical and pulmonary functions assessment of all participants, blood samples were collected from both groups for the detection serum level of IL-6 by ELISA and the detection of
IL6
variant by TaqMan Real-Time PCR.


Results
Our study revealed that there was statistically significant increase in serum level of interleukin-6 in COPD patients compared to normal individuals (P value <0.001) and the presence of G/G variant of interleukin 6 gene in COPD patients more than normal subjects with frequency of 84.4% and 53.3% for COPD patients and healthy controls respectively. There was significant correlation between the serum level of interleukin-6 and COPD staging (P value <0.007).


Conclusion
The genotype GG variant of IL6 contributes to the prediction of COPD and may be used as a marker for the prediction of COPD risk in Egyptian population. Serum level of IL6 is markedly higher in COPD patients and can be used as a parameter of correlation with COPD stages.