Relation of Heme oxygenase-1 Enzyme gen polymorphism and levels of last products with Chronic Obstructive Pulmonary Disease and exacerbations

INTRODUCTION: Genetic predisposition is one of the causes of Chronic Obstructive Pulmonary Disease (COPD). This study is designed to investigate effect of the activity of an important antioxidant enzyme heme oxygenase-1 (HOX-1) by (GT)n dinucleotide repeat (GT)n ≤ 26 S allel, 27≤(GT)n≤ 31 M allel, (GT)n ≥ 32 L (long) allel), levels of serum iron and bilirubin, the last products of enzyme, on severity of COPD and exacerbations of disease.
METHODS: Three different staged 90 COPD patients,who were followed for one year in terms of exacerbation, and 93 controls were included.
RESULTS: By increasing the severity of disease, bilirubin levels were coming closer to the lower limit within normal range. Iron levels of Group 2 (moderate) and 3 (severe) were significantly lower than Group 1 (mild), (p=0,025, p=0,035). There was an inversely related statistically significant correlation between exacerbation numbers and iron (p=0,016). Allel frequency and carrier of L ((GT)n ≥ 32) allel were similar between patient and control group, and patient group in its own (p=0,458, p=0,445). There was no significant relation between individuals with L allel (SL, ML, LL) and without L allel (SS, SM, MM) according to levels of iron and bilirubin, number of exacerbations and FEV1 (p=0,631, p=0,065, p=0,356).
DISCUSSION AND CONCLUSION: By the progression of COPD, levels of bilirubin and iron are liable to decrease while the number of exacerbations is increasing. (GT)n polymorphism of COPD patients in the study group is not a risk factor for development and stage of disease, frequent exacerbation, low iron and bilirubin levels.