Inflammatory markers in chronic obstructive pulmonary disease patients with different α1 antitrypsin genotypes

Impact of I/D polymorphism of ACE gene on risk of development and course of chronic obstructive pulmonary disease

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) affects more than 10% of the world's population over 40 years of age. The main exogenous risk factor is cigarette smoking; however, only 20% of smokers develop COPD, indicating that some other factors, e.g. genetic, may play an important role in the disease pathogenesis. Recent research indicates that ACE (angiotensin-converting enzyme) may be a susceptibility gene for asthma or COPD. The aim of our study was to determine the influence of I/D (insertion/deletion) polymorphism of the ACE gene (AluYa5, rs4646994) on the risk and course of COPD.

MATERIAL AND METHODS

We investigated ACE I/D polymorphism in 206 COPD and 165 healthy Caucasian subjects.

RESULTS

In the generalized linear model (GLZ) analysis of the influence of selected factors on presence of COPD we found a significant independent effect for male sex (repeatedly increases the risk of COPD, OR = 7.7, p = 0.049), as well as smoking or lower body mass index, but only in combination with older age (OR = 0.96, p = 0.003 and OR = 1.005, p = 0.04 respectively). Interestingly, analysis of factors which may influence the risk of a higher number of exacerbations demonstrated that occurrence of DD genotype, but only in men, is associated with a lower risk (OR = 0.7, p = 0.03) of this complication.

CONCLUSIONS

We suggest that ACE may not be a susceptibility gene for the origin of COPD but a disease-modifying gene. Since the impact of I/D polymorphism of the ACE gene on COPD risk is moderate or negligible, other molecular changes, that will help predict the development of this disease, should still be sought.

Analysis of genomic copy number variation in equine recurrent airway obstruction (heaves)

We explored the involvement of genomic copy number variants (CNVs) in susceptibility to recurrent airway obstruction (RAO), or heaves-an asthmalike inflammatory disease in horses. Analysis of 16 RAO-susceptible (cases) and six RAO-resistant (control) horses on a custom-made whole-genome 400K equine tiling array identified 245 CNV regions (CNVRs), 197 previously known and 48 new, distributed on all horse autosomes and the X chromosome. Among the new CNVRs, 30 were exclusively found in RAO cases and were further analyzed by quantitative PCR, including additional cases and controls. Suggestive association (P = 0.03; corrected P = 0.06) was found between RAO and a loss on chromosome 5 involving NME7, a gene necessary for ciliary functions in lungs and involved in primary ciliary dyskinesia in humans. The CNVR could be a potential marker for RAO susceptibility but needs further study in additional RAO cohorts. Other CNVRs were not associated with RAO, although several involved genes of interest, such as SPI2/SERPINA1 from the serpin gene family, which are associated with chronic obstructive pulmonary disease and asthma in humans. The SPI2/SERPINA1 CNVR showed striking variation among horses, but it was not significantly different between RAO cases and controls. The findings provide baseline information on the relationship between CNVs and RAO susceptibility. Discovery of new CNVs and the use of a larger population of RAO-affected and control horses are needed to shed more light on their significance in modulating this complex and heterogeneous disease.