Plasma α1-antitrypsin: a neglected predictor of angiographic severity in patients with stable angina pectoris

Association between α1-antitrypsin and acute coronary syndrome

α1-antitrypsin (AAT) is a protein released as part of the anti-inflammatory response. It regulates the activity of serine proteinases and has a crucial role in the pathogenesis of acute coronary syndrome (ACS). The present study aimed to examine its role in patients with ACS. The plasma samples of 117 patients were collected at the Cardiology Department of the Affiliated Hospital of Youjiang Medical University (Baise, China). These included 46 cases of ACS (who met the diagnostic criteria for ACS and had ≥50% luminal stenosis of any coronary vessel), 35 cases of stable angina (SA; with ≥50% luminal stenosis of any coronary vessel but in a stable condition) and 36 normal healthy controls (subjects with no luminal stenosis in their coronary arteries). Plasma AAT protein concentrations were measured by ELISA and clinical data were collected. The plasma levels of AAT protein in patients with ACS were lower than those in controls and cases of SA (P<0.05), and the levels tended to decrease with the number of coronary artery lesions involved. There were no significant associations of the expression of plasma AAT protein and the number of diseased vessels in patients or the degree of stenosis. There was no correlation between the plasma protein levels of AAT and Gensini scores of patients with ACS. In conclusion, the plasma AAT protein levels in patients with ACS may contribute to the occurrence and development of coronary artery disease.

Intermittent Hypoxia Contributes to the Lung Damage by Increased Oxidative Stress, Inflammation, and Disbalance in Protease/Antiprotease System

INTRODUCTION

Intermittent hypoxia as a surrogate of obstructive sleep apnea is associated with different cardiovascular complications. However, the effects of intermittent hypoxia on the lung tissue are less known. Therefore, the aim of our present study was to investigate if intermittent hypoxia may influence oxidative stress, inflammation, and protease/antiprotease system in the lung. Additionally, potential protective properties of anti-inflammatory and anti-oxidative drugs have been evaluated.

METHODS

32 mice were divided into four groups: (1) intermittent hypoxia, (2) intermittent hypoxia with infliximab, (3) intermittent hypoxia with L-glutathione, and (4) normoxia. After 4 weeks, lungs and blood were collected. Levels of reactive oxygen species in the lung were calculated by L-O12-enhanced chemiluminescence. CD68-positive lung macrophages were detected by immunofluorescence. Concentrations of elastase and desmosine in lung and of alpha-1-antitrypsin in blood were calculated by means of enzyme-linked immunosorbent assay.

RESULTS

Compared to a control, intermittent hypoxia augmented the release of free oxygen radicals, expression of CD68+ macrophages, and concentration of elastase in the lung tissue. Despite increased blood levels of protective alpha-1-antitrypsin, concentrations of desmosine-degradation product of elastin were higher versus control. The application of anti-inflammatory infliximab und anti-oxidative L-glutathione prevented at least partly the above-observed hypoxia-associated changes.

CONCLUSIONS

Intermittent hypoxia contributes to the lung damage by increased oxidative stress, inflammation, and disbalance in protease/antiprotease system. Infliximab and L-glutathione may prevent adverse hypoxia-induced lung alternations.