The Effect of Alpha-1 Proteinase Inhibitor on Biomarkers of Elastin Degradation in Alpha-1 Antitrypsin Deficiency: An Analysis of the RAPID/RAPID Extension Trials

• Published in: Chronic obstructive pulmonary diseases 2016-11, Vol.4 (1), p.34-44
• Main Authors: Ma, Shuren, Lin, Yong Y, Cantor, Jerome O, Chapman, Kenneth R, Sandhaus, Robert A, Fries, Michael, Edelman, Jonathan M, McElvaney, Gerard, Turino, Gerard M
• Format: Article
• Language: English
• Subjects: Original Research
• ISSN: 2372-952X; 2372-952X
• DOI: 10.15326/jcopdf.4.1.2016.0156

The RAPID (NCT00261833; N=180) and RAPID Extension (NCT00670007; N=140) trials demonstrated significantly reduced lung density decline in patients with alpha-1 antitrypsin deficiency (AATD) receiving alpha-1 proteinase inhibitor (A1PI) versus placebo. Desmosine and isodesmosine (DES/IDES) are unique crosslinkers of mature elastin fibers and are utilized as measures of elastin degradation. The aim of this post-hoc study was to determine the effect of A1PI therapy on DES/IDES levels in patients from RAPID/RAPID Extension. Plasma levels of DES/IDES were measured using high-performance liquid chromatography and tandem mass spectrometry. Correlation between changes in DES/IDES levels and computed tomography (CT) lung density decline was assessed. Analysis showed that DES/IDES levels were significantly reduced versus baseline in patients receiving A1PI at all time points, from month 3 through month 48. A significant increase from baseline in DES/IDES was observed with placebo at month 24 (n=54; 0.016; =0.018). DES/IDES change from baseline was significantly different with A1PI versus placebo at months 3 (-0.021; 95% confidence interval [CI] -0.037, 0.004; =0.026), 12 (-0.040; 95% CI -0.055, 0.025;