MEKC of desmosine and isodesmosine in urine of chronic destructive lung disease patients

Abstract

Degradation of extracellular matrix components is central to many pathological features of chronic destructive lung disorders. Desmosine and isodesmosine are elastin-derived cross-linked amino acids whose urine levels are considered representative of elastin breakdown.The aim of this study was to apply a novel methodology, based on high-performance capillary electrophoresis, to the quantification of desmosine and isodesmosine in 11 patients with stable chronic obstructive pulmonary disease (COPD), 10 with an exacerbation of COPD, nine with a 1 -antitrypsin deficiency, 13 with bronchiectasis, and 11 adults with cystic fibrosis, in comparison to 24 controls.It was found that, in patients with stable COPD, urinary desmosine levels were higher than in controls (p=0.03), but lower than in COPD subjects with an exacerbation (p#0.05). The highest desmosine levels were found in subjects with a 1 -antitrypsin deficiency, bronchiectasis and cystic fibrosis (p<0.001 versus stable COPD). In a shortterm longitudinal study, five stable COPD patients showed a constant rate of desmosine excretion (mean coefficient of variation <8% over three consecutive days).In conclusion, the present method is simple and suitable for the determination of elastin-derived cross-linked amino acid excretion in urine, giving results similar to those obtained using other separation methods. In addition, evidence is presented that urinary desmosine excretion is increased in conditions characterized by airway inflammation, such as exacerbations of chronic obstructive pulmonary disease, bronchiectasis and cystic fibrosis. Results obtained in subjects with a 1 -antitrypsin deficiency suggest that this method might be used to evaluate the putative efficacy of replacement therapy. Eur Respir J 2000; 15: 1039±1045. Chronic obstructive pulmonary disease (COPD), with or without inherited deficiency of a 1 -antitrypsin (AAT), disseminated bronchiectasis (Bx) and cystic fibrosis (CF) are destructive lung disorders characterized by chronic and irreversible airflow limitation. Irrespective of the aetiological factors implicated, there is a solid body of evidence suggesting that degradation of the extracellular matrix component, mainly elastin, due to an imbalance between proteinases and their naturally occurring inhibitors, is central to many of the pathological features of these conditions [1±4].Excess lung elastin degradation results in the excretion of elastin-derived peptides containing desmosine (DES) and isodesmosine (IDES) in urine [5]. Since these crosslinked amino acids are unique to mature elastin, their urine levels are considered to be representative of body elastin breakdown. Urinary excretion of DES and IDES has been reported to be increased in patients with COPD, current smokers with normal lung function [6] and adults with CF [7] compared to appropriate controls.There are two validated means of detecting DES and IDES in body fluids: a separation method, based on isotope -dilution/high -performance liquid chromatography (HPLC) [8], and ...

Desmosine as a biomarker of elastin degradation in COPD: current status and future directions

“…However, lack of an internal standard precludes corrections for losses. Normal urinary DES levels determined by HPCE (mean¡SD 9.3¡2.7 mg per g creatinine) [18] are approximately of the same order of magnitude as those obtained by HPLC (7.5¡1.4 mg per g creatinine). Further improvement in the analysis was reported by the use of combined HPLC and liquid chromatography mass spectrometry (LC-MS) analysis [19], in which both DES and IDES can be determined separately with higher sensitivity and specificity.…”

“…In addition, the demonstration that increased elastin degradation occurs in rapid decliners compared with slow decliners offers the prospect that urinary DES could serve as a biological marker for therapies aimed at slowing the progression of COPD. The difference in urinary DES between healthy nonsmokers, smokers with normal lung function and COPD patients was confirmed by a study performed in Italy, using the HPCE separation method [18]. This cross-sectional study also dealt with an additional COPD study group, subjects with acute exacerbations of COPD.…”

“…However, using the HPCE separation method [18], nine PI*ZZ subjects with emphysema (FEV1 29% pred) had a mean urinary DES significantly higher than that of healthy smokers and nonsmokers, but also higher than that in stable (p,0.001) or exacerbated (p,0.01) COPD without AATD [17]. Urinary DES excretion in these PI*ZZ subjects was not different from that found in patients with diffuse bronchiectasis (n513) and in adults with cystic fibrosis (n511; mean¡SD 22.3¡7.7, 23.3¡2 and 23.3¡2 mg per g creatinine, respectively).…”

“…The evidence accumulated over the past 15 yrs indicates that patients with COPD, as well as patients with other destructive lung diseases [18], excrete more urinary DES and IDES than healthy subjects or smokers with normal lung function. These results are consistent with the concept that COPD is associated with accelerated turnover of elastin fibres.…”

Impact of delivery mode of hyaluronan oligomers on elastogenic responses of adult vascular smooth muscle cells

“…Desmosine content was assayed by an ELISA method [25] to confirm the extent of crosslinking within the matrix elastin. Briefly, cell layers were scraped off, re-suspended in 1 ml of 5% v/ v trichloroacetic acid, and centrifuged (3000g, 10 min, 4 °C).…”