desmosine and Lung-Diseases--Obstructive

We investigated whether MR889, a synthetic cyclic thiolic elastase inhibitor, administered for a period of 4 weeks to chronic obstructive pulmonary disease (COPD) patients, is well-tolerated, and whether it modifies biochemical indices of lung destruction. The study was a double-blind, randomized, placebo-controlled clinical trial in COPD patients. Thirty subjects were administered MR889 orally at a dose of 500 mg b.i.d. for 4 weeks, and 30 received placebo following the same schedule. In addition to safety parameters, MR889 efficacy was checked by a pretreatment/postreatment evaluation of levels of plasma elastin-derived peptides and urinary desmosine. There were no statistically significant differences between pretreatment and posttreatment efficacy parameter levels either in the control group or in the treated group. However, in a subset of treated patients with a short disease duration, the level of urinary desmosine dropped significantly with respect to pretreatment values (p = 0.004). We conclude that MR889 is safe to administer to COPD patients for a period of at least 4 weeks. During this time, MR889 does not modify biochemical markers of lung destruction in unselected COPD patients. Nevertheless, a subset of treated patients with fairly short disease duration showed a post-treatment reduction of desmosine urine levels, thus justifying the need for further studies to prove the efficacy of MR889 in modulating indices of lung destruction in COPD.

Topics: Aged; Desmosine; Double-Blind Method; Drug Administration Schedule; Elastin; Female; Humans; Leukocyte Elastase; Lung Diseases, Obstructive; Male; Protease Inhibitors; Thiophenes; Time Factors

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 alpha1-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< or =0.05). The highest desmosine levels were found in subjects with alpha1-antitrypsin deficiency, bronchiectasis and cystic fibrosis (p<0.001 versus stable COPD). In a short-term 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 alphal-antitrypsin deficiency suggest that this method might be used to evaluate the putative efficacy of replacement therapy.

Topics: Adult; Aged; Aged, 80 and over; alpha 1-Antitrypsin Deficiency; Bronchiectasis; Cross-Linking Reagents; Cross-Sectional Studies; Cystic Fibrosis; Desmosine; Elastin; Electrophoresis, Capillary; Emphysema; Extracellular Matrix; Female; Humans; Isodesmosine; Longitudinal Studies; Lung Diseases, Obstructive; Male; Middle Aged

Neutrophil elastase is involved in the pathogenesis of several pulmonary diseases; a strategy for monitoring in vivo elastase activity is to measure changes in biochemical markers. The objective of this study was to determine whether differences in the urinary excretion of the elastin crosslinks, desmosine and isodesmosine (which are unique amino acid products of elastase activity), could be discerned between groups of patients with chronic obstructive pulmonary disease (COPD) or cystic fibrosis (CF), and non-diseased, age-matched controls. Twenty-four-hour urine collections were analysed to eliminate variations in excretion throughout the day, and urine was collected on four separate days in 29-31 subjects/group to investigate the variability in desmosines excretion among the groups. Both sets of patient populations had significantly more variable desmosines readings (higher standard deviations) relative to their respective age-matched control group. The means for three adult groups (COPD, controls and a COPD-smoker subset) ranged from 28.4 to 35.5 pmol desmosines/mg creatinine and there were no differences among the groups. Values in children were higher: 55 pmol desmosines/mg creatinine in the non-CF children and 77 pmol desmosines/mg creatinine for the CF group (P<0.01 vs. age-matched controls). The results of this study show that urinary desmosines, as a surrogate marker for enhanced elastase activity, are more highly variant in both patient populations relative to age-matched controls, and an overall increase in the mean value is further observed in patients with cystic fibrosis.

Topics: Biomarkers; Case-Control Studies; Child; Cystic Fibrosis; Desmosine; Female; Humans; Isodesmosine; Leukocyte Elastase; Lung Diseases, Obstructive; Male; Middle Aged

The presence in urine of desmosine (DES) and isodesmosine (IDES), two crosslinked amino acids unique to the elastic fiber network, can be used as a specific indicator of degradation of mature elastin. Compared to methodologies so far available, the capillary electrophoretic technique reported here seems to be suitable and convenient for determining desmosines in urine of patients affected by chronic obstructive pulmonary disease (COPD). By using 35 mM sodium tetraborate pH 9.3 containing 65 mM SDS as the background electrolyte, the peaks of DES and IDES could be detected in hydrolyzed urine samples from controls and patients. Owing to the simultaneous determination of endogenous urinary creatinine used as appropriate internal standard, the amount of these amino acids could be accurately quantified. The results obtained were of the same order of magnitude as the data already reported in the literature for COPD patients. Thus micellar electrokinetic chromatography (MEKC) may be considered as a reliable technique for studying the turnover of the elastic fiber in clinical conditions.

Topics: Biomarkers; Chromatography, Micellar Electrokinetic Capillary; Desmosine; Humans; Isodesmosine; Lung Diseases, Obstructive; Spectrophotometry, Ultraviolet

It has been hypothesized that emphysema results from damage to the elastic fiber network of the lungs as a result of elastase-antielastase imbalance. We used a new assay for urinary desmosine (DES) and isodesmosine (IDES), specific markers for the degradation of mature crosslinked elastin, and hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP), specific markers for the degradation of mature crosslinked collagen, in order to examine elastin and collagen degradation in relation to current cigarette smoking and the presence of chronic obstructive pulmonary disease (COPD). The study sample consisted of 22 never-smokers (NSM group), 13 current smokers without airflow obstruction (SM group), and 21 patients with COPD (COPD group), including both current and former smokers. The relation between the creatinine-height index and FEV1 was used to correct for possible loss of muscle mass and decreased excretion of creatinine in the COPD group. Mean urinary excretion of elastin-derived crosslinks in the COPD group (DES, 11.8 +/- 5.1 [mean +/- SD]; IDES, 11.3 +/- 5.0 micrograms/g creatinine) and in the SM group (DES, 11.0 +/- 4.2; IDES, 10.2 +/- 2.5 micrograms/g creatinine) was significantly higher than in the NSM group (DES, 7.5 +/- 1.4; IDES, 6.9 +/- 1.3 micrograms/g creatinine). In multivariate analysis, current smoking and the presence of COPD were significantly and independently associated with higher urinary excretion of elastin degradation products, and there was no significant interaction between current smoking and the presence of COPD.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Amino Acids; Biomarkers; Collagen; Desmosine; Elastin; Female; Humans; Isodesmosine; Lung Diseases, Obstructive; Male; Middle Aged; Prospective Studies; Smoking

Topics: Amino Acids; Creatine; Desmosine; Enzyme-Linked Immunosorbent Assay; Humans; Lung Diseases, Obstructive

Desmosine is a cross-link amino acid unique to elastin. Previous work has shown that during turnover in the body, desmosine is not reused, and that desmosine is not absorbed from the intestine. Instead, all desmosine released in the course of elastin metabolism is excreted in the urine attached to low molecular weight peptides. Therefore, measurement of desmosine in acid-hydrolysates of urine might be used to monitor elastin breakdown in several pathologic states, including pulmonary emphysema. In the present report, we have described a sensitive, highly specific radioimmunoassay capable of detecting as little as 200 pg of desmosine in acid-hydrolysates of urine. The assay was specific for desmosine; cross-reactivity with merodesmosine, isodesmosine, lysine, and mixed amino acids was 0.25%, 0.1%, less than 0.0003%, and 0%, respectively. Twenty-three normal, nonsmoking subjects had a mean 24-hr desmosine excretion of 47 +/- 15 microgram. In a group of smokers with evidence of chronic obstructive disease and/or lung infection, the values for desmosine excretion ranged from 40 to 400 microgram/24 h. Desmosine radioimmunoassay may find application in the study of diseases involving increased destruction of elastin in the body.

Topics: Adolescent; Adult; Aged; Amino Acids; Desmosine; Elastin; Humans; Lung Diseases, Obstructive; Middle Aged; Radioimmunoassay; Smoking