Elevated Elastase Levels Research Articles

The Role of Neutrophils and Neutrophil Elastase in Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is a severe vasculopathy characterized by the presence of fibrotic lesions in the arterial wall and the loss of small distal pulmonary arteries. The vasculopathy is accompanied by perivascular inflammation and increased protease levels, with neutrophil elastase notably implicated in aberrant vascular remodeling. However, the source of elevated elastase levels in PAH remains unclear. A major source of neutrophil elastase is the neutrophil, an understudied cell population in PAH. The principal function of neutrophils is to destroy invading pathogens by means of phagocytosis and NET formation, but proteases, chemokines, and cytokines implicated in PAH can be released by and/or prime and activate neutrophils. This review focuses on the contribution of inflammation to the development and progression of the disease, highlighting studies implicating neutrophils, neutrophil elastase, and other neutrophil proteases in PAH. The roles of cytokines, chemokines, and neutrophil elastase in the disease are discussed and we describe new insight into the role neutrophils potentially play in the pathogenesis of PAH.

Neutrophil activation in ivermectin-treated onchocerciasis patients.

Ivermectin is a safe and effective drug for onchocerciasis treatment. In certain individuals, however, therapy is accompanied by adverse reactions. The mechanisms underlying these reactions are not yet known. The aim of the present study was to investigate whether neutrophils are involved in the development of these adverse reactions. Elastase and lactoferrin, two markers for the release of neutrophil azurophilic and specific granule contents respectively, were measured by radioimmunoassays in plasma of onchocerciasis patients with varying degrees of side effects, as well as in control subjects before and 1 and 2 days after ivermectin treatment. A considerable increase of elastase levels after treatment was observed, whereas lactoferrin levels did not change. The percentage of patients with elevated elastase levels was significantly correlated with the degree of side effects. These findings suggest that neutrophil activation may be involved in the development of adverse reactions in these patients.

Temporal changes in factors associated with neutrophil elastase and coagulation in intensive care patients with a biphasic waveform and disseminated intravascular coagulation

Summary. The biphasic waveform is an early marker of disseminated intravascular coagulation (DIC). Neutrophil elastase (NE) cleaves coagulation factors; thus, elevated elastase levels or its dysregulation by alpha-1-protease inhibitor (Alpha1PI) may be linked to DIC. Time courses over a period were determined for factors associated with NE and coagulation in 14 Intensive Care Unit patients with a biphasic waveform who developed DIC. The data were analyzed using a random coefficient linear regression model to predict the variables' mean values on day 0 and their mean rates of change over the period in which the biphasic waveform appeared. The biphasic waveform was normal on day 0, maximized on day 1, and approached normal again by day 4. Alpha1PI/NE complex levels were 2.5-fold greater than normal for the entire period. The A1PI activity, antigen, and specific activity levels were normal on day 0 and increased thereafter by 21.0, 10.5, and 8.9% of normal per day, respectively. Factor II, V, VII, IX, and X activity levels were, respectively, 57, 46, 46, 77, and 46% of normal on day 0, whereas factor VIII and fibrinogen levels were normal. All coagulation factor levels trended upward with time but not significantly. The prothrombin time, but not the activated partial thromboplastin time, was prolonged, and the platelet counts and hematocrits were below normal on day 0 and remained so thereafter. We conclude that events associated with neutrophil activation, elastase release, and perturbations of coagulation precede both the appearance of the biphasic waveform and the diagnosis of DIC in these patients.

115 Carbohydrate‐based Wound Dressings with Elastase‐lowering Activity

The use of carbohydrate‐based wound dressings including cotton, xerogels, charcoal cloth, alginates, and hydrogels, for chronic wounds have afforded properties such as absorbency, ease of application and removal, bacterial protection, fluid balance, occlusion, and elasticity. An additional consideration is the use of the dressing to regulate proteolysis in the non‐healing wound. Elastase is a serine protease that has been associated with a variety of inflammatory diseases, and recently has been implicated as a destructive protease that impedes wound healing. The presence of elevated levels of elastase in non‐healing wounds has been associated with the degradation of important growth factors and fibronectin necessary for wound healing. Here we consider the design, preparation, and assessment of carbohydrate‐based wound dressings that either release protease inhibitors or act as sequestering agents to bind proteases such as elastase and thus reduce their high levels in the chronic wound. Carbohydrates ranging from small monosaccahrides up to large polysaccharides are crosslinked onto cotton wound dressings. The resulting carbohydrate conjugates of cotton cellulose possess unique properties advantageous for chronic wound treatment ranging from gelation and elasticity to elastase‐sequestering propertiesType in text here making sure it is in a single column format.

Plasma proteins modified by tyrosine nitration in acute respiratory distress syndrome.

The present study identifies proteins modified by nitration in the plasma of patients with ongoing acute respiratory distress syndrome (ARDS). The proteins modified by nitration in ARDS were revealed by microsequencing and specific antibody detection to be ceruloplasmin, transferrin, alpha(1)-protease inhibitor, alpha(1)-antichymotrypsin, and beta-chain fibrinogen. Exposure to nitrating agents did not deter the chymotrypsin-inhibiting activity of alpha(1)-antichymotrypsin. However, the ferroxidase activity of ceruloplasmin and the elastase-inhibiting activity of alpha(1)-protease inhibitor were reduced to 50.3 +/- 1.6 and 60.3 +/- 5.3% of control after exposure to the nitrating agent. In contrast, the rate of interaction of fibrinogen with thrombin was increased to 193.4 +/- 8.5% of the control value after exposure of fibrinogen to nitration. Ferroxidase activity of ceruloplasmin and elastase-inhibiting activity of the alpha(1)-protease inhibitor in the ARDS patients were significantly reduced (by 81 and 44%, respectively), whereas alpha(1)-antichymotrypsin activity was not significantly altered. Posttranslational modifications of plasma proteins mediated by nitrating agents may offer a biochemical explanation for the reported diminished ferroxidase activity, elevated levels of elastase, and fibrin deposits detected in patients with ongoing ARDS.

Elastin degradation in the superficial temporal arteries of patients with intracranial aneurysms reflects changes in plasma elastase.

alpha 1-Antitrypsin (AAT) and alpha 2-macroglobulin (AMG) are elastase inhibitors that bind the enzyme and reduce measured levels of free elastase. It was recently demonstrated that some patients with intracranial aneurysms have significantly elevated plasma elastase (PE) levels. Although this elevation is unrelated to plasma AAT, it is unknown whether abnormal AAT phenotypes or reduced AMG levels play a role. Moreover, the pathological significance of this elevation is not understood. Plasma from 24 patients with aneurysms (ruptured, n = 15; unruptured, n = 9) and 10 age-matched patients who comprised a control group was analyzed for PE and AMG levels by enzyme-linked immunosorbent assay and for AAT phenotype by isoelectric focusing. Sections of superficial temporal temporal artery obtained from these patients at the time of surgery were examined for evidence of elastin degradation by using a van Gieson stain, with scoring on a nine-point quantitative scale. Patients with aneurysms showed significantly elevated PE levels (119 +/- 28 versus 17 +/- 7 micrograms/ml, P < 0.05), but AMG levels were not decreased. AAT phenotypic abnormalities were observed in 10% (2 of 20) of the patients with aneurysms, but this was not different from the expected population incidence (7%). Elastin degradation scores were significantly higher in patients with aneurysms than in patients control group (4.26 +/- 0.54 versus 1.21 +/- 0.43, P < 0.05). In addition, patients with higher elastase levels (> 80 micrograms/ml) demonstrated 55% higher degradation scores than did those with lower elastase levels (< 80 micrograms/ml). These data suggest that high PE levels may play a role in systemic arterial elastin degradation seen in patients with intracranial aneurysms. These data also support the contention that elevated elastase levels are not the result of decreased protease inhibitor levels. Although PE levels were significantly higher for the entire group of patients with aneurysms, this assay has relatively low sensitivity for predicting the presence of unruptured aneurysms. Additional study is necessary to determine whether serum elastase levels greater than 80 micrograms/ml, in the setting of other risk factors, are useful in identifying asymptomatic patients for additional screening.

Neutrophil and cytokine activation with neonatal extracorporeal membrane oxygenation

To determine whether extracorporeal membrane oxygenation (ECMO), like cardiopulmonary bypass, produces systemic inflammatory responses that could potentiate organ injury in infants with respiratory failure. We evaluated the effects of neonatal ECMO on neutrophil surface adherence proteins, elastase release, and cytokine levels in blood samples from 15 patients before and during ECMO, and from banked blood and ECMO circuit blood before cannulation. Neutrophil elastase, tumor necrosis factor alpha, and interleukin types 1 beta, 6, and 8 were measured. Chest radiographs were evaluated by a radiologist using a lung injury score in blinded fashion. Primed ECMO circuit blood, in comparison with patient pre-ECMO blood, demonstrated marked up-regulation of CD11b (mean fluorescence intensity 1660 +/- 109 vs 361 +/- 81; p < 0.001 (mean +/- SEM)), shedding of L-selectin (mean fluorescence intensity 10 +/- 2 vs 89 +/- 38; p < 0.01), and elevated elastase levels (349 +/- 76 vs 154 ng/ml +/- 38; p < 0.001), consistent with neutrophil activation. During ECMO, neutrophil CD11b levels increased but L-selectin was not significantly shed. Concentrations of circulating neutrophil elastase increase significantly during ECMO. Corrected circulating quantities of interleukin-8 also rose significantly, but the responses of tumor necrosis factor alpha and interleukin-1 beta were minimal. Radiographic lung injury scores worsened with the initiation of ECMO (median score: 6 before ECMO vs 11 in first hour of ECMO; p = 0.012), in conjunction with indicators of neutrophil activation. Neonates with respiratory failure have activation of the inflammatory cascade. ECMO incites additional neutrophil and cytokine activation in association with early pulmonary deterioration. Routine leukodepletion of blood for circuit priming to remove activated neutrophils may be beneficial.

Fibronectin Degradation in Chronic Wounds Depends on the Relative Levels of Elastase, α1-Proteinase Inhibitor, and α2-Macroglobulin

The goal of our studies was to learn about the mechanism of fibronectin degradation in chronic ulcers. We found that the appearance of fibronectin fragments in chronic ulcer wound fluid correlated with elevated levels of elastase and cleavage of the proteinase inhibitors alpha2-macroglobulin (alpha2-M) and alpha 1-proteinase inhibitor (alpha1-P1). Some wound fluid samples retained the capacity to degrade fibronectin in vitro. Degradation of fibronectin by these samples was blocked by specific inhibitors of neutrophil elastase but not by inhibitors of metalloproteinases. Addition of human neutrophil elastase to mastectomy fluid, an acute wound fluid, resulted in formation of alpha1-PI and alpha2-M complexes and cleavage products resembling those observed in chronic wound fluid. Moreover, degradation of fibronectin and processing of matrix metalloproteinase MMP-9 occurred under these conditions. Taken together, our findings suggest that elevated levels of neutrophil elastase are responsible for fibronectin degradation in the chronic wound environment.

Neutrophil activation and the acute phase response in ivermectin treated onchocerciasis

After treatment, a rise of elastase levels was observed, which correlated with the severity of side effects (p <0.02, multivariance analysis). Also, a significant correlation bet­ ween the percentage of patients with elevated elastase levels and the grade of side effects was found (p < 0.0001, X2 trend test). Contrary to elastase, lactoferrin levels did not change significantly after ivermectin treatment. In none of the patients tested were elevated IL-8 levels found. C-reactive protein levels increased in all patient groups after ivermectin treatment, but not in the control group. Again, the C-reactive protein rise was associated with the degree of side effects (p < 0.0001, Kruskal-Wallis test). In 45 % of the patients with raised CRP, IL-6 levels were also elevated. Also, the percentage of patients with increased IL-6 levels correlated with the grade of adverse reactions (p < 0.0001.

Mediators of leukocyte activation play a role in disseminated intravascular coagulation during orthotopic liver transplantation.

Leukocytes play an important role in the development of disseminated intravascular coagulation (DIC). In the reperfusion phase of OLT a DIC-like situation has been described and has been held responsible for the high blood loss during this phase. We investigated the role of leukocytes in the pathogenesis of DIC in OLT by measuring the leukocytic mediators released upon activation (cathepsin B, elastase, TNF, neopterin) and the levels of thrombin-antithrombin III (TAT) complexes, seen as markers of prothrombin activation. Arterial blood samples were taken at 10 different time points during and after OLT. Samples were also taken of the perfusate released from the liver graft vein during the flushing procedure before the reperfusion phase. Aprotinin was given as a continuous infusion (0.2-0.4 Mill. KIU/hr) and its plasma levels were determined. Significantly elevated levels of neopterin (15-fold; P < 0.01), cathepsin B (440-fold; P < 0.01) in the perfusate, as compared with the systemic circulation, as well as their significant increases in the early reperfusion phase suggested that they were released by the graft liver. This was paralleled by elevated levels of elastase (1.3-fold, P < 0.05), TNF (1.5-fold, P = NS), and TAT complexes (1.4-fold; P < 0.1) in the perfusate. Significant correlations could be identified between the parameters of leukocyte activation and TAT complexes, whereas no correlation was observed between any of the parameters investigated and the aprotinin levels. Our results strongly indicate a release of leukocytic mediators from the graft liver during its reperfusion which seems to be related to the parallely increased prothrombin activation. No correlation could be seen between levels of aprotinin and levels of leukocytic mediators.

Effect of cardiopulmonary bypass on systemic release of neutrophil elastase and tumor necrosis factor

Leukocyte counts, plasma neutrophil elastase, tumor necrosis factor-alpha and C-reactive protein were determined serially in 19 patients undergoing elective coronary artery surgery with cardiopulmonary bypass. Neutrophil counts (mean +/- standard deviation 3.85 +/- 1.20 x 10(9)/L preoperatively) peaked 4 hours postoperatively at 10.35 +/- 4.24 x 10(9)/L (p < 0.001) and remained significantly elevated 48 hours postoperatively at 7.80 +/- 2.70 x 10(9)/L, p < 0.05. Plasma neutrophil elastase level (187 +/- 74 ng/ml preoperatively) peaked at 698 +/- 323 ng/ml at the end of surgery (p < 0.001) and remained significantly elevated at 424 +/- 146 ng/ml 48 hours postoperatively (p < 0.01). Peak elastase levels correlated significantly with duration of bypass (r = 0.47, n = 19, p < 0.05). Monocyte counts (0.29 +/- 0.19 x 10(9)/L preoperatively) peaked 4 hours postoperatively (0.87 +/- 0.41 x 10(9)/L, p < 0.001) and fell to baseline levels by 48 hours postoperatively. Plasma tumor necrosis factor-alpha, detectable in 10 of the 19 patients preoperatively (median 0.39 U/ml, range up to 10.1 U/ml), did not change significantly during or after bypass. Plasma C-reactive protein level (median 1.67 [range 0.69 to 34.33] micrograms/ml preoperatively) rose significantly to 3.99 (range 1.95 to 12.55) micrograms/ml 4 hours postoperatively (p < 0.01) and rose 48 hours postoperatively at 303 (210 to 410) micrograms/ml, p < 0.001. Oxygenation, determined by the respiratory index, was impaired at the end of operation (2.07 +/- 0.82) and remained impaired 24 hours postoperatively (2.48 +/- 0.83). Impairment of oxygenation was temporally related to elevated elastase levels, but neither peak elastase levels nor the change in elastase levels with lung reperfusion correlated significantly with the area under the respiratory index curve up to 6 hours postoperatively. This study demonstrates neutrophil elastase release during cardiopulmonary bypass but fails to show a definite role for neutrophil activation or tumor necrosis factor-alpha in the etiology of pulmonary dysfunction after cardiopulmonary bypass.

Elastase activity in leukaemic cells and plasma in patients with acute leukaemia.

Proteolysis of coagulation factors and inhibitors resulting in haemorrhage can be mediated by elastase. Indirect signs of this are elevated levels of elastase complexed to its inhibitor in plasma, alpha 1-antitrypsin (E alpha 1-AT). We have measured intracellular elastase activity in leukaemic cells from 60 patients with acute leukaemia. Elastase activity was detected in 92% of the patients with acute nonlymphoblastic leukaemia (ANL), no activity was found in the patients with acute lymphoblastic leukaemia (ALL). High levels were found in cells from patients with promyelocytic leukaemia. Moderate to high total circulating blast elastase activity was measured in 70% of the ANL patients with haemorrhage compared with 36% of the patients without bleeding complications (p < 0.05). The available intracellular elastase activity was correlated to the level of E alpha 1-AT (rs = 0.42, p < 0.01) but not to the elastase specific split product of fibrinogen, B beta 30-43. In complete remission the levels of E alpha 1-AT were normalized. Intracellular elastase activity might be a useful supplement to differentiate ANL and ALL.

Phenotypic comparison of Pseudomonas aeruginosa strains isolated from a variety of clinical sites

Pseudomonas aeruginosa elaborates a number of extracellular products which have been shown to play a role in the pathogenesis of disease caused by this organism. In this study, we showed that the host environment markedly affects the levels of exoproducts produced. We compared the phenotypes of a number of P. aeruginosa strains obtained from a variety of clinical sources, including burn wounds, skin wounds, urine, cystic fibrosis sputum, acute pneumonia sputum, and blood. The clinical isolates were examined quantitatively for levels of total protease, elastase, phospholipase C, exotoxin A, and exoenzyme S produced in vitro under defined conditions. The exoproduct levels varied significantly, depending on the site of isolation. Elevated levels of elastase were demonstrated in strains isolated from acute lung infections, phospholipase C levels were elevated in urinary tract and blood isolates, exotoxin A levels were elevated in blood isolates, and exoenzyme S levels were increased in acute pneumonia isolates. Isolates from cystic fibrosis sputum produced low amounts of virtually all of the tested exoproducts, particularly as compared with sputum isolates from acute P. aeruginosa lung infections.