Endothelial Dysfunction and Pentraxin-3 in Clinically Stable Adult Asthma Patients.

BACKGROUND AND OBJECTIVE: Asthma is associated with low-grade systemic inflammation, prothrombotic state, and premature atherosclerosis. Objective: To evaluate the relationships between asthma, inflammatory biomarkers, and parameters of endothelial dysfunction. MATERIAL AND METHODS: We analyzed flow-mediated dilatation (FMD) of the brachial artery and intima-media thickness (IMT) of the common carotid artery using ultrasound in 92 clinically stable adult asthmatics and 62 well-matched controls. We also measured blood levels of selected inflammatory and asthma-specific biomarkers, including interleukin (IL) 4, IL-5, IL-6, IL-10, IL-12 (p70), IL-17A, IL-23, and interferon γ, as well as a disintegrin and metalloproteinase domain-containing protein 33 (ADAM-33). In addition, we assessed endothelial damage using 2 laboratory biomarkers: circulating von Willebrand factor (vWF) and pentraxin-3. We analyzed relationships between the study variables and asthma severity, lung function abnormalities, airway remodeling indices on computed tomography, and transthoracic echocardiography parameters. RESULTS: Asthmatics had higher IL-6, IL-10, and ADAM-33 levels. They were also characterized by 23% lower FMD% and 15% thicker IMT, as compared with controls (P<.001, both). In asthma, vWF was related to age (ß=0.28 [95%CI, 0.15-0.41]) and remained inversely associated with FEV1 (ß=-0.2 [95%CI, -0.05 to -0.35]). Surprisingly, a negative correlation was revealed between vWF and pentraxin-3 (ß=-0.17 [95%CI, -0.3 to -0.04]). Pentraxin-3 remained positively associated with airway remodeling indices. CONCLUSIONS: Asthma is characterized by endothelial dysfunction associated with airway obstruction. The biological role of pentraxin-3 is unknown, although our data suggest a protective role against endothelial damage and atherosclerosis.

Asthma is associated with enhanced thrombin formation and impaired fibrinolysis.

BACKGROUND: There is evidence that altered blood coagulation and fibrinolysis are involved in the pathogenesis of asthma. Increased thromboembolic risk has been reported in asthmatics. OBJECTIVE: To investigate whether enhanced thrombin generation and impaired fibrinolysis occur in asthmatics. METHODS: Plasma thrombin generation profile together with a computational assessment of thrombin dynamics and fibrinolytic capacity expressed as clot lysis time (CLT) were determined in 164 consecutive patients with stable asthma and 72 controls matched for age, gender, weight and smoking. RESULTS: Asthma patients had 20.2% increased endogenous thrombin potential (ETP), 41.4% higher peak thrombin concentration, 61% higher maximal prothrombin conversion rate, 15.5% faster rate of thrombin formation (all, P < 0.0001) and 10% lower thrombin decay capacity (P = 0.0004) compared with controls. Asthmatics had also 14.4% longer CLT (P = 0.001) associated with 21.3% higher plasminogen activator inhibitor-1 (PAI-1) (P < 0.0001), and 13% higher plasma α2 -macroglobulin (P = 0.0002). Using ETP and CLT above 75th percentile of the control values as the cut-off levels, we found increased risks of enhanced thrombin generation and hypofibrinolysis in asthmatics, also after correction for potential confounders. ETP and CLT were associated inversely with forced expiratory volume in 1 s/vital capacity (FEV1 /VC) index, after adjustment for age and body mass index. Non-allergic asthma (n = 70, 42.6%) was characterized by 17.5% longer CLT (P = 0.02), which positively associated with PAI-1. Thrombin generation profile was not affected by allergy. CONCLUSION AND CLINICAL RELEVANCE: Asthma is associated with enhanced thrombin generation and impaired fibrinolysis, which might contribute to thromboembolic events in this disease.

Collagen receptors α(1)ß(1) and α(2)ß(1) integrins are involved in transmigration of peripheral blood eosinophils, but not mononuclear cells through human microvascular endothelial cells monolayer.

UNLABELLED: Asthma development may be driven by T helper lymphocytes with eosinophils playing the role of major effector cells. Recruitment of the inflammatory cells from blood to the airways is mediated by adhesive molecules, e.g. selectins and integrins. The most important in cell trafficking are integrins containing α(4) and ß(2) subunits. We hypothesized that also collagen receptors: α(1)ß(1) and α(2)ß(1), may be involved in cell migration to the inflammatory site in asthma. The aim of the study was to determine whether the inhibition of α(1)ß(1) or α(2)ß(1) integrins, affects transmigration of eosinophils and peripheral blood mononuclear cells (PBMC) through human microvascular endothelial cells monolayer (HMVEC) seeded on collagen IV coated wells in moderate persistent atopic asthmatics. METHODS: PBMC from 9 asthmatics were separated by gradient centrifugation followed by negative magnetic separation of eosinophils. Snake venom derived anti-adhesive proteins: viperistatin and VP12 (potent and selective inhibitors of α(1)ß(1) and α(2)ß(1) integrins, respectively) as well as VLO4 (a non-selective inhibitor of α(4)ß(1), α(5)ß(1) and α(v)ß(3) - used as a positive control), were used for inhibition studies. All anti-adhesive proteins studied, inhibited eosinophils, but only VLO4 affected PBMC transmigration through HMVEC. In bronchial asthma both collagen receptors α(1)ß(1) and α(2)ß(1) are likely to be involved in eosinophil transmigration to the inflammatory site. The role of α(2)ß(1) on lymphocytes is probably different. As the α(2)ß(1) integrin has been described as a stimulator of collagen accumulation, it might be, at least in part, responsible for asthma airway remodelling.