Angiogenesis-associated pathways play critical roles in neonatal sepsis outcomes.

Neonatal sepsis is a major cause of childhood mortality. Limited diagnostic tools and mechanistic insights have hampered our abilities to develop prophylactic or therapeutic interventions. Biomarkers in human neonatal sepsis have been repeatedly identified as associated with dysregulation of angiopoietin signaling and altered arachidonic acid metabolism. We here provide the mechanistic evidence in support of the relevance for these observations. Angiopoetin-1 (Ang-1), which promotes vascular integrity, was decreased in blood plasma of human and murine septic newborns. In preclinical models, administration of Ang-1 provided prophylactic protection from septic death. Arachidonic acid metabolism appears to be functionally connected to Ang-1 via reactive oxygen species (ROS) with a direct role of nitric oxide (NO). Strengthening this intersection via oral administration of arachidonic acid and/or the NO donor L-arginine provided prophylactic as well as therapeutic protection from septic death while also increasing plasma Ang-1 levels among septic newborns. Our data highlight that targeting angiogenesis-associated pathways with interventions that increase Ang-1 activity directly or indirectly through ROS/eNOS provide promising avenues to prevent and/or treat severe neonatal sepsis.

Changes in plasma concentrations of novel vascular and inflammatory biomarkers in obstructive sleep apnea patients pre- and post-stroke.

BACKGROUND: Obstructive sleep apnea (OSA) is increasingly recognized as a common condition in the general population and causes significant OSA-associated morbidities including cardiovascular and cerebrovascular events such as cerebral small vessel disease (CSVD) and stroke. METHODS: In this study, using sensitive ELISA immunoassays, we measured subset of endothelial/vascular and inflammatory biomarkers as well as neurofilament light chain (NfL), a sensitive marker for neuroaxonal injury, using plasma from OSA patients post-stroke (Acute Cerebral Infarction (ACI), N = 26) to determine their usefulness as potential prognostic markers in disease progression. RESULTS: Our results showed significantly increased plasma TNFα and NfL concentrations and decreased concentrations of platelet derived growth factor (PDGF-AA) in post-stroke OSA patients with more severe white matter hyperintensities (WMHs). And after separating the patients based on sex, compared to females, male post-stroke OSA patients with severe WMHs have increased circulating levels of inflammatory chemokine CXCL10 and cytokine Interleukin-10 (IL-10) and significantly decreased levels of Angiopoietin-1 (Ang-1) an important protein responsible for endothelial/vascular integrity functions. Importantly, in a subset of newly diagnosed OSA patients (without prior history of stroke), significantly increased plasma CXCL10 levels and decreased plasma Ang-1 levels were also readily observed when compared to healthy controls, indicating possible altered endothelial integrity and ongoing vascular inflammation in these newly diagnosed OSA patients. CONCLUSIONS: In summary, our study has identified a novel set of plasma biomarkers including PDGF-AA, CXCL10 and Ang-1 for their potential prognostic value for disease outcomes pre- and post-stroke in OSA patients and use as surrogate markers to measure efficacy of treatment modalities.

Myxomatous mitral valve disease and associated pulmonary hypertension might increase serum angiopoietin-2 in dogs.

OBJECTIVE: To evaluate the relationships between the severity of myxomatous mitral valve disease (MMVD) and pulmonary hypertension (PH) and serum angiopoietin (Ang)-1 and Ang-2 concentrations in dogs with MMVD. ANIMALS: 74 dogs (control, n = 12; MMVD, n = 62) were included. METHODS: Serum Ang-1 and Ang-2 concentrations were estimated using the canine-specific ELISA kit. The concentrations were compared between dogs with MMVD and healthy dogs, and they were analyzed according to the severity of MMVD and PH. RESULTS: The median serum Ang-1 concentration did not differ among the study groups. The median serum Ang-2 concentration was higher in dogs with stage B2 MMVD (P = .041) and acute congestive heart failure (P = .002) than in control dogs. In addition, the median serum Ang-2 concentration was higher in MMVD dogs with PH than in those without PH (P = .031). Serum Ang-2 concentration was correlated with vertebral heart score (rs = 0.36, P = .004) and vertebral left atrial score (r = 0.50, P < .001) in dogs with MMVD, and correlated with vertebral heart score (r = 0.63, P = .01), maximum E wave amplitude of the diastolic transmitral flow (rs = 0.61, P = .018), ejection fraction (rs = -0.77, P < .001) and fractional shortening (rs = -0.56, P = .032) in dogs with acute congestive heart failure. CLINICAL RELEVANCE: Circulating Ang-2 levels increase in dogs with the severity of MMVD and the presence of PH.

Angiogenic factors and the lectin pathway of complement in women with secondary recurrent pregnancy loss.

The poor remodeling of placental spiral arteries seen in preeclampsia is also discussed to contribute to recurrent pregnancy loss (RPL) preceded by abnormal angiogenesis and excessive complement activation. Low levels of Mannose-binding-lectin (MBL), a pattern recognition molecule (PRM) of the lectin pathway, have been found in women with RPL. We propose that pregnancy loss is connected to defective angiogenesis with reperfusion damage in the placenta and decreased levels of PRM in the lectin pathway in women with RPL. In this cohort study, we investigate the angiogenic factors and the lectin complement pathway in early pregnancy and their time-dependent relationship with pregnancy outcomes in 76 women with secondary RPL (sRPL) who have at least four prior pregnancy losses and a live birth. We evaluated levels of Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2), Vascular Endothelial Growth Factor (VEGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and the PRMs, MBL, ficolin-1, -2, -3 and an additional soluble PRM, Pentraxin-3, during the 5th, 6th, and 7th gestational weeks. Our results showed that, compared to live births, pregnancies that ended in loss were associated with elevated VEGF levels and decreased levels of the Ang-2/Ang-1 ratio. Also, increasing levels of ficolin-2 were significantly associated with pregnancy loss, with MBL showing no association. Our research suggests that women with sRPL may have inadequate placentation with impaired angiogenesis in pregnancies ending in a loss.

Angiopoietin as a Novel Prognostic Marker in Kidney Disease.

INTRODUCTION: Renal injury is among the leading causes of morbidity and mortality; however, there are no reliable indicators for determining the likelihood of developing chronic kidney disease (CKD), CKD progression, or AKI events. Vascular growth factors called angiopoietins have a role in endothelial function, vascular remodeling, tissue stabilization, and inflammation and have been implicated as prognostic and predictive markers in AKI. METHODS: Although the exact mechanism of the relationship between kidney injury and angiopoietins is unknown, this review demonstrates that AKI patients have higher angiopoietin-2 levels and that higher angiopoietin-1 to angiopoietin-2 ratio may potentially be linked with a reduced risk of the CKD progression. RESULTS: This review therefore emphasizes the importance of angiopoietin-2 and proposes that it could be an important predictor of AKI in clinical settings. CONCLUSION: There is a need for further large-scale randomized clinical trials in order to have a better understanding of the significance of angiopoietin-2 and for the determination of its potential clinical implications.

Angiopoietin-2/-1 ratios and MMP-3 levels as an early warning sign for the presence of giant cell arteritis in patients with polymyalgia rheumatica.

BACKGROUND: Diagnosing patients with giant cell arteritis (GCA) remains difficult. Due to its non-specific symptoms, it is challenging to identify GCA in patients presenting with symptoms of polymyalgia rheumatica (PMR), which is a more common disease. Also, commonly used acute-phase markers CRP and ESR fail to discriminate GCA patients from PMR and (infectious) mimicry patients. Therefore, we investigated biomarkers reflecting vessel wall inflammation for their utility in the accurate diagnosis of GCA in two international cohorts. METHODS: Treatment-naïve GCA patients participated in the Aarhus AGP cohort (N = 52) and the Groningen GPS cohort (N = 48). The AGP and GPS biomarker levels and symptoms were compared to patients presenting phenotypically as isolated PMR, infectious mimicry controls and healthy controls (HCs). Serum/plasma levels of 12 biomarkers were measured by ELISA or Luminex. RESULTS: In both the AGP and the GPS cohort, we found that weight loss, elevated erythrocyte sedimentation rate (ESR) and higher angiopoietin-2/-1 ratios but lower matrix metalloproteinase (MMP)-3 levels identify concomitant GCA in PMR patients. In addition, we confirmed that elevated platelet counts are characteristic of GCA but not of GCA mimicry controls and that low MMP-3 and proteinase 3 (PR3) levels may help to discriminate GCA from infections. CONCLUSION: This study, performed in two independent international cohorts, consistently shows the potential of angiopoietin-2/-1 ratios and MMP-3 levels to identify GCA in patients presenting with PMR. These biomarkers may be used to select which PMR patients require further diagnostic workup. Platelet counts may be used to discriminate GCA from GCA look-alike patients.

Plasma ratio of angiopoietin-2 to angiopoietin-1 is a biomarker of vascular impairment in chronic obstructive pulmonary disease patients.

Chronic obstructive pulmonary disease (COPD) patients have an increased risk of cardiovascular disease. Muscle biopsies have revealed that the muscle vasculature in COPD patients was characterized by a capillary rarefaction with reduced pericyte coverage. Thus, an imbalance of the plasma Angiopoietin-1 / Angiopoietin-2 (Ang2/Ang1) ratio could constitute a non-invasive marker of the muscle vascular impairment. In 14 COPD patients (65.5±5.1-year-old) and 7 HC (63.3±5.8-year-old), plasma samples were obtained at 3 time-points: before, after 5 weeks (W5), and after 10 weeks (W10) of exercise training. COPD patients showed a muscle capillary rarefaction at baseline with a reduced capillary coverage at W5 and W10. The plasma Ang2/Ang1 ratio was significantly higher in COPD patients vs. HC during the training (Group: p=0.01). The plasma Ang2/Ang1 ratio was inversely correlated with the pericyte coverage index regardless of the time period W0 (r=-0.51; p=0.02), W5 (r=-0.48; p=0.04), and W10 (r=-0.61; p<0.01). Last, in ECFC/MSC co-cultures exposed to the W10 serum from COPD patients and HC, the plasma Ang2/Ang1 at W10 were inversely correlated with calponin staining (r=-0.64. p=0.01 and r= 0.71. p<0.01, Fig. 1B), in line with a role of this plasma Ang2/Ang1 in the MSC differentiation into pericytes. Altogether, plasma Ang2/Ang1 ratio could constitute a potential marker of the vascular impairment in COPD patients.

Proximal heat stress up-regulates angiopoietin-1 in fingers and reduces the severity of Raynaud's phenomenon in systemic sclerosis: a single-centre pilot study.

OBJECTIVES: Raynaud's phenomenon (RP) is a peripheral vascular disorder that frequently occurs in systemic sclerosis (SSc). Although therapeutic heating seems reasonable given that RP is elicited by cold stimuli, the effects of heating are still unclear. We examined the effects of heating applied on various body parts in SSc patients with RP of fingers. METHODS: Fourteen SSc patients heated their neck, elbows, and wrists with disposable heating pads for 1 week each. The visual analogue scale (VAS) for RP during each heating period was compared with that of each 1-week pre-treatment interval. On the day after the expiration of each heating period, their finger temperature, the finger blood flow, and angiogenesis-related factors (vascular endothelial growth factor, endostatin, angiopoietin-1, and angiopoietin-2) obtained from the cubital vein and fingertip were measured. RESULTS: The mean VAS was significantly reduced during the heating of the neck and elbows. Fingertip blood samples showed significantly increased angiopoietin-1 after each of the heating periods and increased endostatin after wrist heating. After the termination of heating, changes in finger temperature or blood flow could not be detected. CONCLUSIONS: Heating the neck or elbows can alleviate RP in SSc. The heat up-regulates angiopoietin-1 in the fingers.

Diagnostic and prognostic significance of serum angiopoietin-1 and -2 concentrations in patients with pulmonary hypertension.

Several biomarkers for detecting pulmonary hypertension (PH) have been reported. However, these biomarkers are deemed insufficient to detect PH in its early stages. We evaluated the utility of serum angiopoietin (ANGP), a glycoprotein related to angiogenesis, as a diagnostic and prognostic biomarker of PH. Patients with PH who underwent right-heart catheterization, were retrospectively studied. Serum concentrations of ANGP-1 and ANGP-2 were measured using an enzyme-linked immunosorbent assay in patients with PH (n = 32), those with idiopathic pulmonary fibrosis (IPF) without PH (as a disease control, n = 75), and age-matched healthy controls (HC, n = 60). Nineteen patients (59.4%) with PH had World Health Organization group 3 PH. Serum ANGP-2 concentration, but not ANGP-1, in patients with PH was significantly higher compared with that in HC (p = 0.025) and in patients with IPF without PH (p = 0.008). Serum ANGP-2 concentration in patients with PH positively and significantly correlated with N-terminal pro-B-type natriuretic peptide (r = 0.769, p < 0.001), right ventricular diameter on echocardiography (r = 0.565, p = 0.035), and mean pulmonary arterial pressure (r = 0.449, p = 0.032) and pulmonary vascular resistance (r = 0.451, p = 0.031) on right-heart catheterization. ANGP-1 and ANGP-2 were expressed on lung vascular endothelial cells, as shown by immunohistochemistry. Patients with PH with higher ANGP-2 concentration (≥ 2.48 ng/mL) had significantly worse survival (p = 0.022). Higher ANGP-2 concentration was a significant worse prognostic factor (hazard ratio = 6.063, p = 0.037), while serum ANGP-1 concentration was not. In conclusion, serum ANGP-2 may be a useful diagnostic and prognostic biomarker in patients with PH, especially in patients with group 3 PH.

Circulating lncRNAs HIF1A-AS2 and LINLK-A: Role and Relation to Hypoxia-Inducible Factor-1α in Cerebral Stroke Patients.

Long noncoding RNAs (lncRNAs) have been recently recognized as key players of gene expression in cerebral pathogenesis. Thus, their potential use in stroke diagnosis, prognosis, and therapy is actively pursued. Due to the complexity of the disease, identifying stroke-specific lncRNAs remains a challenge. This study investigated the expression of lncRNAs HIF1A-AS2 and LINK-A, and their target gene hypoxia-inducible factor-1 (HIF-1) in Egyptian stroke patients. It also aimed to determine the molecular mechanism implicated in the disease. A total of 75 stroke patients were divided into three clinical subgroups, besides 25 healthy controls of age-matched and sex-matched. Remarkable upregulation of lncRNA HIF1A-AS2 and HIF1-α along with a downregulation of lncRNA LINK-A was noticed in all stroke groups relative to controls. Serum levels of phosphatidylinositol 3-kinase (PI3K), phosphorylated-Akt (p-Akt), vascular endothelial growth factor (VEGF), and angiopoietin-1 (ANG1) as well as their receptors, malondialdehyde (MDA), and total antioxidant capacity (TAC) were significantly increased, whereas brain-derived neurotrophic factor (BDNF) levels were significantly decreased particularly in hemorrhagic stroke versus ischemic groups. Eventually, these findings support the role of lncRNAs HIF1A-AS2 and LINK-A as well as HIF1-α in activation of angiogenesis, neovascularization, and better prognosis of stroke, especially the hemorrhagic type.

Role of endothelial biomarkers in predicting acute kidney injury in Bothrops envenoming.

Acute kidney injury (AKI) is a frequent and potentially fatal complication of snakebites. In the setting of snakebites, endothelial biomarkers may be used to predict disease severity and can play a major role in AKI pathophysiology. The aim of this study was to investigate the potential role of endothelial biomarkers in predicting AKI in Bothrops envenoming. Therefore, blood and urine samples were collected from 26 patients admitted to the emergency department after Bothrops envenoming at 3 different post-bite points in time: on admission (up to 8 h post-bite), 12-16 h, and 24-28 h post-bite, to investigate the time course of endothelial biomarkers in AKI following Bothrops snakebites. The diagnostic performance of injury biomarkers in Bothrops envenomation was evaluated. AKI was diagnosed using the Kidney Disease Improving Global Outcomes (KDIGO) criteria. There was an association between endothelial injury and increased risk for AKI in bothropic envenoming. Angiopoietin- 1 (Ang-1) and Vascular cell adhesion protein-1 (VCAM-1) were useful biomarkers to predict mild AKI [AUC-ROC: Ang-1 0.82, VCAM-1 0.76] within the interval of 8-16 h post Bothrops snakebites. The use of endothelial biomarkers VCAM-1 e Ang-1 within 12-16 h post-bite may be useful in the early stage of mild AKI related to Bothrops envenoming and might have an effect on the early intervention for renal protection in less severe Bothrops-related AKI.

Angiopoietin-2 as a Prognostic Factor in Patients with Incurable Stage IV Colorectal Cancer.

PURPOSE: Angiopoietin (Ang), a ligand of the endothelium-specific receptor Tie-2 system, is associated with tumor growth and progression that depend on angiogenesis. The present study aimed to investigate the predictive potential of angiopoietin factors in incurable stage IV colorectal cancer (CRC) patients who have undergone primary tumor resection. METHODS: The study included 40 consecutive patients with incurable stage IV CRC who underwent primary tumor resection at our hospital between 2011 and 2015. Patients were divided into subgroups of low and high Ang-1, Ang-2, and Tie-2. Patient age and sex, tumor location, TNM stages, vascular invasion, chemotherapy, and overall survival were assessed. RESULTS: The cut-off values of Ang-1, Ang-2, and Tie-2 were 0.4, 1.8, and 15.0 ng/mL, respectively. Overall survival was significantly longer in the low Ang-2 group than in the high Ang-2 group. High Ang-2 levels were associated with age, N stage, and chemotherapy. Immunofluorescent staining of Ang-2 revealed that endothelial cells and cancer cells expressed Ang-2 in each case. CONCLUSIONS: Our findings suggest that the serum Ang-2 level is associated with disease progression and is an important predictor of mortality in incurable stage IV CRC patients. Thus, it may be a useful prognostic biomarker in these patients.

Autotaxin Activity Predicts 30-Day Mortality in Sepsis Patients and Correlates With Platelet Count and Vascular Dysfunction.

OBJECTIVES: We investigated whether platelet count associated with biomarkers of endothelial function, and additionally sought to identify novel predictors of outcomes in a cohort of patients with severe sepsis at a quaternary care academic medical center. DESIGN: Prospective, observational cohort. PATIENTS: Eighty-six sepsis patients admitted into intensive care units were prospectively enrolled into an on-site sepsis registry and biobank. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Platelet count, mean platelet volume, platelet mass, plasma angiopoietin-1 and angiopoietin-2, syndecan-1, platelet factor 4, sCD40L concentrations, and plasma autotaxin activity were determined for each patient at enrollment. Patient mortality was recorded up to 30 days following hospital discharge. Platelet count and plasma sCD40L was significantly lower in patients who did not survive up to 30 days following hospital discharge. Angiopoietin-2 and the angiopoietin-2/1 ratio were significantly higher in patients who did not survive up to 30 days following discharge. Furthermore, plasma autotaxin activity was significantly higher in patients who did not survive up to 30 days. Interestingly, autotaxin activity correlated with platelet count and the ratio of angiopoietin-2/1 across our population. CONCLUSIONS: Platelet count, the ratio of angiopoietin-2/1, and autotaxin activity all predicted 30-day mortality. Autotaxin activity within the plasma correlates with both platelet counts and vascular dysfunction biomarkers across both survivors and non-survivors indicating a possible involvement of autotaxin within sepsis.

Evaluation of Angiopoietins 1 and 2 in Malaria-Infested Children.

Background: Malaria could affect people of all ages, most especially young children. The study evaluated the levels of serum angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) which are critical regulators of endothelial activation and integrity with some hematological parameters (total white blood cell counts (WBC), total red blood cell counts (RBC), platelet counts, and malaria parasite density) in malaria-infected children. Method: A total of 92 blood samples from children between the ages of 6 months to 15 years were analyzed. The samples consisted of 30 cases of severe malaria, 40 cases of uncomplicated malaria, and 22 apparently healthy subjects served as control. Serum Ang-1 and -2 levels were determined using the enzyme-linked immunosorbent assay technique. The hematological parameters were determined using the WHO standard. Results: There was significant decrease (p < 0.05) in serum Ang-1 of uncomplicated malaria and severe malaria compared with the control, while significant increase (p < 0.05) was observed in Ang-2 and Ang-2/Ang-1 ratio in uncomplicated malaria and severe malaria compared with the control. RBC and platelet showed significant decrease, while WBC showed significant increase in severe malaria compared with uncomplicated malaria and control. Conclusion: This study showed that subjects with malaria infection had a significant increase of Ang-2 and Ang-2 : Ang-1 ratio but presented with a significant decrease of Ang-1. Ang-1 and Ang-2 may be used to determine the severity of malaria infection since their levels differ significantly in malaria subjects compared with the control.

Temporal Dysregulation of the Angiopoietin-2/-1 Ratio After Trauma and Associations With Injury Characteristics and Outcomes.

Traumatic injury and hemorrhagic shock result in endothelial cell activation and vascular dysfunction that, if not corrected, can propagate multiorgan failure. Angiopoietin-1 and angiopoietin-2 are important regulators of endothelial cell function, and the ratio of plasma angiopoietin-2-to-1 is a useful indicator of overall vascular health. We therefore characterized plasma angiopoietin-2/-1 ratios over time after trauma in adults in an effort to gain insight into the pathophysiology that may drive post-traumatic vasculopathy and organ injury. We performed a single-center prospective observational study to measure plasma angiopoietin-1 and -2 levels and determine angiopoietin-2/-1 ratios in adult trauma patients upon hospital arrival and after 12, 24, and 48 h. Compared with levels in healthy adults, angiopoietin-1 levels were significantly elevated at hospital arrival, and angiopoietin-2 levels were significantly elevated at 12, 24, and 48 h. These kinetics translated in angiopoietin-2/-1 ratios that were significantly greater than controls at 24 and 48 h. After regression analysis, elevated angiopoietin-2 levels were independently associated with blunt injuries at admission, with coagulopathy at admission and 12 h, and with hemorrhagic shock at 24 and 48 h. Significant correlations were observed between both angiopoietins and 24-h transfusion requirements. Angiopoietin-2/-1 ratios correlated with mechanical ventilation duration and intensive care unit and hospital lengths of stay. In this study, we demonstrate novel temporal associations between angiopoietin dysregulation and blunt injuries, acute coagulopathy, and hemorrhagic shock. Moreover, our findings highlight the presence of endothelial activation following traumatic insults in adults that may contribute to worse clinical outcomes.

Association of Angiopoietin Dysregulation in Placental Malaria with Adverse Birth Outcomes.

Malaria in pregnancy causes adverse birth outcomes due to sequestration of Plasmodium falciparum-infected erythrocytes in the placenta. Angiopoietins are critical regulators of vascular development and formation of placental villous vasculature. Angiopoietin-1 and Angiopoietin-2 concentrations were measured in peripheral and placental plasma samples from 70 malaria-infected and 216 control women using commercially available DuoSet ELISA development kit. Angiopoietins increased in placental plasma (ANG1-5833.5 pg/ml and ANG2-9580.6 pg/ml) as compared to peripheral plasma (ANG1-2293.1 pg/ml and ANG2-1198.9 pg/ml, p < 0.0001). The concentration of placental and peripheral ANG1 (6099.23 pg/ml and 2320.5 pg/ml) was significantly lower (5013.5 pg/ml, 2208.5 pg/ml), and ANG2 (9553.3 pg/ml, 1180.92 pg/ml) was significantly higher (9664.6 pg/ml, 1254.4 pg/ml) in malaria-positive cases as compared to malaria-negative (p < 0.0001). The association of dysregulated angiopoietins in malaria with adverse birth outcomes showed that the peripheral and placental ANG1 concentration was lower and ANG2 concentration was higher in low-birth-weight baby and stillbirth birth outcome as compared to normal deliveries among malaria-positive group. Therefore, ANG1 and ANG2 could be considered a biomarker for adverse outcome during malaria in pregnancy.

The ratio of plasma angiopoietin-2 to angiopoietin-1 as a prognostic biomarker in patients with sepsis.

BACKGROUND: We aimed to investigate the role of angiopoietin (Angpt) as a predictive biomarker for sepsis by evaluating associations between plasma Angpt and various inflammatory cytokines and mortality in critically ill patients with sepsis. METHODS: This study was a retrospective cohort study of the prospectively collected samples and clinical data of 145 patients with sepsis who were admitted to the medical intensive care unit (ICU) of a 2000-bed university tertiary referral hospital in South Korea. We collected plasma within 24 h of medical ICU admission, and several biomarkers (Angpt-1 and -2, Tie2, vascular endothelial growth factor, interleukin (IL)-1ß, IL-10, IL-18, IL-6, interferon gamma-induced protein-10, and tumor necrosis factor-α) were measured using a Human Magnetic Luminex Screening Assay kit. RESULTS: Plasma Angpt-2 was correlated with IL-6 (rs = 0.555) and tumor necrosis factor-α (rs = 0.559). Plasma Angpt-2 (rs = 0.530) and Angpt-2/1 (rs = 0.562) were correlated with the Sequential Organ Failure Assessment (SOFA) score. The area under the curve (AUC) for the 28-day mortality prediction for the plasma Angpt-2/1 ratio was 0.736; AUCs for the Acute Physiology and Chronic Health Evaluation II (APACHE II) and SOFA scores were 0.659 and 0.745, respectively. Using multivariate Cox proportional hazard regression analysis for 28-day mortality, we found that acute respiratory distress syndrome (hazard ratio (HR) = 2.235, 95% CI = 1.163-4.296,p = 0.016), APACHE II score (HR = 1.127, 95% CI = 1.037-1.224,p = 0.005), and Angpt-2/1 > 3.2 (HR = 2.522, 95% CI = 1.205-5.278,p = 0.014) were risk factors for 28-day mortality. CONCLUSIONS: Plasma Angpt-2 was related to cytokines, but Angpt-2/1 ratio was a good predictor of 28-day mortality in patients with sepsis.

Hereditary angioedema attack: what happens to vasoactive mediators?

Hereditary angioedema is a disabling, life-threatening condition caused by deficiency (type I) or dysfunction (type II) of the C1 inhibitor protein (C1-INH-HAE) leading to bradykinin accumulation and recurrent episodes of edema attack. Vascular leakage is a complex process sustained by the coordinated production of several permeabilizing factors including vascular endothelial growth factors (VEGFs), angiopoietins (ANGPTs) and phospholipase A2 enzymes (PLA2). We previously reported that patients with C1-INH-HAE in remission have increased plasma levels of VEGFs, ANGPTs and secreted PLA2. In this study, we sought to analyze plasma levels of these mediators in 15 patients with C1-INH-HAE during the acute attack compared to remission. Plasma concentrations of VEGF-A, VEGF-C and VEGF-D were not altered during attack compared to remission. Moreover, VEGF-D concentrations were not altered also in remission phase compared to controls. Concentrations of ANGPT1, a vascular stabilizer, were increased during attacks compared to symptoms-free periods, whereas ANGPT2 levels were not altered. The ANGPT2/ANGPT1 ratio was decreased during angioedema attacks. Platelet activating factor acetylhydrolase activity was increased in patients with C1-INH-HAE in remission compared to controls and was decreased during angioedema attacks. Our results emphasize the complexity by which several vasoactive mediators are involved not only in the pathophysiology of C1-INH-HAE, but also during angioedema attacks and its resolution.

Angiotensin-Converting Enzyme Inhibitor-Associated Angioedema: From Bed to Bench.

BACKGROUND AND OBJECTIVE: Angiotensin-converting enzyme inhibitor-associated angioedema (ACEI-AAE) affects 0.1%-0.7% of patients treated with ACEIs. While previous research suggests that angioedema attacks result from increased vascular permeability, the pathogenesis is not completely understood. Objective: This study aimed to describe the clinical, genetic, and laboratory parameters of ACEI-AAE patients and to investigate the role of vascular endothelial growth factors A and C (VEGF-A and VEGF-C), angiopoietins 1 and 2 (Ang1/Ang2), and secretory phospholipase A2 (sPLA2) in the pathogenesis of ACEI-AAE. METHODS: The clinical and laboratory data of ACEI-AAE patients were collected from 2 angioedema reference centers. Healthy volunteers and ACEI-treated patients without angioedema were enrolled to compare laboratory parameters. Genetic analyses to detect mutations in the genes SERPING1, ANGPT1, PLG, and F12 were performed in a subset of patients. RESULTS: A total of 51 patients (57% male) were diagnosed with ACEI-AAE. The average time to onset of symptoms from the start of ACEI therapy was 3 years (range, 30 days-20 years). The most commonly affected sites were the lips (74.5%), tongue (51.9%), and face (41.2%). Switching from ACEIs to sartans was not associated with an increased risk of angioedema in patients with a history of ACEIAAE. VEGF-A, VEGF-C, and sPLA2 plasma levels were higher in ACEI-AAE patients than in the controls. Ang1/2 concentrations remained unchanged. No mutations were detected in the genes analyzed. CONCLUSIONS: Our data suggest that sartans are a safe therapeutic alternative in ACEI-AAE patients. Increased concentrations of VEGF-A, VEGF-C, and sPLA2 in ACEI-AAE patients suggest a possible role of these mediators in the pathogenesis of ACEI-AAE.

In Vivo Imaging of the Buccal Mucosa Shows Loss of the Endothelial Glycocalyx and Perivascular Hemorrhages in Pediatric Plasmodium falciparum Malaria.

Severe malaria is mostly caused by Plasmodium falciparum, resulting in considerable, systemic inflammation and pronounced endothelial activation. The endothelium forms an interface between blood and tissue, and vasculopathy has previously been linked with malaria severity. We studied the extent to which the endothelial glycocalyx that normally maintains endothelial function is involved in falciparum malaria pathogenesis by using incident dark-field imaging in the buccal mucosa. This enabled calculation of the perfused boundary region, which indicates to what extent erythrocytes can permeate the endothelial glycocalyx. The perfused boundary region was significantly increased in severe malaria patients and mirrored by an increase of soluble glycocalyx components in plasma. This is suggestive of a substantial endothelial glycocalyx loss. Patients with severe malaria had significantly higher plasma levels of sulfated glycosaminoglycans than patients with uncomplicated malaria, whereas other measured glycocalyx markers were raised to a comparable extent in both groups. In severe malaria, the plasma level of the glycosaminoglycan hyaluronic acid was positively correlated with the perfused boundary region in the buccal cavity. Plasma hyaluronic acid and heparan sulfate were particularly high in severe malaria patients with a low Blantyre coma score, suggesting involvement in its pathogenesis. In vivo imaging also detected perivascular hemorrhages and sequestering late-stage parasites. In line with this, plasma angiopoietin-1 was decreased while angiopoietin-2 was increased, suggesting vascular instability. The density of hemorrhages correlated negatively with plasma levels of angiopoietin-1. Our findings indicate that as with experimental malaria, the loss of endothelial glycocalyx is associated with vascular dysfunction in human malaria and is related to severity.