Małgorzata Jasiewicz

Serum levels of CD163 and TWEAK in patients with pulmonary arterial hypertension

BACKGROUND Inflammation may play a pivotal role in the pathogenesis of pulmonary arterial hypertension (PAH). We evaluated the concentrations of serum sTWEAK, its scavenger receptor sCD163 and sTWEAK/sCD163 ratio in patients with PAH. DESIGN The study enrolled 26 stable patients with PAH confirmed by right heart catheterization and 24 healthy volunteers matched for age, sex and body weight. All patients underwent transthoracic echocardiography, cardiopulmonary exercise test, 6-min walk test, measurement of lung diffusing capacity for the carbon monoxide (DLCO) and venous blood tests. Concentrations of sTWEAK and sCD163 were determined using ELISA kits. RESULTS The PAH patients were characterized by significantly higher median serum sCD163 levels (1072 vs 890ng/ml, p=0.04) together with lower serum sTWEAK concentrations (200 vs 278.1pg/ml, p=0.003) comparing to control subjects. sTWEAK/sCD163 ratio was therefore significantly lower in PAH group (0.18 vs 0.33, p=0.0005). No correlation was found between sTWEAK and sCD163 concentrations in both groups. We observed statistically significant inverse correlation between peak VO2 consumption and sCD163 concentrations (r=-0.52, p<0.05) and positive with sTWEAK/sCD163 ratio (r=0.45, p<0.05) in PAH group. Moreover, sTWEAK/sCD163 ratio positively correlated with % of predicted values of DLCO (r=0.42, p<0.05). CONCLUSIONS Patients with PAH present altered serum sTWEAK and sCD163 levels. The sTWEAK/sCD163 ratio appears to be a better indicator of the severity of PAH as compared to sTWEAK or sCD163 alone. The exact role of sCD163 or interaction between CD163 and sTWEAK in the initiation or progression of PAH as well as their potential prognostic significance remains to be established.

Enhanced IL-6 trans-signaling in pulmonary arterial hypertension and its potential role in disease-related systemic damage.

BACKGROUND The role of IL-6 in pulmonary arterial hypertension (PAH) has been reported but the prevalence of soluble receptors for IL-6: sIL-6R and sgp130 and its potential role in PAH have not been studied.Our aim was to examine the IL-6 together with the soluble receptors and to assess its relationship with clinical status of PAH patients as well as to assess its potential prognostic significance. METHODS Serum concentrations of IL-6, sIL-6R and sgp130 were quantified by ELISA in 26 patients with PAH and 27 healthy controls and related to functional and biochemical parameters and clinical outcome in PAH group. The PAH patients were followed up for 1 year, noting the end point of clinical deterioration (WHO class change, the need for escalation of therapy) or death. RESULTS The PAH group was characterized by higher median serum IL-6 [2.38 (IQR 1.56-3.75) vs 0.87 (0.63-1.3) pg/ml, p=0.000003] and sIL-6R concentrations [69.7 (IQR 60.4-84.4 vs 45.7 (34.6-70.3) ng/ml, p=0.0036] compared to control subjects. Both groups did not differ in sgp130 concentrations. There were significant correlations in PAH group between IL-6 levels and uric acid, parameters of ventilatory efficiency in cardiopulmonary exercise testing: VE/VO2, VE/VCO2, VE/VCO2 slope and peak PetCO2. sIL-6R levels inversely correlated with LDL cholesterol. After 1 year the clinical deterioration occurred in 11 patients, 15 remained stable. Patients in whom the clinical deterioration occurred showed significantly higher baseline concentrations of IL-6 [3.25 (IQR 2.46-5.4) pg/ml vs 1.68 (1.38-2.78) pg/ml, p=0.004], but not sIL-6R. Median IL-6 ⩾ 2.3 pg/ml (91% sensitivity, 73% specificity) identified subjects with worse clinical course. In the univariate analysis, higher IL-6 level at baseline was associated with increased risk and earlier occurrence of clinical deterioration (HR 1.42, 95%CI 1.08-1.85, p=0.015). CONCLUSIONS IL-6 trans-signaling is enhanced in PAH. Elevated concentration of sIL-6R suggests its potential unfavorable role in systemic amplification of IL-6 signaling in PAH. Levels of IL-6 are associated with clinical indicators of disease severity as well as indirectly with systemic metabolic alterations. IL-6 shows prognostic value regarding predicting clinical deterioration.

Activity of the kynurenine pathway and its interplay with immunity in patients with pulmonary arterial hypertension

Objective We evaluated blood concentrations of kynurenine pathway metabolites, natural and induced regulatory T cells (nTreg, iTreg), and Th17 cells in order to examine the activity of the kynurenine pathway and its relation to immune status in patients with pulmonary arterial hypertension (PAH). Methods Plasma concentrations of tryptophan, kynurenine, kynurenic acid, anthranilic acid, and 3-hydroxykynurenine were quantified in 26 patients with PAH (vs 30 healthy controls) at baseline and after 6 months, and assessed them in relation to clinical parameters, frequencies of lymphocyte subsets, and outcome. Results The PAH group presented higher concentrations of tryptophan (52.9 (IQR 46.3–57.5) vs 40.3 (35.2–46.3) µmol/L, p=0.00003), kynurenine 2.8 (2.4−3.4) vs 1.9 (1.5–2.3) µmol/L, p=0.000007), kynurenine/tryptophan ratio (0.051 (0.044–0.064) vs 0.043 (0.039–0.055), p=0.03), iTreg frequencies (10.5 (8.8–13.9)% vs 6.8 (5.2–9.5)%, p=0.002) and iTreg/Th17 (1.73 (1.2–2.8) vs 0.93 (0.61–1.27), p=0.003) together with lower ratios of kynurenic acid/kynurenine, 3-hydroxykynurenine/kynurenine, and anthranilic acid/kynurenine. Kynurenine concentrations and kynurenine/tryptophan ratio correlated positively with iTreg/Th17, and inversely with Th17 subsets, whereas kynurenic acid/kynurenine and anthranilic acid/kynurenine ratios correlated positively with Th17. Adverse outcomes occurred in 9 of 26 patients and they showed higher baseline concentrations of kynurenine (3.6 (2.8–4.3) vs 2.7 (2.1–3.2) µmol/L, p=0.033). Median kynurenine values ≥3.4 µmol/L (67% sensitivity, 94% specificity) identified patients with a worse clinical course. Conclusions PAH is characterised by upregulated tryptophan metabolism and enhanced biosynthesis of kynurenine. Elevated kynurenine concentration is associated with an adverse clinical course. Dysregulated immunity, delineated by Treg-Th17 imbalance, is directly related to diverse activation of the kynurenine pathway, indicating the potential interplay between kynurenines and the immune system in PAH.

The significance of diminished sTWEAK and P-selectin content in platelets of patients with pulmonary arterial hypertension

HighlightsPatients with PAH present comparable serum sTWEAK concentrations as controls.Platelet content of TWEAK and P‐selectin is diminished in patients with PAH.Lower platelet TWEAK is associated with clinical indices of more advanced disease.Patients with lowest platelet TWEAK more frequently develop detoriation of PAH.sTWEAK secreted by platelets may affect PAH progression and prognosis. &NA; Pulmonary arterial hypertension (PAH) is a progressive disease characterized by proliferative changes in pulmonary arteries. There is growing evidence suggesting that soluble tumor necrosis factor‐like weak inducer of apoptosis (sTWEAK) and P‐selectin could be involved in PAH development and progression. Here we investigate whether circulating platelets may be a source of sTWEAK and contribute to diminished availability of sTWEAK and P‐selectin in PAH patients. We have prospectively enrolled two independent study groups of stable patients with confirmed PAH and age matched controls: derivation (10 PAH; 15 controls) and validation (20 PAH; 12 controls). P‐selectin and sTWEAK concentrations were measured in platelet‐poor plasma and platelet lysate. To avoid procedural bias, in each group we employed different protocols for platelet isolation. Consistently, both in derivation and validation groups PAH patients presented significantly lower sTWEAK content in platelets than control group with no significant differences in plasma levels. Similarly, patients presented comparable to controls plasma P‐selectin concentrations and lower concentration in platelet lysate. Kaplan‐Meier analysis revealed that patients with low platelet sTWEAK/total protein concentration ratio had more frequently detoriation of PAH in the follow‐up (16.51 ± 3.32 months), log‐rank test, p = .03. Patients diagnosed with pulmonary arterial hypertension present diminished sTWEAK and P‐selectin storage capacity in platelets. Thrombocytes appear to be a major source of sTWEAK that could be released upon local injury and its decreased availability could have an impact on pathophysiology and prognosis in PAH.

Increased Platelet Content of SDF-1alpha is Associated with Worse Prognosis in Patients with Pulmonary Arterial Hypertension

Abstract Inflammatory processes and platelet activity play an important role in the pathophysiology of pulmonary arterial hypertension (PAH). Enhanced IL-6 signaling and higher concentration of stromal-derived factor alpha (SDF-1) have been previously shown to be linked with prognosis in PAH. We hypothesized that platelets of PAH patients have higher content of IL-6 and SDF-1 and thus are involved in disease progression. We enrolled into study 22 PAH patients and 18 healthy controls. Patients with PAH presented significantly higher plasma concentrations and platelet contents of IL-6, sIL-6R, and SDF-1 than healthy subjects (platelet content normalized to protein concentration: IL-6 (0.85*10–10 [0.29 – 1.37] vs. 0.45*10–10 [0.19–0.65], sIL-6R 1.54*10–7 [1.32–2.21] vs. 1.14*10–7 [1.01–1.28] and SDF-1 (2.72*10–7 [1.85–3.23] vs. 1.70*10–7 [1.43–2.60], all p < 0.05). Patients with disease progression (death, WHO class worsening, or therapy escalation, n = 10) had a significantly higher platelet SDF-1/total platelet protein ratio (3.68*10–7 [2.45–4.62] vs. 1.69*10–7 [1.04–2.28], p = 0.001), with no significant differences between plasma levels. Kaplan–Meier analysis revealed that patients with higher platelet SDF-1/total platelet protein ratio had more frequently deterioration of PAH in the follow-up (15.24 ± 4.26 months, log-rank test, p = 0.01). Concentrations of IL-6, sIL-6 receptor and SDF-1 in plasma and platelets are elevated in PAH patients. Higher content of SDF-1 in platelets is associated with poorer prognosis. Our study, despite of limitation due to small number of enrolled patients, suggests that activated platelets may be an important source of cytokines at the site of endothelial injury, but their exact role in the pathogenesis of PAH requires further investigation.

LC–MS-based serum fingerprinting reveals significant dysregulation of phospholipids in chronic heart failure

HIGHLIGHTSChronic HF patients presented significant disturbances in phospholipids metabolism.Intensities of PCs, lyso‐PCs, lyso‐PEs were significantly decreased in HF patients.Greater reduction of phospholipids was associated with more advanced disease. ABSTRACT Cardiac and extracardiac lipid metabolism is known to be significantly altered in the course of the heart failure with reduced ejection fraction (HF‐REF), however the precise mechanisms are not fully elucidated. The aim of the study was to use of untargeted metabolomics to identify and validate changes in the blood metabolites profile, occurring as a result of HF‐REF development. The analyses were performed first in the derivation set (36 chronic HF‐REF patients and 19 controls without the disease) and repeated in validation cohort (31 chronic HF‐REF patients and 20 controls). Independent analyses of both sets revealed statistically significant decline in intensities of phosphatidylcholine (PC): 34:4 and 36:5, lysophosphatidylcholine (lyso‐PC): 14:0, 15:0, 18:0, 18:2, 20:3, lysophosphatidylethanolamine (lyso‐PE): 18:1 and 18:2 in chronic HF‐REF patients. More symptomatic patients and those with ischaemic etiology of HF‐REF presented greater deficit in phospholipids (PLs) intensities. The decrease of identified PLs intensities (as compared to controls) correlated with decreased serum cholesterol level, impaired renal function, reduced exercise capacity, enhanced ventilatory response and metabolic parameters associated with altered fatty acids oxidation. In multiple regression analysis PLs deficit was significantly associated with age, carnitines serum intensity, renal function, uric acid, cholesterol level. In conclusion, HF‐REF is associated with significant disturbances in phospholipids metabolism. Greater reduction in serum intensities of particular identified PLs is associated with older age, worse clinical condition, impaired oxidative muscle metabolism and enhanced catabolic status.

The strengths and weaknesses of non-invasive parameters obtained by echocardiography and cardiopulmonary exercise testing in comparison with the hemodynamic assessment by the right heart catheterization in patients with pulmonary hypertension

PURPOSE Pulmonary hypertension (PH) diagnosis requires invasive assessment by right heart catheterization (RHC), but screening and monitoring are performed using non-invasive methods: echocardiography and cardiopulmonary exercise testing (CPET). The aim of the study was to assess correlations between the parameters obtained in non-invasive testing and RHC in patients with PH of different etiologies. MATERIAL/METHODS The study included 53 medical records of PH patients (32 women) aged 29-81 years. We analyzed correlations between RHC (systolic pulmonary artery pressure (sPAP), diastolic pulmonary artery pressure (dPAP), pulmonary vascular resistance (PVR), cardiac output (CO)) and echocardiographic (tricuspid annular plane systolic excursion (TAPSE), sPAP) and CPET parameters (end-tidal oxygen and carbon dioxide pressures (PetO2, PetCO2), ventilation efficiency (VE/VCO2) slope). RESULTS Echocardiographic estimation correlated well with RHC measurement of sPAP (r=0.65, P<0.001). TAPSE correlated with PVR assessed with thermodilution method (r=-0.5, P=0.005), dPAP (r=-0.53, P=0.002) and CO (r=0.53, P=0.002). PVR assessed with thermodilution and Fick methods showed positive correlation with PetO2 (r=0.74, P<0.001 and r=0.72, P<0.001) and negative correlation with PetCO2 (r=-0.59, P=0.004 and r=-0.64, P=0.002) at the anaerobic threshold. VE/VCO2 slope correlated with dPAP (r=0.43, P=0.04) and PVR calculated with both methods (r=0.52, P=0.01 and r=0.52, P=0.02). CONCLUSIONS Simple cardiac function indicators obtained by commonly used non-invasive methods allow only approximate estimation of the main hemodynamic RHC-derived parameters: sPAP, CO and PVR. Obtained results suggest the relationship between RV dysfunction and ventilation abnormalities in PH patients.