Coagulation activation and inflammation in sickle cell disease-associated pulmonary hypertension

BACKGROUND: Pulmonary hypertension (PHT) is common in sickle cell disease (SCD). The purpose of this study was to determine whether markers of coagulation activation and inflammation are associated with PHT in SCD. DESIGN AND METHODS: This cross-sectional study was performed using a cohort of patients followed at an adult Sickle Cell Clinic. Pulmonary artery systolic pressure was determined by Doppler echocardiography, and the diagnosis of PHT was defined using age, sex and body mass index-adjusted reference ranges. Clinical laboratory examinations, including hematologic studies and biochemical tests, as well as various measures of coagulation activation, endothelial activation and inflammation, were conducted on SCD subjects and on healthy, race-matched control subjects without SCD. RESULTS: Patients with SCD (n=76) had higher plasma levels of markers of coagulation (thrombin-antithrombin complex, prothrombin fragment F1+2, D-dimer) and endothelial (soluble vascular endothelial cell adhesion molecule, sVCAM) activation compared with control subjects (n=6). SCD patients with PHT (n=26) had significantly higher levels of sVCAM compared with those patients without PHT (n=50). Although PHT patients showed increased plasma measures of coagulation activation, the differences were not statistically significant when compared to those of patients without PHT. HbSS patients with PHT also had a trend towards higher levels of other inflammatory cytokines (interleukins 6, 8 and 10) than HbSS patients without PHT. There was a modest negative correlation between hemoglobin and plasma measures of coagulation and endothelial activation, and modest positive correlations between markers of hemolysis and plasma measures of coagulation and endothelial activation. CONCLUSIONS: SCD patients with PHT have higher levels of markers of endothelial activation and other inflammatory markers than patients without PHT. A trend towards an increased level of markers of coagulation activation was observed in SCD patients with PHT compared with that in patients without PHT. Markers of hemolysis are associated with coagulation activation and endothelial dysfunction in SCD patients. Clinical trials of anticoagulants and anti-inflammatory agents are warranted in SCD patients with PHT

Longitudinal study of echocardiography-derived tricuspid regurgitant jet velocity in sickle cell disease

Although echocardiography-derived tricuspid regurgitant jet velocity (TRV) is associated with increased mortality in sickle cell disease (SCD), its rate of increase and predictive markers of its progression are unknown. We evaluated 55 subjects (median age: 38 years, range: 20 – 65 years) with at least 2 measurable TRVs, followed for a median of 4.5 years (range: 1.0 – 10.5 years) in a single-centre, prospective study. Thirty-one subjects (56%) showed an increase in TRV, while 24 subjects (44%) showed no change or a decrease in TRV. A linear mixed effects model indicated an overall rate of increase in the TRV of 0.02 m/s per year (p = 0.023). The model showed that treatment with hydroxycarbamide was associated with an initial TRV that was 0.20 m/s lower than no such treatment (p = 0.033), while treatment with angiotensin converting enzyme inhibitors and inhibitors/ angiotensin receptor blockers was associated with an increase in the TRV (p = 0.006). In summary, although some patients have clinically meaningful increases, the overall rate of TRV increase is slow. Treatment with hydroxycarbamide may decrease the progression of TRV. Additional studies are required to determine the optimal frequency of screening echocardiography and the effect of therapeutic interventions on the progression of TRV in SCD

Urinary Albumin Excretion is Associated with Pulmonary Hypertension in Sickle Cell Disease: Potential Role of Soluble Fms-Like Tyrosine Kinase-1

Pulmonary hypertension (PHT) is reported to be associated with measures of renal function in patients with sickle cell disease (SCD). The purpose of this exploratory study was to determine the relationship between albuminuria and both clinical and laboratory variables in SCD

Association of Coagulation Activation with Clinical Complications in Sickle Cell Disease

Background: The contribution of hypercoagulability to the pathophysiology of sickle cell disease (SCD) remains poorly defined. We sought to evaluate the association of markers of coagulation and platelet activation with specific clinical complications and laboratory variables in patients with SCD. Design and Methods: Plasma markers of coagulation activation (D-dimer and TAT), platelet activation (soluble CD40 ligand), microparticle-associated tissue factor (MPTF) procoagulant activity and other laboratory variables were obtained in a cohort of patients with SCD. Tricuspid regurgitant jet velocity was determined by Doppler echocardiography and the presence/history of clinical complications was ascertained at the time of evaluation, combined with a detailed review of the medical records. Results: No significant differences in the levels of D-dimer, TAT, soluble CD40 ligand, and MPTF procoagulant activity were observed between patients in the SS/SD/Sb 0 thalassemia and SC/Sb + thalassemia groups. Both TAT and D-dimer were significantly correlated with measures of hemolysis (lactate dehydrogenase, indirect bilirubin and hemoglobin) and soluble vascular cell adhesion molecule-1. In patients in the SS/SD/Sb 0 thalassemia group, D-dimer was associated with a history of stroke (p = 0.049), TAT was associated with a history of retinopathy (p = 0.0176), and CD40 ligand was associated with the frequency of pain episodes (p = 0.039). In multivariate analyses, D-dimer was associated with reticulocyte count, lactat

Pulmonary hypertension in sickle cell disease.

BACKGROUND: Recurrent vaso-occlusive episodes lead to progressive end-organ damage in patients with sickle cell disease. We sought to determine the prevalence of pulmonary hypertension in adult patients with sickle cell disease and to identify factors associated with this life-threatening complication. METHODS: Sixty patients (\u3e or =18 years of age; mean [+/- SD] age, 37 +/- 13 years) followed at a University Medical Center were evaluated. They were selected by a systematic sampling of patients presenting to the clinic for routine follow-up visits. All enrolled subjects underwent a clinical examination, Doppler echocardiography, pulmonary function tests, and hematologic tests during a single visit. Pulmonary hypertension was defined using an age- and body mass index-adjusted nomogram. RESULTS: The prevalence of pulmonary hypertension was 30% (18/60). Ten patients had mild pulmonary hypertension (up to 44 mm Hg), 5 had moderate pulmonary hypertension (45 to 74 mm Hg), and 2 had severe pulmonary hypertension (\u3e or =75 mm Hg). In a logistic regression model, both lower fetal hemoglobin level and lower systolic blood pressure were associated with the presence of pulmonary hypertension. CONCLUSION: We found that the prevalence of pulmonary hypertension in adult patients with sickle cell disease was substantial, particularly in those with lower levels of fetal hemoglobin and lower systolic blood pressure

TAT is correlated with D-dimer in sickle cell disease.

<p>Plasma TAT is significantly correlated with plasma D-dimer in our study cohort (r = 0.66; p<0.0001).</p

Multivariate Analysis.

<p>TAT – Thrombin-antithrombin complexes.</p><p>MPTF PCA – Microparticle-associated tissue factor procoagulant activity.</p><p>NT-proBNP – N-terminal pro-brain natriuretic peptide.</p

TAT is correlated with lactate dehydrogenase in sickle cell disease.

<p>TAT is correlated with lactate dehydrogenase in our study cohort (r = 0.57, p<0.0001).</p

D-dimer is correlated with lactate dehydrogenase in sickle cell disease.

<p>D-dimer is correlated with lactate dehydrogenase in our study cohort (r = 0.56; p<0.0001).</p

Correlation of Markers of Coagulation Activation with Laboratory Variables.

<p>TAT – Thrombin-antithrombin complexes.</p><p>NT-proBNP – N-terminal pro-brain natriuretic peptide.</p