Key, Nigel S.

ABSTRACT Background: Damage-associated molecular patterns (DAMPs) stimulate endothelial syndecan-1 shedding and neutrophil extracellular traps (NET) formation. The role of NETs in trauma and trauma-induced hypercoagulability is unknown. We hypothesized that trauma patients with accelerated thrombin generation would have increased NETosis and syndecan-1 levels. Methods: In this pilot study, we analyzed 50 citrated plasma samples from 30 trauma patients at 0 h (n = 22) and 6 h (n = 28) from time of injury (TOI) and 21 samples from healthy volunteers, for a total of 71 samples included in analysis. Thrombin generation was quantified using calibrated automated thrombogram (CAT) and reported as lag time (LT), peak height (PH), and time to peak (ttPeak). Nucleosome calibrated (H3NUC) and free histone standardized (H3Free) ELISAs were used to quantify NETs. Syndecan-1 levels were quantified by ELISA. Results are presented as median [interquartile range] and Spearman rank correlations. Results: Plasma levels of H3NUC were increased in trauma patients as compared with healthy volunteers both at 0 h (89.8 ng/mL [35.4, 180.3]; 18.1 ng/mL [7.8, 37.4], P = 0.002) and at 6 h (86.5 ng/mL [19.2, 612.6]; 18.1 ng/mL [7.8, 37.4], P = 0.003) from TOI. H3Free levels were increased in trauma patients at 0 h (5.74 ng/mL [3.19, 8.76]; 1.61 ng/mL [0.66, 3.50], P = 0.002) and 6 h (5.52 ng/mL [1.46, 11.37]; 1.61 ng/mL [0.66, 3.50], P = 0.006). Syndecan-1 levels were greater in trauma patients (4.53 ng/mL [3.28, 6.28]; 2.40 ng/mL [1.66, 3.20], P < 0.001) only at 6 h from TOI. H3Free and syndecan-1 levels positively correlated both at 0 h (0.376, P = 0.013) and 6 h (0.583, P < 0.001) from TOI. H3NUC levels and syndecan-1 levels were positively correlated at 6 h from TOI (0.293, P = 0.041). TtPeak correlated inversely to H3 NUC (−0.358, P = 0.012) and syndecan-1 levels (−0.298, P = 0.038) at 6 h from TOI. Conclusions: Our pilot study demonstrates that trauma patients have increased NETosis, measured by H3NUC and H3Free levels, increased syndecan-1 shedding, and accelerated thrombin generation kinetics early after injury.

AbstractHigher and lower hemoglobin concentrations are associated with coronary heart disease (CHD), but whether this risk is consistent across age, sex, and race is unclear. The Reasons for Geographic And Racial Differences in Stroke (REGARDS) study is an observational cohort study of 30 239 black, and white, adults aged 45 and older recruited 2003‐7. Participants were included if they had hemoglobin measures, were CHD‐free at baseline, and had all baseline variables. The primary outcome was incident CHD. Multivariable Cox proportional hazards models were used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) for incident CHD by hemoglobin concentration. This was expressed as a continuous variable and divided into age‐, sex‐, and race‐specific quintiles. The 16 332 participants were included, contributing 114 362 person‐years of follow‐up and 915 incident CHD events. The mean age was 63 years, 35% were male, 41% were black, and the mean baseline hemoglobin was 13.6 g/dL (SD 1.4). A significant non‐linear association between hemoglobin and CHD was identified (P < .001). This association differed significantly by race (P = .025) but not by sex or age. In whites, the risk for incident CHD was higher in the lowest (HR 2.28, 95% CI 1.61, 3.33) and highest (HR 1.94, 95% CI 1.35, 2.79) hemoglobin quintiles relative to the third quintile. For blacks, only those in the lowest hemoglobin quintile had an increased risk for incident CHD events (HR 1.70, 95% CI 1.20, 2.41). Hemoglobin is an independent risk factor for CHD in whites and blacks but with different hemoglobin concentrations conferring different risks.

Abstract Background: Compared to Whites, Black-Americans may have a 40% higher incidence of idiopathic VTE. However, whether other VTE characteristics vary by race is uncertain. Objective: To compare demographic and baseline characteristics among White- and Black-Americans with VTE. Methods: Using a standardized data-collection form, demographic and baseline characteristics were prospectively collected from consecutive consenting patients enrolled in seven Thrombosis and Hemostasis Centers from August 2003 to March 2008. For patients with objectively diagnosed VTE, demographic and baseline characteristics were compared among White- and Black-American VTE patients, both overall, and by age and gender. Results: Among 1960 White- and 368 Black-Americans with VTE, compared to Whites, Blacks had significantly less isolated DVT (73.9% vs. 86.5%, p<0.001) and significantly more PE ± DVT (45.1 vs. 39.6%, p=0.05). Blacks and Whites did not differ in mean age (43.4 vs. 44.3 years), but a significantly higher proportion of Black men VTE patients were in age groups 20–39 and 80+ years. Blacks and Whites differed significantly by gender, with a significantly higher proportion of Black women with VTE (69.8% vs. 59.1%, p=0.0001). Blacks had a significantly higher mean BMI (32.3 vs. 29.4 kg/m2, p<0.0001), a significantly lower proportion with recent surgery or trauma, active cancer and infection, and a significantly lower proportion with a family history of VTE or documented thrombophilia (solely due to reduced Factor V Leiden and Prothrombin G20210A prevalence). Conversely, Blacks had a significantly higher proportion with hypertension, hyperlipidemia, diabetes mellitus, chronic renal disease and dialysis, HIV and sickle cell disease. The two races did not differ significantly regarding the proportion with idiopathic VTE, CHF, CAD/MI, peripheral artery disease, stroke or other chronic neurological disease (i.e., cerebral palsy), chronic liver disease or autoimmune disease, including antiphospholipid syndrome. Compared to White women VTE patients, Black women VTE patients had a significantly lower proportion with recent surgery, trauma, infection, oral contraceptive use and possibly hormone therapy; and a significantly higher proportion with idiopathic VTE, hypertension, diabetes mellitus, chronic renal disease, HIV and sickle cell disease. Compared to White men VTE patients, Black men VTE patients did not differ significantly regarding recent surgery, trauma, cancer, infection or autoimmune disease, but Black men had a significantly higher proportion with hypertension, diabetes mellitus, HIV and sickle cell disease. Black and White men with VTE did not differ significantly regarding idiopathic VTE, CHF, CAD/MI, stroke, peripheral arterial disease and chronic renal disease. Conclusion: White- and Black-Americans with VTE differ significantly regarding demographic and baseline characteristics that may be risk factors for VTE.