Haptoglobin 1-1 Isoform Predicts Higher Serum Haptoglobin Concentration and Lower Multiorgan Failure Risk in Sickle Cell Disease

Haptoglobin (HP) is the major scavenger of cell-free hemoglobin in circulation. When haptoglobin is depleted, cell-free hemoglobin can lead to organ damage through direct oxidative injury, upregulation of inflammatory pathways, and depletion of nitric oxide. A common polymorphism in HP gives rise to structurally and functionally distinct phenotypes: HP 1-1, HP 2-1, and HP 2-2. In people of African descent, the HP 1-1 and 2-1 phenotypes have been associated with higher serum HP concentrations compared to the HP 2-2 phenotype (PMID 10807979). In hemolytic diseases, such as sickle cell disease (SCD), the consequence of the HP polymorphism is unclear but could influence cell-free hemoglobin processing and susceptibility to organ damage. We first investigated whether the HP isoforms are associated with HP concentrations at steady-state. Between 10/2009 and 6/2018, we recruited 431 SCD patients into a longitudinal registry at our institution during a routine clinic visit, which we defined as steady-state. Baseline clinical and laboratory data were collected at the time of enrolment. The median age of the cohort was 32 (interquartile range [IQR], 24 - 43) years, 43% were male, 76% were SCD SS or Sβ 0-thalassemia genotype, and 46% were on hydroxyurea at the time of enrolment. Genotyping of the HP polymorphisms by PCR demonstrated the HP 1-1 isoform in 30% (n = 129), the HP 2-1 isoform in 47% (n = 203), and the HP 2-2 isoform in 23% (n = 99) of the SCD cohort. Serum samples were available in 244 of the 431 SCD patients at steady-state. Serum concentrations of HP, measured by ELISA, were higher in those with the HP 1-1 isoform compared to the HP 2-1 or 2-2 isoform (Figure). In a linear regression model, independent variables associated with steady-state serum HP concentration included SCD SS or Sβ 0-thalassemia genotype (β -1.8; 95% CI: -2.5 to -1.0; P < 0.001), LDH (natural log β -0.9; 95% CI: -0.2 to -1.6; P = 0.018), hydroxyurea use (β 0.6; 95% CI: 0.1 to 1.1; P = 0.02), and HP 1-1 isoform (β 0.5, 95% CI: 0 to 1.1; P = 0.049), adjusting for age and sex. Between 9/2020 and 5/2021, we collected an additional 38 serum samples from SCD patients during a hospitalization for vaso-occlusive crisis (VOC) and serum samples from 7 SCD patients during a hospitalization for acute chest syndrome. The HP 1-1 isoform was associated with higher serum HP concentrations during VOC and during acute chest syndrome compared to the HP 2-1 or 2-2 isoforms (Figure). Interestingly, the serum HP trended higher from steady-state to VOC and to acute chest syndrome in SCD patients with the HP 1-1 isoform (β +1.1, P = 0.085) but trended lower in those with the HP 2-1 or 2-2 isoform (β -0.5, P = 0.099). Next we tested whether the HP 1-1 isoform is protective against multi-organ failure during hospitalizations for acute chest syndrome. For the longitudinal analysis, we focused on SCD patients with > 6 months of follow up at our institution (n = 391). A multiorgan failure event was defined as organ dysfunction involving at least 2 of the following organ systems: lung, kidney, liver, or central nervous system (PMID 8109600). With a median follow up of 6.8 (IQR, 3.5 - 8.9) years, we observed an acute chest syndrome episode complicated by multiorgan failure in 14% (53/391) of SCD patients. A significantly lower proportion of SCD patients with the HP 1-1 isoform developed a multiorgan failure event versus those with the 2-1 or 2-2 isoforms (5.7% vs. 17.2%, respectively; P < 0.001). On logistic regression analysis, acute chest syndrome with multiorgan failure was associated with the HP 1-1 isoform (OR 0.3, 95% CI: 0.1 to 0.6; P = 0.002) and baseline LDH (natural log OR 2.7, 95% CI: 1.2 - 6.3; P = 0.02), after adjusting for age, sex, SCD genotype and hydroxyurea use. In conclusion, we demonstrate that the HP 1-1 isoform is independently associated with higher serum HP concentrations at steady-state as well as during hospitalizations for VOC or acute chest syndrome compared to the HP 2-1 or 2-2 isoforms. Furthermore, the HP 1-1 isoform is protective against developing the devastating multiorgan failure syndrome during acute chest syndrome episodes. Our findings highlight the clinical significance of the HP isoforms and cell-free hemoglobin scavenging in SCD. Future studies assessing HP induction and scavenging function based on HP isoform may help elucidate high-risk patients for aggressive measures, such as rapid initiation of exchange transfusion therapy or HP replacement therapy. Figure 1 Figure 1. Disclosures Gordeuk: Modus Therapeutics: Consultancy; Novartis: Research Funding; Incyte: Research Funding; Emmaus: Consultancy, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; CSL Behring: Consultancy. Saraf: Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Research Funding; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Gravel Mining Activity Impact on Riverbed Erosion and Bridge Foundation Stability

Geomorphological processes pose a risk that deserves attention and planning to avoid that, especially in the section near to east of Tuz bridge. This section of the valley facing a dramatic increase in gravel excavation and sorting of aggregates, consequence led to a change in the pattern of river branches flow from an anabranching river to a single-channel river, which led to a concentration of river discharge during floods. On 9th December 2018, Tuz Bridge was failed due to a heavy rainstorm three days preceding the failure event. The current study aims to conduct a field survey of all the human activities in the study area to assess river changes from remote sensing data the amount of runoff and river peak discharge based on rainfall data using SCS-CN method. In this study, ArcGIS, ArcGIS Earth, Google Earth, and WMS software are incorporated in the data analysis. The revealed results indicate the severe modification of valley morphology and converting the river pattern to flow during flood within a single channel with flow speed exceeded the critical velocity to induce vertical erosion of gravel and sands under the foundations of the bridge and causing the displacement and settlement of the bridge. The study recommends the local administration prevent gravel mining from the river valley at the upstream area of the bridge

Characteristics and Outcomes of Patients With Heart Failure With Reduced Ejection Fraction After a Recent Worsening Heart Failure Event

Background Contemporary trials of patients with heart failure with reduced ejection fraction (HFrEF) required a recent worsening heart failure (WHF) event for inclusion. We aimed to describe characteristics and outcomes of patients with HFrEF and a recent WHF event at a large tertiary referral center. Methods and Results We identified adult patients with chronic symptomatic HFrEF (ejection fraction ≤35%) treated at Duke University between January 1, 2009, and December 31, 2018, and applied a set of exclusion criteria to generate a cohort similar to those enrolled in contemporary heart failure trials. Patients were stratified by presence or absence of a recent WHF event, defined as an emergency department visit for heart failure or hospitalization for heart failure in the prior 12 months. Characteristics and outcomes including death and hospitalization were assessed. Of 3867 patients with HFrEF meeting study criteria, 2823 (73.0%) had a WHF event in the prior 12 months. Compared with patients without a WHF event, those with a WHF event were more likely to be under‐represented racial and ethnic groups and had lower ejection fraction, a greater burden of comorbidities, and more echocardiographic evidence of cardiac dysfunction. Despite higher use of guideline‐directed therapies, patients with a WHF event had higher rates of death (hazard ratio, 2.30; 95% CI, 2.01–2.63), all‐cause hospitalization (hazard ratio, 1.56; 95% CI, 1.42–1.71), and heart failure hospitalization (hazard ratio, 1.59; 95% CI, 1.44–1.75) through 5 years compared with those without a recent WHF event. Conclusions WHF events are common in patients with HFrEF and are associated with more advanced disease. Patients with recent WHF have high rates of death and hospitalization, underscoring the need for novel therapies in this large subgroup of patients with HFrEF.

Survivability in ATM networks

n ATM network design, self-healing is the ability of the network to continue to provide service in the event of failures, and this compromises both planning and operational aspects. The planning aspect involves optimal/near-optimal network design problems while the operational aspect deals with the implementation of protection schemes using restoration mechanisms, for allocating spare capacity to the network to be used in case of a failure event. This project investigates the survivability (i.e. restoration ratio) - here defined by means of the aggregate restoration ratio - in existing ATM networks based on various spare capacity distribution schemes, with the goal to (1) compare the network survivability for link and path restorations, and (2) determine the effects of various traffic and design related patterns on the restoration ratio.

Survivability in ATM networks

n ATM network design, self-healing is the ability of the network to continue to provide service in the event of failures, and this compromises both planning and operational aspects. The planning aspect involves optimal/near-optimal network design problems while the operational aspect deals with the implementation of protection schemes using restoration mechanisms, for allocating spare capacity to the network to be used in case of a failure event. This project investigates the survivability (i.e. restoration ratio) - here defined by means of the aggregate restoration ratio - in existing ATM networks based on various spare capacity distribution schemes, with the goal to (1) compare the network survivability for link and path restorations, and (2) determine the effects of various traffic and design related patterns on the restoration ratio.