Morbidity In Sickle Cell Disease Research Articles

Heme Scavenging by Hemopexin Attenuates Sepsis-Induced Proinflammatory Cytokines and Kidney Insuffciency in a Humanized Mouse Model of Sickle Cell Disease

Sickle cell disease (SCD) is a genetic blood disorder characterized by abnormal hemoglobin production, leading to sickle-shaped red blood cells (RBC). Alteration in RBC shape results in vasoocclusion, chronic hemolysis, and multiple organ damage. One of the severe complications of SCD is an increased susceptibility to infections, including sepsis, which can be life-threatening. Kidney injury, a common and severe complication of sepsis, contributes to the complexity and poor outcomes associated with morbidity and mortality in SCD. However, the mechanisms that underlie septic acute kidney injury (AKI) in SCD are poorly understood. Here, we examined the effects of sepsis in transgenic homozygous SCD (SS; Townes model) mice and their non-sickling (AA) counterparts. We tested the hypothesis that aggravation of inflammation and oxidative stress by free heme released during hemolysis contribute to sepsis-induced kidney insuffciency in SCD. AA and SS mice were subjected to 18 h of sham operation and cecal ligation and puncture (CLP), a pre-clinical model of polymicrobial sepsis, after which kidney function was evaluated by transdermal measurement of glomerular filtration rate (GFR). AKI biomarkers, renal oxidative stress, and cytokines levels were also investigated. We demonstrate that mid- to high-grade CLP (ligation of 60-75% of the cecum and multiple punctures with 21-gauge needles) caused 100% mortality in SS mice. Unlike AA mice (100% survival), SS mice subjected to low-grade CLP (LgCLP; ligation of <45% of the cecum and a single puncture with 21-gauge needles) exhibited 40% survival. LgCLP reduced body weight but did not exacerbate splenomegaly in SS mice. Basal plasma bilirubin, heme, and ferritin were significantly higher in SS than in AA mice. In contrast to AA, LgCLP amplified the increase in plasma bilirubin, heme, and ferritin in SS mice. LgCLP also decreased GFR and increased renal oxidative stress, AKI biomarkers, and kidney-to-body weight ratio in SS mice. Luminex multiplex cytokine analysis indicated that the plasma levels of multiple pro-inflammatory cytokines were elevated in septic SS mice. Heme scavenger hemopexin (HX) diminished LgCLP-induced plasma heme increase. HX also mitigated kidney insuffciency, inflammation, and mortality in the septic SS mice. Our findings suggest that free heme contributes to septic AKI in SCD mice and that HX therapy may attenuate the harmful effect of heme in SCD during sepsis. NHLBI: R01 HL151735. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

A miniaturized wash-free microfluidic assay for electrical impedance-based assessment of red blood cell-mediated microvascular occlusion

The production of HbS — an abnormal hemoglobin (Hb) — in sickle cell disease (SCD) results in poorly deformable red blood cells (RBCs) that are prone to microcapillary occlusion, causing tissue ischemia and organ damage. Novel treatments, including gene therapy, may reduce SCD morbidity, but methods to functionally evaluate RBCs remain limited. Previously, we presented the microfluidic impedance red cell assay (MIRCA) for rapid assessment of RBC deformability, employing electrical impedance-based readout to measure RBC occlusion of progressively narrowing micropillar openings. We describe herein the design, development, validation, and clinical utility of the next-generation MIRCA assay, featuring enhanced portability, rapidity, and usability. It incorporates a miniaturized impedance analyzer and features a simplified wash-free operation that yields an occlusion index (OI) within 15 min as a new metric for RBC occlusion. We show a correlation between OI and percent fetal hemoglobin (%HbF), other laboratory biomarkers of RBC hemolysis, and SCD severity. To demonstrate the assay’s versatility, we tested RBC samples from treatment-naïve SCD patients in Uganda that yielded OI levels similar to those from hydroxyurea (HU)-treated patients in the U.S., highlighting the role of %HbF in protecting against microcapillary occlusion independent of other pharmacological effects. The MIRCA assay could also identify a subset of HU-treated patients with high occlusion risks, suggesting that they may require treatment adjustments including a second-line therapy to improve their outcomes. This work demonstrates the potential of the MIRCA assay for accelerated evaluation of RBC health, function, and therapeutic effect in an ex vivo model of the microcapillary networks.

Sickle Cell Disease Update: New Treatments and Challenging Nutritional Interventions.

Sickle cell disease (SCD), a distinctive and often overlooked illness in the 21st century, is a congenital blood disorder characterized by considerable phenotypic diversity. It comprises a group of disorders, with sickle cell anemia (SCA) being the most prevalent and serious genotype. Although there have been some systematic reviews of global data, worldwide statistics regarding SCD prevalence, morbidity, and mortality remain scarce. In developed countries with a lower number of sickle cell patients, cutting-edge technologies have led to the development of new treatments. However, in developing settings where sickle cell disease (SCD) is more prevalent, medical management, rather than a cure, still relies on the use of hydroxyurea, blood transfusions, and analgesics. This is a disease that affects red blood cells, consequently affecting most organs in diverse manners. We discuss its etiology and the advent of new technologies, but the aim of this study is to understand the various types of nutrition-related studies involving individuals suffering from SCD, particularly in Africa. The interplay of the environment, food, gut microbiota, along with their respective genomes collectively known as the gut microbiome, and host metabolism is responsible for mediating host metabolic phenotypes and modulating gut microbiota. In addition, it serves the purpose of providing essential nutrients. Moreover, it engages in direct interactions with host homeostasis and the immune system, as well as indirect interactions via metabolites. Nutrition interventions and nutritional care are mechanisms for addressing increased nutrient expenditures and are important aspects of supportive management for patients with SCD. Underprivileged areas in Sub-Saharan Africa should be accompanied by efforts to define and promote of the nutritional aspects of SCD. Their importance is key to maintaining well-being and quality of life, especially because new technologies and products remain limited, while the use of native medicinal plant resources is acknowledged.

Sickle cell disease in the Zanzibar Archipelago, the Republic of Tanzania.

Sickle cell disease (SCD) is one of the most severe haemoglobinopathies, a group of blood disorders, typically inherited. The condition affects over 7.7 million people globally and results in more than 370,000 deaths per year. The highest morbidity and mortality rates are seen in Africa and most children with SCD are born in Tanzania. The available literature on SCD morbidity in Tanzania focus primarily on the residents of the mainland, while there is little data available on SCD morbidity among residents of the Tanzanian islands in the Indian Ocean. The aim of the present study was to confirm the presence of sickle cell disease among residents of the Zanzibar Archipelago. The study group consisted of 27 people, residents of Pemba Island in the Zanzibar Archipelago, aged between 2 months and 26 years old, whose at least one parent has been diagnosed with sickle cell anaemia. Blood samples collected from the study participants were tested using HemoTypeSCTM, a rapid, point-of-care diagnostic test. The tests were performed at the Amal Hospital (Chake Chake town, Pemba Island) in June 2023. Sickle cell disease was diagnosed in 11 study subjects (40.7%); their haemoglobin concentration ranged between 6.6 and 8.5 g/dL. The presence of the sickle cell trait (HbAS phenotype) was confirmed in 14 patients (51.9%). Only two of the tested patients had normal haemoglobin phenotype. The results of the present study support the necessity to introduce large-scale population- -based screening for SCD in the Zanzibar Archipelago, especially in infants whose family members have sickle cell anaemia. The introduction of such a programme will help monitor the number of new SCD cases in the region and may potentially reduce infant mortality due to SCD as well as minimize complications from SCD in older children through the adoption of effective disease prevention measures.

Reversal of Cerebral Arteriopathy Post-Hematopoietic Stem Cell Transplant for Sickle Cell Disease.

Sickle cell disease (SCD) is a chronic hematologic disorder which causes progressive cerebral arteriopathy beginning in childhood. As a result, arterial ischemic stroke is a major cause of morbidity and mortality in SCD, and SCD is a leading cause of childhood stroke worldwide. Allogenic hematopoietic stem cell transplant (HSCT) may be curative for individuals with SCD. Long-term outcomes and effects are currently being studied. In this report, we describe a child with SCD who presented with arterial ischemic stroke at 6 years of age and was found to have a severe form of cerebral large vessel arteriopathy by catheter-directed angiography. The patient initially underwent revascularization surgery by indirect superficial temporal artery to middle cerebral artery bypass, and 1 year later, he underwent curative HSCT. Approximately 3 years after HSCT, repeat catheter-directed angiography revealed a striking reversal of cerebral large vessel arteriopathy. This article reveals a previously unrecognized and potentially beneficial effect of HSCT that may ameliorate cerebral large vessel arteriopathy and improve cerebrovascular health for children with SCD.

Genetic cause and therapy of sickle cell disease

Sickle cell disease (SCD) is an influential genetic disorder on a global scale. The sickle cell population has been a large collective in recent years. Vaso-occlusion, membrane injury, and cardiovascular complications were discovered to result from its presence. There is currently no treatment that can completely cure SCD. Using a method of literature review, this paper discusses the history, pathology, and potential treatments. A point mutation of the sixth amino acid in the -hemoglobin gene (HBB) is the genetic etiology of sickle cell disease. The replacement of glutamic acid with valine reduces the oxygen-carrying capacity of erythroid. Even though the cause of SCD is evident, the treatments, including blood transfusion, hydroxyurea, gene-editing, and GBT440 agent therapy, are still uncertain. Further research and testing are required to reduce the morbidity of SCD, and additional efforts are required to increase the rate of SCD cure.

Nocturnal Autonomic and Vasoconstriction Parameters By Wearable Wrist Photoplethysmography Predict Intensity of Imminent Pain in Subjects with Sickle Cell Disease

Introduction: Sudden and unpredictable onset of pain is one of the biggest contributors to the morbidity of sickle cell disease (SCD), thought to occur due to obstruction of microvascular blood flow by rigid sickle-shaped red blood cells. Autonomic mediated vasoconstriction in the peripheral vasculature, with resulting decrease in tissue perfusion, is likely a triggering mechanism for the onset of vaso-occlusive pain, while the autonomic nervous system is also implicated in the pathogenesis of chronic neuropathic pain. Our analysis of 212 polysomnograms in SCD subjects showed that greater magnitude of nocturnal vasoconstriction (Mvasoc) is predictive of increased frequency of hospitalizations for vaso-occlusive pain crises (VOC) in the subsequent years (Chalacheva et al., Am J Hematol, 2020). In order to further develop this finding into a biomarker of more imminent pain, we monitored nocturnal photoplethysmography (PPG) at home with a wearable wristband device to measure vasoconstriction activity and heart rate variability, along with a daily electronic pain survey. Methods: 10 subjects with SCD were consented and underwent autonomic monitoring with a wristband device (Biostrap Inc) that uses an optical sensor to measure continuous PPG during sleep, with the raw PPG waveforms available from a cloud-based server. A unique biomarker (Mvasoc) was used to quantify the magnitude of vasoconstriction from the raw PPG signal, considering the frequency, magnitude, and duration of autonomic mediated spontaneous vasoconstrictions each night. Heart rate variability was derived from the pulse-to-pulse interval (PPI) of the PPG signal. Spectral indices of the PPI represent parasympathetic activity (high frequency power; HFP) and sympatho-vagal balance (Low to high Ratio; LHR = low frequency power(LFP)/HFP). Subjects concurrently documented daily pain incidence using an electronic text-based REDCap survey, with pain intensity measured on a scale of 1-10 if experiencing pain. Daily stress levels were also recorded on a scale of 1-10. Multivariate regression analysis was performed. Results: The subjects had a mean age of 25 years (range 14- 40 years) with an average hemoglobin of 8.8 g/dl . A total of 68 usable nocturnal PPG recordings were made (3-16 nights per subject). Therewere 25 incidents of pain on the day following autonomic monitoring with Biostrap, with the pain intensity ranging from 3-8. Multivariate analysis of nocturnal autonomic and vasoconstriction parameters revealed that a lower HFP ( p =0.0002) and a higher Mvasoc ( p=0.02) both preceded a higher intensity of pain the following day (Table 1). These results are consistent with a greater parasympathetic withdrawal and a higher magnitude of peripheral vasoconstriction predicting higher intensity of imminent pain. Age, gender, hemoglobin, stress levels and LHR were not predictive of pain the following day. Conclusion: Augmented nocturnal vasoconstriction and parasympathetic withdrawal noted prior to high intensity of pain imply that dysautonomia, with attendant changes in peripheral perfusion, has a significant role in pathogenesis of pain in SCD. Furthermore, autonomic vasoreactivity parameters were not significantly altered on the night after pain onset suggesting that the dysautonomia precedes pain. These results support the possibility of employing indices of nocturnal autonomic vasoreactivity as a predictive biomarker for imminent pain in SCD and provides a potential window for therapeutic intervention. This pilot study demonstrates the successful use of a wearable device PPG to remotely monitor nocturnal autonomic vasoreactivity and the ability to objectively quantify peripheral vasoconstriction responses. These findings will need to be applied in a larger cohort of SCD subjects with longer term monitoring for further validation and development of autonomic vasoreactivity as a predictive tool for pain in SCD.

Socioeconomic and Inflammatory Correlates of Plasma Cortisol Among Individuals with Sickle Cell Disease

Introduction: Cortisol plays a critical role in the biological link between stress and health outcomes. It is frequently investigated in the association between socioeconomic stress and morbidity, and the hypothesized biological mechanism by which socioeconomic stress and cortisol impact health is through chronically elevated systemic inflammation. This research is relevant to individuals with sickle cell disease (SCD) for several reasons. First, up to 40% of children and adolescents with SCD are impacted by neighborhood poverty. Furthermore, individuals with SCD are faced with significant disease-related morbidities, such as chronic and acute pain, renal injury, and cerebrovascular disease that are further complicated by elevated inflammatory markers. Finally, cortisol is heavily understudied in this population, with no research investigating socioeconomic or inflammatory correlates. The purpose of this study was to investigate plasma cortisol and its association with neighborhood-level socioeconomic factors (income and poverty) and immunomodulatory cytokines (IL-6, IL-10), among individuals with SCD. Method: Plasma from individuals with SCD within Children's Hospital of Philadelphia (CHOP) and University of Pennsylvania School of Medicine (Penn Medicine) BioBanks were identified. A cortisol radioimmunoassay was used to determine plasma cortisol levels. The Olink immune response panel was used to measure plasma levels of 92 proteins involved in inflammatory pathways. Home address collected from electronic health records was used to determine neighborhood census tract geoid, which was then used to collect data on median neighborhood income and percentage of families living in poverty from the 2020 American Census Survey. Bivariate and multivariate analyses were conducted across 4 subgroups in the total sample: pediatric patients, adult patients, SCA (HbSS/HbSß 0), and other SCD genotypes (HbSC/HbSß +). Control samples (healthy and sickle cell trait; n = 22) without neighborhood information were also available for comparison. Results: Fifty-four independent outpatient samples were identified after excluding duplicates and siblings. Twenty-seven samples were from children and adolescents receiving pediatric care at CHOP (Range age = .8 to 21; Mage= 13.6, SD = 5.3; 51.9% female, 74.1% SCA) and 27 samples were from adults receiving care at Penn Medicine (Range age = 19 to 56; Mage= 35.8, SD = 10.1; 51.9% female, 51.9% SCA). There were no significant differences in cortisol levels across each subgroup ( Mpeds= 16.6, SDpeds = 6.2; Madult= 13.4, SDadult = 6.9; MSCA= 15.1, SDSCA = 7.1; MSCD= 14.9, SDSCD = 6.3). Neighborhood income and poverty did not differ across pediatric and adult patients, and income did not differ across SCD types. However, neighborhood poverty was lower among patients with SCA ( M = 13.9; SD = 11.9) relative to other SCD genotypes ( M = 21.7; SD = 13.5; p = .041). Bivariate Spearman analyses found that neighborhood variables were not correlated with cortisol or cytokines in the total sample or subgroups. Yet, multivariate analyses controlling for sex and time of blood draw showed a positive main effect for patient age ( p = .019) and a significant age by poverty interaction ( p = .041) predicting cortisol among pediatric patients. Cortisol levels were higher with age, yet the association among poverty and cortisol was strongest in younger patients. Analyses also showed a sex*poverty interaction among pediatric patients that approached significance ( p = .081), such that poverty only predicted cortisol in male patients. There were no significant differences for immunomodulatory cytokines across each SCD subgroups; however, IL-6 and IL-10 were elevated in patients with SCA relative to healthy controls ( p IL6 = .021; p IL10 = .003). Bivariate Spearman correlations showed that cortisol was positively related to IL-6 (rho [ρ]= .38, p = .027) and IL-10 (ρ= .34, p = .048) among patients with SCA. There were no additional significant bivariate or multivariate effects. Conclusion: Neighborhood factors likely have downstream effects on the biological stress response and inflammation in SCD. Further research must be conducted to elucidate concurrent and prospective associations among neighborhood socioeconomic factors, stress-related cortisol response, and inflammatory outcomes when extending this work to investigate the impact of stress on SCD morbidity and mortality.

Hydroxyurea's Impact on Erythropoiesis, Cell Death and HbF Expression in the Hudep-2 Model

Background : Sickle cell disease (SCD) is an inherited disorder caused by a mutation in the beta-globin gene, leading to the synthesis of sickle hemoglobin called HbS. Under deoxygenated conditions, HbS polymerizes and forms fibers that weakens red blood cells (RBC) resulting in hemolysis and vaso-occlusion. Recently, ineffective erythropoiesis in SCD has been reported, characterized by higher apoptosis levels during late erythropoiesis. Interestingly, fetal hemoglobin (HbF)-expressing erythroblasts during erythroid differentiation seem to be protected from the apoptosis. Hydroxyurea (HU) is the first major approved drug for SCD in US and Europe; its proven efficacy in decreasing SCD morbidity and mortality is mainly mediated by the induction of HbF expression that is well-known as a modulator of disease severity through its ability to interfere with HbS polymerization. Despite being used for decades, HU action mechanism still remains to be fully elucidated. More precisely, HU impact on RBC maturation process is poorly documented as well as its mode of action on gamma-globin gene expression. Aim : Our aim is to investigate the effect of HU on erythropoiesis kinetics, HbF induction and apoptosis. Methods : We used HUDEP-2 (Human Umbilical cord Derived Erythroid Progenitors-2) cell line as a model for erythropoiesis. Cells were differentiated in normoxia (20% oxygen) or hypoxia (5% oxygen) - to mimic bone marrow environment, and were treated or not with HU allowing the comparison of HU effect both in normoxia and hypoxia. Analysis was performed at day D1, D3, D6, D8 and D10 of differentiation using flow cytometry, microscopy (MGG staining) and High-Performance Liquid Chromatography (HPLC). Kinetics of differentiation were followed by microscopy with MGG coloration and by flow cytometry using GPA, CD49d, Band3 and HbF antibodies. Apoptosis was assessed using annexin V staining. Results : Wedid first assess HU effect on HbF expression during erythropoiesis by flow cytometry and HPLC. Both methods showed that HU induced HbF expression from D1 to D6 of differentiation and that this induction is higher when the cells are in hypoxic conditions. We also investigated the apoptotic rate during erythropoiesis. Interestingly, HU treatment does not induce apoptosis in differentiating erythroblast, but decreased proliferation rates by 2-fold change in normoxia. Hypoxic conditions also decreased proliferative rate similarly to HU in normoxia but interestingly, in hypoxic conditions, HU did not furthermore decrease cell proliferation. Then, we investigated HU effect on the differentiation kinetics. Based on the differential expression of CD49d and Band3 along the differentiation, the percentage of each stage of differentiation (proerythroblast, basophilic, polychromatic and orthochromatic) was estimated by flow cytometry in GPA + cells at D1, D3, D6, D8 and D10 of the differentiation. Figure 1 depicted flow cytometry representative results from our 4 culture conditions at D1. Our results did show that HU accelerates HUDEP-2 differentiation as soon as D1 of culture (normoxia D1 NT vs HU: ProE 53.3% vs 44%, Baso 29.9% vs 33.1%, Poly 15.2% vs 18% and Ortho 3.3% vs 3.8%) until the end of the differentiation (D8 and 10) in normoxia. This acceleration is accentuated in hypoxic conditions (Hypoxia D1 NT vs HU: ProE 34.7% vs 17.9%, Baso 42.2% vs 50.3%, Poly 17.7% vs 25.8% and Ortho 3.8% vs 4.7%) with a cumulative effect of hypoxia and HU. All the flow cytometry results were confirmed by MGG staining and quantification by microscopy. For the same day of differentiation, HU-treated HUDEP-2 are in later stages than HU-non treated cells. Conclusion : Our study is the first to investigate the impact of HU on RBC maturation - erythropoiesis. HU treatment increases HbF expression without impacting apoptosis. The treatment tends to promote erythroid differentiation by accelerating maturation processes with stronger effect in hypoxic conditions that mimic the in vivo low oxygen environment of the bone marrow, strongly suggesting that HU has other molecular targets than inducing HbF. All these results will be confirmed in CD34 + erythroid progenitors from patients with SCD. Our results give new insights on the effect of HU on erythropoiesis that would ultimately lead to a better understanding of its mechanism of action and to the identification of new therapeutical targets to counteract SCD ineffective erythropoiesis.

Incidence of Maternal and Perinatal Morbidity in Sickle Cell Disease and Sickle Cell Trait Patients during Pregnancy

Background: Sickle cell disease (SCD) patients have a higher risk of maternal and neonatal morbidity during pregnancy than the general population. Pregnancy in SCD is associated with increased metabolic demands, a hypercoagulable state, endothelial dysfunction, severe anemia, and increased vaso-occlusive episodes. We designed a study to retrospectively review the clinical outcomes of pregnant patients with SCD and SCD trait to examine the incidence of maternal and perinatal morbidity and mortality. We hypothesized that SCD patients should have a higher morbidity during pregnancy and SCD trait patients should not have higher morbidity. Methods: We conducted a retrospective cohort study and reviewed 29,822 patient encounters. Pregnant patients with the SCD genotype - Hb SS, Hb S beta 0 thalassemia, Hb S beta + thalassemia and Hb SC disease, and sickle cell trait (SCD trait) - Hb AS were included. Maternal clinical outcome variables for the entire pregnancy duration were vaso-occlusive crisis (VOC), deep vein thrombosis (DVT), pulmonary embolism (PE), infections - sepsis, septic shock, asymptomatic bacteriuria, acute pyelonephritis, and urinary tract infection (UTI), cerebrovascular accident (CVA), myocardial infarction (MI) and transient ischemic attack (TIA). Clinical outcome variables for pregnancy complications were preeclampsia, gestational diabetes mellitus (GDM), and C-section rate. Clinical outcome variables for neonatal complications included preterm birth and low birth weight. ICD 9 and ICD 10 codes were used to search for the pregnancy, SCD, sickle cell trait, maternal and neonatal outcomes. Data was collected from the Health Facts Database, which contains de-identified information from electronic medical records (EMR) of hospitals in which Cerner© has a data use agreement. The categorical clinical outcome variables were analyzed using Chi-square test. Results: There were 29,822 patient encounters reviewed. Patients with SCD had higher percentages for C-section rates, CVA, preeclampsia, sepsis, septic shock, and VOC compared to those with SCD trait. C-section rates were higher in SCD patients with 76.43% versus 13.76% in SCD trait patients. CVA was higher in SCD patients with 73.78% versus 0% in SCD trait patients. Preeclampsia was higher in SCD patients with 75.92% in SCD patients versus 5.43% in SCD trait patients. Sepsis and septic shock were higher in SCD patients with 73.75% in SCD patients versus 0% in SCD trait patients. VOC was evident in SCD patients with 0.06% versus 0% in SCD trait patients. Patients with SCD trait had higher percentages for asymptomatic bacteriuria, GDM, low birth weight, preterm birth, and UTI compared to patients with SCD. Asymptomatic bacteriuria was higher in SCD trait patients with 0.25% versus 0.08 in SCD patients. GDM was higher in SCD trait patients with 3.09% versus 0% in SCD patients. Low birth weight was higher in SCD trait patients with 0.61% versus 0.17% in SCD patients. Preterm birth was higher in SCD trait patients with 0.78% versus 0.44% in SCD patients. UTI was noted in SCD trait patients with 0.02% versus 0% in SCD patients. There were no findings for DVT, PE, acute pyelonephritis, MI, and TIA in both SCD and SCD trait patients. Conclusion: Pregnant patients with SCD were more likely to have C-sections, CVA, preeclampsia, sepsis, septic shock, and VOC. Pregnant patients with SCD trait were more likely to have asymptomatic bacteriuria, GDM, low birth weight, preterm birth, and UTI. Our findings indicate that prevention and management of CVA, preeclampsia, sepsis, and septic shock is important for pregnant patients with SCD to prevent adverse maternal and neonatal outcomes. The higher rate of C-sections may have been to reduce the severity of maternal and perinatal morbidity in SCD patients. Our study has significant limitations - retrospective nature and use of ICD9 and ICD10 codes for clinical outcome variables. Certain clinical outcome variables, such as CVA, sepsis or septic shock, may have been overestimated as these diagnoses may have been recorded prior to the start of pregnancy in the EMR. Nevertheless, SCD patients have higher maternal and perinatal morbidity that needs to be addressed.

Fucosyltransferase VII (FUT7) Activity in Patients with Sickle Cell Disease and Healthy Controls

Background:Sickle cell disease (SCD) is a severe monogenic disorder with a majority of the affected individuals living in Africa. Vaso-occlusion is a significant cause of morbidity and mortality in SCD, and selectin mediated intercellular adhesion is recognized as an important target for therapy. As such Anti-P-selectin agents are in clinical use to reduce the frequency of vaso-occlusive crises (VOCs) in SCD patients. Sialyl lewis x is a crucial ligand common to all members of the selectin family and the final step in the biosynthesis of sialyl lewis X antigen (fucosylation), is catalysed by Fucosyltransferase VII (FUT7). This enzyme is most expressed in leukocytes and endothelial cells. We hypothesized that FUT7 enzyme activity is abnormal in SCD patients and differs by VOC severity. We sought to measure plasma levels of FUT7 in SCD patients and healthy controls, and investigate their association with clinical and laboratory features, such as the frequency of VOCs. Methods:This wasa single centre cross-sectional analytical study at the University of Nigeria Teaching Hospital, Enugu. 38 steady state adult SCD patients and 40 HbAA age- and sex-matched healthy control subjects were enrolled. SCD patients were stratified by clinical severity into: Group A- 19 subjects with mild disease (0-1 crises and no disease complication such as stroke, chronic leg ulcers, nephropathy, or avascular necrosis in the previous year), and Group B- 19 patients with moderate to severe disease (2 or more crises in the previous year, with or without complications). We excluded patients with red cell transfusion within 4 months, on hydroxyurea, or other agents that may affect vaso-occlusive crisis frequency, and co-existing chronic disorders unrelated to SCD, such as asthma and diabetes mellitus. We performed a CBC and plasma FUT7 enzyme concentration measurements (ELISA kit, MyBiosource Inc, USA). Statistical analysis was performed with SPSS version 22.0 for Windows. A 2-tailed P value of <0.05 was used. Results:Our subjects were predominantly female (SCD 52.5%, HbAA 55%), with median age 28 years (range 19-46 and 19-45 for SCD and HbAA, respectively). Median frequency of VOCs in patients was 1 (range 0-5). Avascular necrosis (32.5%) was the most common complication, while stroke, acute chest syndrome, and eye disease were the least common. As expected, SCD patients had lower haemoglobin levels than HbAA (7.9±1.3g/dL vs. 12.6±1.4g/dL, P<0.001). Significantly higher WBC, ANC, and platelet counts were observed in SCD patients compared with HbAA controls (P<0.001). No significant correlations were found between FUT7 and haematocrit (r =0.06), WBC count (r = -0.08), neutrophil count (r = -0.12), and platelet count (r =0.1), with P values of 0.7, 0.6, 0.5, and 0.6, respectively. We found no difference between the median and IQR values of plasma FUT7 of SCD (2.1; 1.8-2.5) and controls (2.2; 1.8-2.8), P = 0.7. FUT7 activity was higher in SCD subjects in Group A (2.2; 1.9-2.9) than in Group B (2.0; 1.2- 2.4), with a trend towards significance P = 0.1. Discussion:In this study, FUT7 activity did not differ between SCD patients and controls. We also did not find correlations between FUT7 and blood cell counts, suggesting that plasma FUT7 activity is not increased at baseline in SCD and that the degrees of anemia or leukocytosis are not associated with changes in FUT7. Nonetheless, a mild decrease in FUT7 levels was found in more severe SCD patients and should be confirmed in a larger study. Our study did not evaluate patients in crises or who received hydroxyurea and/or other SCD-modifying therapies. Since FUT7 catalyses selectin expression, variation in its activity may be more relevant in subgroups of SCD patients on anti-selectin therapies. Future studies should be carried out in such patients to explore FUT7 activity as a marker of acute vaso-occlusion and as a modifier of response to therapy.

Associating a standardized reporting tool for chest radiographs with clinical complications in pediatric acute chest syndrome.

Acute chest syndrome (ACS) is an important cause of morbidity in sickle cell disease (SCD). A standardized tool for reporting chest radiographs in pediatric SCD patients did not previously exist. To analyze the interobserver agreement among pediatric radiologists' interpretations for pediatric ACS chest radiographs utilizing a standardized reporting tool. We also explored the association of radiographic findings with ACS complications. This was a retrospective cohort study of pediatric ACS admissions from a single institution in 2019. ICD-10 codes identified 127 ACS admissions. Two radiologists independently interpreted the chest radiographs utilizing a standardized reporting tool, a third radiologist adjudicated discrepancies, and κ analysis assessed interobserver agreement. Clinical outcomes were correlated with chest radiograph findings utilizing Pearsons' χ2 , ttests, and Mann-Whitney U tests. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Interobserver agreement was moderate to near-perfect across variables, with κ analysis showing near-perfect agreement for opacity reported in the right upper lobe (0.84), substantial agreement for right lower lobe (0.63), and vertebral bony changes (0.72), with moderate agreement for all other reported variables. On the initial chest radiograph, an opacity located in the left lower lobe (LLL) correlated with pediatricintensive care unit transfer (p = .03). Pleural effusion on the initial chest radiograph had a 3.98 OR (95% CI: 1.35-11.74) of requiring blood products and a 10.67 OR (95%CI: 3.62-31.39) for noninvasive ventilation. The standardized reporting tool showed moderate to near-perfect agreement between radiologists. LLL opacity, and pleural effusion were associated with increased risk of ACS complications.

Reticulocyte mitochondrial retention increases reactive oxygen species and oxygen consumption in mouse models of sickle cell disease and phlebotomy-induced anemia

Sickle cell disease (SCD) is caused by a mutation of the β-globin gene that results in the production of hemoglobin S (HbS). People with SCD experience anemia, severe acute pain episodes, persistent chronic pain, multiorgan damage, and a reduced life span. The pathophysiology of SCD caused by the polymerization of HbS on deoxygenation results in red cell deformability and the generation of reactive oxygen species (ROS). These 2 factors lead to red cell fragility and hemolysis. Reticulocytosis is an independent predictor of disease morbidity and mortality in SCD. We previously established that humans and mice with SCD exhibit abnormal mitochondrial retention in erythrocytes increasing ROS-associated hemolysis. Here, we investigated the hypothesis that mitochondrial retention and increased ROS are a consequence of stress erythropoiesis. Our results show clearly that stress erythropoiesis in phlebotomized, anemic AA mice results in mitochondrial retention and increased ROS in reticulocytes. We observed that elevated mitochondrial retention in reticulocytes also alters oxygen consumption and potentially contributes to increased HbS polymerization and red blood cell hemolysis. Therefore, these events occurring due to stress erythropoiesis contribute significantly to the pathology of SCD and suggest new therapeutic targets.

Early Strokes Are Associated with More Global Cognitive Deficits in Adults with Sickle Cell Disease.

This study sought to link neurocognitive profiles in sickle cell disease (SCD) patients with clinical characteristics. We conducted a prospective cohort study of adults with SCD who underwent comprehensive neuropsychological assessment at the UMGGR clinic at Henri Mondor Hospital, Créteil (France). A cluster analysis was performed based on neuropsychological testing scores. The association between clusters and clinical profiles was assessed. Between 2017 and 2021, 79 patients with a mean age of 36 [range 19-65] years were included. On principal component analysis, a 5-factor model presented the best fit (Bartlett's sphericity test [χ2 (171) = 1345; p < 0.001]), explaining 72% of the variance. The factors represent distinct cognitive domains and anatomical regions. On hierarchical classification, three clusters emerged. Cluster 1 (n = 24) presented deficits in all five factors compared to Cluster 3 (n = 33). Cluster 2 (n = 22) had deficits in all factors, but to a lesser extent than Cluster 1. MoCA scores mirrored the severity of these cognitive deficits. Age, genotype and stroke prevalence did not differ significantly between clusters. However, the time of first stroke occurrence differed significantly between Cluster 1 and 2-3: 78% of strokes occurred during childhood, whereas 80% and 83% occurred during adulthood in Clusters 2 and 3, respectively. Educational attainment was also reduced in Cluster 1. SCD patients with childhood stroke seem to be at increased risk of a global cognitive deficit profile. In addition to existing methods of primary and secondary stroke prevention, early neurorehabilitation should be prioritized in order to reduce the long-term cognitive morbidity of SCD.

Effects of regional brain volumes on cognition in sickle cell anemia: A developmental perspective.

Cognitive difficulties in people with sickle cell anemia (SCA) are related to lower processing speed index (PSI) and working memory index (WMI). However, risk factors are poorly understood so preventative strategies have not been explored. Brain volumes, specifically white matter volumes (WMV) which increases through early adulthood, have been associated with better cognition in healthy typically developing individuals. In patients with SCA, the reduced WMV and total subcortical volumes noted could explain cognitive deficits. We therefore examined developmental trajectories for regional brain volumes and cognitive endpoints in patients with SCA. Data from two cohorts, the Sleep and Asthma Cohort and Prevention of Morbidity in SCA, were available. MRI data included T1-weighted axial images, pre-processed before regional volumes were extracted using Free-surfer. PSI and WMI from the Weschler scales of intelligence were used to test neurocognitive performance. Hemoglobin, oxygen saturation, hydroxyurea treatment and socioeconomic status from education deciles were available. One hundred and twenty nine patients (66 male) and 50 controls (21 male) aged 8-64 years were included. Brain volumes did not significantly differ between patients and controls. Compared with controls, PSI and WMI were significantly lower in patients with SCA, predicted by increasing age and male sex, with lower hemoglobin in the model for PSI but no effect of hydroxyurea treatment. In male patients with SCA only, WMV, age and socioeconomic status predicted PSI, while total subcortical volumes predicted WMI. Age positively and significantly predicted WMV in the whole group (patients + controls). There was a trend for age to negatively predict PSI in the whole group. For total subcortical volume and WMI, age predicted decrease only in the patient group. Developmental trajectory analysis revealed that PSI only was significantly delayed in patients at 8 years of age; the rate of development for the cognitive and brain volume data did not differ significantly from controls. Increasing age and male sex negatively impact cognition in SCA, with processing speed, also predicted by hemoglobin, delayed by mid childhood. Associations with brain volumes were seen in males with SCA. Brain endpoints, calibrated against large control datasets, should be considered for randomized treatment trials.

Influence of Haptoglobin and Hemoglobin Phenotypic Polymorphisms on Sickle Cell Disease Morbidity

Influence of Haptoglobin and Hemoglobin Phenotypic Polymorphisms on Sickle Cell Disease Morbidity

Frequency and Patterns of Bacteraemia in Children with Sickle Cell Disease: A Prospective Cohort Study

Introduction: Sickle Cell Disease (SCD) is one of the most common inherited haemoglobinopathies and is associated with high morbidity and mortality, particularly in early childhood among the affected population. Infection is a significant contributor to morbidity and mortality in SCD. Aim: To investigate the frequency and pattern of bacteraemia in children with SCD. Materials and Methods: This prospective cohort study was conducted in the Department of Paediatricss at Acharya Vinoba Bhave Hospital, Sawangi (M), Wardha, Maharashtra, India, a tertiary care hospital attached to Jawaharlal Nehru Medical College from October 2019 to September 2021. A total of 70 patients with SCD, aged upto 18 years, who presented with fever on two separate occasions and were admitted to the hospital, were included in the study. Blood culture, complete blood counts, and C-reactive Protein (CRP) tests were conducted to detect bacteraemia immediately after admission and when required. Quantitative data was analysed using mean, median, and standard deviation. Results: In the present study, out of 70 patients, 40 (57.14%) were male and 30 (42.86%) were female. A total of 54 (77.14%) were homozygous and 16 (22.86%) were heterozygous for SCD. A total of 30 (42.86%) patients belonged to the 6-10 years age group. Fever and pallor were the most common clinical findings. The rate of bacteraemia was found to be 15.71%. Gramnegative organisms were more frequently isolated compared to gram-positive isolates. The most common organism isolated in sickle cell patients was Klebsiella species (36.36%). Conclusion: Bacteraemia was observed in only approximately 15.71% of the patients. Gram-negative bacteraemia was more prevalent in patients with SCD. Patients with acute chest syndrome were more susceptible to bacterial infections. Mortality was higher in sickle cell patients from whom organisms were isolated in blood cultures.

COVID-19 Outcomes at a Comprehensive Sickle Cell Center: A Two-Year Report

The Georgia Comprehensive Sickle Cell (SC) center at Grady health system is the largest adult comprehensive sickle cell center in the United States and has the first 24/7 acute care unit for management of sickle cell vaso-occlusive events (VOE). in 2019, the center provided around 3000 sickle cell clinic visits and 4000 acute care visits. When the COVID-19 pandemic reached the US, the SC center had seen a precipitous drop in the number of both clinic and acute care visits as local and state regulations for lockdown were passed. On the two-year anniversary for the COVID-19 pandemic, we are submitting this report of all the COVID-19 cases at a single adult center for sickle cell disease. Since the start of the pandemic, we have been tracking any COVID-19 cases reported in the patient population the SC center follows. Out of 1343 patients currently following in the center, 173 patients contracted COVID-19 between March 2020 and February 2022, and were tracked in the clinical database under IRB approval. The results show that of the 173 patients, 85 were female and 89 were male. By genotype, 62% of patients were SS, 29% were SC and 9% were Sβ+ thalassemia or Sβ0 thalassemia. 32% of patients were on hydroxyurea for disease modification with the majority of them being of the SS genotype and 45% had elevated fetal hemoglobin determined by a percentage fetal hemoglobin above 5% by hemoglobin electrophoresis. Chronic pain was defined in the patients experiencing daily pain episodes for more than 4 days a week for the last 3 months and calculation of daily morphine equivalents was reported based on the clinic follow-ups and the narcotic database utilization. 35% of the SC patients had chronic pain and the median morphine equivalents was 90 mg daily with a range between 45 and 225mg. On evaluating the rate of emergency department (ED) visits or hospitalizations for the sickle cell patients with COVID-19, 85% of patients had either an ED visit or hospitalization. 54% of the SC patients had the reason for the visit related to VOE and 29% had the reason related to COVID-19 primarily. 15% of SC patients were not seen in any emergency setting or required any hospitalization. 22% of the patients had lung findings on imaging. The treatment utilized for the patients was most commonly Remdesivir in 33, dexamethasone in 26, red cell products in 21 and monoclonal antibody in 13 patients. Of the 3 deaths reported, 2 happened early in the pandemic. One patient had presented in June 2020 with VOE and was found to have bilateral lung opacities but was asymptomatic and was discharged home to return few days later with clinical picture of multi-organ failure (MOF) for which a red cell erythrocytapheresis was attempted to no avail. The second patient had presented in July 2020 with COVID-19 pneumonia and was treated with Remdesivir and convalescent plasma to no avail after development of MOF and ARDS. The third death occurred in August 2021 during the delta variant wave and the patient was hospitalized for COVID-19 pneumonia and had initial improvement after initial treatment but after worsened lung findings, ARDS developed followed by MOF. Several reports from different centers have been published regarding the rate of COVID-19 related mortality and morbidity in sickle cell disease. The Grady comprehensive sickle cell center experience differs in the fact that 63 out of 173 (36%) patients who had contracted COVID-19 required treatment and 3 of those 63 had died. In fact, the deaths occurred early in the course of the pandemic in June and July 2020 respectively and since then, the rate of complicated COVID-19 hospitalizations has decreased with better treatment available. No deaths were registered during the omicron wave and 1 death was registered during the delta wave. In addition, the timeline for the COVID-19 cases reported fits the population timeline of peaks respectively happening in the summer of 2020, winter of 2021, summer of 2021 and winter of 2021. During the initial peak, we have noted a decrease in the number of clinic and acute care visits respectively. This was anticipated given the statewide lockdown that was implemented. To circumvent that, the SC center resorted to virtual visits utilization to deliver the needed healthcare visits to the patients. This measure has aided in protecting patients against COVID-19 during the multiple COVID-19 peaks occurring in the last 2 years and has accordingly reduced the mortality and morbidity of the patient population. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Are Women at High Risk of Complications from Sickle Cell Disease: Insights from National Database Analysis

Introduction: Published data reporting gender-related differences in outcomes from sickle cell disease (SCD) is scarce, consisting of small single-center studies. Therefore, using a large sample size from a nationally representative database, we looked into the effect of gender on outcomes from SCD. Methods: We investigated the National Inpatient Sample 2019 using International Classification of Diseases-10 (ICD-10) codes to include adult SCD patients. Morbidity, disease complication, and resource utilization were compared, stratified by patients' gender. Analyses were performed using STATA (version 14.2), considering 2-sided P< 0.05 as statistically significant. Proportions were compared using Fisher exact test and continuous variables using the Student's t-test. Confounding variables were adjusted using multivariate logistic and linear regression analyses. Results: A total of 97,244 patients were included (mean age 34.61 years, 57.26% females). Female patients had 24% lower odds of acute chest syndrome on presentation (Adjusted odds ratio (aOR) 0.76, 95% confidence interval (CI): 0.64 - 0.91, P<0.01). The rates of splenic sequestration crisis, posterior reversible encephalopathy syndrome, myocardial infarction, and gallbladder stones were comparable between the two groups. Males had higher odds of developing acute kidney injury during hospitalization (aOR 0.80, 95% CI: 0.70 - 0.92, P<0.01), but the rates of in-hospital mortality and other morbidity markers were not different between the two groups. Packed Red Blood Cell (pRBC) transfusion, total hospital costs, and length of stay were not statistically different between males and females. Discussion: Using a large sample size, we found that females are not at high risk of SCD complications or adverse hospitalization outcomes. Male patients have a higher risk of presenting with acute chest syndrome and developing acute kidney injury. This could be due to the estrogen protective effect or other factors. Despite menstrual losses, females did not have significantly higher pRBC transfusions or lower secondary hemochromatosis. Our study showed that gender does not represent an indicator of morbidity and mortality in SCD. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Is Severity Score Associated With Indication for Hematopoietic Stem Cell Transplantation in Individuals With Sickle Cell Anemia?

Manifestations of sickle cell disease (SCD) begin early in childhood and cause morbidity and decreased life expectancy. Hematopoietic stem cell transplantation (HSCT) is curative but associated with risk of mortality attributable to the transplant. This risk should be counterbalanced with SCD morbidity and mortality. A severity score using a Bayesian network model was previously validated to predict the risk of death in adult individuals with SCD. The objective of this study is to calculate the severity scores of participants in a multicenter cohort of Brazilians with SCD, using a previously published Bayesian network-derived score, associated with risk of death and then compare the severity scores between participants with and without an indication for HSCT as defined by the Brazilian Ministry of Health (MoH) criteria. This is an observational, retrospective study. We analyzed 2063 individuals with sickle cell anemia from the Recipient Epidemiology and Donor Evaluation Study-III Brazil SCD cohort and applied a Bayesian network-derived score to compare candidates and non-candidates for HSCT according to the Brazilian MoH transplant criteria. Classical statistical methods were used to analyze data and make comparisons. We compared severity scores between cohort members with (n=431) and without (n=1632) HSCT indications according to Brazilian MoH. Scores were not different in adult participants with ≥1 HSCT indication when compared to those with no indication (mean 0.342 versus 0.292; median 0.194 versus 0.183, P=.354) and receiver operating characteristic curves did not demonstrate an obvious threshold to differentiate participants with or without HSCT indications. Severity score may predict risk of death but does not differentiate HSCT candidates. Current indications should be evaluated to ensure that patients with more severe disease who might benefit from HSCT are appropriately identified.