Crises in Sickle Cell Disease

Unexpected Death of a Sickle Cell Disease Patient: A Case Report and Literature Review

Sickle cell disease (SCD) is an autosomal recessive genetic disorder characterized by the abnormal formation of sickle hemoglobin (HbS). Under conditions of deoxygenation, HbS undergoes polymerization, resulting in microvascular occlusion, tissue hypoxia, and infarction. The elevated mortality rate associated with SCD is primarily attributed to complications such as sepsis, acute chest syndrome, stroke, acute multiorgan failure, and pulmonary hypertension. Despite advancements in awareness and treatments, preventing mortality in young individuals with SCD remains a formidable challenge. In an effort to shed light on these challenges, we present a case of unexpected death associated with SCD to emphasize the pressing need for continued research and intervention strategies to improve patient outcomes.

Strong opioids-induced cardiac, neurologic, and respiratory disorders: a real-world study from 2004 to 2023 based on FAERS

Opioids are mainly used as adjuncts to the induction and maintenance of general anesthesia, postoperative analgesia, and treating moderate to severe cancer pain and chronic pain. However, the hazards of these drugs to various organ organs still need to be further explored. This study used the US FDA Adverse Event Reporting System (FAERS) database to determine whether commonly receiving opioids was higher than the baseline risk for all other medications. FAERS was asked about adverse events (AEs) for the opioids "morphine," "fentanyl," "oxycodone," "hydromorphone," "sufentanil," and "remifentanil" from the first quarter of 2004 (2004Q1) through the second quarter of 2023 (2023Q2). Disproportionality signaling analysis was performed by calculating reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network (BCPNN), and Empirical Bayesian Geometric Mean (EBGM). AEs with system organ classes (SOCs) of "cardiac disease," "neurologic disease," and "respiratory, thoracic, and mediastinal disease" were then screened. The statistical analysis included 12,819,518 reports in the FAERS database from 2004Q1 to 2023Q2, of which 236,619 AEs were reported as "primary suspect" for the six drugs mentioned above, which were selected as "cardiac disorders," "nervous system disorders," and "respiratory, thoracic and mediastinal disorders." Some AEs identified in this study are consistent with the drug labeling, such as bradycardia, respiratory depression, and somnolence. In addition, some unexpected and significant acute adverse drug reactions (ADRs), such as toxic leukoencephalopathy and coma, may occur. This study identified potential new and unexpected ADRs for opioids, providing valuable evidence for safety studies of opioids.

Lipid and hemolysis parameters predicting acute chest syndrome in adulthood with sickle cell disease

Sickle cell disease (SCD) is a lifelong blood disorder affecting approximately 100,000 people in the United States and is one of the most common monogenic diseases. A serious complication of SCD is acute chest syndrome (ACS). ACS is a condition with a high rate of morbidity and mortality. The aim of the study was to assess hemolysis and lipid parameters in a cohort of confirmed SCD patients to predict ACS development in the following year.Standard lipid were performed (triglycerides, total cholesterol, high-density cholesterol, low-density cholesterol) panel to calculate of non-HDL-C, large buoyant LDL cholesterol (lbLDL-C) and small dense LDL cholesterol (sdLDL-C) with Sampson equation. Hemolysis and hematologic parameters were also evaluated.Among 91 patients included between September 2018 and June 2021, thirty-seven patients had history of ACS and 6 patients developed ACS during following year. In unadjusted logistic regression, total bilirubin was associated with ACS occurrence (RR: 1.2 [1.05-1.51] p = 0.013). Concerning lipid profile, non-HDL-C (RR: 0.87 [0.0.67-0.99] p = 0.04) and sdLDL-C (RR: 0.78 [0.49-0.96] p = 0.03) were associated with ACS occurrence decrease. C-reactive protein was associated with ACS occurrence (RR: 1.27 [1.065-1.85] p = 0.011).Based on these findings, this study demonstrated that several biomarker easily available can be used at steady state to predict ACS in the following year. The validation of these results are required to ensure the reproducibility of the findings.

Acute sickle cell hepatopathy: A case report and literature review

Sickle cell disease (SCD) is an inherited hemoglobinopathy with protean clinical manifestations. The liver could be affected by various SCD-associated complications of an overlapping nature. The clinical presentations of "sickle cell hepatopathy" range from clinically asymptomatic patients to those with life-threatening complications. Herein we report an SCD patient who presented with right upper quadrant abdominal pain and jaundice, eventually diagnosed as a self-limited form of acute sickle cell hepatopathy with overlapping features of acute hepatic crisis and benign intrahepatic cholestasis. Using this patient as an illustration, we will review the spectrum of hepatobiliary presentations in the SCD population.

Clinical Biomarkers of Acute Vaso-Occlusive Sickle Cell Crisis

It is known that an inherited blood condition called sickle cell disease (SCD) is a result of one gene. A number of blood and urine biomarkers have been determined in association with lab and clinical history for SCD patients. SCD has numerous interacting pathways associated with it, which have been identified by biomarkers. These mechanisms consist of some examples, such as endothelial vasodilation response, hypercoagulability, hemolysis, inflammation, oxidative stress, vascular dysfunction, and reperfusion injury among others. To effectively manage SCD, a comprehensive panel of validated blood and urine biomarkers must be established. Despite its monogenic inheritance, the complex nature of the SCD phenotype has impeded progress in its treatment. However, significant strides have been made in clinical biotechnology, paving the way for potential breakthroughs. In SCD, a panel of verified blood and urine biomarkers must be established, however. Despite monogenic inheritance, the great complexity of the SCD phenotype has hindered progress in its management. With few exceptions, clinical biomarkers of illness severity have been found through epidemiological investigations; nevertheless, systematic integration of these biomarkers into clinical treatment algorithms has not occurred. Furthermore, sickle cell crisis, the primary acute consequence of SCD, has been difficult to diagnose with the biomarkers now in use. Inadequate care and a lack of appropriate outcome measures for clinical research are the consequences of these diagnostic constraints. A new chapter in SCD customized treatment has begun with recent advancements in molecular and imaging diagnostics. Strategies in precision medicine are especially relevant now that molecular therapies are within reach. The significance of biochemical indicators linked to clinical manifestation and sub-phenotype identification in SCD is reviewed in this research.

Transfusion of packed red blood cells in adults with sickle cell anemia treated at an emergency hospital

OBJECTIVE

The aim of this study was to analyze the prescription of packed red blood cells performed by emergency physicians for adults with sickle cell anemia.

METHODS

Transfusions performed in adults with sickle cell anemia treated at an emergency service in São Bernardo do Campo, São Paulo Brazil, between January 2018 and January 2022 were evaluated. For data comparison, the chi-square2 test was used. The significance level adopted was 5%.

RESULTS

A total of 114 transfusions were performed. The mean age was 41.8±16.4 years, and pretransfusion hemoglobin was 6.1±1.23 g/dL. Regarding the indication, the adequacy of transfusions performed in symptomatic individuals was significantly higher compared to asymptomatic individuals (100% vs. 3.9%, p<0.001). Symptomatic individuals received excessive volumes of packed red blood cells less frequently than asymptomatic individuals (17.5% vs. 56.9%, p<0.001). The filtered subtype, indicated for sickle cell anemia, was prescribed in only a quarter of the patients. However, non-indicated subtypes were frequently prescribed.

CONCLUSION

This study found low adequacy in the indication and calculation of the transfusion volume of packed red blood cells in asymptomatic individuals. Few patients received filtered red blood cells, resulting in increased risks of transfusion reactions. On the contrary, non-indicated subtypes were prescribed in a quarter of transfusions, which resulted in higher costs and delay in receiving packed red blood cells.

Enhancing diagnostic precision for acute chest syndrome in sickle cell disease: insights from dual-energy CT lung perfusion mapping

PURPOSE

Acute chest syndrome (ACS) is secondary to occlusion of the pulmonary vasculature and a potentially life-threatening complication of sickle cell disease (SCD). Dual-energy CT (DECT) iodine perfusion map reconstructions can provide a method to visualize and quantify the extent of pulmonary microthrombi.

METHODS

A total of 102 patients with sickle cell disease who underwent DECT CTPA with perfusion were retrospectively identified. The presence or absence of airspace opacities, segmental perfusion defects, and acute or chronic pulmonary emboli was noted. The number of segmental perfusion defects between patients with and without acute chest syndrome was compared. Sub-analyses were performed to investigate robustness.

RESULTS

Of the 102 patients, 68 were clinically determined to not have ACS and 34 were determined to have ACS by clinical criteria. Of the patients with ACS, 82.4% were found to have perfusion defects with a median of 2 perfusion defects per patient. The presence of any or new perfusion defects was significantly associated with the diagnosis of ACS (P = 0.005 and < 0.001, respectively). Excluding patients with pulmonary embolism, 79% of patients with ACS had old or new perfusion defects, and the specificity for new perfusion defects was 87%, higher than consolidation/ground glass opacities (80%).

CONCLUSION

DECT iodine map has the capability to depict microthrombi as perfusion defects. The presence of segmental perfusion defects on dual-energy CT maps was found to be associated with ACS with potential for improved specificity and reclassification.

Intravenous Hydration and Associated Outcomes in Patients With Sickle Cell Disease Admitted With Vaso-Occlusive Crises: A Systematic Review

Acute painful vaso-occlusive crisis (VOC) is the common presentation of sickle cell disease (SCD) leading to emergency room visits, admissions, morbidity, mortality, and negative impacts on quality of life. Among various treatment approaches commonly employed to manage the condition, intravenous (IV) hydration is also frequently used in emergency and inpatient settings. Although helpful to overcome dehydration, IV hydration often leads to adverse outcomes like fluid overload, pulmonary edema, increased length of stay, transfer to intensive care unit, new oxygen requirement, etc. Small-scale retrospective studies are conducted to study the outcomes of IV hydration but have failed to conclusively demonstrate its benefits as well as choice of IV fluids, rate of IV fluid replacement, etc. We conduct this review as an attempt to summarize the available evidence on the role and utility of IV hydration in sickle cell crises along with reported adverse outcomes.

Rates of Opioid Misuse Amongst Patients Receiving Pain Management for Sickle Cell Disease in An Urban Setting

Background and Objective: Sickle Cell Disease (SCD) is known to cause acute severe pain episodes known as vaso-occlusive crisis (VOC) mainly treated with opioid analgesics. Since the opioid epidemic there is an interest in determining the opioid misuse potential in these patients. Therefore, the primary objective of this study is to determine the rates of opioid misuse among patients with SCD by assessing the rate of unexpected drug screening results in a sickle cell disease clinic. Methods: This was a retrospective chart review study conducted at the outpatient sickle cell disease clinic. The primary independent variables were the prescribed opioid medications while the primary dependent variable was the collected opioid metabolite. Descriptive statistics, linear regression and multivariate logistic regression analysis were conducted using SPSS version 24. Results: A total of 100 participants were recruited from July 1, 2018, to June 30, 2020 with 71 included in the analysis. The total mean of morphine milligram equivalents (MME) for all participants was 71.1±104.9 with 71% of participants having a daily calculated MME of <90MME. The odds of misusing an opioid were 6.72 times higher (P<.02) if a participant used marijuana compared to a participant who didn't. In addition, the odds of misusing an opioid were 2.47 times higher (P<.04) if the patient was prescribed an opioid daily dose greater than 90 MME as opposed to a daily dose less than 90 MME. Conclusion: Participants who consumed greater than 90 MME's per day and utilized marijuana were more likely to misuse opioids.

Inflammation and autoimmunity are interrelated in patients with sickle cell disease at a steady-state condition: implications for vaso-occlusive crisis, pain, and sensory sensitivity

This study aimed to comprehensively analyze inflammatory and autoimmune characteristics of patients with sickle cell disease (SCD) at a steady-state condition (StSt) compared to healthy controls (HCs) to explore the pathogenesis of StSt and its impact on patients' well-being. The study cohort consisted of 40 StSt participants and 23 HCs enrolled between July 2021 and April 2023. StSt participants showed elevated white blood cell (WBC) counts and altered hematological measurements when compared to HCs. A multiplex immunoassay was used to profile 80 inflammatory cytokines/chemokines/growth factors in plasma samples from these SCD participants and HCs. Significantly higher plasma levels of 35 analytes were observed in SCD participants, with HGF, IL-18, IP-10, and MCP-2 being among the most significantly affected analytes. Additionally, autoantibody profiles were also altered, with elevated levels of anti-SSA/Ro60, anti-Ribosomal P, anti-Myeloperoxidase (MPO), and anti-PM/Scl-100 observed in SCD participants. Flow cytometric analysis revealed higher rates of red blood cell (RBC)/reticulocyte-leukocyte aggregation in SCD participants, predominantly involving monocytes. Notably, correlation analysis identified associations between inflammatory mediator levels, autoantibodies, RBC/reticulocyte-leukocyte aggregation, clinical lab test results, and pain crisis/sensitivity, shedding light on the intricate interactions between these factors. The findings underscore the potential significance of specific biomarkers and therapeutic targets that may hold promise for future investigations and clinical interventions tailored to the unique challenges posed by SCD. In addition, the correlations between vaso-occlusive crisis (VOC)/pain/sensory sensitivity and inflammation/immune dysregulation offer valuable insights into the pathogenesis of SCD and may lead to more targeted and effective therapeutic strategies.

Clinical Trial Registration

ClinicalTrials.gov, Identifier: NCT05045820.

A mass spectrometry assay for detection of endogenous and lentiviral engineered hemoglobin in cultured cells and sickle cell disease mice

Sickle cell disease (SCD) results from a sequence defect in the β-globin chain of adult hemoglobin (HbA) leading to expression of sickle hemoglobin (HbS). It is traditionally diagnosed by cellulose-acetate hemoglobin electrophoresis or high-performance liquid chromatography. While clinically useful, these methods have both sensitivity and specificity limitations. We developed a novel mass spectrometry (MS) method for the rapid, sensitive and highly quantitative detection of endogenous human β-globin and sickle hβ-globin, as well as lentiviral-encoded therapeutic hβAS3-globin in cultured cells and small quantities of mouse peripheral blood. The MS methods were used to phenotype homozygous HbA (AA), heterozygous HbA-HbS (AS) and homozygous HbS (SS) Townes SCD mice and detect lentiviral vector-encoded hβAS3-globin in transduced mouse erythroid cell cultures and transduced human CD34+ cells after erythroid differentiation. hβAS3-globin was also detected in peripheral blood 6 weeks post-transplant of transduced Townes SS bone marrow cells into syngeneic Townes SS mice and persisted for over 20 weeks post-transplant. As several genome-editing and gene therapy approaches for severe hemoglobin disorders are currently in clinical trials, this MS method will be useful for patient assessment before treatment and during follow-up.

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

BACKGROUND

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.

OBJECTIVE

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.

METHODS

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 , t tests, and Mann-Whitney U tests. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.

RESULTS

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 pediatric intensive 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.

CONCLUSION

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.

Sickle cell anemia and pregnancy: Profile of hemodynamic changes in sickle cell pregnant women in Kinshasa

Pregnancy is accompanied by hormonal changes. These relate mainly to progesterone and placenate growth factor. Hemodynamic changes are also observed. in a sickle cell pregnant woman, all these changes have a direct effect on hypoxia. This is responsible for the polymerization of HbS. The latter causes the sickling of sickle red blood cells. sickling of red blood cells is responsible for hemolysis and vasoocclusion, two major acute manifestations during pregnancy in a sickle cell patient.

The Prevalence of Obstructive Sleep Apnea and Associated Symptoms among Patients with Sickle Cell Disease: A Systematic Review and Meta-analysis

Previous studies have shown that patients with sickle cell disease (SCD) are at high risk for obstructive sleep apnea (OSA). In the current study, we aimed to systematically review the literature to address the prevalence of OSA and associated symptoms among patients with SCD. Electronic databases, including Web of Science, Scopus, PubMed, Google Scholar, and Embase were systematically searched to identify the relevant original articles on patients with SCD. Newcastle Ottawa scale was used for quality assessment. Data were pooled by using random effects models. Subgroup analyses were performed by age groups. Thirty-nine studies containing details of 299,358 patients with SCD were included. The pooled results showed that more than half of these patients had OSA with different severities. The prevalence rates of OSA among children with apnea hypopnea index (AHI) cutoffs of above 1, 1.5, and 5 were 51% (95% confidence interval (CI) 36-67%), 29% (95% CI 19-40%), and 18% (95% CI 14-23%), respectively. The prevalence of OSA among adults with AHI cutoff of 5 was 43% (95% CI 21-64%). The pooled rates of snoring, nocturnal enuresis, nocturnal desaturation, and daytime sleepiness were 55% (95% CI 42-69%), 37% (95% CI 33-41%), 49% (95% CI 26-72%), and 21% (95% CI 12-30%), respectively. Given the high prevalence of OSA in patients with SCD, probable greater burden of SCD complications, and irreversible consequences of OSA, screening for OSA symptoms and signs seems useful in these patients. By screening and identifying this heterogeneous disorder earlier, available treatment modalities can be individualized for each patient.

Longer length peripheral catheters in sickle cell treatment: a more efficient and cost-effective care pathway

Patients with sickle cell disease require frequent venous access for red blood cell exchange transfusions to manage their condition. Such frequent access can lead to scar tissue formation, increased pain on insertion, and difficult vascular access for the patients. Previous attempts at achieving successful venous access for patients with difficult venous access has been made with central venous lines, usually femoral lines, which required a large amount of nursing input and resulted in anxiety and pain on insertion for patients. In this article, the author reports on a new pathway with a longer-length peripheral intravenous catheter that reduces the nursing time burden during line insertion, requires less equipment and, crucially, results in a less painful procedure for patients. The increased efficiency of the pathway resulted in a cost saving of £149 per insertion, and patient feedback revealed that the longer-length catheter was preferred over femoral lines.

Inflammation and autoimmunity are interrelated in patients with sickle cell disease at a steady-state condition: implications for vaso-occlusive crisis, pain, and sensory sensitivity

This study aimed to comprehensively analyze inflammatory and autoimmune characteristics of patients with sickle cell disease (SCD) at a steady-state condition (StSt) compared to healthy controls (HCs) to explore the pathogenesis of StSt and its impact on patients' well-being. The study cohort consisted of 40 StSt participants and 23 HCs enrolled between July 2021 and April 2023. StSt participants showed elevated white blood cell (WBC) counts and altered hematological measurements when compared to HCs. A multiplex immunoassay was used to profile 80 inflammatory cytokines/chemokines/growth factors in plasma samples from these SCD participants and HCs. Significantly higher plasma levels of 37 analytes were observed in SCD participants, with HGF, IL-18, IP-10, and MCP-2 being among the most significantly affected analytes. Additionally, autoantibody profiles were also altered, with elevated levels of anti-SSA/Ro60, anti-Ribosomal P, anti-Myeloperoxidase (MPO), and anti-PM/Scl-100 observed in SCD participants. Flow cytometric analysis revealed higher rates of red blood cell (RBC)/reticulocyte-leukocyte aggregation in SCD participants, predominantly involving monocytes. Notably, correlation analysis identified associations between inflammatory mediator levels, autoantibodies, RBC/reticulocyte-leukocyte aggregation, clinical lab test results, and pain crisis/sensitivity, shedding light on the intricate interactions between these factors. The findings underscore the potential significance of specific biomarkers and therapeutic targets that may hold promise for future investigations and clinical interventions tailored to the unique challenges posed by SCD. In addition, the correlations between vaso-occlusive crisis (VOC)/pain/sensory sensitivity and inflammation/immune dysregulation offer valuable insights into the pathogenesis of SCD and may lead to more targeted and effective therapeutic strategies.

Circulating Iron in Patients with Sickle Cell Disease Mediates the Release of Neutrophil Extracellular Traps

Introduction

Neutrophils promote chronic inflammation and release neutrophil extracellular traps (NETs) that can drive inflammatory responses. Inflammation influences progression of sickle cell disease (SCD), and a role for NETs has been suggested in the onset of vaso-occlusive crisis (VOC). We aimed to identify factors in the circulation of these patients that provoke NET release, with a focus on triggers associated with hemolysis.

Methods

Paired serum and plasma samples during VOC and steady state of 18 SCD patients (HbSS/HbSβ0-thal and HbSC/HbSβ+-thal) were collected. Cell-free heme, hemopexin, and labile plasma iron have been measured in the plasma samples of the SCD patients. NETs formation by human neutrophils from healthy donors induced by serum of SCD patients was studied using confocal microscopy and staining for extracellular DNA using Sytox, followed by quantification of surface coverage using ImageJ.

Results

Eighteen patients paired samples obtained during VOC and steady state were available (11 HbSS/HbSβ0-thal and 7 HbSC/HbSβ+-thal). We observed high levels of systemic heme and iron, concomitant with low levels of the heme-scavenger hemopexin in sera of patients with SCD, both during VOC and in steady state. In our in vitro experiments, neutrophils released NETs when exposed to sera from SCD patients. The release of NETs was associated with high levels of circulating iron in these sera. Although hemin triggered NET formation in vitro, addition of hemopexin to scavenge heme did not suppress NET release in SCD sera. By contrast, the iron scavengers deferoxamine and apotransferrin attenuated NET formation in a significant proportion of SCD sera.

Discussion

Our results suggest that redox-active iron in the circulation of non-transfusion-dependent SCD patients activates neutrophils to release NETs, and hence, exerts a direct pro-inflammatory effect. Thus, we propose that chelation of iron requires further investigation as a therapeutic strategy in SCD.

Diagnostic Test Accuracy of Lung Ultrasound for Acute Chest Syndrome in Sickle Cell Disease: A Systematic Review and Meta-analysis

BACKGROUND

Acute chest syndrome (ACS) is a leading cause of death in patients with sickle cell disease. Lung ultrasound (LUS) is emerging as a point-of-care method to diagnose ACS, allowing for more rapid diagnosis in the ED setting and sparing patients from ionizing radiation exposure.

RESEARCH QUESTION

What is the diagnostic accuracy of LUS for ACS diagnosis, using the current reference standard of chest radiography?

STUDY DESIGN AND METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed for this systematic review and meta-analysis. Embase, MEDLINE, Web of Science, and Google Scholar were used to compile all relevant studies. Two reviewers screened the studies for inclusion in this review. Cases of discrepancy were resolved by a third reviewer. Meta-analyses were conducted using both metadta and midas STATA software packages to retrieve summary receiver operating characteristic curves, sensitivities, and specificities. Three reviewers scored the studies with QUADAS-2 for risk of bias assessment.

RESULTS

From a total of 713 unique studies retrieved, six studies were included in the final quantitative synthesis. Of these, five studies were in pediatric EDs. Two studies were conference abstracts and not published manuscripts. Data were available for 625 possible ACS cases (97% of cases in patients aged ≤ 21 years) and 95 confirmed ACS diagnoses (pretest probability of 15.2%). The summary sensitivity was 0.92 (95% CI, 0.68-0.98) and the summary specificity was 0.89 (95% CI, 0.69-0.97) with an area under the curve of the summary receiver operating characteristic curve of 0.96 (95% CI, 0.94-0.97).

INTERPRETATION

LUS has excellent sensitivity and very good specificity for ACS diagnosis and may serve as an initial point-of-care test to facilitate rapid treatment of ACS and spare pediatric patients from ionizing radiation; however, further research is warranted to improve the generalizability to the adult sickle cell disease population.

Functional capacity and quality of life in children and adolescents with sickle cell anemia

OBJECTIVE

To evaluate the functional and exercise capacity, lung function, quality of life of children and adolescents with sickle cell anemia (SCA HbSS) and to test the reproducibility of functional capacity tests in this population.

METHOD

Cross-sectional study with volunteers with SCA Hb-SS (SCAG), aged 6-18 years matched in age and gender to the control group (CG) with healthy individuals. Spirometry, 5-repetition sit-to-stand test (5STS-test), modified shuttle test (MST), and Pediatric Quality of Life Questionnaire (PedsQL) were performed. The reproducibility of 5STS-test and MST was evaluated: RESULTS: Forty eight volunteers of SCAG and 48 of CG were evaluated. Lung function of SCAG (FVC: 92 ± 15% pred.; FEV₁ /FVC: 84 ± 8% pred.) was worse than the CG (104 ± 15% pred.; FEV₁ /FVC: 90 ± 6% pred.) p < 0.05. SCAG had worse functional capacity registered by distance walked: 576 m (515-672 m) and 5STS-test: 8 s (7.4-8.9 s) compared with the CG who showed distance walked: 1010 m (887-1219 m) and 5STS-test: 7 s (7.0-8.1 s), p < 0.001. SCAG had worse quality of life compared to CG, p < 0.05. The reproducibility of MST (ICC 0.99 (0.98-0.99 IC-95%)) and 5STS-test (ICC 0.80 (0.69-0.88) was considered good, p < 0.001.

CONCLUSION

Children and adolescents with sickle cell anemia presented worse capacity to walk or run, and to perform sit-to-stand test when compared with their control peers. Additionally, they have poorer quality of life. The MST and 5STS-test showed good reproducibility to be applied in pediatric individuals with SCA.

Assessment and Prediction of Cardiovascular Contributions to Severe Maternal Morbidity

Severe maternal morbidity (SMM) refers to any unexpected outcome directly related to pregnancy and childbirth that results in both short-term delivery complications and long-term consequences to a women's health. This affects about 60,000 women annually in the United States. Cardiovascular contributions to SMM including cardiac arrest, arrhythmia, and acute myocardial infarction are on the rise, probably driven by changing demographics of the pregnant population including more women of extreme maternal age and an increased prevalence of cardiometabolic and structural heart disease. The utilization of SMM prediction tools and risk scores specific to cardiovascular disease in pregnancy has helped with risk stratification. Furthermore, health system data monitoring and reporting to identify and assess etiologies of cardiovascular complications has led to improvement in outcomes and greater standardization of care for mothers with cardiovascular disease. Improving cardiovascular disease-related SMM relies on a multipronged approach comprised of patient-level identification of risk factors, individualized review of SMM cases, and validation of risk stratification tools and system-wide improvements in quality of care. In this article, we review the epidemiology and cardiac causes of SMM, we provide a framework of risk prediction clinical tools, and we highlight need for organization of care to improve outcomes.

Diaphragm excursion correlates with performance and ventilation on the 6-min walk test in children with sickle cell disease

INTRODUCTION

Diaphragm function may be impaired in children with sickle cell disease (SCD). We hypothesized that diaphragm function is related to performance and ventilation on the 6-min walk test (6MWT).

METHODS

Respiratory muscle testing, diaphragm ultrasonography, and the 6MWT with portable gas analysis were performed on children with SCD and age- and sex-matched controls.

RESULTS

Fourteen children with SCD were enrolled. Comparisons were made between nine children with SCD (9.89  ± $\pm $  2.93 years) and nine controls (10.33  ± $\pm $  2.35 years). Diaphragm thickness at total lung capacity, thickening fraction, and excursion time during quiet breaths and deep breaths (DB), all normalized by forced vital capacity, were greater in children with SCD ( p < $p\lt $ 0.05 for all). 6MWT distance was shorter in children with SCD (450.87  ± $\pm $  74.2 m vs. 579.22 ± $\pm $ 72.46 m, p = $p=$ 0.01). Tidal volume ( V T ${V}_{T}$ ), minute ventilation ( V ˙ E ${\dot{V}}_{E}$ ), and oxygen consumption ( V ˙ O 2 ${\dot{V}}_{{O}_{2}}$ ) were also lower ( p < $p\lt $ 0.05 for all). DB excursion correlated positively with 6MWT distance ( r = $r=$ 0.648, p = $p=$ 0.023) and negatively with rate of perceived exertion (RPE) ( r = $r=$ -0.759, p = $p=$ 0.003). RPE correlated negatively with distance ( r = $r=$ -0.680, p = $p=$ 0.015). DB excursion time correlated positively with distance ( r = $r=$ 0.611, p = $p=$ 0.035), V T ${V}_{T}$ ( r = $r=$ 0.770, p = $p=$ 0.009), V ˙ E ${\dot{V}}_{E}$ ( r = $r=$ 0.736, p = $p=$ 0.015), and V ˙ O 2 ${\dot{V}}_{{O}_{2}}$ ( r = $r=$ 0.751, p = $p=$ 0.012).

CONCLUSIONS

Increased diaphragm excursion may be a strategy used to relieve air hunger while longer excursion time may reflect compensations to increase lung recruitment. Further studies are needed to better understand how these mechanisms affect exercise tolerance in children with SCD.

Insights into Sickle Cell Disease through the Retinal Microvasculature: Adaptive Optics Scanning Light Ophthalmoscopy Correlates of Clinical OCT Angiography

PURPOSE

Clinical OCT angiography (OCTA) of the retinal microvasculature offers a quantitative correlate to systemic disease burden and treatment efficacy in sickle cell disease (SCD). The purpose of this study was to use the higher resolution of adaptive optics scanning light ophthalmoscopy (AOSLO) to elucidate OCTA features of parafoveal microvascular compromise identified in SCD patients.

DESIGN

Case series of 11 SCD patients and 1 unaffected control.

PARTICIPANTS

A total of 11 eyes of 11 SCD patients (mean age, 33 years; range, 23-44; 8 female, 3 male) and 1 eye of a 34-year-old unaffected control.

METHODS

Ten sequential 3 × 3 mm parafoveal OCTA full vascular slab scans were obtained per eye using a commercial spectral domain OCT system (Avanti RTVue-XR; Optovue). These were used to identify areas of compromised perfusion near the foveal avascular zone (FAZ), designated as regions of interest (ROIs). Immediately thereafter, AOSLO imaging was performed on these ROIs to examine the cellular details of abnormal perfusion. Each participant was imaged at a single cross-sectional time point. Additionally, 2 of the SCD patients were imaged prospectively 2 months after initial imaging to study compromised capillary segments across time and with treatment.

MAIN OUTCOME MEASURES

Detection and characterization of parafoveal perfusion abnormalities identified using OCTA and resolved using AOSLO imaging.

RESULTS

We found evidence of abnormal blood flow on OCTA and AOSLO imaging among all 11 SCD patients with diverse systemic and ocular histories. Adaptive optics scanning light ophthalmoscopy imaging revealed a spectrum of phenomena, including capillaries with intermittent blood flow, blood cell stasis, and sites of thrombus formation. Adaptive optics scanning light ophthalmoscopy imaging was able to resolve single sickled red blood cells, rouleaux formations, and blood cell-vessel wall interactions. OCT angiography and AOSLO imaging were sensitive enough to document improved retinal perfusion in an SCD patient 2 months after initiation of oral hydroxyurea therapy.

CONCLUSIONS

Adaptive optics scanning light ophthalmoscopy imaging was able to reveal the cellular details of perfusion abnormalities detected using clinical OCTA. The synergy between these clinical and laboratory imaging modalities presents a promising avenue in the management of SCD through the development of noninvasive ocular biomarkers to prognosticate progression and measure the response to systemic treatment.

Risk of vaso-occlusive episodes in patients with sickle cell disease exposed to systemic corticosteroids: a comprehensive review

INTRODUCTION

Sickle cell disease (SCD) is the most frequent inherited disorder in the world. It is caused by a single amino acid mutation on the beta-globin chain, which lead to red blood cell deformation, haemolysis, and chronic inflammation. Clinical consequences are vaso-occlusives crisis, acute chest syndrome, thrombosis, infection, and chronic endothelial injury.

AREAS COVERED

Corticosteroids are an old therapeutic class, that are inexpensive and widely available, which can be administered in different forms. Their adverse effects are numerous and well-known. This class could appear to be useful in SCD treatment due to its anti-inflammatory effect. Moreover, corticosteroids remain an essential therapeutic class for many indications, besides SCD. Although specific adverse effects of corticosteroids have been suspected in SCD patients for decades, recent papers has reported strong evidence of specific and severe adverse effects in this population. Based on a literature review, we will discuss pathophysiological considerations, consequences, and practical use of corticosteroids in SCD.

EXPERT OPINION

High corticosteroid doses, for any indication , induce vaso-occlusive crises, acute chest syndrome, and re-hospitalization in patients with SCD. There is no evidence of any benefits of corticosteroid use in the SCD acute events. Prevention by hydroxyurea and/or red blood cell transfusion or exchange should be discussed when corticosteroid use is indispensable.

Cutaneous manifestations of sickle cell disease: an updated review

Sickle cell disease is a common and highly morbid genetic condition that is characterized by multi-system involvement, including numerous cutaneous manifestations. Persistent and recurrent leg ulceration has long been considered the dermatological hallmark of those with sickle cell disease, but there have been recent descriptions of associated infection with rare pathogens and episodes of liverdoid vasculopathy. Growing considerations for this population in the literature include cutaneous reactions to common treatments such as hydroxyurea and clinical management of the intersection between sickle cell disease and conditions like plaque psoriasis. Recent studies have also demonstrated an increased resistance to skin carcinogenesis for those with sickle cell disease through unclear mechanisms. However, though the body of knowledge regarding cutaneous manifestations and considerations of sickle cell disease is slowly expanding, it does not match the considerable disease and symptom burden faced by these patients. More research is needed to better delineate our understanding of these cutaneous manifestations of sickle cell disease to improve outcomes and further management.

Chronic anemia: The effects on the connectivity of white matter

Chronic anemia is commonly observed in patients with hemoglobinopathies, mainly represented by disorders of altered hemoglobin (Hb) structure (sickle cell disease, SCD) and impaired Hb synthesis (e.g. thalassemia syndromes, non-SCD anemia). Both hemoglobinopathies have been associated with white matter (WM) alterations. Novel structural MRI research in our laboratory demonstrated that WM volume was diffusely lower in deep, watershed areas proportional to anemia severity. Furthermore, diffusion tensor imaging analysis has provided evidence that WM microstructure is disrupted proportionally to Hb level and oxygen saturation. SCD patients have been widely studied and demonstrate lower fractional anisotropy (FA) in the corticospinal tract and cerebellum across the internal capsule and corpus callosum. In the present study, we compared 19 SCD and 15 non-SCD anemia patients with a wide range of Hb values allowing the characterization of the effects of chronic anemia in isolation of sickle Hb. We performed a tensor analysis to quantify FA changes in WM connectivity in chronic anemic patients. We calculated the volumetric mean of FA along the pathway of tracks connecting two regions of interest defined by BrainSuite's BCI-DNI atlas. In general, we found lower FA values in anemic patients; indicating the loss of coherence in the main diffusion direction that potentially indicates WM injury. We saw a positive correlation between FA and hemoglobin in these same regions, suggesting that decreased WM microstructural integrity FA is highly driven by chronic hypoxia. The only connection that did not follow this pattern was the connectivity within the left middle-inferior temporal gyrus. Interestingly, more reductions in FA were observed in non-SCD patients (mainly along with intrahemispheric WM bundles and watershed areas) than the SCD patients (mainly interhemispheric).

Recent advances in "sickle and niche" research - Tribute to Dr. Paul S Frenette

In this retrospective, we review the two research topics that formed the basis of the outstanding career of Dr. Paul S. Frenette. In the first part, we focus on sickle cell disease (SCD). The defining feature of SCD is polymerization of the deoxygenated mutant hemoglobin, which leads to a vicious cycle of hemolysis and vaso-occlusion. We survey important discoveries in SCD pathophysiology that have led to recent advances in treatment of SCD. The second part focuses on the hematopoietic stem cell (HSC) niche, the complex microenvironment within the bone marrow that controls HSC function and homeostasis. We detail the cells that constitute this niche, and the factors that these cells use to exert control over hematopoiesis. Here, we trace the scientific paths of Dr. Frenette, highlight key aspects of his research, and identify his most important scientific contributions in both fields.

Transcranial doppler as screening method for sickling crises in children with sickle cell anemia: a latin America cohort study

Background

Sickle cell anemia (SCA) is the leading cause of childhood stroke. We aimed to evaluate whether altered cerebral flow velocities, as measured by transcranial Doppler (TCD), are associated with vaso-occlusive complications in addition to stroke in pediatric SCA patients.

Methods

We evaluated 37 children aged between 2 and 16 years with SCA who underwent screening for TCD between January 2012 and October 2018. Genotypic profiles and demographic data were collected, TCD examinations were performed during follow-up, and the presence of sickling crises was compared. Survival analyses were performed using simple frailty models, in which each predictor variable was analyzed separately in relation to the occurrence of a sickling crisis.

Results

The variables related to sickle cell crises in the univariate analysis were peak systolic velocity (PSV) in the middle cerebral artery (MCA), hazard ratio (HR) 1.01 (1.00—1.02) p = 0.04; end-diastolic velocity (EDV) in the MCA, HR 1.02 (1.01—1.04) p = 0.01; time average mean maximum velocity (TAMMV) in the basilar artery (BA), HR 1.02 (1.00—1.04) p = 0.04; hemoglobin, HR 0.49 (0.38—0.65) p < 0.001; hematocrit, HR 0.78 (0.71—0.85) p < 0.001; leukocyte counts, HR 1.1 (1.05—1.15) p < 0.001; platelets counts, HR 0.997 (0.994—0.999) p = 0.02; and reticulocyte numbers, HR 1.14 (1.06—1.23) p < 0.001.

Conclusions

Our results indicate PSV and EDV in the MCA and TAMMV in the BA as markers of risk for the occurrence of sickling crises in SCA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03429-5.

Molecular Mechanisms of Hepatic Dysfunction in Sickle Cell Disease: Lessons From The Townes Mouse Model

Sickle cell disease (SCD) is an autosomal-recessive-genetic disorder that affects ~100,000 Americans and millions of people worldwide. Erythrocyte sickling, vaso-occlusion, sterile inflammation and hemolysis are the major pathophysiological pathways leading to liver injury in SCD. Although hepatic dysfunction affects up to 10-40% of SCD patients, therapeutic approaches to prevent liver injury in SCD are not known, and the molecular mechanisms promoting progressive liver injury in SCD remain poorly understood. Animal models have been beneficial in bridging the gap between preclinical and translational research in SCD. Recent advances in methodology have allowed the development of several humanized mouse models to address various aspects of SCD related liver diseases. This review provides an overview of current knowledge of the molecular mechanisms and potential therapeutic options of SCD associated liver dysfunction using the Townes mouse model.

High risk and low prevalence diseases: Acute chest syndrome in sickle cell disease

INTRODUCTION

Acute chest syndrome (ACS) in sickle cell disease (SCD) is a serious condition that carries with it a high rate of morbidity and mortality.

OBJECTIVE

This review highlights the pearls and pitfalls of ACS in SCD, including diagnosis and management in the emergency department (ED) based on current evidence.

DISCUSSION

ACS is defined by respiratory symptoms and/or fever and a new radiodensity on chest imaging in a patient with SCD. There are a variety of inciting causes, including infectious and non-infectious etiologies. Although ACS is more common in those with homozygous SCD, clinicians should consider ACS in all SCD patients, as ACS is a leading cause of death in SCD. Patients typically present with or develop respiratory symptoms including fever, cough, chest pain, and shortness of breath, which can progress to respiratory failure requiring mechanical ventilation in 20% of adult patients. However, the initial presentation can vary. While the first line imaging modality is classically chest radiograph, lung ultrasound has demonstrated promise. Further imaging to include computed tomography may be necessary. Management focuses on analgesia, oxygen supplementation, incentive spirometry, bronchodilators, rehydration, antibiotics, consideration for transfusion, and specialist consultation. Empiric antibiotics that cover atypical pathogens are necessary along with measures to increase oxygen-carrying capacity in those with hypoxemia such as simple transfusion or exchange transfusion.

CONCLUSIONS

An understanding of ACS can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Axillary intra-aortic balloon pump, biventricular assist device implantation and subsequent orthotopic heart transplantation in a patient with sickle cell trait

A 38-year-old male with sickle cell trait and acute refractory heart failure received an axillary intra-aortic balloon pump and short-term biventricular assist device. He underwent orthotopic heart transplantation 45 days later, which was complicated by major bleeding necessitating significant intra-operative transfusion. Support with veno-arterial extracorporeal membrane oxygenation was provided and successfully weaned five days later. He made a full recovery and remains alive and well 34 months after discharge. We hypothesize that the protective peri-operative measures undertaken, including normothermia during surgery and post-operative haemodynamic stability due to the use of mechanical circulatory support, conveyed a degree of protection against complications associated with sickle cell dysfunction and contributed to the successful outcome.

Validation of patient-reported vaso-occlusive crisis day as an endpoint in sickle cell disease studies

Individuals with sickle cell disease (SCD) experience vaso‐occlusive crises (VOC). Historically, VOC episodes have been assessed through medical utilization, thereby excluding events managed at home. In order to validate a daily patient‐reported outcome for patients with SCD to accurately report their VOC status and experience of a pain crisis, a SCD Diary was included in Evaluation of Longitudinal Pain Study in Sickle Cell Disease (ELIPSIS), a longitudinal, six‐month, non‐interventional study. The daily patient‐completed diary included a description of SCD pain crisis, followed by questions on: pain crisis in the past 24 h (VOC Day question; respective response yes or no), worst pain, tiredness, and functioning. Thirty‐five patients with SCD participated in ELIPSIS. Analyses were performed to validate the patient‐reported VOC Day. Mean symptoms and functioning scores on the first or last VOC Day of a VOC Event were compared using t‐tests with the mean of the three non‐VOC Days before and after the event. Mean severity of symptoms and functioning scores on all VOC Days compared to all non‐VOC Days were higher, with statistically significant mean differences between first/last VOC Days and respective three non‐VOC Days (p's < .01). A subset of patients (n = 15) and caregivers (n = 9) were interviewed to evaluate their understanding of the SCD Diary questions. Nearly all confirmed that the pain crisis description accurately described the VOC experience, and participants expressed confidence differentiating SCD crisis pain from everyday pain. These results demonstrate patients can reliably report their experiences with VOC‐related pain crises using the SCD Diary.

Acute chest syndrome of sickle cell disease: genetics, risk factors, prognosis and management

IntroductionSickle cell disease, one of the world's most prevalent Mendelian disorders, is a chronic hemolytic anemia punctuated by acute vasoocclusive events. Both hemolysis and vasoocclusion lead to irreversible organ damage and failure. Among the many sub-phenotypes of sickle cell disease is the acute chest syndrome (ACS) characterized by combinations of chest pain, cough, dyspnea, fever, abnormal lung exam, leukocytosis, hypoxia, and new radiographic opacities. ACS is a major cause of morbidity and mortality.Area coveredWe briefly review the diagnosis, epidemiology, etiology, and current treatments for ACS and focus on understanding and estimating the risks for developing this complication, how prognosis and outcomes might be improved and the genetic elements that might impact the risk of ACS.Expert opinionThe clinical heterogeneity of ACS has hindered our understanding of risk stratification. Lacking controlled clinical trials most treatment is based on expert opinion. Fetal hemoglobin levels and coexistent α thalassemia affect the incidence of ACS; other genetic associations are tenuous. Transfusions, whose use not innocuous, should be targeted to the severity and likelihood of ACS progression. Stable, non-hypoxic patients with favorable hematologic and radiographic findings usually do not need transfusion; severe progressive ACS is best managed with exchange transfusion.

Do Genetic Polymorphisms Affect Fetal Hemoglobin (HbF) Levels in Patients With Sickle Cell Anemia Treated With Hydroxyurea? A Systematic Review and Pathway Analysis

Hydroxyurea has long been used for the treatment of sickle cell anemia (SCA), and its clinical effectiveness is related to the induction of fetal hemoglobin (HbF), a major modifier of SCA phenotypes. However, there is substantial variability in response to hydroxyurea among patients with SCA. While some patients show an increase in HbF levels and an ameliorated clinical condition under low doses of hydroxyurea, other patients present a poor effect or even develop toxicity. However, the effects of genetic polymorphisms on increasing HbF levels in response to hydroxyurea in patients with SCA (Hb SS) have been less explored. Therefore, we performed a systematic review to assess whether single-nucleotide polymorphisms (SNPs) affect HbF levels in patients with SCA treated with hydroxyurea. Moreover, we performed pathway analysis using the set of genes with SNPs found to be associated with changes in HbF levels in response to hydroxyurea among the included studies. The systematic literature search was conducted on Medline/PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, and Web of Science. Seven cohort studies were included following our inclusion and exclusion criteria. From the 728 genetic polymorphisms examined in the included studies, 50 different SNPs of 17 genes were found to be associated with HbF changes in patients with SCA treated with hydroxyurea, which are known to affect baseline HbF but are not restricted to them. Enrichment analysis of this gene set revealed reactome pathways with the lowest adjusted p-values and highest combined scores related to VEGF ligand–receptor interactions (R-HSA-194313; R-HSA-195399) and the urea cycle (R-HSA-70635). Pharmacogenetic studies of response to hydroxyurea therapy in patients with SCA are still scarce and markedly heterogeneous regarding candidate genes and SNPs examined for association with HbF changes and outcomes, suggesting that further studies are needed. The reviewed findings highlighted that similar to baseline HbF, changes in HbF levels upon hydroxyurea therapy are likely to be regulated by multiple loci. There is evidence that SNPs in intron 2 of BCL11A affect HbF changes in response to hydroxyurea therapy, a potential application that might improve the clinical management of SCA.

Systematic Review Registration: (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=208790).

Etavopivat, a Pyruvate Kinase Activator in Red Blood Cells, for the Treatment of Sickle Cell Disease

Etavopivat is an investigational, oral, small molecule activator of erythrocyte pyruvate kinase (PKR) in development for the treatment of sickle cell disease (SCD) and other hemoglobinopathies. PKR activation is proposed to ameliorate the sickling of SCD red blood cells (RBC) through multiple mechanisms, including reduction of 2,3-diphosphoglycerate (2,3-DPG), which consequently increases hemoglobin (Hb)-oxygen affinity; increased binding of oxygen reduces HbS polymerization and sickling. In addition, PKR activation increases adenosine triphosphate (ATP) produced via glycolytic flux, which helps preserve membrane integrity and RBC deformability. We evaluated the pharmacodynamic response to etavopivat in non-human primates (NHP) and in healthy human subjects, and the effects in RBC from patients with SCD after ex vivo treatment with etavopivat. A single dose of etavopivat decreased 2,3-DPG in NHP and healthy subjects. Hb-oxygen affinity was significantly increased in healthy subjects after 24 hours. Following daily dosing of etavopivat over 5 consecutive days in NHP, ATP was increased by 38% from baseline. Etavopivat increased Hb-oxygen affinity and reduced sickling in RBC collected from SCD patients with either HbSS or HbSC disease. Collectively, these results demonstrate the ability of etavopivat to decrease 2,3-DPG and increase ATP, resulting in increased Hb-oxygen affinity and improved sickle RBC function. Etavopivat is currently being evaluated in clinical trials for the treatment of SCD. ClinicalTrials.gov identifier: NCT03815695 Significance Statement Etavopivat-a small molecule activator of the glycolytic enzyme erythrocyte pyruvate kinase -decreased 2,3-diphosphoglycerate in red blood cells (RBC) from non-human primates and healthy subjects and significantly increased hemoglobin (Hb)-oxygen affinity in healthy subjects. Using ex vivo RBC from donors with sickle cell disease (SCD) (HbSS or HbSC genotype), etavopivat increased Hb-oxygen affinity and reduced sickling under deoxygenation. Etavopivat shows promise as a treatment for SCD, that potentially might reduce vaso-occlusion and improve anemia.

Multifocal Calvarial Infarction with Epidural Hemorrhage in a Patient with Sickle Cell Vaso-Occlusive Crisis: A Case Report

While primarily a hematologic disease, sickle cell anemia is notorious for its multisystemic manifestations, particularly in episodes of vaso-occlusive crisis. Multifocal acute calvarial infarction with associated epidural hemorrhage has rarely been reported in sickle cell vaso-occlusive crisis. In this article, we reported a unique case of a 15-year-old male presenting with sickle cell vaso-occlusive crisis and neuroimaging findings of multifocal calvarial bone infarction and epidural hemorrhage. Radiologists and clinicians should be cognizant of this rare complication of sickle cell anemia to ensure appropriate diagnosis and timely treatment.

Parvovirus Infection and Thrombotic Thrombocytopenic Purpura in an Adult Patient With Sickle Cell Beta-Thalassemia

Parvovirus infection and thrombotic thrombocytopenic purpura (TTP) are rare manifestations in adults with sickle cell beta-thalassemia. Due to the lack of a clear demarcation between the complications related to sickle cell disease (SCD) and TTP, the diagnosis is often challenging. The treatment requirements for both these entities are divergent and complicated, thus necessitating a careful plan of action during atypical presentations. Here we present a case of a 22-year-old woman during the peripartum period with fever, generalized body aches, and large joint pains that soon evolved into labor. The patient’s history was suggestive of an undiagnosed and inherited blood disorder. The presentation of aplastic crisis-splenic sequestration during early adulthood is atypical for the SCD course in general populations. Moreover, as the patient’s clinical status deteriorated with blood transfusion, the diagnosis and management of a sickle cell crisis event and TTP added to the dilemma in the presence of non-classic parvovirus infection. Though the causation of TTP due to SCD-parvovirus infection is questionable, the treatment of the baseline sickle cell crisis with the novel supportive measures resolved the underlying complications in our patient, suggesting the causal effect. As a result of this, we emphasize the importance of being vigilant about such atypical presentations to avoid delays in diagnosis and treatment of such life-threatening emergencies like TTP.

Integrin VLA-4 as a PET imaging biomarker of hyper-adhesion in transgenic sickle mice

In sickle cell disease (SCD), very late antigen-4 (VLA-4 or integrin α4β1) mediates the adhesion of reticulocytes to inflamed, proinflammatory endothelium, a key process in promoting vaso-occlusive episodes (VOEs). We hypothesized that a radionuclide tracer targeting VLA-4 could be harnessed as a positron emission tomography (PET) imaging biomarker of VOEs. We tested the VLA-4 peptidomimetic PET tracer 64Cu-CB-TE1A1P-PEG4-LLP2A (64Cu-LLP2A) for imaging hyper-adhesion-associated VOEs in the SCD Townes mouse model. With lipopolysaccharide (LPS)-induced VOEs, 64Cu-LLP2A uptake was increased in the bone marrow of the humeri and femurs, common sites of VOEs in SCD mice compared with non-SCD mice. Treatment with a proven inhibitor of VOEs (the anti-mouse anti-P-selectin monoclonal antibody [mAb] RB40.34) during LPS stimulation led to a reduction in the uptake of 64Cu-LLP2A in the humeri and femurs to baseline levels, implying blockade of VOE hyper-adhesion. Flow cytometry with Cy3-LLP2A demonstrated an increased percentage of VLA-4-positive reticulocytes in SCD vs non-SCD mice in the bone and peripheral blood after treatment with LPS, which was abrogated by anti-P-selectin mAb treatment. These data, for the first time, show in vivo imaging of VLA-4-mediated hyper-adhesion, primarily of SCD reticulocytes, during VOEs. PET imaging with 64Cu-LLP2A may serve as a valuable, noninvasive method for identifying sites of vaso-occlusion and may provide an objective biomarker of disease severity and anti-P-selectin treatment efficacy in patients with SCD.

Sevuparin for the treatment of acute pain crisis in patients with sickle cell disease: a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial

BACKGROUND

There are no approved treatments for vaso-occlusive crises in sickle cell disease. Sevuparin is a novel non-anticoagulant low molecular weight heparinoid, with anti-adhesive properties. In this study, we tested whether sevuparin could shorten vaso-occlusive crisis duration in hospitalised patients with sickle cell disease.

METHODS

We did a multicentre, double-blinded, placebo-controlled, phase 2 study in 16 public access clinical hospitals in the Netherlands, Lebanon, Turkey, Bahrain, Oman, Saudi Arabia, and Jamaica. Patients aged 12-50 years with a diagnosis of sickle cell disease (types HbSS, HbSC, HbSβ⁰-thalassaemia, or HbSβ⁺-thalassaemia) on a stable dose of hydroxyurea, hospitalised with vaso-occlusive crisis for parenteral opioid analgesia with a projected stay of more than 48 h were included in the study. Patients were randomly assigned (1:1) using a computer-generated randomisation scheme to receive sevuparin (18 mg/kg per day) or placebo (NaCl, 0·9% solution) intravenously for 2-7 days until vaso-occlusive crisis resolution. All individuals involved in the trial were masked to treatment allocation. The analysis was done in the intention-to-treat population. The primary endpoint was time to vaso-occlusive crisis resolution defined as freedom from parenteral opioid use (in preceding 6-10 h); and readiness for discharge as judged by the patient or physician. The trial is registered with ClinicalTrials.gov, NCT02515838.

FINDINGS

Between Oct 7, 2015, and Feb 10, 2019, 144 patients were randomly assigned and administered sevuparin (n=69) or placebo (n=75). The median age was 22·2 years (range 12·2-33·6), 104 (72%) 144 were adults (18 years or older), and 90 (63%) were male and 54 (37%) were female. The intention-to-treat analysis for the primary endpoint showed no significant difference in median time to vaso-occlusive crisis resolution between the sevuparin and placebo groups (100·4 h [95% CI 85·5-116·8]) vs 86·4 h [70·6-95·1]; hazard ratio 0·89 [0·6-1·3]; p=0·55). Serious adverse events occurred in 16 (22%) of 68 patients in the sevuparin group and in 21 (22%) of patients in the placebo group. The most frequent treatment-emergent adverse events were pyrexia (17 [25%] in the sevuparin group vs 17 [22%] in the placebo group), constipation (12 [18%] vs 17 [22%]), and decreased haemoglobin (18 [26%] vs 9 [12%]). There were no deaths in the sevuparin group and there was one (1%) death in the placebo group after a hyper-haemolytic episode due to alloimmunisation.

INTERPRETATION

This result, as well as the results seen in other clinical studies of inhibitors of adhesion in sickle cell disease, suggest that selectin-mediated adhesion might be important in the initiation, but not maintenance of vaso-occlusion, indicating that strategies to treat vaso-occlusive crises differ from strategies to prevent this complication.

FUNDING

Modus Therapeutics.

P-selectin-deficient mice to study pathophysiology of sickle cell disease

P-selectin–deficient SCD mice are protected from lung vaso-occlusion. P-selectin–deficient SCD mice will be useful in assessing the benefits of anti–P-selectin therapy in diverse complications of SCD.

Impact of sickle cell disease on patients' daily lives, symptoms reported, and disease management strategies: Results from the international Sickle Cell World Assessment Survey (SWAY)

Sickle cell disease (SCD) is a genetic disorder, characterized by hemolytic anemia and vaso‐occlusive crises (VOCs). Data on the global SCD impact on quality of life (QoL) from the patient viewpoint are limited. The international Sickle Cell World Assessment Survey (SWAY) aimed to provide insights into patient‐reported impact of SCD on QoL. This cross‐sectional survey of SCD patients enrolled by healthcare professionals and advocacy groups assessed disease impact on daily life, education and work, symptoms, treatment goals, and disease management. Opinions were captured using a Likert scale of 1‐7 for some questions; 5‐7 indicated “high severity/impact.” Two thousand one hundred and forty five patients (mean age 24.7 years [standard deviation (SD) = 13.1], 39% ≤18 years, 52% female) were surveyed from 16 countries (six geographical regions). A substantial proportion of patients reported that SCD caused a high negative impact on emotions (60%) and school achievement (51%) and a reduction in work hours (53%). A mean of 5.3 VOCs (SD = 6.8) was reported over the 12 months prior to survey (median 3.0 [interquartile range 2.0‐6.0]); 24% were managed at home and 76% required healthcare services. Other than VOCs, fatigue was the most commonly reported symptom in the month before survey (65%), graded “high severity” by 67% of patients. Depression and anxiety were reported by 39% and 38% of patients, respectively. The most common patient treatment goal was improving QoL (55%). Findings from SWAY reaffirm that SCD confers a significant burden on patients, epitomized by the high impact on patientsʼ QoL and emotional wellbeing, and the high prevalence of self‐reported VOCs and other symptoms.

Agonistic Anti-CD40 Antibody Triggers an Acute Liver Crisis With Systemic Inflammation in Humanized Sickle Cell Disease Mice

Sickle cell disease (SCD) is an inherited hemolytic disorder, defined by a point mutation in the β-globin gene. Stress conditions such as infection, inflammation, dehydration, and hypoxia trigger erythrocyte sickling. Sickled red blood cells (RBCs) hemolyze more rapidly, show impaired deformability, and increased adhesive properties to the endothelium. In a proinflammatory, pro-coagulative environment with preexisting endothelial dysfunction, sickled RBCs promote vascular occlusion. Hepatobiliary involvement related to the sickling process, such as an acute sickle hepatic crisis, is observed in about 10% of acute sickle cell crisis incidents. In mice, ligation of CD40 with an agonistic antibody leads to a macrophage activation in the liver, triggering a sequence of systemic inflammation, endothelial cell activation, thrombosis, and focal ischemia. We found that anti-CD40 antibody injection in sickle cell mice induces a systemic inflammatory and hemodynamic response with accelerated hemolysis, extensive vaso-occlusion, and large ischemic infarctions in the liver mimicking an acute hepatic crisis. Administration of the tumor necrosis factor-α (TNF-α) blocker, etanercept, and the heme scavenger protein, hemopexin attenuated end-organ damage. These data collectively suggest that anti-CD40 administration offers a novel acute liver crisis model in humanized sickle mice, allowing for evaluation of therapeutic proof-of-concept.

Characterization of microvascular disease in pediatric sickle cell disease using nailfold capillaroscopy

Sickle cell disease (SCD) is a disorder with repetitive vaso-occlusive crises resulting in microvascular obstruction and tissue ischemia that may lead to multi-organ ischemia and dysfunction. Nailfold videocapillaroscopy (NFC) is an imaging technique utilized in clinical rheumatology to visualize capillaries located near the fingertip. To characterize NFC abnormalities in the setting of pediatric SCD, we performed NFC using a video capillaroscope on 8 digits in 44 stable SCD patients and 65 age matched healthy controls. Mean capillary number was lower (6.4 ± 1.3 vs 7.5 ± 1.8, p = 0.001) in the SCD group compared to controls. The percentage of dilated capillaries was similar (7.1 ± 8.3 vs. 5.9 ± 8.2, p = 0.4). The large majority of capillaries visualized in the SCD and control groups were normal capillary types per the EULAR definition, with a similar percentage of normal, nonspecific capillary morphologies and abnormal types. Regarding normal capillary sub-types, the SCD group and controls exhibited similar percentages of stereotype hairpin shapes, and tortuous or once or twice crossing type capillaries. On multivariate analyses, mean capillary number was independently associated with SCD after adjusting for age, body mass index, systolic blood pressure and gender. In conclusion, pediatric SCD is associated with lower capillary number but similar percentage of dilated capillaries and morphology on NFC. In our SCD cohort, capillary number was unrelated to our available markers of disease severity, including history of sickle crises, previous hospitalization for crises or Hemoglobin F levels.

Xanthine Oxidase Drives Hemolysis and Vascular Malfunction in Sickle Cell Disease

OBJECTIVE

Chronic hemolysis is a hallmark of sickle cell disease (SCD) and a driver of vasculopathy; however, the mechanisms contributing to hemolysis remain incompletely understood. Although XO (xanthine oxidase) activity has been shown to be elevated in SCD, its role remains unknown. XO binds endothelium and generates oxidants as a byproduct of hypoxanthine and xanthine catabolism. We hypothesized that XO inhibition decreases oxidant production leading to less hemolysis. Approach and Results: Wild-type mice were bone marrow transplanted with control (AA) or sickle (SS) Townes bone marrow. After 12 weeks, mice were treated with 10 mg/kg per day of febuxostat (Uloric), Food and Drug Administration-approved XO inhibitor, for 10 weeks. Hematologic analysis demonstrated increased hematocrit, cellular hemoglobin, and red blood cells, with no change in reticulocyte percentage. Significant decreases in cell-free hemoglobin and increases in haptoglobin suggest XO inhibition decreased hemolysis. Myographic studies demonstrated improved pulmonary vascular dilation and blunted constriction, indicating improved pulmonary vasoreactivity, whereas pulmonary pressure and cardiac function were unaffected. The role of hepatic XO in SCD was evaluated by bone marrow transplanting hepatocyte-specific XO knockout mice with SS Townes bone marrow. However, hepatocyte-specific XO knockout, which results in >50% diminution in circulating XO, did not affect hemolysis levels or vascular function, suggesting hepatocyte-derived elevation of circulating XO is not the driver of hemolysis in SCD.

CONCLUSIONS

Ten weeks of febuxostat treatment significantly decreased hemolysis and improved pulmonary vasoreactivity in a mouse model of SCD. Although hepatic XO accounts for >50% of circulating XO, it is not the source of XO driving hemolysis in SCD.

Postoperative acute multiple organ failure after hepatectomy in a Nigerian male with sickle cell trait: a case report

Background

Sickle cell disease (SCD) is a monogenic disease characterized by sickle hemoglobin (HbS). Patients homozygous for HbS experience symptoms resulting from sickled erythrocytes no later than adolescence. However, heterozygous HbS carriers, or those with the so-called sickle cell trait (SCT), may undergo surgery without their hemoglobinopathy being known.

Case presentation

A 53-year-old Nigerian male with hepatitis C infection underwent radiofrequency ablation therapy for multiple hepatocellular carcinomas (HCCs) 17 months prior. Follow-up computed tomography (CT) revealed a solitary tumor (3.2 cm) in the medial section of the cirrhotic liver. The Child–Pugh score was five, and the indocyanine green retention rate at 15 min was 17.4%. The nontumorous liver of the medial section accounted for 10% of the total liver volume according to CT volumetry. With the diagnosis of recurrent HCC, left medial sectionectomy was performed under intermittent blood flow occlusion by Pringle’s maneuver. Intraoperative ultrasonography confirmed that hepatic blood flow had been preserved after hepatectomy. However, laboratory tests on postoperative day (POD) 1 revealed severe liver damage: aspartate aminotransferase 9250 IU/L, alanine aminotransferase 6120 IU/L, total bilirubin 2.8 mg/dL, and prothrombin time% 20.9%. The patient’s renal and respiratory functions also deteriorated; therefore, continuous hemodiafiltration and plasma exchange were initiated under mechanical ventilation. Whole-body contrast-enhanced CT showed no apparent ischemia of the remnant liver, but diffuse cerebral infarction was detected. Despite intensive treatments, he died of multiple organ failure on POD 20. The pathological examination of the resected specimen revealed that the intrahepatic peripheral vessels were occluded by sickled erythrocytes. Additionally, chromatographic analysis of hemoglobin detected the presence of abnormal hemoglobin, although microscopic examination of the peripheral blood erythrocytes did not show morphological abnormalities. Based on these findings, we determined that he had SCT and developed vaso-occlusive crisis involving multiple organs just after hepatectomy.

Conclusion

SCD is a rare disease in eastern Asia, but its prevalence is increasing globally. Surgeons should pay increased attention to this disease, especially when performing hepatectomy under blood flow occlusion.

Crizanlizumab and comparators for adults with sickle cell disease: a systematic review and network meta-analysis

OBJECTIVES

Treatment options for preventing vaso-occlusive crises (VOC) among patients with sickle cell disease (SCD) are limited, especially if hydroxyurea treatment has failed or is contraindicated. A systematic literature review (SLR) and network meta-analysis (NMA) were conducted to evaluate the efficacy and safety of crizanlizumab for older adolescent and adult (≥16 years old) SCD patients.

METHODS

The SLR included randomised controlled trials (RCTs) and uncontrolled studies. Bayesian NMA of VOC, all-cause hospitalisation days and adverse events were conducted.

RESULTS

The SLR identified 51 studies and 9 RCTs on 14 treatments that met the NMA inclusion criteria. The NMA found that crizanlizumab 5.0 mg/kg was associated with a reduction in VOC (HR 0.55, 95% credible interval (0.43, 0.69); Bayesian probability of superiority >0.99), all-cause hospitalisation days (0.58 (0.50, 0.68); >0.99) and no evidence of difference on adverse events (0.91 (0.59, 1.43) 0.66) or serious adverse events (0.93 (0.47, 1.87); 0.59) compared with placebo. The HR for reduction in VOC for crizanlizumab relative to L-glutamine was (0.67 (0.50, 0.88); >0.99). These results were sensitive to assumptions regarding whether patient age is an effect modifier.

CONCLUSIONS

This NMA provides preliminary evidence comparing the efficacy of crizanlizumab with other treatments for VOC prevention.

Respiratory pathogens and acute chest syndrome in children with sickle cell disease

BACKGROUND

Acute chest syndromes (ACS) may be associated with upper respiratory tract infections, but the epidemiology of viral and intracellular respiratory pathogens in children with sickle cell disease (SCD) is not precisely known. The aim of this study was to describe the epidemiology of viral and intracellular respiratory pathogens in children with SCD presenting with fever and/or ACS.

MATERIALS AND METHODS

An observational, prospective, single-centre cohort study with nested case-control analysis was conducted on children with SCD admitted from October 2016 to October 2017 for fever and/or ACS to the paediatric department of Robert Debré university hospital, Paris, France. They were screened for 20 respiratory pathogens by a multiplex PCR in the nasopharynx (FilmArray).

RESULTS

We included 101 children. M/F sex ratio of 0.45. The median age was 3.2 years (IQR: 1.4-8.2). At least one pathogen was isolated in 67 patients (67%). The most frequent viruses were as follows: rhinovirus (n=33), adenovirus (n=14), respiratory syncytial virus (n=13) and parainfluenza viruses (n=11). Mycoplasma pneumoniae was detected in one case. Twenty-three (23%) presented with or developed ACS. A nested case-control analysis was performed, after pairing ACS with non-ACS children for age and inclusion period. There was no statistical association between any viral detection or multiple viral infection, and ACS (p=0.51) even though parainfluenza viruses were twice as common in ACS.

CONCLUSIONS

Viral detection in febrile children with SCD is frequent, but its association with ACS was not demonstrated. In this study, M. pneumoniae was rare in young children with SCD experiencing ACS.