Vaso-occlusive Episodes Research Articles

Trends and hospital practice variation for analgesia for children with sickle cell disease with vaso-occlusive pain episodes: An 11-year analysis

This cross-sectional analysis of 86,111 visits for sickle cell disease and vaso-occlusive episodes (VOE) in U.S. pediatric emergency departments between 2013 and 2023 shows increased use of NSAIDs, ketamine, and acetaminophen, with unchanged opioid use. Hospitals with a higher volume of VOE visits more frequently administered opioids. BackgroundVaso-occlusive episodes (VOEs) are a hallmark of sickle cell disease (SCD), leading to frequent emergency department (ED) visits. Effective pain management is crucial, with guidelines recommending routine use of non-steroidal anti-inflammatory drugs (NSAIDs) with opioids, and emerging evidence supporting ketamine use. However, these recommendations are based on low-certainty evidence, and the impact of these guidelines on analgesia use over time remains unclear. ObjectiveThis study aimed to analyze trends in analgesia use over an 11-year period in pediatric SCD patients presenting to U.S. EDs with VOE and assess variations in treatment across hospitals. MethodsA cross-sectional study was conducted using data from the Pediatric Health Information System covering 34 U.S. children's hospitals from January 1, 2013, to December 31, 2023. The primary outcomes were the proportions of visits where opioids, NSAIDs, acetaminophen, and/or ketamine were administered on the first calendar day of the initial visit. Secondary outcomes included the co-administration of NSAIDs with opioids. Logistic and linear regression models were used to assess trends and hospital-level variations. ResultsA total of 86,111 ED visits for VOE were analyzed. Opioids were administered in 82 % of encounters, NSAIDs in 72 %, acetaminophen in 17 %, and ketamine in 1 %. Co-administration of NSAIDs with opioids occurred in 59 % of the visits. Among discharged patients, there was a positive trend for NSAID use (slope: 1.68 %/year, 95 % CI: 0.91 %, 2.45 %) and NSAID-opioid co-administration (slope: 1.03 %/year, 95 % CI: 0.37 %, 1.69 %) over time. Acetaminophen use also increased over the study period (slope: 0.99 %/year, 95 % CI: 0.80 %, 1.17 %). In hospitalized patients, there was a significant upward trend for acetaminophen (slope: 1.29 %/year, 95 % CI: 0.69 %, 1.89 %) and ketamine (slope: 0.36 %/year, 95 % CI: 0.27 %, 0.45 %), while opioid use remained unchanged. Significant hospital-level variations were observed, with larger hospitals more likely to administer opioids but less likely to co-administer NSAIDs with opioids compared to medium-volume hospitals. ConclusionOver the past decade, the use of NSAIDs, acetaminophen, and ketamine has increased in the management of VOE in pediatric SCD patients, while opioid use remains consistent. The co-administration of NSAIDs and opioids has also increased, reflecting guideline adherence. Variations in analgesia practices across hospitals underscore the need for standardizing pain management strategies in this population.

Development, implementation, and acceptability of a bedside mindfulness intervention for adults with sickle cell disease

ABSTRACT Acute and chronic pain are the most frequent complications of sickle cell disease (SCD), often severely reducing quality of life and requiring management with long-term pharmacological interventions. A biopsychosocial approach conceptualizing pain in SCD as the result of complex biological, psychological, and social factors could facilitate targeted behavioral interventions. Mindfulness is one procedure for management of pain in individuals with chronic pain/illness. The goal of the current project was to design and implement a bedside mindfulness intervention to help patients with SCD enhance self-efficacy of pain management and reduce distress. As part of a quality improvement project in SCD clinics in a large health system, we developed a bedside mindfulness intervention to be provided during infusion sessions for patients presenting for acute vaso-occlusive episodes (VOE). The approach to development and implementation involved engagement of professionals working directly with patients. Concept planning meetings with these professionals along with qualitative patient and provider feedback informed feasibility, design, and intervention application. During a quantitative phase, patients completed validated surveys items on acceptability. Interview data (N = 11) supported patient interest in mindfulness skills and highlighted a need for tailored, person-centered interventions and non-pharmacological treatment strategies. On quantitative items, participants (N = 14) liked the intervention and agreed mindfulness skills would help manage disease-related distress. Following the interventions, participants reported increased mindfulness (p = .005). While preliminary, these results provide support for the continued development of evidence-based, mindfulness-oriented services to help individuals with SCD manage pain and other psychological difficulties.

Inpatient Management of Pain Episodes in Children with Sickle Cell Disease: A Review.

Sickle cell disease (SCD) is the most common hemoglobinopathy in the world. Sickle cell vaso-occlusive episodes (VOEs) are very painful acute events and the most common complication as well as reason for hospitalization. SCD pain is best evaluated holistically with a pain functional assessment to aid in focusing pain management on reducing pain in addition to improving function. Patients with SCD have long endured structural racism and negative implicit bias surrounding the management of pain. Thus, it is important to approach the management of inpatient pain systematically with the use of multi-modal medications and nonpharmacologic treatments. Furthermore, equitable pain management care can be better achieved with standardized pain plans for an entire system and individualized pain plans for patients who fall outside the scope of the standardized pain plans. In this article, we discuss the best practices to manage SCD VOEs during an inpatient hospitalization.

Lactated Ringer vs Normal Saline Solution During Sickle Cell Vaso-Occlusive Episodes

Sickle cell disease (SCD), a clinically heterogenous genetic hemoglobinopathy, is characterized by painful vaso-occlusive episodes (VOEs) that can require hospitalization. Patients admitted with VOEs are often initially resuscitated with normal saline (NS) to improve concurrent hypovolemia, despite preclinical evidence that NS may promote erythrocyte sickling. The comparative effectiveness of alternative volume-expanding fluids (eg, lactated Ringer [LR]) for resuscitation during VOEs is unclear. To compare the effectiveness of LR to NS fluid resuscitation in patients with SCD and VOEs. This multicenter cohort study and target trial emulation included inpatient adults with SCD VOEs who received either LR or NS on hospital day 1. The Premier PINC AI database (2016-2022), a multicenter clinical database including approximately 25% of US hospitalizations was used. The analysis took place between October 6, 2023, and June 20, 2024. Receipt of LR (intervention) or NS (control) on hospital day 1. The primary outcome was hospital-free days (HFDs) by day 30. Targeted maximum likelihood estimation was used to calculate marginal effect estimates. Heterogeneity of treatment effect was explored in subgroups. A total of 55 574 patient encounters where LR (n = 3495) or NS (n = 52 079) was administered on hospital day 1 were included; the median (IQR) age was 30 (25-37) years. Patients who received LR had more HFDs compared with those who received NS (marginal mean difference, 0.4; 95% CI, 0.1-0.6 days). Patients who received LR also had shorter hospital lengths of stay (marginal mean difference, -0.4; 95% CI, -0.7 to -0.1 days) and lower risk of 30-day readmission (marginal risk difference, -5.8%; 95% CI, -9.8% to -1.8%). Differences in HFDs between LR and NS were heterogenous based on fluid volume received: among patients who received less than 2 L, there was no difference in LR vs NS; among those who received 2 or more L, LR was superior to NS. This cohort study found that, compared with NS, LR had a small but significant improvement in HFDs and secondary outcomes including 30-day readmission. These results suggest that, among patients with VOEs in whom clinicians plan to give volume resuscitation fluids on hospital admission, LR should be preferred over NS.

Identification of genetic variants associated with clinical features of sickle cell disease

Sickle cell disease (SCD) is an inherited blood disorder marked by homozygosity of hemoglobin S, which is a defective hemoglobin caused by a missense mutation in the β-globin gene. However, clinical phenotypes of SCD vary among patients. To investigate genetic variants associated with various clinical phenotypes of SCD, we genotyped DNA samples from 520 SCD subjects and used a genome-wide association study (GWAS) approach to identify genetic variants associated with phenotypic features of SCD. For HbF levels, the previously reported 2p16.1 locus (BCL11A) reached genome significance (rs1427407, P = 8.58 × 10–10) in our GWAS as expected. In addition, we found a new genome-wide significance locus at 15q14 (rs8182015, P = 2.07 × 10–8) near gene EMC7. GWAS of acute chest syndrome (ACS) detected a locus (rs79915189, P = 3.70 × 10–8) near gene IDH2 at 15q26.1. The SNP, rs79915189, is also an expression quantitative trait locus (eQTL) of IDH2 in multiple tissues. For vasoocclusive episode (VOE), GWAS detected multiple significant signals at 2p25.1 (rs62118798, P = 4.27 × 10–8), 15q26.1 (rs62020555, P = 2.04 × 10–9) and 15q26.3 (rs117797325, P = 4.63 × 10–8). Our findings provide novel insights into the genetic mechanisms of SCD suggesting that common genetic variants play an important role in the presentation of the clinical phenotypes of patients with SCD.

Gene Therapies for Sickle Cell Disease.

Background: Sickle cell disease (SCD) is a prevalent autosomal recessive hemoglobinopathy affecting millions worldwide, particularly individuals of African ancestry. Sickle cell disease is a lifelong condition associated with a negative impact on quality of life and mortality, causing complications such as painful vaso-occlusive episodes, acute chest syndrome, stroke, long-term anemia, and end-organ damage. Currently, there are 4 U.S. Food and Drug Administration (FDA)-approved drugs, including hydroxyurea, l-glutamine, voxelotor, and crizanlizumab, which work to alleviate symptoms and prevent complications associated with SCD, albeit without addressing the underlying cause of SCD. Allogeneic hematopoietic stem cell transplant (HSCT) has shown promise as a curative approach to SCD but is limited by donor availability and associated complications. This paper aims to review the efficacy and safety of exagamglogene autotemcel and lovotibeglogene autotemcel for managing patients with SCD, including their place in therapy, cost, and accessibility in clinical care. Data Sources: The authors searched PubMed and Medline from 2017 to 2024, for primary literature on both exagamglogene autotemcel and lovotibeglogene autotemcel. Results: The authors identified relevant studies and summarized the data on the two gene therapies. Conclusion: Exagamglogene autotemcel and lovotibeglogene autotemcel are two management strategies that address the underlying cause of SCD and provide curative potential for patients with SCD.

Comparison of Measures of Pain Intensity During Sickle Cell Disease Vaso-Occlusive Episodes

We aimed to determine the minimal clinically important difference (MCID) in pain severity and agreement between the visual analog scale (VAS) and the verbal numeric rating scale (NRS) in people with sickle cell disease (SCD) experiencing an acute vaso-occlusive episode in the emergency department. In the COMPARE-VOE trial (NCT03933397), participants were administered the VAS (0–100), NRS (0–100), and descriptor scale (a lot better, a little better, same, a little worse, much worse) every 30 minutes while in the emergency department. We analyzed data from 100 participants (mean age 30.2 years; 61% female). We calculated the mean differences and 95% confidence intervals (CIs) between current and preceding scores when the participant reported a little worse or a little better pain for each scale (255 VAS and 150 NRS observations) to assess the MCID for the VAS and NRS. Pearson correlation and the Bland-Altman method were used to assess the agreement among 411 paired VAS and NRS observations. Our results indicated that the MCID for the VAS was 8.77 mm (95% CI: 7.43 mm, 10.83 mm) and the NRS was 8.29 (95% CI: 6.47, 11.60). The VAS and NRS scales had a correlation of .88 (P < .001). The Bland-Altman method indicated a mean difference of −4.6 ± 1.96 and the 95% limits of agreement ranged from 20 to −29. Despite high correlation, there was considerable variability of agreement between the VAS and NRS scales, indicating that these scales are not interchangeable to assess pain during a vaso-occlusive event. PerspectiveThe MCID in pain severity for individuals with a SCD vaso-occlusive episode using the VAS (8.77 mm) is lower than previously reported, and the MCID for NRS was 8.29. The agreement between the VAS and NRS was determined and the scales cannot be used interchangeably to measure SCD pain intensity.

SNAP: Supportive non-invasive ventilation for acute chest syndrome prevention for hospitalized children with sickle cell disease: Perspectives of patients, parents, and the healthcare team.

Acute chest syndrome (ACS) often develops during hospitalizations for sickle cell disease (SCD) vaso-occlusive episodes and may be triggered by a combination of chest wall splinting, opioid use, hypoventilation, and atelectasis. In 2017, Boston Medical Center's general pediatric inpatient unit instituted the novel use of bi-level positive airway pressure (BiPAP) as "supportive non-invasive ventilation for ACS prevention" (SNAP) to prevent ACS and respiratory decompensation. The goals of this qualitative study were to identify perceived benefits, harms, facilitators, and barriers to use of SNAP. We conducted semi-structured key informant interviews at three sites with different levels of SNAP implementation (Site 1: extensive implementation; Site 2: limited implementation; Site 3: not yet implemented) regarding experiences with and/or perceptions of SNAP. Interviews and coding were guided by the Promoting Action on Research Implementation in Health Services (PARiHS) framework. Thirty-four participants (physicians, nurses, respiratory therapists, child life specialists, psychologists, youth with SCD, and parents) completed interviews. Major themes included: (i) participants perceive BiPAP as effective at preventing ACS, and for those with medically stable ACS, for preventing respiratory decompensation. (ii) BiPAP use is appropriate on the general pediatric inpatient unit for medically stable patients with SCD. (iii) Improving the patient experience is the most important factor to optimize acceptance of BiPAP by patients and families. SNAP is perceived as effective and appropriate for hospitalized pediatric patients with SCD. Improving the patient experience is the biggest challenge. These data will inform a future protocol for a multicenter hybrid effectiveness/implementation trial of SNAP.

Impact of an individualized pain plan to treat sickle cell disease vaso-occlusive episodes in the emergency department

AbstractTo address acute vaso-occlusive episodes (VOEs), the leading cause of emergency department (ED) visits among individuals with sickle cell disease (SCD), we conducted the clinical study, ALIGN (An Individualized Pain Plan with Patient and Provider Access for Emergency Department care of SCD), across 8 sites. We hypothesized an improvement of 0.5 standard deviations in perceived quality of ED pain treatment of a VOE after implementing individualized pain plans (IPPs) accessible to both patients and providers. Patients with SCD were aged 18 to 45 years, owned a cell phone, and had an ED VOE visit within 90 days prior. Patients completed the perceived quality of care surveys at baseline and within 96 hours after an ED VOE visit. Providers completed surveys regarding comfort managing VOEs at baseline and after managing an enrolled patient. Most of the 153 patients were African American (95.4%), female (64.7%), and had Hb SS/Sβ0 genotype (71.9%). The perceived quality of ED pain treatment was high at both baseline and after implementation of IPPs; our primary outcome hypothesis was not met, because no statistically significant change in the patient-perceived quality of ED treatment occurred. A total of 135 providers completed baseline and follow-up surveys. On a scale of 1 to 7, with 7 being extremely comfortable managing VOEs, 60.5% reported a score ≥6 after IPP implementation vs 57.8% at baseline. Almost all (97.6%) ordered the recommended medication, and 94.7% intended to use IPPs. In this implementation protocol, all sites successfully implemented IPPs. Patients and ED providers both endorsed the use of IPPs. This trial was registered at www.ClinicalTrials.gov as # NCT04584528.

Exploring the Interplay between Asthma and Hemoglobinopathies: A Comprehensive Review.

Asthma, a prevalent chronic respiratory condition characterized by inflammation of the airways and bronchoconstriction, has demonstrated a potential association with hemoglobinopathies such as thalassemia and sickle cell disease (SCD). Numerous studies have highlighted a higher prevalence of asthma among thalassemia patients compared to the general population, with rates ranging around 30%. Similarly, asthma frequently coexists with SCD, affecting approximately 20-48% of patients. Children with SCD often experience heightened lower airway obstruction and airway hyper-reactivity. Notably, the presence of asthma in SCD exacerbates respiratory symptoms and increases the risk of severe complications like acute chest syndrome, stroke, vaso-occlusive episodes, and early mortality. Several studies have noted a decrease in various cytokines such as IFN-γ and IL-10, along with higher levels of both IL-6 and IL-8, suggesting an overactivation of pro-inflammatory mechanisms in patients with hemoglobinopathies, which could trigger inflammatory conditions such as asthma. The exact mechanisms driving this association are better elucidated but may involve factors such as chronic inflammation, oxidative stress, and immune dysregulation associated with thalassemia-related complications like chronic hemolytic anemia and iron overload. This review aims to comprehensively analyze the relationship between asthma and hemoglobinopathies, with a focus on thalassemia and SCD. It emphasizes the importance of interdisciplinary collaboration among pulmonologists, hematologists, and other healthcare professionals to effectively manage this complex interplay. Understanding this link is crucial for improving care and outcomes in affected individuals.

The Risk of Kidney Injury in Patients With Sickle Cell Disease Treated With Ketorolac for Acute Pain.

Ketorolac, a nonsteroidal anti-inflammatory drug, is used in combination with opioids to manage vaso-occlusive episodes (VOEs). The relationship between ketorolac use and kidney injury in pediatric patients with sickle cell disease (SCD) remains incompletely understood. We hypothesize that ketorolac is associated with acute kidney injury (AKI) in patients with SCD presenting with pain. All nonsurgical hospitalizations for VOEs treated with ketorolac between January 2014 and December 2022 were included. We used optimal matching methodology to identify control admissions (2:1 ratio) and used nonparametric tests to compare ketorolac administration between cases and controls. A total of 1319 encounters/253 patients were included in this study. AKI was noted in 1.1% of encounters and 5.5% of patients. Cases had significantly higher initial BUN than controls (9.0 vs. 6.0mg/dL, P =0.012). In cases versus controls, there was significantly lower serum sodium (136.0 vs. 138.0mmol/L, P =0.021). There was no association between ketorolac dose and development of AKI among children with SCD. Higher BUN and lower sodium in cases suggest that patients with AKI were more volume depleted on admission than controls. This highlights the need for strict assessment of fluid status upon admission for VOE.

New Horizons in Emergency Department Management of Pediatric Sickle Cell Disease.

Sickle cell disease (SCD) is an important topic for emergency medicine audiences because complications of the disease account for a large proportion of hematologic emergencies that are seen in the emergency department each year. Early recognition and aggressive management of emergency complications of SCD can help to reduce the morbidity and mortality associated with this disease. Although the treatment recommendations for some complications of SCD are based on expert opinion, there has been advancement in the understanding of the pathogenesis of the disease and evidence regarding the treatment options available for managing acute complications. This continuing medical education article will provide a summary of the clinical manifestation and management of the most common acute complications of SCD: infection, vaso-occlusive episode, acute chest syndrome, splenic sequestration, stroke, and priapism.

Multicenter, phase 1 study of etavopivat (FT-4202) treatment for up to 12 weeks in patients with sickle cell disease

AbstractEtavopivat is an investigational, once daily, oral, selective erythrocyte pyruvate kinase (PKR) activator. A multicenter, randomized, placebo-controlled, double-blind, 3-part, phase 1 study was conducted to characterize the safety and clinical activity of etavopivat. Thirty-six patients with sickle cell disease (SCD) were enrolled into 4 cohorts: 1 single-dose, 2 multiple ascending doses, and 1 open-label (OL). In the OL cohort, 15 patients (median age 33.0 years [range, 17-55]) received 400 mg etavopivat once daily for 12 weeks; 14 patients completed treatment. Consistent with the mechanism of PKR activation, increases in adenosine triphosphate and decreases in 2,3-diphosphoglycerate were observed and sustained over 12 weeks’ treatment. This translated clinically to an increase in hemoglobin (Hb; mean maximal increase 1.6 g/dL [range, 0.8-2.8]), with >1 g/dL increase in 11 (73%) patients during treatment. In addition, the oxygen tension at which Hb is 50% saturated was reduced (P = .0007) with a concomitant shift in point of sickling (P = .0034) to lower oxygen tension in oxygen-gradient ektacytometry. Hemolysis markers (absolute reticulocyte count, indirect bilirubin, and lactate dehydrogenase) decreased from baseline, along with matrix metalloproteinase-9 and erythropoietin. In the OL cohort, adverse events (AEs) were mostly grade 1/2, consistent with underlying SCD; 5 patients had serious AEs. Vaso-occlusive pain episode was the most common treatment-emergent AE (n = 7) in the OL cohort. In this, to our knowledge, the first study of etavopivat in SCD, 400 mg once daily for 12 weeks was well tolerated, resulting in rapid and sustained increases in Hb, improved red blood cell physiology, and decreased hemolysis. This trial was registered at www.ClinicalTrials.gov as #NCT03815695.

Early Administration of Intravenous Hydration and Opioid Analgesics Is Correlated with Decreased Admission Rates during Vaso-Occlusive Episodes in Sickle Cell Disease.

Background: Painful vaso-occlusive episodes (VOEs) are the hallmark of sickle cell disease (SCD) and account for frequent visits to the emergency department (ED) or urgent care (UC). Currently, the early administration of analgesics is recommended as initial management; however, there is a need for further understanding of the effect of prompt analgesics and hydration during VOEs. The objective of this study is to analyze the factors associated with the rate of hospital admission in the setting of time to intravenous (IV) analgesics and hydration. Method: This retrospective single-institution study reviewed adult and pediatric patients with SCD who presented with VOEs from January 2018 to August 2023. Results: Of 303 patient encounters, the rates of admission for the overall group, the subgroup which received IV hydration within 60 min of arrival, and the subgroup which received both IV analgesics and hydration within 60 min were 51.8%, 25.6% (RR = 0.46), and 18.2% (RR = 0.33), respectively. Further, factors such as gender and the use of hydroxyurea were found to be significantly associated with the rate of admission. Conclusions: This signifies the importance of standardizing the management of VOEs through the timely administration of IV analgesics and hydration in both adult and pediatric ED/UC.

Arginine in sickle cell vaso-occlusive crisis: A randomised placebo control trial

Sickle cell disease is one of the most common hemoglobinopathies in India. A vaso-occlusive crisis is one of the most common indications for hospitalization, it accounts for 70% of hospitalization. To compare efficacy of Arginine in vaso-occlusive episode(VOE) management in terms of mean fall in pain score at discharge between intervention (Arginine) &amp; placebo group among sickled children with skeletal vaso-occlusive crisis between 2-14 years of age. This randomized placebo control study was carried out after getting clearance from the institutional ethical &amp; research committee, from November 2019 to October 2021 in the Indoor of Pediatrics Department, Veer Surendra Sai Institute of Medical Science (VIMSAR), Burla, Sambalpur. There is significant fall in pain score in case group as compared with control group as evidenced by p value being less than 0.001, indicating that l-arginine has significant role in reducing sickle cell vaso-occlusive episode. Mean Length of stay (LOS) in hospital in case group was 2.16, while in control group was 2.69. p value being calculated showed the value to be less than 0.001, which shows importance of l-arginine in reducing in mean length of stay in hospitalization. L-arginine plays a vital role in treating vaso-occlusive episodes. It helps to reduce the pain gradually as evidenced by noting down pain score at the time of admission &amp; every 24 hours of therapy till discharge. It also helps to reduce the mean duration of hospitalization in vaso-occlusive episode.

DHA and EPA in Sickle Cell Disease Favor Clinical Improvement and Contribute to Better Quality of Life: A Qualitative Systematic Review.

Sickle cell disease is a severe genetic disorder, and searching for therapeutic strategies is indispensable for prolonged and improved life for people affected by this condition. This qualitative systematic review aimed to highlight the therapeutic potential of omega- 3 (n-3) in people with sickle cell disease. The search was performed by combining sickle cell disease and n-3 descriptors in DeCS/ MeSH databases, including Scopus, PubMed, ScienceDirect, Web of Science, and Virtual Health Library. The risk of bias assessment in the primary studies was performed using the Cochrane risk of bias tool for randomized controlled trials. The evidence quality was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool. From the 187 records identified, seven were selected for data collection. Based on the evidence, n-3 supplementation contributes to lower activation of pro-inflammatory biomarkers, improves the concentration of docosahexaenoic and eicosapentaenoic acids in the erythrocyte membrane, provides better hemostatic response, and helps in vaso-occlusive crisis, pain episodes, and hospitalization reduction. The findings suggest that n-3 adjuvant therapy favors the clinical and general aspects of people with sickle cell disease.

Incidence and risk factors of pain crisis after hematopoietic cell transplantation for sickle cell disease

AbstractVaso-occlusive episodes (VOC) or pain crises are the most common indications for hematopoietic cell transplantation (HCT) for sickle cell disease (SCD). Elimination of pain crisis after HCT is an important patient-centered outcome and may improve understanding of the natural history of pain syndromes in SCD. We examined deidentified records of 763 patients followed-up for a median of 36.7 months (range, 0.3-168.6 months), with 69.6% patient's age <18 years at HCT, 83.3% patient's Karnofsky-Lansky performance score (KPS) ≥90, overall survival 92.9%, event-free survival 72.4%, graft failure (GF) 22.4%, AGVHD 21.4%, CGVHD 27%, and pain crisis 8.65%. On unadjusted logistic regression, increased risk of pain crisis after HCT was observed in patient's aged >10 years at HCT (range, 11-17 years; OR, 9.43; 95% CI, 3.20-27.79; P < .0001), in age ≥18 years (OR, 16.62; 95% CI, 5.85-47.16; P < .0001), in those with history of pain crisis 2 years before HCT (OR, 13.16; 95% CI, 4.08-42.42; P < .0001), alternate donors (haploidentical [OR, 4.80; 95% CI, 2.48-9.31; P < .0001], unrelated matched [OR, 2.71; 95% CI, 1.23-5.97; P = .0132], and mismatched unrelated [OR, 3.19; 95% CI, 1.44-7.05; P = .0041], and those with GF (n = 41 [5.37%]; OR, 7.15; 95% CI, 4.20-12.18; P < .0001). Pain crisis was less frequent with KPS of ≥90 (OR, 0.31; 95% CI, 0.18-0.55; P < .0001). Multivariable logistic regression models confirmed age at HCT, KPS, graft type, donor type, history of VOC 2 years before HCT, and GF as independent predictors of pain crisis after HCT and generated predictive models and nomograms for pain crisis after HCT for SCD, which can support shared decision making.

Differential expression of adhesion molecules in sickle cell anemia and gut microbiome effect

Sickle cell anemia (SCA) causes a long-standing vascular inflammation state, leading to endothelial dysfunction and chronic overexpression of several adhesion molecules, which contributes to acute and constant vaso-occlusive (VOC) episodes. It has been demonstrated that hydroxyurea (HU) can reduce VOC events, organ damage, blood transfusions, and even the adhesion properties to endothelial cells of SCA subjects. Due to VOC episodes, these patients are also more susceptible to recurrent bacterial translocation and dysbiosis. Given this, our study aimed to uncover the interplay between adhesion molecules, gut microbiome, and hydroxyurea in a population of Angolan SCA children. Serum and fecal samples were obtained before and after HU treatment in 35 children. After HU, four of these adhesion molecules were significantly reduced: sE-selectin (p = 0.002), ADAMTS13 (p = 0.023), sICAM-1 (p = 0.003), and sVCAM-1 (p = 0.018). A positive correlation was observed between the number of neutrophils and sICAM-1, platelets, and sP-selectin, and also between leukocytes, sICAM-1, and sVCAM-1. Most taxa showing a significant correlation mainly belonged to the Clostridiales order. Specifically, from the Clostridium genera, the groups g19, g21, and g34 were all negatively correlated with HbF levels; g19, g21, and g24 positively correlated with leukocytes; g19 positively with neutrophils and sVCAM-1; and g34 positively with E- and P-selectin. Serratia, an opportunistic pathogen, was positively correlated with sE-selectin and sICAM-1 levels. Additionally, a negative correlation was observed between sP-selectin and Bifidobacterium. Research studies in this area could improve our understanding and contribute to finding new prognostic biomarkers to guarantee precise SCA patient stratification and predict severe complications.

Clearance of VWF by hepatic macrophages is critical for the protective effect of ADAMTS13 in sickle cell anemia mice

AbstractAlthough it is caused by a single-nucleotide mutation in the β-globin gene, sickle cell anemia (SCA) is a systemic disease with complex, incompletely elucidated pathologies. The mononuclear phagocyte system plays critical roles in SCA pathophysiology. However, how heterogeneous populations of hepatic macrophages contribute to SCA remains unclear. Using a combination of single-cell RNA sequencing and spatial transcriptomics via multiplexed error-robust fluorescence in situ hybridization, we identified distinct macrophage populations with diversified origins and biological functions in SCA mouse liver. We previously found that administering the von Willebrand factor (VWF)–cleaving protease ADAMTS13 alleviated vaso-occlusive episode in mice with SCA. Here, we discovered that the ADAMTS13-cleaved VWF was cleared from the circulation by a Clec4f+Marcohigh macrophage subset in a desialylation-dependent manner in the liver. In addition, sickle erythrocytes were phagocytized predominantly by Clec4f+Marcohigh macrophages. Depletion of macrophages not only abolished the protective effect of ADAMTS13 but exacerbated vaso-occlusive episode in mice with SCA. Furthermore, promoting macrophage-mediated VWF clearance reduced vaso-occlusion in SCA mice. Our study demonstrates that hepatic macrophages are important in the pathogenesis of SCA, and efficient clearance of VWF by hepatic macrophages is critical for the protective effect of ADAMTS13 in SCA mice.

Dual P-Selectin and Complement Inhibition with Subcutaneous IHP-102 Treatment Potently Reduces Lung Vaso-Occlusion in Sickle Cell Disease Mice

One of the most debilitating manifestations of sickle cell disease (SCD) are the excruciatingly painful vaso-occlusive episodes (VOEs), commonly referred to as “pain crises.” Vaso-occlusion, which underlies the pathomechanism of VOE, also causes downstream tissue and organ damage resulting in complications that plummet life-expectancy by more than 20 years. Current treatment options for VOE are limited and all require chronic administration, often with intolerable side-effects, and none fully prevent VOE. An acute VOE rescue therapy that could be administered in the home-setting would transform care for the more than 100,000 people in the U.S. and over 7 million worldwide who suffer from this inherited condition. IHP-102 is a novel glycan-based drug with dual anti-P-selectin and anti-complement activity. It is bioavailable by subcutaneous route of administration and could therefore be self-administered at the earliest sign of VOE. Early intervention in VOE is critical, before ischemia and tissue damage becomes irreversible. This treatment paradigm would also circumvent the wholly inadequate treatment experience that the SCD community has widely described, being treated as an opioid “drug-seeker” when engaging the healthcare system during a debilitating VOE. There are multiple pathomechanisms of VOE. P-selectin is a clinically validated therapeutic target for partially attenuating VOE, while complement has more recently been identified as an important driver of VOE, in part due to hemolysis and ischemia. While several therapeutics targeting P-selectin or complement are currently in clinical development, no therapy targets both pathomechanisms. We have previously shown that IHP-102 inhibits P-selectin mediated cell adhesion in vitro (IC50 = 0.7 µg/mL) and that intravenous administration of IHP-102 reduces lung vaso-occlusion by 75% in Townes SCD mice challenged with oxy-hemoglobin (oxy-Hb). Here, we extend these studies with subcutaneous delivery of IHP-102, achieving greater than 75% reduction in lung vaso-occlusion. This magnitude of effect is greater than that achieved in P-selectin deficient Townes SCD mice (~50% reduction), thus indicating additional activity of IHP-102 beyond P-selectin inhibition. In studies using human serum, IHP-102 inhibits complement by upstream mechanisms, including through inhibition of Factor B. Factor B is responsible for alternative pathway amplification of complement. Its fragment Bb has been found in elevated concentrations during VOE in patient serum, suggesting it plays an important role in the pathomechanism of VOE. By inhibiting Factor B, IHP-102 reduces downstream complement fragments of C3 and C5, which are widely recognized complement targets given their critical role in the complement system and promoting inflammation. The dual anti-complement and anti-P-selectin activity of IHP-102, together with its potential for home-based treatment, offers great potential to fill a major treatment gap for acute VOE. Its potent in vivo activity suggests that this dual target approach could provide robust therapeutic benefit and warrants further investigation toward clinical trials.