Managing the Cerebrovascular Complications of Sickle Cell Disease: Current Perspectives

Clinical and Economic Burden of Managing Patients with Sickle Cell Disease Receiving Frequent Red Blood Cell Transfusions in the United States

Purpose

Standard of care for patients with sickle cell disease (SCD) includes red blood cell transfusions (RBCTs). Data on clinical and economic outcomes of patients with SCD receiving frequent RBCTs are limited.

Materials and Methods

This longitudinal, retrospective, claims-based analysis used the Merative™ MarketScan® Commercial, Medicare, and Multi-State Medicaid databases. Patients with SCD (identified using ICD-9/10 codes) receiving frequent RBCTs (≥6 RBCTs during any 12-month period) between January 1, 2015, and March 1, 2019, were included. The index date was the date of the sixth RBCT. Eligible patients were required to have ≥12 months of continuous enrollment pre- and post-index. Patients were followed from index to end of enrollment, death, or end of the study period (February 29, 2020), whichever came first. Clinical complications, all-cause healthcare resource utilization (HCRU), and healthcare costs were descriptively summarized during follow-up.

Results

A total of 919 patients with SCD receiving frequent RBCTs met the eligibility criteria for inclusion. Patients experienced a mean of 4.0 vaso-occlusive crises (VOCs) per patient per year (PPPY) and received a mean of 8.3 RBCTs PPPY during follow-up. The most common clinical complications were iron overload (77%), infections (66%), and cerebrovascular disease (48%). Patients had a mean of 2.3 inpatient admissions, 83.5 outpatient visits, and 37.4 outpatient prescriptions PPPY during follow-up. Mean total annual healthcare costs were $106,123 PPPY, including mean inpatient, outpatient medical, and outpatient pharmacy costs of $48,463, $28,307, and $29,353, respectively. Compared to those with <2 baseline VOCs, patients with ≥2 baseline VOCs had more HCRU and higher annual healthcare costs.

Conclusion

Despite utilizing available care with frequent RBCTs, patients with SCD experienced a variety of disease and transfusion-related complications, including frequent VOCs and iron overload, which led to substantial HCRU and costs. These findings highlight the need for novel therapies for this patient group.

Neurological management of ischemic stroke in sickle cell disease- a case report with an updated review of the literature

BACKGROUND

In children and adults with sickle-cell disease (SCD), acute ischemic stroke (AIS) associated with a vaso-occlusive crisis is a leading cause of physical and cognitive disability and death. However, neurological guidelines for acute management of AIS fail to directly address this issue. We here report a case of a man with severe cerebrovascular complications and illustrate the current evidence on the management of SCD-related AIS.

CASE REPORT

A 46-year-old man suffering from SCD and poorly controlled diabetes was admitted to the emergency room complaining of the onset, more than 10 h before, of headache, paresthesia, and right hemianopia. The brain Angio-CT study revealed bilateral occlusion of the internal carotids and the posterior cerebral arteries, with remarkable compensatory hypertrophy of other vessels. The laboratory exams confirmed severe anemia with high hemoglobin-S levels (50%) and severe dehydration. IV hydration was prompted, along with erythrocyte apheresis and antiplatelet therapy. The patient successfully underwent these treatments, and the neurological deficits significantly improved. Nonetheless, due to the time window, he could not be treated with intravenous thrombolysis (IVT).

DISCUSSION

AIS is a time-sensitive condition. In SCD, vaso-occlusive phenomena are the leading cause of AIS, but "classical" vascular risk factors can also play a role. Since current guidelines on the acute management of SCD complications are mainly focused on the hematological- rather than neurological- aspects, it is not clear whether these patients should undergo IVT before or after fluid resuscitation and erythrocyte apheresis. Furthermore, the principles of secondary prophylaxis are still controversial and require further investigation.

Hypercoagulability in hemoglobinopathies: Decoding the thrombotic threat

Beta (β)-thalassemia and sickle cell disease (SCD) are characterized by a hypercoagulable state, which can significantly influence organ complication and disease severity. While red blood cells (RBCs) and erythroblasts continue to play a central role in the pathogenesis of thrombosis in β-thalassemia and SCD, additional factors such as free heme, inflammatory vasculopathy, splenectomy, among other factors further contribute to the complexity of thrombotic risk. Thus, understanding the role of the numerous factors driving this hypercoagulable state will enable healthcare practitioners to enhance preventive and treatment strategies and develop novel therapies for the future. We herein describe the pathogenesis of thrombosis in patients with β-thalassemia and SCD. We also identify common mechanisms underlying the procoagulant profile of hemoglobinopathies translating into thrombotic events. Finally, we review the currently available prevention and clinical management of thrombosis in these patient populations.

Current understanding of stroke and stroke mimics in adolescents and young adults: a narrative review

BACKGROUND

Stroke in adolescents and young adults are uncommon, and unlike in older adults, the etiology can be a challenging puzzle to solve. Patients often lack traditional risk factors such as hypertension or may be too young for suspected atherosclerotic disease. Additionally, among this group, various stroke mimics exist that can cloud physician judgment, leading to under- or overtreatment.

AIM

There is a significant gap in the current literature and clinical evidence regarding stroke in this population. This review of the literature aims to extract important information surrounding the etiology, risk factors, diagnosis, management, and complications of stroke in younger people and address stroke mimics and how they can appear similar and different from ischemic or hemorrhagic stroke. Additionally, we discuss the importance of furthering research in this specific population in all areas due to a concerning rise in stroke frequency and unique associated disabilities.

CONCLUSION

The acute treatment of stroke in young patients is similar to older adults. While stroke mimics may complicate suspicion and cause hesitance, delays in stroke care should be avoided. There remains a need for research in the areas of diagnosis, management, and assessment of long-term care and challenges in this population of patients.

Stroke Prevention and Treatment for Youth with Sickle Cell Anemia: Current Practice and Challenges and Promises for the Future

PURPOSE OF REVIEW

Sickle cell anemia (SCA) is an autosomal recessive inherited hemoglobinopathy that results in a high risk of stroke. SCA primarily affects an underserved minority population of children who are frequently not receiving effective, multi-disciplinary, preventative care. This article reviews primary and secondary stroke prevention and treatment for children with SCA for the general adult and pediatric neurologist, who may play an important role in providing critical neurologic evaluation and care to these children.

RECENT FINDINGS

Primary stroke prevention is efficacious at reducing ischemic stroke risk, but it is not consistently implemented into clinical practice in the United States, resulting in these children remaining at high risk. Acute symptomatic stroke management requires neurology involvement and emergent transfusion to limit ischemia. Furthermore, while chronic transfusion therapy is a proven secondary preventative modality for those with prior symptomatic or silent cerebral infarcts, it carries significant burden. Newer therapies (e.g., stem cell therapies and voxelotor) deserve further study as they may hold promise in reducing stroke risk and treatment burden. Effective primary and secondary stroke prevention and treatment remain a challenge. Informing and engaging neurology providers to recognize and provide critical neurologic evaluation and treatment has potential to close care gaps.

Asymptomatic Maternal Diseases Presenting with Symptomatic Neonatal Manifestations: A Short Case Series

It is documented that maternal diseases or treatments influence a newborn's clinical status at birth. If a prenatal medical history is not available, or if signs or symptoms of a mother's disease are revealed for the first time during pregnancy or postpartum, their effects on the newborn may be misattributed.

OBJECTIVE

The objective of this study is to emphasize the paramount importance of prenatal care, for both mothers and newborns, as a lack of maternal signs and symptoms during pregnancy does not exclude a potential severe neonatal condition.

MATERIALS AND METHODS

We present a series of three cases of pregnant women who gave birth to very sick preterm newborns that required admission to the Neonatal Intensive Care Unit (NICU). The mothers were asymptomatic during pregnancy and unaware of their subclinical disease. The newborns' complications, considered initially as consequences of prematurity or infection, subsequently revealed transient autoimmune disease in two of the cases (myasthenia gravis and hyperthyroidism) and a severe form of thrombophilia in the third case.

RESULTS

The newborns' diagnosis preceded maternal diagnosis and contributed to the identification of the maternal pathology; adequate treatment was prescribed, with favorable short- and long-term outcomes.

CONCLUSIONS

Prenatal exams and investigations throughout pregnancy are a good opportunity to detect subclinical diseases or predispositions. As newborns usually develop non-specific signs, one should have experience and pay attention to differentiating among etiologies. Our paper takes a reversed approach to the usual medical diagnosis pathway: from infant to mother instead of from mother to infant, proving that inter-specialty collaboration can work bi-directionally.

Stroke in sickle cell patients, epidemiology, pathophysiology, systemic and surgical treatment options and prevention strategies

Background

A hereditary haemoglobinopathy known as sickle cell disease (SCD) affects over 100 000 people in the United States severely. Cerebrovascular disease is a prominent consequence of SCD. By the age of 30, 53% of patients have silent cerebral infarcts (SCIs) (a stroke that occurs without any obvious symptoms because it damages a small part of the brain that isn't responsible for any essential functions), and by the age of 40, 3.8% have overt strokes.

Main body

The multidimensional burden of cerebrovascular illness in SCD is reviewed in detail in this article, which includes both clinical strokes and the frequently asymptomatic SCIs. The intricate pathophysiology of SCD and stroke is explored. With SCD, there are currently very few methods for preventing primary and secondary stroke; the most common ones are hydroxyurea and blood transfusion. Nevertheless, not enough research has been done on the possible contributions of anticoagulation and aspirin to strokes linked to SCD. Promising evidence is also highlighted in the study, suggesting that new drugs intended to treat SCD may be able to alleviate leg ulcers and renal impairment in addition to reducing unusually high transcranial Doppler flow velocity – a crucial component of cerebrovascular events. Given that these novel medications specifically target haemolysis and vaso‐occlusion, the two main causes of strokes in this population, more research is desperately needed to determine whether they are effective in avoiding strokes in people with SCD. The literature review also emphasizes how common healthcare inequities are and how they hinder advancements in SCD research and management in the United States.

Conclusion

To successfully address these inequities, the evaluation recommends more funding for both SCD management and research, as well as for patient and clinician education. This multimodal viewpoint highlights the intricate terrain of cerebrovascular problems associated with SCD and the urgent need for all‐encompassing and fair strategies to improve patient outcomes and advance research.

Haematopoietic stem cell transplantation in children with sickle cell disease: Still to do?

Sickle cell disease affects the whole body through acute and chronic organ damage and results in significant physical and neurological constraints. The report by Cseh et al. demonstrates in a retrospective multinational study that allogeneic haematopoietic stem cell transplantation from HLA-identical siblings using a contemporary conditioning regimen is safe and effective in more than 96% of patients. Commentary on: Cseh et al. Busulfan-fludarabine- or treosulfan-fludarabine-based conditioning before allogeneic HSCT from matched sibling donors in paediatric patients with sickle cell disease: A study on behalf of the EBMT Paediatric Diseases and Inborn Errors Working Parties. Br J Haematol 2024;204:e1-e5. [Correction added on 23 November 2023, after first online publication: In the preceding sentence, the article title and doi have been updated in this version.].

Overview of the Association Between the Pathophysiology, Types, and Management of Sickle Cell Disease and Stroke

Sickle cell disease (SCD) is a genetic blood disorder that affects hemoglobin and increases stroke risk, particularly in childhood. This review examines the pathophysiological association between SCD and stroke, the classification of stroke types, risk factors, diagnosis, management, prevention, and prognosis. A comprehensive literature search was conducted via PubMed, Scopus, and Cochrane databases. Relevant studies on SCD and stroke pathophysiology, classification, epidemiology, diagnosis, treatment, and prevention were identified. Sickle cell disease causes red blood cells to become rigid and sickle-shaped, obstructing blood vessels. Recurrent sickling alters cerebral blood flow and damages vessel walls, often leading to ischemic or hemorrhagic strokes (HS). These occur most frequently in childhood, with ischemic strokes (IS) being more common. Key risk factors include a prior transient ischemic attack (TIA), low hemoglobin, and a high leukocyte count. Neuroimaging is essential for diagnosis and determining stroke type. Primary prevention centers on blood transfusions and hydroxyurea for those at high risk. Acute treatment involves promptly restoring blood flow and managing complications. However, significant knowledge gaps remain regarding stroke mechanisms, optimizing screening protocols, and improving long-term outcomes. This review synthesizes current evidence on SCD and stroke to highlight opportunities for further research and standardizing care protocols across institutions. Ultimately, a holistic perspective is critical for mitigating the high risk of debilitating strokes in this vulnerable patient population.

From Stress to Sick(le) and Back Again-Oxidative/Antioxidant Mechanisms, Genetic Modulation, and Cerebrovascular Disease in Children with Sickle Cell Anemia

Sickle cell anemia (SCA) is a genetic disease caused by the homozygosity of the HBB:c.20A>T mutation, which results in the production of hemoglobin S (HbS). In hypoxic conditions, HbS suffers autoxidation and polymerizes inside red blood cells, altering their morphology into a sickle shape, with increased rigidity and fragility. This triggers complex pathophysiological mechanisms, including inflammation, cell adhesion, oxidative stress, and vaso-occlusion, along with metabolic alterations and endocrine complications. SCA is phenotypically heterogeneous due to the modulation of both environmental and genetic factors. Pediatric cerebrovascular disease (CVD), namely ischemic stroke and silent cerebral infarctions, is one of the most impactful manifestations. In this review, we highlight the role of oxidative stress in the pathophysiology of pediatric CVD. Since oxidative stress is an interdependent mechanism in vasculopathy, occurring alongside (or as result of) endothelial dysfunction, cell adhesion, inflammation, chronic hemolysis, ischemia-reperfusion injury, and vaso-occlusion, a brief overview of the main mechanisms involved is included. Moreover, the genetic modulation of CVD in SCA is discussed. The knowledge of the intricate network of altered mechanisms in SCA, and how it is affected by different genetic factors, is fundamental for the identification of potential therapeutic targets, drug development, and patient-specific treatment alternatives.