Transfusion Therapy in Children With Sickle Cell Disease

Precision, integrative medicine for pain management in sickle cell disease

Sickle cell disease (SCD) is a prevalent and complex inherited pain disorder that can manifest as acute vaso-occlusive crises (VOC) and/or chronic pain. Despite their known risks, opioids are often prescribed routinely and indiscriminately in managing SCD pain, because it is so often severe and debilitating. Integrative medicine strategies, particularly non-opioid therapies, hold promise in safe and effective management of SCD pain. However, the lack of evidence-based methods for managing SCD pain hinders the widespread implementation of non-opioid therapies. In this review, we acknowledge that implementing personalized pain treatment strategies in SCD, which is a guideline-recommended strategy, is currently fraught with limitations. The full implementation of pharmacological and biobehavioral pain approaches targeting mechanistic pain pathways faces challenges due to limited knowledge and limited financial and personnel support. We recommend personalized medicine, pharmacogenomics, and integrative medicine as aspirational strategies for improving pain care in SCD. As an organizing model that is a comprehensive framework for classifying pain subphenotypes and mechanisms in SCD, and for guiding selection of specific strategies, we present evidence updating pain research pioneer Richard Melzack's neuromatrix theory of pain. We advocate for using the updated neuromatrix model to subphenotype individuals with SCD, to better select personalized multimodal treatment strategies, and to identify research gaps fruitful for exploration. We present a fairly complete list of currently used pharmacologic and non-pharmacologic SCD pain therapies, classified by their mechanism of action and by their hypothesized targets in the updated neuromatrix model.

Impact of magnetic resonance angiography parameters on stroke prevention therapy in pediatric patients with sickle cell anemia

BACKGROUND

Degree of cerebrovascular stenosis in pediatric patients with sickle cell anemia (SCA) informs need for chronic transfusion therapy, which has significant risks. Flow artifact, intrinsic to magnetic resonance angiography (MRA), is dependent on technical parameters and can lead to overinterpretation of stenosis. The primary objective of this study was to document any change in stroke prevention therapy that could be attributed to the implementation of a standardized MRA scanning protocol for patients with SCA.

METHODS

A standardized MRA scanning protocol with an echo time of less than 5 ms was implemented at Montefiore Medical Center (MMC), NY in May 2016. Retrospective chart review identified 21 pediatric patients with SCA, with an MRA head both pre- and post-May 2016. Arterial stenosis on MRA, machine parameters, and treatment plans were compared pre- and post-implementation.

RESULTS

Ten of the 21 patients met inclusion criteria. Previously seen stenosis was re-classified to a lower degree in six of the 10 patients, leading to discontinuation of transfusions in five patients. No patients required escalation of therapy to chronic transfusions.

CONCLUSION

Optimizing flow artifact by decreasing echo time to less than 5 ms can improve accurate interpretation of cerebrovascular disease, and ensure appropriate treatment plans are in place for stroke prevention. This is especially important for implementing "TCD With Transfusions Changing to Hydroxyurea (TWiTCH)" clinical trial results in the real-world setting.

Iron stores in steady-state sickle cell disease children accessing care at a sickle cell disease clinic in Kumasi, Ghana: A cross-sectional study

Background and Aims

Children with sickle cell disease (SCD) have an increased risk of multiple hemotransfusions and this can predispose them to elevated iron stores. The objectives of the study were to determine the extent of elevated iron stores and the associated risk factors in a population of steady-state SCD children in Ghana.

Methods

This cross-sectional study was conducted at the pediatric sickle cell clinic at the Komfo Anokye Teaching Hospital. Complete blood count and serum ferritin assay were performed for (n = 178) steady-state SCD children. Descriptive and multivariate logistic regression analysis were performed. Elevated iron stores were defined as serum ferritin levels >300 ng/ml. Statistical significance was considered at p < 0.05.

Results

The mean (standard deviation) age of the participants was 9.61 (±4.34) years, and 51% of them were males. About 17% of SCD children had elevated iron stores and receiving at least three hemotransfusions during the last 12 months was strongly associated with elevated iron stores (p < 0.001). History of chronic hemotransfusion increased the odds of having elevated iron store (adjusted odds ratio [aOR] = 11.41; 95% confidence interval [CI] = 3.11-30.85; p < 0.001) but SCD patients on hydroxyurea treatment had reduced-odds of having elevated iron stores (aOR = 0.18; 95% CI = 0.06-0.602; p = 0.006). Moreover, red blood cell (Coef. = -0.84; 95% CI = -0.37, -1.32; p = 0.001), hemoglobin (Coef. = -0.83; 95% CI = -0.05, -1.61; p = 0.04), hematocrit (Coef. = -0.85; 95% CI = -0.08, -1.63; p = 0.03), mean cell volume (Coef. = 0.02; 95% CI = 0.01, 0.03; p = 0.001) and mean cell hemoglobin (Coef. = 0.04; 95% CI = 0.01, 0.07; p = 0.002) could significantly predict serum ferritin levels.

Conclusion

The magnitude of elevated iron stores was high among children with SCD in steady-state. Red cell indices could provide invaluable information regarding the risk of elevated iron stores. SCD children who have a history of chronic hemotransfusion or had received at least three hemotransfusions in a year should be monitored for elevated iron stores.

Indications for transfusion in the management of sickle cell disease

The transfusion of red blood cells (RBCs) is a crucial treatment for sickle cell disease (SCD). While often beneficial, the frequent use of transfusions is associated with numerous complications. Transfusions should be offered with specific guidelines in mind. Here we present updates to the indications for transfusion of RBCs in SCD. We review recent publications and include expert perspectives from hematology and transfusion medicine. For some clinical indications, such as ischemic stroke, the role of transfusion has been well studied and can be applied almost universally. For many other clinical scenarios, the use of transfusion therapy has less conclusive data and therefore must be tailored to individual needs. We highlight the roles of RBC transfusions in preventing or mitigating neurological disease, in reducing perioperative complications, in managing acute chest syndrome, and in optimizing pregnancy outcomes in SCD. We further highlight various transfusion techniques and when each might be considered. Potential complications of transfusion are also briefly discussed.

Screening for new red blood cell alloantibodies after transfusion in patients with sickle cell disease

BACKGROUND

Patients with sickle cell disease (SCD) are frequent recipients of red blood cell (RBC) transfusions and are at risk for RBC alloimmunization. RBC alloimmunization is diagnosed by identifying RBC alloantibodies as part of pre-transfusion testing, but this testing fails to detect alloantibodies that have evanesced. It may be beneficial to screen for new RBC alloantibody development after transfusion before possible antibody evanescence.

STUDY DESIGN AND METHODS

Our institution started a new initiative for episodically transfused patients with SCD to obtain at least one antibody screen 2-6 months after transfusion as part of their clinical care. A database was created to prospectively track all transfused patients for 1 year and their post-transfusion antibody screen results. Patients received prophylactically CEK-matched RBC units.

RESULTS

During the study year, 138 patients with SCD received a total of 242 RBC transfusions. Patients with a history of an RBC alloantibody (n = 13, 9.4%) had previously received more RBC units than non alloimmunized patients (median 11 vs. 2 RBC units, p = .0002). A total of 337 post-transfusion antibody screens were obtained in 127 patients (92.0%) with 110 patients (79.7%) having at least one antibody screen 2-6 months post-transfusion. With this prospective testing, two new RBC alloantibodies (anti-C and -M) were identified in two patients.

CONCLUSION

It is feasible to test for new RBC alloantibody development in most episodically transfused patients with SCD as part of their routine care. The yield of this screening appears low with CEK matching, but it could still provide important information for individual patients.

Hydroxyurea and blood transfusion therapy for Sickle cell disease in South Asia: inconsistent treatment of a neglected disease

Background

Hydroxyurea and blood transfusion therapies remain the main therapeutic strategies for Sickle cell disease. Preliminary data suggest substantial variation and inconsistencies in practice of these two therapeutic modalities in South Asia. In this systematic review we searched Medline, Cochrane library and Scopus for articles on usage of hydroxyurea and blood transfusion therapies for sickle cell disease in South Asia published in English between October 2005 and October 2020.

Results

We selected 41 papers: 33 from India, 3 from Sri Lanka, 2 each from Pakistan and Bangladesh and one from Nepal. Only 14 prospective trials focused on hydroxyurea therapy from which majority (n = 10; 71.4%) adopted fixed low dose (10 mg/kg/day) regimen. With hydroxyurea therapy, 12 and 9 studies reported significant reductions in vaso-occlusive crises and transfusion requirement respectively. Severe anaemia (haemoglobin level < 6–7 g/dl) was the commonest indicator (n = 8) for transfusion therapy followed by vaso-occlusive crisis.

Conclusions

Published data on the hydroxyurea and transfusion therapies in South Asia are limited and heterogeneous. A clear gap of knowledge exists about the nature of the sickle cell disease in the Indian subcontinent particularly from countries outside India necessitating further evidence-based assessments and interventions.

Distribution of sickle cell disease and assessment of risk factors based on transcranial Doppler values in the Gulf region

Background/Objective: Stroke is a potentially fatal complication of sickle cell disease (SCD). Transcranial Doppler (TCD) is useful at identifying increased risk of stroke in children with SCD and vasospasm after subarachnoid hemorrhage. The main aim of this study was to determine the proportion of patients with SCD in the Gulf region who are at a high risk of stroke, as determined by TCD.Methods: This multicenter (Oman, Qatar, and UAE), descriptive, cross-sectional study in patients (aged 2-16 years) with SCD included a baseline visit, 1 follow-up visit for patients with conditional TCD, and 3-year retrospective data analysis for all patients.Results: Of the 410 eligible patients (Oman, 86.5%; Qatar, 8.2%; UAE, 5.1%), most had a TCD finding (left side, 91.7%; right side, 92.0%) of normal velocity (<155 cm/s) at baseline. For 6 of 7 patients with conditional velocity (155-179 cm/s) and 1 patient with high velocity (≥180 cm/s), baseline TCD results were not confirmed at follow-up. As per bivariate linear regression, age, race, transfusion type, and transfusion frequency were significant predictors of the TCD velocities. Multivariate logistic regressions revealed that TCD velocities were significantly correlated with sex, race, and type of transfusion. No patients reported any adverse events at follow-up. No deaths occurred during the study.Discussion/Conclusions: The study results show that far fewer patients with SCD in the Gulf have abnormal TCD findings than the internationally reported. Larger studies are needed to identify the factors underlying this observation.

Blood Transfusion Frequency and Indications in Yemeni Children with Sickle Cell Disease

Background

Blood transfusion is an essential component in the care of patients with sickle cell disease (SCD), but it might be associated with serious acute and delayed complications. This study was aimed to describe red cell transfusion patterns and indications among hospitalized SCD children in a low-resource setting. Patients and Methods. A retrospective, descriptive study of all children (≤16 years) with SCD who received blood transfusion therapy during their hospital admissions in the pediatric department at Al-Sadaqa Teaching Hospital in Aden, Yemen, for a period of one year.

Results

Out of 217 hospitalized children with SCD, 169 (77.9%) were transfused and received 275 RBC transfusion episodes. The mean age of transfused children was 6.9 ± 4.6 years and 103 (60.9%) were males, with a male/female ratio of 1.6 : 1 (p=0.004). Hemoglobin (Hb) levels were significantly lower in the transfused than in the nontransfused (Hb 5.5 ± 1.5 vs. 7.7 ± 1.5 g/dL, p=0.03). Pretransfusion Hb levels were ˂7.0 g/dL in 86.2% and ˂5.0 g/dL in 39.3% of patients. Single transfusion was given to 122 (72.2%) and 5 or more transfusions in 9 (4.15%) of patients on different occasions. Simple (top-up) transfusion was used in all transfusion events. Commonest indications for transfusion were anemic crises (41.1%), vasoocclusive crises (VOC) (13.8%), VOC with anemic event (11.3%), acute chest syndrome (8.7%), and stroke (7.3%).

Conclusion

Intermittent blood transfusion remains a common practice for the management of children with acute SCD complications. Main indications were acute anemic crises, severe pain crises, ACS, and stroke. In limited resource settings, such as Yemen, conservative transfusion policy appears to be appropriate.

Higher executive abilities following a blood transfusion in children and young adults with sickle cell disease

Individuals with sickle cell disease (SCD) experience cognitive deficits; however, it remains unclear whether medical treatments for SCD improve cognition. Given that executive abilities are typically impaired in individuals with SCD, they were the focus of the current study. Our primary hypothesis was that executive abilities would be higher acutely soon after a blood transfusion in children and young adults with SCD. We used tests from the NIH Toolbox to assess executive abilities in 27 participants with SCD receiving chronic transfusion in comparison to 34 participants with SCD receiving hydroxyurea (HU) and 41 non-SCD demographically matched controls, all of whom were tested at two time points. Participants in the transfusion group completed cognitive testing within 3 days after a transfusion (soon after transfusion) and then within 3 days before their next transfusion (long after transfusion) over an interval of 3-7 weeks. We found that executive abilities were significantly poorer for the transfusion and HU groups than for the control group. In support of our primary hypothesis, executive abilities for the transfusion group were significantly better soon after a transfusion compared to long after a transfusion, χ² (1) = 17.8, P < .0001. Our results demonstrate that executive abilities were higher acutely following a blood transfusion. These findings have implications for daily functioning, medical decision making, and academic achievement in children and young adults with SCD.