The role of red blood cell exchange transfusion in the treatment and prevention of complications of sickle cell disease

Position paper on advancing sickle cell disease management in France by bridging the clinical practices and guidelines through expert insights

In France, sickle cell disease (SCD) is the most common rare disease and represents the most prevalent genetic disorder, with 19,800 to 32,400 patients diagnosed in 2016 and 1:714 newborns affected in 2019. SCD is caused by a single mutation in the β-globin gene, resulting in the production of abnormal hemoglobin (called HbS), chronic hemolytic anemia, and impaired red blood cell rheology. SCD patients face several severe acute and chronic complications, including stroke, acute chest syndrome (ACS), painful vaso-occlusive crisis (VOC), organ failure, and a high risk of infections. As patients' care pathway remains unclear in France, a roundtable advisory board meeting was organized in the country to provide insights into the management of SCD in alignment with clinical guidelines. The meeting brought together a panel of esteemed key opinion leaders (KOLs) in SCD management, encompassing both clinical practice and research. During the meeting, the KOLs discussed clinical practices and their alignment with French guidelines, identifying areas of concordance and discrepancy. They also addressed disparities in SCD clinical practices across regions and medical centers. The KOLs discussed the prophylactic and therapeutic options currently available for SCD patients in France, with a focus on transfusion therapies, especially automated red blood cell exchange (aRBCX). The results of this advisory board meeting provide a valuable platform for gathering expert perspectives on SCD management, clinical practices, guideline alignment, and the potential for contributions to guideline updates.

Budget Impact of Disease-Modifying Treatments and a CRISPR Gene-Edited Therapy for Sickle Cell Disease

BACKGROUND AND OBJECTIVE

Treatment of sickle cell disease (SCD) has traditionally focused on symptomatic and preventative care. Recent advances in novel therapeutic developments, likely to be orphan-designated, are anticipated to carry a substantial price tag. This study assesses the potential budget impact of adopting disease-modifying treatments, crizanlizumab and voxelotor, and pioneering CRISPR gene-edited therapy, CTX001, in the Belgian healthcare system.

METHODS

The perspective of the Belgian healthcare payer (RIZIV-INAMI including patient copayments), a 5-year horizon with a 2-10% uptake of disease-modifying interventions, and a 2% uptake of CTX001 were considered. Data, encompassing target population, current (chronic and acute management, curative hematopoietic stem cell transplantation) and new (crizanlizumab, voxelotor, and CTX001) interventions, clinical effectiveness, adverse events, healthcare resource utilization, and associated costs, were gathered through a comprehensive literature review (first phase) and two Delphi panels involving hematologists (second phase). The cost difference between a "world with and without crizanlizumab, voxelotor, and CTX001" was calculated to obtain the budget impact. Three scenario analyses were conducted: a 5-13% and 4% uptake analysis, a 10-18% and 8% uptake analysis, respectively for disease-modifying treatments (crizanlizumab and voxelotor) and CTX001, and a 0% crizanlizumab uptake and managed entry agreements analysis . A ± 20% univariate sensitivity analysis was performed to test the robustness of the analysis.

RESULTS

The total five-year cumulative budget impact was estimated at €30,024,968, with 91% attributed to drug acquisition costs. The largest budget impact share was for CTX001 (€25,575,150), while crizanlizumab (€2,301,095) and voxelotor (€2,148,723) was relatively small. In scenarios one and three, a two-fold increase of the cumulative budget impact to €60,731,772 and a four-fold increase to €120,846,256 from the base case was observed. In scenario three, this budget impact decreased by 63% to €11,212,766. Patient population size, number of treated patients, and drug costs influenced the analysis the most, while discontinuation, acute crisis, and adverse event rates had comparatively minimal impact.

CONCLUSIONS

Belgian decision-makers may consider alternative financing models, such as outcome-based risk-sharing agreements or annuities, to ensure sustainable coverage of these treatments. This study adheres to recommended practices for assessing budget impact of orphan drugs, distinguishing it from earlier studies with potentially weaker methodologies.

Systemic medications for sickle cell disease and potential applications for sickle cell retinopathy

PURPOSE OF REVIEW

To review the literature evaluating systemic medications for treatment of sickle cell disease (SCD) and their applications for sickle cell retinopathy.

RECENT FINDINGS

Prior studies have demonstrated the efficacy of traditional systemic therapies in reducing the risk of development of sickle cell retinopathy. Since 2017, several new and promising disease-modifying therapies for sickle cell disease have been approved for clinical use, including the first genetic therapies such as exagamglogene autotemcel (exa-cel) and lovotibeglogene autotemcel (lovo-cel). These treatments have shown promising results for systemic management but are not widely utilized due to limited access and high cost. The efficacy of these therapies for the prevention of sickle cell retinopathy remains unknown and opens the door to new avenues for research. Furthermore, the role of systemic therapy for the management of hemoglobin SC (HbSC) disease, which has milder systemic effects but higher likelihood of causing retinopathy, remains poorly understood.

SUMMARY

Hydroxyurea has been a mainstay of systemic management of SCD with prior work suggesting its ability to reduce the likelihood of developing retinopathy. There are several new and potentially curative systemic therapies for SCD, though their role in retinopathy prevention and management has not been studied extensively. Future studies are necessary to understand the implications of these emerging therapies for sickle cell retinopathy.

Maximizing longevity: erythropoietin's impact on sickle cell anaemia survival rates

Sickle cell anaemia (SCA) stands as a hereditary blood disorder characterized by mutated haemoglobin, causing red blood cells to adopt a sickle shape, leading to complications like vaso-occlusive crises, anaemia, and organ damage. Despite advancements in treatment, managing SCA remains challenging, with limited options to increase life expectancy and improve quality of life for affected individuals. This paper reviews the potential impact of erythropoietin (EPO) therapy in enhancing life expectancy and ameliorating complications in individuals with SCA. EPO, primarily recognized for its role in stimulating red blood cell production, holds promise in mitigating anaemia, reducing transfusion dependence, and possibly diminishing the frequency and severity of vaso-occlusive crises in SCA patients. Moreover, by stimulating red blood cell production, EPO therapy might alleviate the vaso-occlusive process, thus reducing the frequency of painful crises and associated complications. Additionally, considering the potential side effects and the need for continuous monitoring, the use of EPO in SCA treatment requires cautious consideration. The potential of EPO therapy in SCA offers a glimpse into novel strategies aimed at improving the quality of life and extending the life expectancy of affected individuals. In conclusion, while the application of EPO in SCA treatment holds promise, additional research is indispensable to comprehend its precise role, optimize dosing strategies, and ensure safety, thereby paving the way for enhanced life expectancy and improved outcomes for individuals living with SCA.

Comprehensive guide to managing a chronic automated red cell exchange program in sickle cell disease

Sickle cell disease (SCD) is associated with significant morbidity and mortality, and limits both the quality and quantity of life. Transfusion therapy, specifically automated red cell exchange (aRCE), plays a key role in management of SCD and is beneficial for certain indications in the chronic, outpatient setting. The approach to maintain a successful chronic aRCE program for SCD is multifaceted. This review will highlight important considerations including indications for aRCE, patient selection, transfusion medicine pearls, vascular access needs, complications of therapy, aRCE prescription, and therapy optimization. Moreover, the importance of a multidisciplinary approach with frequent communication between the services involved cannot be overstated. Ultimately, the underlying goal of a chronic RCE program is to improve the quality of life and longevity of patients with SCD.

Implementation of national blood conservation recommendations at an adult sickle cell center

BACKGROUND

Due to the national blood supply crisis caused by the COVID-19 pandemic, the American Society of Hematology proposed guidance to decrease blood utilization for sickle cell patients on chronic transfusion therapy (CTT). Little evidence exists to support the efficacy and safety of these blood conservation strategies.

STUDY DESIGN AND METHODS

Through retrospective analysis, we sought to describe outcomes following implementation of these recommendations in 58 adult sickle cell patients on chronic exchange transfusions. The strategies employed included: relaxing the goal fraction of cells remaining (FCR) to 30%-50%, utilizing depletion exchanges in select patients, and transitioning select patients to monthly simple transfusions. We compared hemoglobin S%, hemoglobin values, and other laboratory parameters, acute care visits, and red blood cell usage during the first year of the COVID-19 pandemic to the year prior using Wilcoxon signed rank test.

RESULTS

Of 53 patients who remained on chronic exchanges during the pandemic, use of depletion exchange increased (15%-23%) and FCR increased (34.9 [SD 4.7] vs. 37.6 [SD 4.5], p < .05). These changes resulted in 854 units conserved without clinically significant changes to pre-exchange laboratory parameters, including hemoglobin S%, or number of acute care presentations. In contrast, five patients who transitioned to predominantly simple transfusions, experienced difficulty maintaining hemoglobin S% less than 30 and worsening anemia.

DISCUSSION

Our data suggest that in a blood shortage crisis, optimizing the exchange procedure itself may be the safest means of conserving blood in a population of adult patients with sickle cell disease.

Coma secondary to cerebral fat embolism syndrome due to sickle cell disease fully recovering following red cell exchange transfusion

A 51-year-old woman known for sickle cell disease presented with 2 weeks of headache and bilateral lower limb pain. During admission, she suffered from multiple generalised tonic-clonic seizures but had an unremarkable CT of the brain. Incidentally, she had worsening baseline renal function. She was admitted to the intensive care unit with an acute confusional state. A bedside electroencephalogram showed triphasic waves and diffuse slow activity suggestive of encephalopathy with no epileptiform discharges. She remained obtunded despite appropriate medical therapy of hydration, antiepileptic and pain control. Lumbar puncture failed to identify an infectious cause. An urgent MRI of the brain was done and revealed features compatible with fat embolism syndrome (FES). Her haemoglobin S was 84.2%. Urgent red cell exchange transfusion was done, and within 3 days she fully regained her orientation and motor function. This represents the first case of such profound obtundation due to FES with a complete response to exchange transfusion.

Exploring the Use of Exchange Transfusion in the Surgical Management of Priapism in Sickle Cell Disease: A Population-Based Analysis

INTRODUCTION

Priapism is a urologic emergency that may require surgical intervention in cases refractory to supportive care. Exchange transfusion (ET) has been previously used to manage sickle cell disease (SCD), including in priapism; however, its utilization in the context of surgical intervention has not been well-established.

AIM

To explore the utilization of ET, as well as other patient and hospital-level factors, associated with surgical intervention for SCD-induced priapism METHODS: Using the National Inpatient Sample (2010-2015), males diagnosed with SCD and priapism were stratified by need for surgical intervention. Survey-weighted regression models were used to analyze the association of ET to surgical intervention. Furthermore, negative binomial regression and generalized linear models with logarithmic transformation were used to compare ET vs surgery to length of hospital stay (LOS) and total hospital charges, respectively.

MAIN OUTCOME MEASURES

Predictors of surgical intervention among patients with SCD-related priapism RESULTS: A weighted total of 8,087 hospitalizations were identified, with 1,782 (22%) receiving surgical intervention for priapism, 484 undergoing ET (6.0%), and 149 (1.8%) receiving combined therapy of both ET and surgery. On multivariable regression, pre-existing Elixhauser comorbidities (e.g. ≥2 Elixhauser: OR: 2.20; P < 0.001), other forms of insurance (OR: 2.12; P < 0.001), and ET (OR: 1.99; P = 0.009) had increased odds of undergoing surgical intervention. In contrast, Black race (OR: 0.45; P < 0.001) and other co-existing SCD complications (e.g. infectious complications OR: 0.52; P < 0.001) reduced such odds. Compared to supportive care alone, patients undergoing ET (adjusted IRR: 1.42; 95% CI: 1.10-1.83; P = 0.007) or combined therapy (adjusted IRR: 1.42; 95% CI: 111-1.82; P < 0.001) had a longer LOS vs. surgery alone (adjusted IRR: 0.85; 95% CI: 0.74-0.97; P = 0.017). Patients receiving ET (adjusted Ratio: 2.39; 95% CI: 1.52-3.76; P < 0.001) or combined therapy (adjusted Ratio: 4.42; 95% CI: 1.67-11.71; P = 0.003) had higher ratio of mean hospital charges compared with surgery alone (adjusted Ratio: 1.09; 95% CI: 0.69-1.72; P = 0.710).

CONCLUSIONS

Numerous factors were associated with the need for surgical intervention, including the use of ET. Those receiving ET, as well as those with combined therapy, had a longer LOS and increased total hospital charges. Ha AS, Wallace BK, Miles C, et al. Exploring the Use of Exchange Transfusion in the Surgical Management of Priapism in Sickle Cell Disease: A Population-Based Analysis. J Sex Med 2021;18:1788-1796.

Stuttering Priapism in a Patient with Sickle Cell Trait Treated with Automated Red Cell Exchange Transfusion

Red blood cell exchange should be considered in sickle cell trait with refractory stuttering priapism.

Sickle cell trait (SCT) is typically an asymptomatic carrier state, but sickling complications can occur under extreme conditions. Priapism is known to be associated with sickle cell disease (SCD); The link with SCT is less well established. We report the case of a 19-year-old man with SCT presenting with prolonged priapism and a refractory, stuttering course requiring multiple invasive procedures over a 5-day period with no clear alternative triggers. In light of ongoing, stuttering priapism, he underwent red blood cell (RBC) exchange transfusion with decrease of hemoglobin S from 45.8% to 11.7%. This was followed by immediate and sustained cessation of stuttering priapism, with no further episodes at 5 months. Multiple cases of priapism associated with SCT have been reported in the literature. In most cases invasive interventions were required but RBC exchange was not attempted. RBC exchange has been reported in 2 people with exertional rhabdomyolysis in the context of SCT, with improvement in 1 case. In patients with SCT and priapism, conservative measures are used to treat brief episodes, but invasive management is required for persistent or prolonged episodes. RBC exchange transfusion may be considered for treatment of refractory, stuttering priapism in individuals with SCT.

MRI-based R2* mapping in patients with suspected or known iron overload

PURPOSE

R2* relaxometry is a quantitative method for assessment of iron overload. The purpose is to analyze the cross-sectional relationships between R2* in organs across patients with primary and secondary iron overload. Secondary analyses were conducted to analyze R2* according to treatment regimen.

METHODS

This is a retrospective, cross-sectional, institutional review board-approved study of eighty-one adult patients with known or suspected iron overload. R2* was measured by segmenting the liver, spleen, bone marrow, pancreas, renal cortex, renal medulla, and myocardium using breath-hold multi-echo gradient-recalled echo imaging at 1.5 T. Phlebotomy, transfusion, and chelation therapy were documented. Analyses included correlation, Kruskal-Wallis, and post hoc Dunn tests. p < 0.01 was considered significant.

RESULTS

Correlations between liver R2* and that of the spleen, bone marrow, pancreas, and heart were respectively 0.49, 0.33, 0.27, and 0.34. R2* differed between patients with primary and secondary overload in the liver (p < 0.001), spleen (p < 0.001), bone marrow (p < 0.01), renal cortex (p < 0.001), and renal medulla (p < 0.001). Liver, spleen, and bone marrow R2* were higher in thalassemia than in hereditary hemochromatosis (all p < 0.01). Renal cortex R2* was higher in sickle cell disease than in hereditary hemochromatosis (p < 0.001) and in thalassemia (p < 0.001). Overall, there was a trend toward lower liver R2* in patients assigned to phlebotomy and higher liver R2* in patients assigned to transfusion and chelation therapy.

CONCLUSION

R2* relaxometry revealed differences in degree or distribution of iron overload between organs, underlying etiologies, and treatment.

Interventions for treating intrahepatic cholestasis in people with sickle cell disease

BACKGROUND

Sickle cell disease is the most common hemoglobinopathy occurring worldwide and sickle cell intrahepatic cholestasis is a complication long recognized in this population. Cholestatic liver diseases are characterized by impaired formation or excretion (or both) of bile from the liver. There is a need to assess the clinical benefits and harms of the interventions used to treat intrahepatic cholestasis in people with sickle cell disease. This is an update of a previously published Cochrane Review.

OBJECTIVES

To assess the benefits and harms of the interventions for treating intrahepatic cholestasis in people with sickle cell disease.

SEARCH METHODS

We searched the Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register, which comprises references identified from comprehensive electronic database searches and handsearching of relevant journals and abstract books of conference proceedings. We also searched the LILACS database (1982 to 21 January 2020), the WHO International Clinical Trials Registry Platform Search Portal and ClinicalTrials.gov (21 January 2020). Date of last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register: 25 November 2019.

SELECTION CRITERIA

We searched for published or unpublished randomised controlled trials.

DATA COLLECTION AND ANALYSIS

Each author intended to independently extract data, assess the risk of bias of the trials by standard Cochrane methodologies and assess the quality of the evidence using the GRADE criteria; however, no trials were included in the review.

MAIN RESULTS

We did not identify any randomised controlled trials.

AUTHORS' CONCLUSIONS

This updated Cochrane Review did not identify any randomised controlled trials assessing interventions for treating intrahepatic cholestasis in people with sickle cell disease. Randomised controlled trials are needed to establish the optimum treatment for this condition.

Sickle cell disease: Clinical presentation and management of a global health challenge

Sickle cell disease is an autosomal recessive, multisystem disorder, characterised by chronic haemolytic anaemia, painful episodes of vaso-occlusion, progressive organ failure and a reduced life expectancy. Sickle cell disease is the most common monogenetic disease, with millions affected worldwide. In well-resourced countries, comprehensive care programs have increased life expectancy of sickle cell disease patients, with almost all infants surviving into adulthood. Therapeutic options for sickle cell disease patients are however, still scarce. Predictors of sickle cell disease severity and a better understanding of pathophysiology and (epi)genetic modifiers are warranted and could lead to more precise management and treatment. This review provides an extensive summary of the pathophysiology and management of sickle cell disease and encompasses the characteristics, complications and current and future treatment options of the disease.

Limited Exchange Transfusion Can Be Very Beneficial in Sickle Cell Anemia with Acute Chest Syndrome: A Case Report from Tanzania

Acute chest syndrome (ACS) is a life-threatening complication of sickle cell disease (SCD) with blood transfusion an integral part in its management. Red cell exchange (RCE) transfusion is usually regarded as preferable to top-up transfusion, because it reduces the proportion of Hemoglobin (Hb) S while at the same time avoiding circulatory overload. Despite its obvious benefits, RCE is underutilized, particularly in low-resource settings which may be due to scarcity of blood products and of expertise in carrying out exchange transfusion. We report on a young woman with SCD with severe ACS who responded promptly and dramatically to a RCE of only 0.95 L (instead of the recommended 1.4 L) and had in the end an HbS level of 48% (instead of the recommended level below 30%). Limited RCE resulted in significant clinical improvement. We suggest that limited RCE may be of benefit than no RCE in SCD patients with ACS, particularly in settings where RCE is not available.

Medical and economic implications of strategies to prevent alloimmunization in sickle cell disease

BACKGROUND

The pathogenesis of alloimmunization is not well understood, and initiatives that aim to reduce the incidence of alloimmunization are generally expensive and either ineffective or unproven. In this review, we summarize the current medical literature regarding alloimmunization in the sickle cell disease (SCD) population, with a special focus on the financial implications of different approaches to prevent alloimmunization.

STUDY DESIGN AND METHODS

A review of EMBASE and MEDLINE data from January 2006 through January 2016 was conducted to identify articles relating to complications of SCD. The search was specifically designed to capture articles that evaluated the costs of various strategies to prevent alloimmunization and its sequelae.

RESULTS

Currently, there is no proven, inexpensive way to prevent alloimmunization among individuals with SCD. Serologic matching programs are not uniformly successful in preventing alloimmunization, particularly to Rh antigens, because of the high frequency of variant Rh alleles in the SCD population. A genotypic matching program could offer some cost savings compared to a serologic matching program, but the efficacy of gene matching for the prevention of alloimmunization is largely unproven, and large-scale implementation could be expensive.

CONCLUSIONS

Future reductions in the costs associated with genotype matching could make a large-scale program economically feasible. Novel techniques to identify patients at highest risk for alloimmunization could improve the cost effectiveness of antigen matching programs. A clinical trial comparing the efficacy of serologic matching to genotype matching would be informative.

Interventions for treating intrahepatic cholestasis in people with sickle cell disease

BACKGROUND

Sickle cell disease is the most common hemoglobinopathy occurring worldwide and sickle cell intrahepatic cholestasis is a complication long recognized in this population. Cholestatic liver diseases are characterized by impaired formation or excretion (or both) of bile from the liver. There is a need to assess the clinical benefits and harms of the interventions used to treat intrahepatic cholestasis in people with sickle cell disease. This is an update of a previously published Cochrane Review.

OBJECTIVES

To assess the benefits and harms of the interventions for treating intrahepatic cholestasis in people with sickle cell disease.

SEARCH METHODS

We searched the Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register, which comprises references identified from comprehensive electronic database searches and handsearching of relevant journals and abstract books of conference proceedings. We also searched the LILACS database (1982 to 23 May 2017), the WHO International Clinical Trials Registry Platform Search Portal (23 May 2017) and ClinicalTrials.gov.Date of last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register: 12 April 2017.

SELECTION CRITERIA

We searched for published or unpublished randomised controlled trials.

DATA COLLECTION AND ANALYSIS

Each author intended to independently extract data and assess the risk of bias of the trials by standard Cochrane methodologies; however, no trials were included in the review.

MAIN RESULTS

There were no randomised controlled trials identified.

AUTHORS' CONCLUSIONS

This updated Cochrane Review did not identify any randomised controlled trials assessing interventions for treating intrahepatic cholestasis in people with sickle cell disease. Randomised controlled trials are needed to establish the optimum treatment for this condition.

How we manage iron overload in sickle cell patients

Blood transfusion plays a prominent role in the management of patients with sickle cell disease (SCD), but causes significant iron overload. As transfusions are used to treat the severe complications of SCD, it remains difficult to distinguish whether organ damage is a consequence of iron overload or is due to the complications treated by transfusion. Better management has resulted in increased survival, but prolonged exposure to iron puts SCD patients at greater risk for iron-related complications that should be treated. The success of chelation therapy is dominated by patient adherence to prescribed treatment; thus, adjustment of drug regimens to increase adherence to treatment is critical. This review will discuss the current biology of iron homeostasis in patients with SCD and how this informs our clinical approach to treatment. We will present the clinical approach to treatment of iron overload at our centre using serial assessment of organ iron by magnetic resonance imaging.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.

Arterio-venous fistula for automated red blood cells exchange in patients with sickle cell disease: Complications and outcomes

Erythrocytapheresis (ER) can improve outcome in patients with sickle cell disease (SCD). A good vascular access is required but frequently it can be difficult to obtain for sickle cell patients. Arterio-venous fistulas (AVFs) have been suggested for ER in SCD supported by limited evidence. We report the largest cohort of ER performed with AVFs from three French SCD reference centers. Data of SCD patients undergoing ER with AVFs in the French SCD reference center were retrospectively collected. The inclusion criteria were: SS or Sβ-Thalassemia and AVF surgery for ER. SCD-related complications, transfusion history, details about AVF surgical procedure, echocardiographic data before and after AVF, AVF-related surgical and hemodynamical complications were collected. Twenty-six patients (mean age 20.5 years, mean follow-up 68 months [11-279]) were included. Twenty-three patients (88.5%) required central vascular access before AVF. Fifteen AVFs (58%) were created on the forearm and 11 (42%) on the arm. Nineteen patients (73%) had stenotic, thrombotic or infectious AVF complications. A total of 0.36 stenosis per 1,000 AVF days, 0.37 thrombosis per 1,000 AVF days and 0.078 infections per 1.000 AVF days were observed. The mean AVF lifespan was 51 months [13-218]. One patient with severe pulmonary hypertension worsened after AVF creation and died. We report the first series of SCD patients with AVF for ER, demonstrating that AVFs could be considered as a potential vascular access for ER. Patients with increased risk for hemodynamic intolerance of AVFs must be carefully identified, so that alternative vascular accesses can be considered. Am. J. Hematol. 92:136-140, 2017. © 2016 Wiley Periodicals, Inc.

Use of Cellular and Plasma Apheresis in the Critically Ill Patient: Part II: Clinical Indications and Applications

Apheresis is the process of separating the blood and removing or manipulating a cellular or plasma component for therapeutic benefit. Such procedures may be indicated in the critical care setting as primary or adjunctive therapy for certain hematologic, neurologic, renal, and autoimmune/rheumatologic disorders. In part I of this series, the technical aspects of apheresis were described and the physiologic rationale and clinical considerations were discussed. This review highlights the pathophysiologic basis, specific clinical indications, and treatment parameters for disorders that more commonly require management in the intensive care unit. The choice of plasma or cellular apheresis in these cases is guided by wellaccepted, evidence-based clinical treatment guidelines. For some disorders, such as liver failure, severe sepsis, and multiple-organ dysfunction syndrome, apheresis treatment approaches remain experimental. Ongoing studies are investigating the potential utility of conventional plasma exchange, ex vivo plasma manipulation, and newer technologies for these and other disorders in severely ill patients.

Pattern and prevelence of alloimmunization in multiply transfused patients with sickle cell disease in Nigeria

BACKGROUND AND STUDY OBJECTIVES

Blood transfusion is central in the prevention and treatment of certain chronic complications of sickle cell disease. It is indispensible in correcting anaemias as well as in the practice of exchange blood transfusion. These gains are largely limited by formation of allo-antibodies. Several studies demonstrated varying frequencies of allo-immunization in various patient groups. The effect of the racial differences between the donor and recipient pool, which has been subsumed in this study, has continuously created a confounding effect on the results of previous studies.

AIM

This study was aimed at determining the pattern and frequency of allo-immunization in multiply transfused sickle cell patients, in a racially matched donor and recipient population.

PATIENTS AND METHODS

This was a cross-sectional case-controlled study involving 80 Nigerian sickle cell disease patients who had received three or more units of packed red cells in the within 4 weeks of the study and 40 controls (who were SCD that had not been transfused in their life time). Antibody screening and identification was done using the Diamed microtyping system.

RESULTS

Frequency of allo-immunization was determined to be 18.7 % (15/80) among the previously transfused and 5 % (15/120) in all sickle cell disease patients. Auto-antibodies were detected in 1.25 % of the study group and 2.5 % of the control, and all reacted with the Kell and Lutheran blood group antigens. The pattern of allo-antibodies found showed; 46.7 % Rhesus, 40 % Kell, while Lutheran and Duffy 13.3 %, each.

CONCLUSION

Sickle cell disease patients are particularly susceptible to development of allo-antibodies despite racial similarities between the donor and recipient population. The most common allo-antibodies are Rhesus, Kell and Lutheran and Duffy respectively in order of decreasing frequency. Development of auto-antibodies seems to be independent of blood transfusion in sickle cell disease with possibly different pathogenetic mechanism. Policy on extended red cell phenotyping for common antigens will reduce allo-immunization among multiply transfused patients.

Alloimmunization is associated with older age of transfused red blood cells in sickle cell disease

Red blood cell (RBC) alloimmunization is a significant clinical complication of sickle cell disease (SCD). It can lead to difficulty with cross-matching for future transfusions and may sometimes trigger life-threatening delayed hemolytic transfusion reactions. We conducted a retrospective study to explore the association of clinical complications and age of RBC with alloimmunization in patients with SCD followed at a single institution from 2005 to 2012. One hundred and sixty six patients with a total of 488 RBC transfusions were evaluated. Nineteen patients (11%) developed new alloantibodies following blood transfusions during the period of review. The median age of RBC units was 20 days (interquartile range: 14-27 days). RBC antibody formation was significantly associated with the age of RBC units (P = 0.002), with a hazard ratio of 3.5 (95% CI: 1.71-7.11) for a RBC unit that was 7 days old and 9.8 (95% CI: 2.66-35.97) for a unit that was 35 days old, 28 days after the blood transfusion. No association was observed between RBC alloimmunization and acute vaso-occlusive complications. Although increased echocardiography-derived tricuspid regurgitant jet velocity (TRV) was associated with the presence of RBC alloantibodies (P = 0.02), TRV was not significantly associated with alloimmunization when adjusted for patient age and number of transfused RBC units. Our study suggests that RBC antibody formation is significantly associated with older age of RBCs at the time of transfusion. Prospective studies in patients with SCD are required to confirm this finding.

How I treat priapism

Priapism is a disorder of persistent penile erection unrelated to sexual interest or desire. This pathologic condition, specifically the ischemic variant, is often associated with devastating complications, notably erectile dysfunction. Because priapism demonstrates high prevalence in patients with hematologic disorders, most commonly sickle cell disease (SCD), there is significant concern for its sequelae in this affected population. Thus, timely diagnosis and management are critical for the prevention or at least reduction of cavernosal tissue ischemia and potential damage consequent to each episode. Current guidelines and management strategies focus primarily on reactive treatments. However, an increasing understanding of the molecular pathophysiology of SCD-associated priapism has led to the identification of new potential therapeutic targets. Future agents are being developed and explored for use in the prevention of priapism.

Interventions for treating intrahepatic cholestasis in people with sickle cell disease

BACKGROUND

Sickle cell disease is the most common hemoglobinopathy occurring worldwide and sickle cell intrahepatic cholestasis is a complication long recognized in this population. Cholestatic liver diseases are characterized by impaired formation or excretion (or both) of bile from the liver. There is a need to assess the clinical benefits and harms of the interventions used to treat intrahepatic cholestasis in people with sickle cell disease.

OBJECTIVES

To assess the benefits and harms of the interventions for treating intrahepatic cholestasis in people with sickle cell disease.

SEARCH METHODS

We searched the Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register, which comprises references identified from comprehensive electronic database searches and handsearching of relevant journals and abstract books of conference proceedings. We also searched the LILACS database (1982 to 7 July 2014) and the WHO International Clinical Trials Registry Platform Search Portal (7 July 2014).Date of last search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register: 10 October 2014.

SELECTION CRITERIA

We searched for published or unpublished randomised controlled trials.

DATA COLLECTION AND ANALYSIS

Each author intended to independently extract data and assess the risk of bias of the trials by standard Cochrane Collaboration methodologies; however, no trials were included in the review.

MAIN RESULTS

There were no randomised controlled trials identified.

AUTHORS' CONCLUSIONS

This Cochrane Review did not identify any randomised controlled trials assessing interventions for treating intrahepatic cholestasis in people with sickle cell disease. Randomised controlled trials are needed to establish the optimum treatment for this condition.

A pilot study of manual chronic partial exchange transfusion in children with sickle disease

Objective Red cell exchange transfusion is frequently used in the management of patients with sickle cell disease (SCD) either electively or chronically to maintain hemoglobin S (HbS) <30%. The purpose of this retrospective study was to evaluate the results of manual chronic partial exchange transfusion (MCPET) on level of Hb and HbS, on iron load and on the need for chelation, on risk of immunization, monitoring transfusion-transmitted viral infection, and clinical outcome. Methods We reviewed the long-term effect of MCPET in 10 children (six men and four women) with SCD and evaluated the iron balance during a median follow-up of 20 months (range: 6-36) in which 248 exchanges were performed. Results The pre-exchange median Hb value was 9.5 g/dl (range: 7.7-10.9 g/dl) and the median post-exchange value was 9.4 g/dl (range: 8.4-11.1 g/dl).The majority of patients reached an HbS of <50% with a median HbS value of 40.04% (range: 30-54). At start of the MCPET program, the median ferritin was 439 ng/ml (range: 80-1704 ng/ml). In the final evaluation, the median value of ferritin was 531 ng/ml (range: 84-3840 ng/ml). The annual calculated iron balance was 0. 28 ± 0.08 mg/kg/day. MCPET was well tolerated, and adverse effects were limited. Discussion MCPET in children with SCD is safe to prevent iron overload, and is effective and easy to use in our cohort. Conclusion Indication for chronic exchange blood transfusion is essential for patients with SCD with recurrent and frequent crises who do not respond to hydroxyurea. However, there is no consensual study for the period at which chronic transfusion can safely be stopped and further research in large population of patients with SCD will need to clarify this question.

A safe therapeutic apheresis protocol in paediatric patients weighing 11 to 25 kg

BACKGROUND AND OBJECTIVES

Erythrocytapheresis and leukapheresis (LPE) of small children are logistically complex and many centres are reluctant to perform these procedures. In children, both sickle cell and leukaemic emergencies demand prompt action to prevent additional morbidity but detailed protocols for small children are lacking, and often are performed using guidelines shown to work in larger patients. We report a 3-year experience with children weighing 11-25 kg at a large academic medical centre.

MATERIALS AND METHODS

All patients were treated with the COBE® Spectra apheresis system; circuit was primed with blood not adjusted for haematocrit and anticoagulant citrate dextrose A was used as anticoagulation. Procedures were performed in the paediatric intensive care unit by apheresis nursing staff.

RESULTS

Twenty-five apheresis procedures in 19 patients were performed; 17 of 19 patients presented with sickle cell-related acute complications and two (2/19) with newly diagnosed acute leukaemia and hyperleucocytosis. None of the patients required medications during the procedures. Vital signs and clinical condition remained stable and did not worsen during or postapheresis. One patient had a delayed haemolytic transfusion reaction 1 week posterythrocytapheresis as he developed alloantibodies as a result of the procedure. All sickle cell patients achieved a target haematocrit of 21-30% and Haemoglobin A of ≥68%. Both leukaemia patients who underwent LPE had no further signs of leukostasis and achieved marked reductions in leucocyte counts.

CONCLUSIONS

Apheresis of children weighing 11-25 kg can be safely performed without increased morbidity. We outline a protocol that can be used to perform apheresis with minimal complications.

Clinical complications in pregnant women with sickle cell disease: prospective study of factors predicting maternal death or near miss

OBJECTIVE

To evaluate complications in pregnant women with sickle cell disease, especially those leading to maternal death or near miss (severe obstetric complications).

METHODS

A prospective cohort of 104 pregnant women registered in the Blood Center of Belo Horizonte (Hemominas Foundation) was followed up at high-risk prenatal units. They belonged to Group I (51 hemoglobin SS and three hemoglobin S/β(0)-thalassemia) or Group II (49 hemoglobin SC and one hemoglobin S/β(+)-thalassemia). Both groups had similar median ages. Predictive factors for 'near miss' or maternal death with p-value≤0.25 in the univariate analysis were included in a multivariate logistic model (significance set for p-value≤0.05).

RESULTS

Group I had more frequent episodes of vaso-occlusive crises, more transfusions in the antepartum and postpartum, and higher percentage of preterm deliveries than Group II. Infections and painful crises during the postpartum period were similar in both the groups. The mortality rate was 4.8%: three deaths in Group I and two in Group II. One-third of the women in both the groups experienced near miss. The most frequent event was pneumonia/acute chest syndrome. Alpha-thalassemia co-inheritance and β-gene haplotypes were not associated with near miss or maternal death. In multivariate analysis predictors of near miss or death were parity above one and baseline red blood cell macrocytosis. In Group I, baseline hypoxemia (saturation<94%) was also predictive of near miss or death.

CONCLUSION

One-third of pregnant women had near miss and 4.8% died. Both hemoglobin SS and SC pregnant women shared the same risk of death or of severe complications, especially pulmonary events.

Treatment of Priapism with Automated Red Cell Exchange and Hyperbaric Oxygen in an 11-year-old Patient with Sickle Cell Disease

Priapism affects up to 50% of all males with sickle cell disease, and there is no standard treatment. Delayed and unsuccessful treatment leads to corporal fibrosis and impotence. It is therefore necessary to determine the best treatment methods for this complication in order to offer effective interventions to all affected patients. Herein we report an 11-year-old patient with sickle cell disease that presented with priapism 72 h after onset, and was successfully treated with automated red cell exchange and hyperbaric oxygen following unsuccessful surgical and conventional interventions.

Guidelines on the use of therapeutic apheresis in clinical practice--evidence-based approach from the Apheresis Applications Committee of the American Society for Apheresis

The American Society for Apheresis (ASFA) Apheresis Applications Committee is charged with a review and categorization of indications for therapeutic apheresis. Beginning with the 2007 ASFA Special Issue (fourth edition), the subcommittee has incorporated systematic review and evidence-based approach in the grading and categorization of indications. This Fifth ASFA Special Issue has further improved the process of using evidence-based medicine in the recommendations by refining the category definitions and by adding a grade of recommendation based on widely accepted GRADE system. The concept of a fact sheet was introduced in the Fourth edition and is only slightly modified in this current edition. The fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis. The article consists of 59 fact sheets devoted to each disease entity currently categorized by the ASFA as category I through III. Category IV indications are also listed.

Clinical effects of different types of red cell concentrates in patients with thalassemia and sickle cell disease

The treatment of thalassemia is still essentially based on continuous transfusion supporting using red cell concentrates (RCC) prepared in different ways. For patients with sickle-cell disorders, either urgent or chronic red blood cell transfusion therapy, is widely used in the management of sickle cell disease (SCD) because it reduces HbS level and generally prevents recurrent vaso-occlusive disease (VOD). Recently, the introduction of pre-storage filtration to remove leukocytes and the use of techniques for multicomponent donation have increased the types of blood components available for transfusion purposes. The clinical effects of different types of blood components in thalassaemic and sickle-cell patients have not been extensively studied so far. We evaluated the impact of the various different blood components currently available on transfusion needs, transfusion intervals and adverse reactions in order to determine which is the most advantageous for transfusion-dependent thalassaemic and sickle-cell patients followed in our centre. We believe that the optimal characteristics of the RCC are aged less than 10 days from time of collection; Hb content greater than 56 g per unit; Hct: 55-60%; volume (including additive) 300 mL+/-20%; leucodepleted to less than 200,000 leukocytes per unit; low cytokine content (achievable by pre-storage filtration carried out between two and 24 hours after the collection); lack of microaggregates (achievable by pre-storage filtration or filtration in the laboratory) and protein content less than 0.5 g per unit for patients allergic to plasma proteins (achievable with manual or automated washing). It is still recommended that the blood transfused should be as fresh as possible, compatible with the centre's product availability and the centre's organisation should be continuously adapted to this aim. We always transfuse blood within 10 days of its collection, respecting Rh and Kell system phenotypes. Pre-storage filtration is strongly recommended, both in order to prevent adverse reactions through the marked leucodepletion (less than 200,000 leukocytes per unit) and for a better standardisation of the final product, including the certainty that the product does not contain clots, an assurance that bed-side filtration cannot give. The RCC should be produced using a method causing as little as possible stress to the red cell membrane. The use of RCC with a high content of Hb (less than 56 g per unit) is strongly recommended, because our study clearly shows that this reduces the number of exposures to donors and the number of accesses to hospital, thus improving the patient's quality of life.

[Therapeutic erythrocytapheresis: technical aspects and clinical applications]

PURPOSE

Therapeutic erythrocytapheresis is a selective red cell-depletion aphaeresis technique.

CURRENT KNOWLEDGE AND KEY POINT

Using a discontinuous or continuous flow blood cell separator, the technique safely allows quickly and automatically collecting a large volume of red cells. The main obstacle of implementation is a poor peripheral venous access. The procedure is well-tolerated. Polycythemia vera, hereditary hemochromatosis, complicated sickle-cell-disease and retinal venous occlusion are the main clinical applications.

PROSPECT AND PROJECT

Therapeutic erythrocytapheresis is a more modern and more effective method than the classic patient-bleeding. It has to be preferred in the early treatment of patients with polycythemia vera and hereditary hemochromatosis.

Blood bank issues associated with red cell exchanges in sickle cell disease

Sickle cell disease (SCD) patients are prone to develop complications that include stroke, acute chest syndrome, and other crises. Some of these complications require chronic transfusion therapy or red cell exchange (RCE), either for therapeutic or prophylactic reasons. Due to a discrepancy of red cell antigens between African Americans and Caucasians (majority blood donors), the incidence of alloantibody formation is very high, which makes it difficult to find compatible red cell units, especially for urgent RCE. Some of the above conditions require immediate oxygen delivery to the tissues. Thus, SCD patients undergoing RCE should receive red blood cells with special attributes that include matching for Rh and Kell blood group antigens; RBCs should be fresh in order to provide (1) immediate oxygen delivery and (2) longer surviving cells to reduce the interval between RCE. Also, these units should be pre-storage leukoreduced to prevent febrile non-hemolytic reactions and screened for sickle cell traits to avoid transfusing red cells containing HbS. This requires a concerted effort between the apheresis unit, the local blood bank, and the central blood supplier.

Sickle cell vasoocclusive crisis and acute chest syndrome at term pregnancy

Women with sickle cell anemia are surviving longer and may desire pregnancy. Rare, life-threatening complications of sickle cell anemia, such as acute chest syndrome, may occur at the time of delivery. A 22-year-old woman with sickle cell (HbS/beta+ thalassemia) at 35 weeks of gestation presented with shortness of breath and generalized pain. She was diagnosed with vasoocclusive crisis and acute chest syndrome, managed with exchange transfusion and cesarean delivery, and discharged home with her newborn one week later. Prompt recognition of life-threatening complications of sickle cell anemia in a pregnant woman and collaborative medical and obstetric management are essential to optimize maternal and fetal outcome.

Guidelines on the use of therapeutic apheresis in clinical practice—Evidence-based approach from the apheresis applications committee of the American society for apheresis

The American Society for Apheresis (ASFA) Apheresis Applications Committee is charged with a review and categorization of indications for therapeutic apheresis. This elaborate process had been undertaken every 7 years resulting in three prior publications in 1986, 1993, and 2000 of "The ASFA Special Issues." This article is the integral part of the Fourth ASFA Special Issue. The Fourth ASFA Special Issue is significantly modified in comparison to the previous editions. A new concept of a fact sheet has been introduced. The fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis. A detailed description of the fact sheet is provided. The article consists of 53 fact sheets devoted to each disease entity currently categorized by the ASFA. Categories I, II, and III are defined as previously in the Third Special Issue. However, a few new therapeutic apheresis modalities, not yet approved in the United States or are currently in clinical trials, have been assigned category P (pending) by the ASFA Clinical Categories Subcommittee. The diseases assigned to category IV are discussed in a separate article in this issue.

Third‐trimester erythrocytapheresis in pregnant patients with sickle cell disease

OBJECTIVE

To evaluate the effects of prophylactic transfusion by means of erythrocytapheresis at the beginning of the third trimester of pregnancy in women with sickle cell disease (SCD).

METHODS

A cohort of 14 pregnant women with SCD who received prophylactic erythrocytapheresis transfusions at the beginning of the third trimester was retrospectively compared with a cohort of 17 pregnant women who received simple prophylactic transfusions for no indication other than SCD severity.

RESULTS

Prophylactic erythrocytapheresis transfusions were associated with a lower risk of intrauterine growth restriction (OR, 0.11; 95% confidence interval, 0.01-1.00) and oligohydramnios (OR, 0.65; 95% confidence interval, 0.45-0.92) in pregnant women with SCD.

CONCLUSION

These results suggest that erythrocytapheresis transfusions are beneficial in women with SCD who are in the third trimester of pregnancy. Given the decrease in transfusion risks, this therapy deserves further evaluation in future trials.

Cytapheresis in the treatment of cell-affected blood disorders and abnormalities

This report presents our experience with cytaphereses performed in treatment of 476 patients. Leukapheresis was used in management of 68 patients with hyperleukocytosis leukostasis (WBC > or = 150 x 10(9)L(-1)). Average decrease in cell count after treatment was 73.3%. Plateletapheresis for 32 patients (platelets > or = 1500 x 10(9)L(-1)) was applied in order to prevent the thrombotic-hemorrhagic syndrome and resulted in a moderate platelet count reduction (84.3%). Erythrocytaphereses performed in treatment of 376 patients by manual or automated technique resulted in a rapid blood viscosity drop (42.4+/-7.1%). Patients with red blood cell exchanges (severe malaria and autoimmune hemolytic crisis) were in life-threatening situations and resulted in a prompt reduction of parasitized or antibody-coated RBCs and anemia correction. This study indicates that "conventional" TCs resulted in considerable cytoreduction only in patients with especially high cell count. This effect was not associated with bone marrow remission. The best clinical effect and long-term benefits were obtained using RBCX and antimalarial drugs in malaria patients who have had high-level parasitized-RBCs with multiorgan dysfunction.