Global burden of transfusion in sickle cell disease.

Sickle cell disease (SCD) is the most common hereditary hemoglobinopathy. The underlying pathophysiology of the red blood cell (RBC) leads to pan-systemic complications which manifest at an early age. While curative and disease-modifying treatments exist for SCD, a key intervention in the management and treatment of SCD is RBC transfusion, which can alleviate or prevent many complications. SCD patients often require chronic RBC transfusion therapy which can result in complications, such as iron overload, alloimmunization and infection. In low- and middle-income countries (LMICs), SCD patients lack appropriate access to healthcare such as newborn screening, health education, prophylaxis for infection, and treatments to reduce both mortality and SCD-related adverse effects. Poor access to RBCs for transfusion, coupled with donated blood not meeting safety standards set by the World Health Organization, presents a significant barrier for patients requiring chronic transfusions in LMICs. Unmet needs associated with blood collection, blood component processing and recipient matching all pose a serious problem in many LMICs, although this varies depending on geographic location, political organizations and economy. This review aims to provide an overview of the global burden of SCD, focusing on the availability of current treatments and the burden of chronic RBC transfusions in patients with SCD.

Burden of disease, treatment utilization, and the impact on education and employment in patients with sickle cell disease: A comparative analysis of high- and low- to middle-income countries for the international Sickle Cell World Assessment Survey.

The international Sickle Cell World Assessment Survey (SWAY) reported a high impact of sickle cell disease (SCD) on patients' daily lives globally. In this study, we analyzed whether the reported burden differed between patients from the USA (n = 384) and other high-income (HI; n = 820) or low- to middle-income (LMI; n = 941) countries. We assessed symptoms and complications, incidence/management of vaso-occlusive crises (VOCs), treatment utilization/satisfaction, and the impact of SCD on education/employment. Certain symptoms (bone aches, insomnia, and joint stiffness) and complications (swollen/painful fingers/toes, gallstones, vision problems, blood clots, and asthma) were reported proportionally more by patients in the USA than in the HI/LMI countries. Self-reported VOCs were more common (mean [SD]: 7.1 [5.7] vs. 5.5 [8.9] and 4.4 [4.6] in the previous 12 months) and were managed more often by hospitalization (52% vs. 24% and 32%) in the USA than the HI and LMI countries. A higher proportion of patients from the USA than the HI/LMI countries reported a negative impact of SCD on their employment/schooling. Although high overall satisfaction with current treatments was reported globally, most patients indicated a strong desire for alternative pain medications. There are likely several reasons for the relatively high patient-reported burden in the USA group compared with the HI/LMI countries, including an older population and differences in newborn screening programs and pediatric/adult transition of care. It is clear that there is an urgent need for improved understanding and management of SCD globally, not just in the USA.

Pain Burden in the CASiRe International Cohort of Sickle Cell Patients: United States and Ghana.

OBJECTIVES: Sickle Cell Disease (SCD) is a genetic blood disorder affecting over 1 million people globally. The aim of this analysis is to explore the pain burden of patients with SCD in two countries: the United States and Ghana. METHODS: The Consortium for the Advancement of Sickle Cell Research (CASiRe) was created to better understand the clinical severity of patients with SCD worldwide. Data regarding gender, SCD genotype, prior medical diagnoses, and validated pain burden measures were analyzed from the CASiRe database. The Sickle Cell Pain Burden Interview (SCPBI) was used to assess pain burden, the impact of pain on physical, emotional, and social function. RESULTS: Most subjects identified as Black/African American (n = 298, 97.0%). Patient ages ranged from 6 to 73 years. 35.9% resided in the United States, 64.1% resided in Ghana, 40.9% were men, and 58.7% were women. The mean SCPBI score for US SCD patients was 6.53(±5.89) vs 4.04(±5.10) for Ghanaian patients, P <0.001. Pain burden was higher in US men vs Ghanaian men (6.74(±5.68) vs 3.54(±4.46), P = .003) and in US women vs Ghanaian women (6.37 ± 6.06 vs 4.44(±5.54), P = .032). Pain burden was higher in US patients than Ghanaian patients for both the Hb SC/SBeta+ genotype (5.40(±5.29) vs 2.82(±4.86), P = .054) and Hb SS/SBeta0 genotype (6.79(±6.01) vs 4.49(±5.13), P = .003). Pain burden was significantly higher in SCD patients with comorbid conditions independent of geographic origin including stroke, cholecystectomy, gallstones, depression, and headache. DISCUSSION: US patients with SCD have a higher pain burden than Ghanaian patients. Further studies should investigate underlying contributors to pain burden in these populations and further explore the etiology of geographic differences in pain.

Age of first pain crisis and associated complications in the CASiRe international sickle cell disease cohort.

Pain is a hallmark of Sickle Cell Disease (SCD) affecting patients throughout their life; the first pain crisis may occur at any age and is often the first presentation of the disease. Universal newborn screening identifies children with SCD at birth, significantly improving morbidity and mortality. Without early screening, diagnosis is generally made after disease manifestations appear. The Consortium for the Advancement of Sickle Cell Research (CASiRe) is an international collaborative group evaluating the clinical severity of subjects with SCD using a validated questionnaire and medical chart review, standardized across 4 countries (United States, United Kingdom, Italy and Ghana). We investigated the age of first pain crisis in 555 sickle cell subjects, 344 adults and 211 children. Median age of the first crisis in the whole group was 4 years old, 5 years old among adults and 2 years old among children. Patients from the United States generally reported the first crisis earlier than Ghanaians. Experiencing the first pain crisis early in life correlated with the genotype and disease severity. Early recognition of the first pain crisis could be useful to guide counseling and management of the disease.

Global geographic differences in healthcare utilization for sickle cell disease pain crises in the CASiRe cohort.

BACKGROUND: Sickle cell disease (SCD) is characterized by frequent, unpredictable pain episodes and other vaso-occlusive crises (VOCs) leading to significant healthcare utilization. VOC frequency is often an endpoint in clinical trials investigating novel therapies for this devastating disease. PROCEDURE: The Consortium for the Advancement of Sickle Cell Research (CASiRe) is an international collaboration investigating clinical severity in SCD using a validated questionnaire and medical chart review standardized across four countries (United States, United Kingdom, Italy and Ghana). RESULTS: This study, focused on pain crisis incidence and healthcare utilization, included 868 patients, equally represented according to age and gender. HgbSS was the most common genotype. Patients from Ghana used the Emergency Room/Day Hospital for pain more frequently (annualized mean 2.01) than patients from other regions (annualized mean 1.56 U.S.; 1.09 U.K.; 0.02 Italy), while U.K. patients were hospitalized for pain more often (annualized mean: U.K. 2.98) than patients in other regions (annualized mean 1.98 U.S.; 1.18 Ghana; Italy 0.54). Italy's hospitalization rate for pain (annualized mean: 0.57) was nearly 20 times greater than its emergency room/day hospital only visits for pain (annualized mean: 0.03). When categorized by genotype and age, similar results were seen. CONCLUSIONS: Geographic differences in pain crisis frequency and healthcare utilization may correlate with variable organization of healthcare systems among countries and should be considered regarding trial design, endpoints, and analysis of results when investigating novel agents for clinical benefit.

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

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

A study of the geographic distribution and associated risk factors of leg ulcers within an international cohort of sickle cell disease patients: the CASiRe group analysis.

Vasculopathy is a hallmark of sickle cell disease ultimately resulting in chronic end organ damage. Leg ulcer is one of its sequelae, occurring in ~ 5-10% of adult sickle cell patients. The majority of leg ulcer publications to date have emanated from single center cohort studies. As such, there are limited studies on the geographic distribution of leg ulcers and associated risk factors worldwide. The Consortium for the Advancement of Sickle Cell Research (CASiRe) was formed to improve the understanding of the different phenotypes of sickle cell disease patients living in different geographic locations around the world (USA, UK, Italy, Ghana). This cross-sectional cohort sub-study of 659 sickle cell patients aimed to determine the geographic distribution and risk factors associated with leg ulcers. The prevalence of leg ulcers was 10.3% and was associated with older age, SS genotype, male gender, and Ghanaian origin. In fact, the highest prevalence (18.6%) was observed in Ghana. Albuminuria, proteinuria, increased markers of hemolysis (lower hemoglobin, higher total bilirubin), lower oxygen saturation, and lower body mass index were also associated with leg ulceration. Overall, our study identified a predominance of leg ulcers within male hemoglobin SS patients living in sub-Saharan Africa with renal dysfunction and increased hemolysis.

Serious adverse events in African-American cancer patients with sickle cell trait and inherited haemoglobinopathies in a SEER-Medicare claims cohort.

African-American (AA) cancer patients have long-experienced worse outcomes compared to non-Hispanic whites (NHW). No studies to date have evaluated the prognostic impact of sickle cell trait (SCT) and other inherited haemoglobinopathies, of which several are disproportionately high in the AA population. In a cohort analysis of treated patients diagnosed with breast or prostate cancer in the linked SEER-Medicare database, the relative risk (RR) for ≥1 serious adverse events (AEs), defined as hospitalisations or emergency department visits, was estimated for 371 AA patients with a haemoglobinopathy (AA+) compared to patients without haemoglobinopathies (17,303 AA-; 144,863 NHW-). AA+ patients had significantly increased risk for ≥1 AEs compared to AA- (RR = 1.19; 95% CI 1.11-1.27) and NHW- (RR = 1.23; 95% CI 1.15-1.31) patients. The magnitude of effect was similar by cancer type, and in analyses of AA+ with SCT only. Our findings suggest a novel hypothesis for disparities in cancer outcomes.

Sickle cell disease diagnosis based on spatio-temporal cell dynamics analysis using 3D printed shearing digital holographic microscopy.

We present a spatio-temporal analysis of cell membrane fluctuations to distinguish healthy patients from patients with sickle cell disease. A video hologram containing either healthy red blood cells (h-RBCs) or sickle cell disease red blood cells (SCD-RBCs) was recorded using a low-cost, compact, 3D printed shearing interferometer. Reconstructions were created for each hologram frame (time steps), forming a spatio-temporal data cube. Features were extracted by computing the standard deviations and the mean of the height fluctuations over time and for every location on the cell membrane, resulting in two-dimensional standard deviation and mean maps, followed by taking the standard deviations of these maps. The optical flow algorithm was used to estimate the apparent motion fields between subsequent frames (reconstructions). The standard deviation of the magnitude of the optical flow vectors across all frames was then computed. In addition, seven morphological cell (spatial) features based on optical path length were extracted from the cells to further improve the classification accuracy. A random forest classifier was trained to perform cell identification to distinguish between SCD-RBCs and h-RBCs. To the best of our knowledge, this is the first report of machine learning assisted cell identification and diagnosis of sickle cell disease based on cell membrane fluctuations and morphology using both spatio-temporal and spatial analysis.

Regulation of Active ICAM-4 on Normal and Sickle Cell Disease RBCs via AKAPs Is Revealed by AFM.

Human healthy (wild-type (WT)) and homozygous sickle (SS) red blood cells (RBCs) express a large number of surface receptors that mediate cell adhesion between RBCs, and between RBCs and white blood cells, platelets, and the endothelium. In sickle cell disease (SCD), abnormal adhesion of RBCs to endothelial cells is mediated by the intercellular adhesion molecule-4 (ICAM-4), which appears on the RBC membrane and binds to the endothelial αvß3 integrin. This is a key factor in the initiation of vaso-occlusive episodes, the hallmark of SCD. A better understanding of the mechanisms that control RBC adhesion to endothelium may lead to novel approaches to both prevention and treatment of vaso-occlusive episodes in SCD. One important mechanism of ICAM-4 activation occurs via the cyclic adenosine monophosphate-protein kinase A (cAMP-PKA)-dependent signaling pathway. Here, we employed an in vitro technique called single-molecule force spectroscopy to study the effect of modulation of the cAMP-PKA-dependent pathway on ICAM-4 receptor activation. We quantified the frequency of active ICAM-4 receptors on WT-RBC and SS-RBC membranes, as well as the median unbinding force between ICAM-4 and αvß3. We showed that the collective frequency of unbinding events in WT-RBCs is not significantly different from that of SS-RBCs. This result was confirmed by confocal microscopy experiments. In addition, we showed that incubation of normal RBCs and SS-RBCs with epinephrine, a catecholamine that binds to the ß-adrenergic receptor and activates the cAMP-PKA-dependent pathway, caused a significant increase in the frequency of active ICAM-4 receptors in both normal RBCs and SS-RBCs. However, the unbinding force between ICAM-4 and the corresponding ligand αvß3 remained the same. Furthermore, we demonstrated that forskolin, an adenylyl cyclase activator, significantly increased the frequency of ICAM-4 receptors in WT-RBCs and SS-RBCs, confirming that the activation of ICAM-4 is regulated by the cAMP-PKA pathway. Finally, we showed that A-kinase anchoring proteins play an essential role in ICAM-4 activation.

Mortality risk from comorbidities independent of triple-negative breast cancer status: NCI-SEER-based cohort analysis.

PURPOSE: A comparatively high prevalence of comorbidities among African-American/Blacks (AA/B) has been implicated in disparate survival in breast cancer. There is a scarcity of data, however, if this effect persists when accounting for the adverse triple-negative breast cancer (TNBC) subtype which occurs at threefold the rate in AA/B compared to white breast cancer patients. METHODS: We reviewed charts of 214 white and 202 AA/B breast cancer patients in the NCI-SEER Connecticut Tumor Registry who were diagnosed in 2000-2007. We employed the Charlson Co-Morbidity Index (CCI), a weighted 17-item tool to predict risk of death in cancer populations. Cox survival analyses estimated hazard ratios (HRs) for all-cause mortality in relation to TNBC and CCI adjusting for clinicopathological factors. RESULTS: Among patients with SEER local stage, TNBC increased the risk of death (HR 2.18, 95 % CI 1.14-4.16), which was attenuated when the CCI score was added to the model (Adj. HR 1.50, 95 % CI 0.74-3.01). Conversely, the adverse impact of the CCI score persisted when controlling for TNBC (Adj. HR 1.49, 95 % CI 1.29-1.71; per one point increase). Similar patterns were observed in SEER regional stage, but estimated HRs were lower. AA/B patients with a CCI score of ≥3 had a significantly higher risk of death compared to AA/B patients without comorbidities (Adj. HR 5.65, 95 % CI 2.90-11.02). A lower and nonsignificant effect was observed for whites with a CCI of ≥3 (Adj. HR 1.90, 95 % CI 0.68-5.29). CONCLUSIONS: comorbidities at diagnosis increase risk of death independent of TNBC, and AA/B patients may be disproportionately at risk.

Adverse events in cancer patients with sickle cell trait or disease: case reports.

PURPOSE: Given the relatively high prevalence of sickle cell trait and disease among African Americans and established racial disparities in cancer outcomes, we reviewed the literature regarding adverse events in cancer patients with these hematologic genotypes. Erythrocyte sickling can result from extreme hypoxia and other physiologic stressors, as might occur during cancer therapy. Further, tumoral hypoxia, a poor prognostic and predictive factor, could lead to a cycle of local sickling and increased hypoxia. METHODS: A search of PubMed produced 150 publications, most of which were excluded because of incidental relevance. Eleven case reports of patients diagnosed from 1993 to 2013 were reviewed. RESULTS: Two reports of patients with sickle cell trait describe an abundance of sickled erythrocytes within tumors, and a third report describes sickling-related events requiring multiday hospitalization. Eight reports of patients with sickle cell disease delineated multiorgan failure, vaso-occlusive crises, and rapid renal deterioration. Hypothesized triggers are delayed clearance of anticancer agents attributable to baseline kidney damage, activation of vasoadherent neutrophils from treatment to counter chemotherapy-induced neutropenia, hypoxia from general anesthesia, and intratumoral hypoxia. CONCLUSION: Clinical implications include pretreatment genotyping for prophylaxis, dose adjustment, and enhanced patient monitoring. With the current lack of high-quality evidence, however, the scope of poor outcomes remains unknown.

AKAP-dependent modulation of BCAM/Lu adhesion on normal and sickle cell disease RBCs revealed by force nanoscopy.

Human normal and sickle red blood cells (RBCs) adhere with high affinity to the alpha5 chain of laminin (LAMA5) via the basal cell adhesion molecule/Lutheran (BCAM/Lu) receptor, which is implicated in vasoocclusive episodes in sickle cell disease and activated through the cyclic adenosine monophosphate (cAMP) signaling pathway. However, the effect of the cAMP pathway on the expression of active BCAM/Lu receptors at the single-molecule level is unknown. We established an in vitro technique, based on atomic force microscopy, which enables detection of single BCAM/Lu proteins on the RBC surface and measures the unbinding force between BCAM/Lu and LAMA5. We showed that the expression of active BCAM/Lu receptors is higher in homozygous sickle RBCs (SS-RBCs) than normal RBCs and that it is critically dependent on the cAMP signaling pathway on both normal and SS-RBCs. Of importance, we illustrated that A-kinase anchoring proteins are crucial for BCAM/Lu receptor activation. Furthermore, we found that SS-RBCs from hydroxyurea-treated patients show a lower expression of active BCAM/Lu receptors, a lower unbinding force to LAMA5, and insignificant stimulation by epinephrine as compared to SS-RBCs from untreated patients. To our knowledge, these findings may lead to novel antiadhesive targets for vasoocclusive episodes in sickle cell disease.

Identification of risk factors for an unsuccessful transition from pediatric to adult sickle cell disease care.

BACKGROUND: A successful transition from pediatric to adult sickle cell disease (SCD) care is paramount to continued improvements in survival. In order to enhance transition success, our pediatric SCD transition process was modified to include combined adult and pediatric provider clinics that incorporated participation by our local SCD community-based organization. All children ages 16 and over participated in this newly-formed transition program. PROCEDURE: After 5 years of implementation of the modified SCD transition program, we retrospectively studied clinical and non-clinical risk factors for an unsuccessful transition. Risk factor categories studied included patient demographics, transition clinic attendance, and disease severity. RESULTS: Thirty-two percent of patients did not transition successfully. Demographic factors such as gender, race, and type of insurance did not influence transition outcome, although travel distance to the adult SCD center was an identifiable risk factor for an unsuccessful transition. While transition clinic attendance rate did not affect transition outcomes, older age at first modified combined transition clinic visit was a significant risk factor for lack of transition. Patients with clinical markers of milder disease severity (SC and Sß(+) genotypes and no chronic transfusion therapy) were at higher risk for an unsuccessful transition than patients with severe disease. CONCLUSIONS: We have identified several risk factors for lack of transition success which will allow us to modify our transition efforts going forward to capture this highest risk subset.

Cost-Effectiveness of Lovotibeglogene Autotemcel (Lovo-Cel) Gene Therapy for Patients with Sickle Cell Disease and Recurrent Vaso-Occlusive Events in the United States.

BACKGROUND AND OBJECTIVE: Gene therapies for sickle cell disease (SCD) may offer meaningful benefits for patients and society. This study evaluated the cost-effectiveness of lovotibeglogene autotemcel (lovo-cel), a one-time gene therapy administered via autologous hematopoietic stem cell transplantation, compared with common care for patients in the United States (US) with SCD aged ≥ 12 years with ≥ 4 vaso-occlusive events (VOEs) in the past 24 months. METHODS: We developed a patient-level simulation model accounting for lovo-cel and SCD-related events, complications, and mortality over a lifetime time horizon. The pivotal phase 1/2 HGB-206 clinical trial (NCT02140554) served as the basis for lovo-cel efficacy and safety. Cost, quality-of-life, and other clinical data were sourced from HGB-206 data and the literature. Analyses were conducted from US societal and third-party payer perspectives. Uncertainty was assessed through probabilistic sensitivity analysis and extensive scenario analyses. RESULTS: Patients treated with lovo-cel were predicted to survive 23.84 years longer on average (standard deviation [SD], 12.80) versus common care (life expectancy, 62.24 versus 38.40 years), with associated discounted patient quality-adjusted life-year (QALY) gains of 10.20 (SD, 4.10) and direct costs avoided of $1,329,201 (SD, $1,346,446) per patient. Predicted societal benefits included discounted caregiver QALY losses avoided of 1.19 (SD, 1.38) and indirect costs avoided of $540,416 (SD, $262,353) per patient. Including lovo-cel costs ($3,282,009 [SD, $29,690] per patient) resulted in incremental cost-effectiveness ratios of $191,519 and $124,051 per QALY gained from third-party payer and societal perspectives, respectively. In scenario analyses, the predicted cost-effectiveness of lovo-cel also was sensitive to baseline age and VOE frequency and to the proportion of patients achieving and maintaining complete resolution of VOEs. CONCLUSIONS: Our analysis of lovo-cel gene therapy compared with common care for patients in the US with SCD with recurrent VOEs estimated meaningful improvements in survival, quality of life, and other clinical outcomes accompanied by increased overall costs for the health care system and for broader society. The predicted economic value of lovo-cel gene therapy was influenced by uncertainty in long-term clinical effects and by positive spillover effects on patient productivity and caregiver burden.

Splenic morphological changes are accompanied by altered baseline immunity in a mouse model of sickle-cell disease.

Although functional asplenia from infarctions may be a major contributor to increased infectious mortality in sickle-cell disease (SCD), this relationship has not been fully defined. We used the transgenic Berkeley SCD mouse to define blood and splenic immunophenotypic differences in this model compared with C57BL/6 and hemizygous controls. In the serum of SCD mice, we found increased IgG2a and suppressed IgM, IgG2b, and IgA levels. Serum IL-6 levels in SCD mice were elevated, whereas IL-1α, CXCL10, and CCL5 levels were decreased. The blood of SCD mice had higher white blood cell counts, with an increased percentage of lymphocytes and decreases in other leukocytes. Immunophenotyping of lymphocytes revealed higher percentages of CD8(+) and T-regulatory cells and lower percentages of B cells. SCD mouse spleens exhibited histological disorganization, with reduction of defined lymphoid follicles and expansion of red pulp, a greater than fourfold increase in splenic mononuclear cells, marked expansion of the nucleated red blood cell fraction, and B-cell and CD8(+) T-cell lymphopenia. Within the splenic B-cell population, there was a significant decrease in B-1a B cells, with a corresponding decrease in IgA secreting plasma cells in the gut. Confocal microscopy of spleens demonstrated complete disruption of the normal lymphofollicular structure in the white pulp of SCD mice without distinct B, T, and marginal zones. Our findings suggest that altered SCD splenic morphological characteristics result in an impaired systemic immune response.

Transgenic sickle cell disease mice have high mortality and dysregulated immune responses after vaccination.

BACKGROUND: Children with sickle cell disease (SCD) are susceptible to recurrent infections, which are often life threatening and necessitate frequent vaccinations. Given the altered baseline immunity and proinflammatory state associated with SCD, we sought to determine the relative safety and efficacy of vaccination in transgenic SCD mice. METHODS: Eight-week-old SCD mice were vaccinated with ovalbumin and aluminum hydroxide weekly for 3 wk by the intraperitoneal or intramuscular route. One week after the third vaccination, serum cytokines/chemokines, immunoglobulins, and bronchoalveolar lavage fluid cytokines were measured. RESULTS: Only SCD mice were prone to mortality associated with vaccination, as 40% of the animals died after the intraperitoneal vaccinations and 50% died after the intramuscular vaccinations. Serum IgG2b and IgM were significantly lower in SCD mice than in C57BL/6 mice after vaccination, but ovalbumin-specific IgE was significantly higher. Serum interleukin (IL)-1α, IL-2, IL-5, macrophage inflammatory protein 1α, and granulocyte macrophage-colony stimulating factor were significantly lower in SCD mice than in C57BL/6 mice after vaccination, whereas bronchoalveolar lavage fluid IL-1ß and IL-6 were increased. CONCLUSION: Mice with SCD appear to have a dysregulated immune response to vaccination. Thus, the relative safety and immunogenicity of vaccination should be studied in greater detail in the context of SCD.

Economic and clinical burden of managing transfusion-dependent ß-thalassemia in the United States.

AIMS: To describe clinical complications, treatment use, healthcare resource utilization (HCRU), and costs among patients with transfusion-dependent ß-thalassemia (TDT) in the United States. MATERIALS AND METHODS: Merative MarketScan Databases were used to identify patients with ß-thalassemia between 1 March 2010, and 1 March 2019. Patients were eligible for inclusion with ≥1 inpatient claim or ≥2 outpatient claims for ß-thalassemia and ≥8 red blood cell transfusions (RBCTs) during any 12-month period after and including the date of the first qualifying ß-thalassemia diagnosis code. Matched controls consisted of individuals without ß-thalassemia. Clinical and economic outcomes of patients were assessed during ≥12 months of follow-up, defined as the period from the index date (i.e. the first RBCT) to either the end of continuous enrollment in benefits, inpatient death, or 1 March 2020. RESULTS: Overall, 207 patients with TDT and 1035 matched controls were identified. Most patients received iron chelation therapy (ICT) (91.3%), with a mean of 12.1 (standard deviation [SD] = 10.3) ICT claims per-patient-per-year (PPPY). Many also received RBCTs, with a mean of 14.2 (SD = 4.7) RBCTs PPPY. TDT was associated with higher annual ($137,125) and lifetime ($7.1 million) healthcare costs vs. matched controls ($4183 and $235,000, respectively). Annual costs were driven by ICT (52.1%) and RBCT use (23.6%). Patients with TDT had 7-times more total outpatient visits/encounters, 3-times more prescriptions, and 33-times higher total annual costs than matched controls. LIMITATIONS: This analysis may underestimate the burden of TDT, as indirect healthcare costs (e.g. absenteeism, presenteeism, etc.) were not included. Results may not be generalizable to patients excluded from this analysis, including those with other types of insurance or without insurance. CONCLUSIONS: Patients with TDT have high HCRU and direct healthcare costs. Treatments that eliminate the need for RBCTs could reduce the clinical and economic burden of managing TDT.