Concentration of voxelotor in sickle cell disease can be estimated using electrophoresis and high-performance liquid chromatography.

OBJECTIVES: Voxelotor can increase hemoglobin levels in patients living with sickle cell disease (SCD). A clinician who is monitoring voxelotor response may want to know whole-blood voxelotor concentration, but this cannot be measured in most clinical settings. However, voxelotor has been demonstrated to cause "peak splitting" in common methods of hemoglobin measurement such as capillary zone electrophoresis (CZE) and high-performance liquid chromatography (HPLC). We hypothesized that we could use the size of the peak split to estimate the whole-blood concentration. METHODS: Blood from people with SCD was dosed with known concentrations of voxelotor, and multiparameter regression was used to derive the relationship of voxelotor concentration to the degree of peak splitting observed. To validate these equations, 21 patients started on voxelotor at 1500 mg/d had blood samples drawn at days 0, 14, 30, and 60. Samples were sent out for gold standard voxelotor concentration testing. The derived equations were then used to calculate voxelotor concentration. RESULTS: Calculated concentrations correlated strongly with measured concentrations for both CZE (R2 = 0.83, P < .001) and HPLC (R2 = 0.76, P < .001). Voxelotor concentration also had a significant effect on increases in hemoglobin (R2 = 0.40, P < .001). CONCLUSIONS: Thus, peak splitting CZE and HPLC can be used to estimate voxelotor concentration.

Leg ulcers are indicators of systemic dysfunction in individuals with sickle cell disease.

Leg ulcers in individuals living with Sickle Cell Disease are evidence of systemic dysfunction. Data from a U.S. study link leg ulcers to wider pulse pressure and markers of chronic hemolysis, inflammation, renal, and liver dysfunction.

Riociguat in patients with sickle cell disease and hypertension or proteinuria (STERIO-SCD): a randomised, double-blind, placebo controlled, phase 1-2 trial.

BACKGROUND: Although nitric oxide based therapeutics have been shown in preclinical models to reduce vaso-occlusive events and improve cardiovascular function, a clinical trial of a phosphodiesterase 5 inhibitor increased rates of admission to hospital for pain. We aimed to examine if riociguat, a direct stimulator of the nitric oxide receptor soluble guanylate cyclase, causes similar increases in vaso-occlusive events. METHODS: This was a phase 1-2, randomised, double blind, placebo-controlled trial. Eligible patients were 18 years or older, had confirmed sickle cell disease documented by haemoglobin electrophoresis or HPLC fractionation (haemoglobin SS, SC, Sß-thalassemia, SD, or SO-Arab), and stage 1 hypertension or proteinuria. Participants were randomly assigned 1:1 to receive either riociguat or matching placebo via a web-based system to maintain allocation concealment. Both treatments were administered orally starting at 1·0 mg three times a day up to 2·5 mg three times a day (highest tolerated dose) for 12 weeks. Dose escalation by 0·5 mg was considered every 2 weeks if systolic blood pressure was greater than 95 mm Hg and the participant had no signs of hypotension; otherwise, the last dose was maintained. The primary outcome was the proportion of participants who had at least one adjudicated treatment-emergent serious adverse event. The analysis was performed by the intention-to-treat. This trial is registered with ClinicalTrials.gov (NCT02633397) and was completed. FINDINGS: Between April 11, 2017, and Dec 31, 2021, 165 participants were screened and consented to be enrolled into the study. Of these, 130 participants were randomly assigned to either riociguat (n=66) or placebo (n=64). The proportion of participants with at least one treatment-emergent serious adverse event was 22·7% (n=15) in the riociguat group and 31·3% (n=20) in the placebo group (difference -8·5% [90% CI -21·4 to 4·5]; p=0·19). A similar pattern emerged in other key safety outcomes, sickle cell related vaso-occlusive events (16·7 [n=11] vs 21·9% [n=14]; difference -5·2% [-17·2 to 6·5]; p=0·42), mean pain severity (3·18 vs 3·32; adjusted mean difference -0·14 [-0·70 to 0·42]; p=0·69), and pain interference (3·15 vs 3·12; 0·04 [-0·62 to 0·69]; p=0·93) at 12 weeks were similar between groups. Regarding the key clinical efficacy endpoints, participants taking riociguat had a blood pressure of -8·20 mm Hg (-10·48 to -5·91) compared with -1·24 (-3·58 to 1·10) in those taking placebo (-6·96 mm Hg (90% CI -10·22 to -3·69; p<0·001). INTERPRETATION: Riociguat was safe and had a significant haemodynamic effect on systemic blood pressure. The results of this study provide measures of effect and variability that will inform power calculations for future trials. FUNDING: Bayer Pharmaceuticals.

Venous thromboembolism prophylaxis practices for patients with sickle cell disease prior to and during the COVID-19 pandemic.

Patients with sickle cell disease (SCD) are predisposed to a hypercoagulable state due to alterations in the coagulation system. Despite concern for the development of venous thromboembolism (VTE) in this population, there are no standardized guidelines for routine thromboprophylaxis. The objective of this study was to assess thromboprophylaxis practices of adult and pediatric treaters of SCD before and during the coronavirus disease of 2019 (COVID-19) pandemic. A cross-sectional electronic survey was distributed to pediatric and adult hematology oncology practitioners through seven SCD-specific interest groups between May 29, 2020, and July 13, 2020. Of 93 total responses, 14% ( N  = 13) reported they only treat patients more than 21 years old; 38.7% ( N  = 36) only treat patients 0-21 years old and 47.3% ( N  = 44) reported they treat both. Our study showed that before the COVID-19 pandemic, 96% of adult practitioners would recommend pharmacologic thromboprophylaxis, mechanical thromboprophylaxis or both for hospitalized adults with thromboprophylaxis, but only 76% of pediatric treaters would recommend any thromboprophylaxis in hospitalized children ( P  < 0.0001), with 24% of pediatric treaters choosing no thromboprophylaxis at all. During the COVID-19 pandemic, pharmacologic thromboprophylaxis specifically was recommended for adults by 94% of treaters and for pediatric patients by 76% of treaters. These findings suggest that despite the lack of evidence-based thromboprophylaxis guidelines in adults and children with thromboprophylaxis, subspecialty treaters routinely provide pharmacologic thromboprophylaxis in their adult patients and will modify their practice in pediatric patients who are considered at a high risk for VTE.

Routine Ophthalmological Examination Rates in Adults with Sickle Cell Disease Are Low and Must Be Improved.

The American Academy of Ophthalmology and the National Heart, Lung and Blood Institute recommend patients with sickle cell disease (SCD) undergo dilated funduscopic exams (DFE) every 1-2 years to screen for sickle retinopathy. There is a paucity of data on the adherence rate to these guidelines; a retrospective study was performed to evaluate our institution's adherence. A chart review of 842 adults with SCD, seen 3/2017-3/2021 in the Montefiore healthcare system (All Patients), was done. Only about half of All Patients (n = 842) had >1 DFE during the study period (Total Examined Patients, n = 415). The Total Examined Patients were categorized as screening, those without retinopathy (Retinopathy-, n = 199), or follow-up, including individuals previously diagnosed with retinopathy (Retinopathy+, n = 216). Only 40.3% of screening patients (n = 87) had DFE at least biennially. As expected, there was a significant decrease in the average DFE rate of the Total Examined Patients after the COVID-19 pandemic started (13.6%) compared to pre-COVID (29.8%, p < 0.001). Similarly, there was a significant decrease in the screening rate of Retinopathy- patients from 18.6% on average pre-COVID to 6.7% during COVID (p < 0.001). This data shows the sickle retinopathy screening rate is low and innovative approaches may need to be employed to remedy this issue.

Sickle Cell Trevor Thompson Transition Project (ST3P-UP) protocol for managing care transitions: Methods and rationale.

BACKGROUND: Emerging adults with sickle cell disease (EASCD) experience significant challenges transitioning from pediatric to adult care. Acute care utilization increases, quality of life (QOL) declines, with an increased risk of mortality. Currently, there are no practice standards to guide emerging adults through the transition process. We are creating a structured transition education (STE) based program for EASCD by customizing the Six Core Elements (6 CE) of Health Care Transition model and are evaluating the effectiveness of adding peer mentoring (PM). METHODS: The Sickle Cell Trevor Thompson Transition Project (ST3P-UP) is an ongoing multi-site, cluster randomized clinical trial with a target enrollment of 537 EASCD aged 16 to 25 years in pediatric care. Each site (n = 14) comprises a pediatric clinic, adult clinic, and a sickle cell disease (SCD) community-based organization (CBO). Sites are randomized 1:1 to either STE or STE + PM. EASCDs are followed prospectively for 24 months. Rapid cycle plan-do-study-act quality improvement (QI) methods are used to implement the STE. The primary objective is to compare the effectiveness of STE + PM versus STE only at decreasing the number of acute care visits per year over 24 months. The secondary objectives are to compare overall healthcare utilization and patient-reported QOL outcomes at 24 months. CONCLUSION: We aim to demonstrate the feasibility of using a QI approach to implement 6 CE-based practice standards at 14 disparate SCD clinical programs to guide EASCD through the transition process. We hypothesize that adding PM to the STE program will improve acute care reliance, QOL, and satisfaction with transition outcomes.

Clinical Vignettes Part I.

Patients with sickle cell disease and/or (rarely) trait are at increased risk for developing recurrent episodes of priapism, also known as stuttering priapism, and major ischemic priapism. Treatment of acute ischemic priapism is reactive; whereas ideal management consists of preventative approaches to ultimately promote the best improvement in patient's quality of life. Leg ulcers in patients with sickle cell disease (SCD) are quite common, with ∼20 % of patients with HBSS reporting either having an active or a past ucler. They can be confused with venous ulcers, with lower extremity hyperpigmentation confounding further the diagnosis. Several factors believed to contribute to the development of leg ulcers in patients with SCD are discussed in this article. Sickle cell liver disease (SCLD) occurs because of a wide variety of insults to the liver that happen during the lifetime of these patients. SCLD includes a range of complications of the hepatobiliary system and is increasing in prevalence with the aging adult sickle population. Liver nodular regenerative hyperplasia (NRH) is more common than realized and underappreciated as a diagnosis and requires liver biopsy with reticulin staining. Undiagnosed, the insidious damage from liver NRH can lead to noncirrhotic portal hypertension or cirrhosis.

COVID19 vaccination in adults with sickle cell disease is not associated with increases in rates of pain crisis.

ABSTRACTPeople with sickle cell disease (SCD) are more vulnerable to hospitalization, pneumonia, and pain following COVID-19 infection. However, given the association between the inflammatory response and vaso-occlusive crises in SCD and a case report of vaso-occlusive crises following administration of the ChAdOx1 nCov-195-7/AstraZeneca vaccine, there is concern that the administration of COVID-19 vaccines in people with SCD might provoke a vaso-occlusive crisis. To address this critical gap in knowledge, we sought to examine acute care usage for vaso-occlusive crisis and frequency and severity of side effects following COVID-19 vaccination among patients at the Montefiore Sickle Cell Center for Adults. As part of regular care, patients were asked if they had received COVID-19 vaccination and any side effects were noted. Electronic medical records were reviewed for the type of vaccine, dates received, episodes of vaso-occlusive crises within seven days of a dose, and side effects noted. The risk of average hospital utilization per week in 2019 was calculated as a baseline. We found that fewer than 1 in 10 patients presented to the hospital within seven days of vaccination and that the risk of hospital utilization was similar to the average risk in a week in 2019. Of patients who reported side effects, one reported a possible case of sensorineural hearing loss otherwise no other rare side effects, including thrombosis or death, were reported.

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.

Hydroxyurea and fetal hemoglobin effect on leg ulcers in patients with sickle cell disease.

The presence of leg ulcers in individuals with sickle cell disease often represents an early sign of vasculopathy and future end organ damage. Pathophysiological mechanisms of formation and evolution of leg ulcers are poorly understood; nevertheless, HbF has been associated with lower incidence of leg ulcers, while hydroxyurea has been correlated with high risk of leg ulcers. As a result, there is hesitation regarding hydroxyurea use in patients with SCD and leg ulcers. In this study, we aim to define (1) a target of HbF that offers protection against leg ulcer development and (2) the impact of hydroxyurea therapy on leg ulcer prevalence. Our study demonstrated that in order to reduce leg ulcer incidence by one-third, a HbF > 25% is needed, a threshold not commonly reached and maintained in the adult SCD population. Importantly, leg ulcer incidence appears to be independent of HU use (p = 0.50). Our interpretation of this data is that the use of HU in a patient with SCD and leg ulcers should be guided by a careful assessment of risks and benefits of this therapeutic modality.

Transition Navigator Intervention Improves Transition Readiness to Adult Care for Youth With Sickle Cell Disease.

OBJECTIVE: Adolescents and young adults (AYA) with sickle cell disease (SCD) experience high rates of acute care utilization and increased morbidity. At this high-risk time, they also face the need to transition from pediatric to adult services, which, if poorly coordinated, adds to heightened morbidity and acute care utilization. The study objective was to characterize the feasibility, acceptability, and short-term efficacy of a protocolized transition navigator (TN) intervention in AYA with SCD. METHODS: We developed a protocolized TN intervention that used ecological assessment and motivational interviewing to assess transition readiness, identify goals, and remove barriers to transition, and to provide disease and pain management education and skills to AYAs with SCD. RESULTS: Ninety-three percent (56/60) of enrolled individuals completed the intervention. Participation in the TN program was associated with significant improvement in mean transition readiness scores (3.58-4.15, P < .0001), disease knowledge scale (8.91-10.13, P < .0001), Adolescent Medication Barriers Scale (40.05-35.39, P = .003) and confidence in both disease (22.5-23.96, P = .048) and pain management (25.07-26.61, P = .003) for youth with SCD. CONCLUSION: The TN intervention was acceptable to youth with SCD, feasible to implement at an urban academic medical center, and addressed barriers to transition identified by the youth. Longer-term assessment is needed to determine if the TN intervention improved successful transfer to and retention in adult care.

Colocating Wound Care for Patients with Sickle Cell Ulcers in a Hematology Clinic.

OBJECTIVE: Leg ulcers affect 15% of people with sickle cell disease. However, wound centers typically treat few people with this condition, which makes it difficult to concentrate clinical expertise or support the scientific study of this orphan disease. This article describes an initiative to increase engagement in care through a partnership between wound healing and hematology leadership that led to colocating wound services within a sickle cell clinic. METHODS: Via a retrospective chart review, the authors collected records of all adult patients with sickle cell disease who received wound care in the last decade, including 7 years of wound center data and 3 years of data from the colocated services. Patient and visit characteristics were analyzed using descriptive analytics. RESULTS: The general wound center had previously treated 35 patients with sickle cell ulcers over 7 years. In contrast, colocated services engaged 56 patients within 3 years, including 20 who transferred care and 36 new patients. The majority of patients at the colocated site were women, unlike at the wound center (58% vs 47%, P = .07). Results indicated that 36% of patients healed initial wounds, and 45% had new wound occurrences. CONCLUSIONS: Colocation successfully increases the number of patients with sickle cell ulcers who will engage in wound care at a single site, laying the foundation for clinical studies to improve the evidence base for this difficult-to-treat condition.

A reanalysis of pain crises data from the pivotal l-glutamine in sickle cell disease trial.

The pivotal Endari trial in sickle cell disease showed a reduction in pain crises events. This reanalysis of the l-glutamine phase 3 trial using annual rates of pain crises, consistent with other SCD studies, supported the statistically significant outcomes of the original analysis. The observed 45% difference in the VOC rate is comparable to what was reported in other sickle cell therapeutics used to reduce the incidence of pain. The results presented in this communication are informative for clinicians evaluating treatment effects across available SCD therapeutic options based on studies that utilized VOC as the primary endpoint.

First Report of Compound Heterozygosity for Hb S (HBB: c.20A>T) and Hb Haringey (HBB: c.131A>G).

Sickle cell disease variants include hemoglobinopathies that result from inheritance of the sickle cell globin mutation with another globin mutation. The most common variants include the homozygous disease state (Hb SS disease), Hb S (HBB: c.20A>T)/Hb C (HBB: c.19G>A) disease and Hb S/ß-thalassemia (Hb S/ß-thal). Other rare/less common variants such as Hb S/Hb E (HBB: c.79G>A) and Hb S/HPFH [hereditary persistence of fetal hemoglobin (Hb)] disease exist. We report the first case of compound heterozygosity for Hb S and Hb Haringey (HBB: c.131A>G) in a 35-year-old male following a positive sickle screen test on hospital admission for pancreatitis. Ion exchange high performance liquid chromatography (HPLC), Hb electrophoresis and genetic sequencing were utilized to identify a new sickle Hb variant: Hb S/Hb Haringey. Hb S/Hb Haringey is a newly discovered sickle cell variant which seems to portray a mild/benign clinical phenotype of sickle cell disease.