Oxygen gradient ektacytometry-derived biomarkers are associated with acute complications in sickle cell disease.

ABSTRACT: We investigated the potential of the point of sickling (PoS; the pO2 tension at which red cells start to sickle), determined by oxygen gradient ektacytometry to serve as a biomarker associated with the incidence of acute sickle cell disease-related complications in 177 children and 50 adults. In the pediatric cohort, for every 10 mmHg increase in PoS reflecting a greater likelihood of sickling, the likelihood of an individual experiencing >1 type of acute complication increased; the adjusted odds ratio (aOR) was 1.65. For every 0.1 increase in minimum elongation index (EImin; reflecting improved red blood cell deformability at hypoxia), the aOR was 0.50. In the adult cohort, for every 10 mmHg increase in PoS, we found an aOR of 3.00, although this was not significant after correcting for multiple testing. There was a trend for an association between higher PoS and greater likelihood of vaso-occlusive episodes (VOEs; children aOR, 1.35; adults aOR, 2.22). In children, only EImin was associated with VOEs (aOR, 0.68). When data of both cohorts were pooled, significant associations with PoS and/or EImin were found for all acute complications, independently and when >1 type of acute complication was assessed. These findings indicate that oxygen gradient ektacytometry generates novel biomarkers and provides a rationale for further development of these biomarkers in the assessment of clinical severity, evaluation of novel therapies, and as surrogate clinical trial end points. These biomarkers may be useful in assessing efficacy of novel therapies like pyruvate kinase activators, voxelotor, and L-glutamine.

Patient-reported outcomes in autosomal inherited bleeding disorders: A systematic literature review.

AIM: Currently, it is unknown which patient-reported outcomes are important for patients with autosomal inherited bleeding disorders. Therefore, the purpose of this study is to systematically review the available literature assessing patient-reported outcomes and their measurement methods in autosomal inherited bleeding disorders. METHODS: The Embase, Medline ALL, Web of Science Core Collection, Cochrane Central Register of Controlled Trails and Google Scholar databases were searched from inception until 14 August 2020. Studies on patient-reported outcomes in patients with von Willebrand disease, inherited platelet function disorders and coagulation factor deficiencies were included. RESULTS: Twenty-one articles met the inclusion criteria. Three studies were assessed as having poor quality, and therefore a high risk of bias. Nineteen studies had fair quality rating. Different measurements methods were used, ranging from predefined to self-developed questionnaires. The majority of included studies focused on von Willebrand disease. Patients with von Willebrand disease reported lower health-related quality of life compared to the general population. Overall, this trend was especially visible in the following domains: vitality, physical and social functioning and pain. Women with inherited bleeding disorders scored lower on health-related quality of life compared to men, especially women with heavy menstrual bleeding. Patients with joint bleeds or heavy menstrual bleeding reported an increased level of pain. CONCLUSION: Patients with autosomal inherited bleeding disorders report lower health related quality of life, especially those with joint bleeds or heavy menstrual bleeding. Numerous measurement methods are used in patients with autosomal inherited bleeding disorders, highlighting the need for studies using established, standardized measurement methods.

Health-related quality of life in infants, toddlers and young children with sickle cell disease.

BACKGROUND: Little is known about health-related quality of life (HRQoL) in young children with sickle cell disease living in a European country. METHODS: A retrospective cross-sectional evaluation of TNO-AZL Preschool Children Quality of Life questionnaire (TAPQOL, 0-1 year) and Pediatric Quality of Life Inventory (PedsQL, 2-7 years) data was conducted. Study participants included caregivers of children with sickle cell disease aged 0-7 years attending the sickle cell centre at the Erasmus Medical Center or the Amsterdam University Medical Centers between April 2012 and October 2020. Comparisons were made with normative data on HRQoL in the general paediatric population. RESULTS: The study enrolled 136 caregivers of 136 children. In children aged 0-5 years, no significant differences emerged between children with sickle cell disease and the general population. However, in children aged 5-7 years, children with sickle cell disease scored significantly lower on all subscales except for emotional functioning. Multiple regression models showed a negative association between age and HRQoL. No association was found between HRQoL and disease severity or sociodemographic characteristics. CONCLUSIONS: This study demonstrates that HRQoL is negatively correlated with age in young children with sickle cell disease with a significantly lower HRQoL in 5- to 7-year-olds when compared to the general population. Our study underlines the importance of measuring HRQoL in young children to identify patients with impaired HRQoL early in life in order to be able to intervene accordingly. Future research should focus on deepening the knowledge of factors influencing HRQoL in children with sickle cell disease.

Improving access to healthcare for paediatric sickle cell disease patients: a qualitative study on healthcare professionals' views.

BACKGROUND: In well-resourced countries, comprehensive care programs have increased life expectancy of patients with sickle cell disease, with almost all infants surviving into adulthood. However, families affected by sickle cell disease are more likely to be economically disenfranchised because of their racial or ethnic minority status. As every individual child has the right to the highest attainable standard of health under the United Nations Convention on the Rights of the Child, it is essential to identify both barriers and facilitators with regard to the delivery of adequate healthcare. Optimal healthcare accessibility will improve healthcare outcomes for children with sickle cell disease and their families. Healthcare professionals in the field of sickle cell care have first-hand experience of the barriers that patients encounter when it comes to effective care. We therefore hypothesised that these medical professionals have a clear picture of what is necessary to overcome these barriers and which facilitators will be most feasible. Therefore, this study aims to map best practises and lessons learnt in order to attain more optimal healthcare accessibility for paediatric patients with sickle cell disease and their families. METHODS: Healthcare professionals working with young patients with sickle cell disease were recruited for semi-structured interviews. An interview guide was used to ensure the four healthcare accessibility dimensions were covered. The interviews were transcribed and coded. Based on field notes, initial codes were generated, to collate data (both barriers and solutions) to main themes (such as "transportation", or "telecommunication"). Through ongoing thematic analysis, definitive themes were formulated and best practices were reported as recommendations. Quotations were selected to highlight or illustrate the themes and link the reported results to the empirical data. RESULTS: In 2019, 22 healthcare professionals from five different university hospitals in the Netherlands were interviewed. Participants included (paediatric) haematologists, nurses and allied health professionals. Six themes emerged, all associated with best practices on topics related to the improvement of healthcare accessibility for children with sickle cell disease and their families. Firstly, the full reimbursement of invisible costs made by caregivers. Secondly, clustering of healthcare appointments on the same day to help patients seeing all required specialists without having to visit the hospital frequently. Thirdly, organisation of care according to shared care principles to deliver specialised services as close as possible to the patient's home without compromising quality. Fourthly, optimising verbal and written communication methods with special consideration for families with language barriers, low literacy skills, or both. Fifthly, improving the use of eHealth services tailored to users' health literacy skills, including accessible mobile telephone contact between healthcare professionals and caregivers of children with sickle cell disease. Finally, increasing knowledge and interest in sickle cell disease among key stakeholders and the public to ensure that preventive and acute healthcare measures are understood and safeguarded in all settings. CONCLUSION: This qualitative study describes the views of healthcare professionals on overcoming barriers of healthcare accessibility that arise from the intersecting vulnerabilities faced by patients with sickle cell disease and their families. The recommendations gathered in this report provide high-income countries with a practical resource to meet their obligations towards individual children under the United Nations Convention on the Rights of the Child.

Characteristics and outcome of pediatric renal cell carcinoma patients registered in the International Society of Pediatric Oncology (SIOP) 93-01, 2001 and UK-IMPORT database: A report of the SIOP-Renal Tumor Study Group.

In children, renal cell carcinoma (RCC) is rare. This study is the first report of pediatric patients with RCC registered by the International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG). Pediatric patients with histologically confirmed RCC, registered in SIOP 93-01, 2001 and UK-IMPORT databases, were included. Event-free survival (EFS) and overall survival (OS) were analyzed using the Kaplan-Meier method. Between 1993 and 2019, 122 pediatric patients with RCC were registered. Available detailed data (n = 111) revealed 56 localized, 30 regionally advanced, 25 metastatic and no bilateral cases. Histological classification according to World Health Organization 2004, including immunohistochemical and molecular testing for transcription factor E3 (TFE3) and/or EB (TFEB) translocation, was available for 65/122 patients. In this group, the most common histological subtypes were translocation type RCC (MiT-RCC) (36/64, 56.3%), papillary type (19/64, 29.7%) and clear cell type (4/64, 6.3%). One histological subtype was not reported. In the remaining 57 patients, translocation testing could not be performed, or TFE-cytogenetics and/or immunohistochemistry results were missing. In this group, the most common RCC histological subtypes were papillary type (21/47, 44.7%) and clear cell type (11/47, 23.4%). Ten histological subtypes were not reported. Estimated 5-year (5y) EFS and 5y OS of the total group was 70.5% (95% CI = 61.7%-80.6%) and 84.5% (95% CI = 77.5%-92.2%), respectively. Estimated 5y OS for localized, regionally advanced, and metastatic disease was 96.8%, 92.3%, and 45.6%, respectively. In conclusion, the registered pediatric patients with RCC showed a reasonable outcome. Survival was substantially lower for patients with metastatic disease. This descriptive study stresses the importance of full, prospective registration including TFE-testing.

Silent cerebral infarcts in patients with sickle cell disease: a systematic review and meta-analysis.

BACKGROUND AND PURPOSE: Silent cerebral infarcts (SCIs) are the most common neurological complication in children and adults with sickle cell disease (SCD). In this systematic review, we provide an overview of studies that have detected SCIs in patients with SCD by cerebral magnetic resonance imaging (MRI). We focus on the frequency of SCIs, the risk factors involved in their development and their clinical consequences. METHODS: The databases of Embase, MEDLINE ALL via Ovid, Web of Science Core Collection, Cochrane Central Register of Trials via Wiley and Google Scholar were searched from inception to June 1, 2019. RESULTS: The search yielded 651 results of which 69 studies met the eligibility criteria. The prevalence of SCIs in patients with SCD ranges from 5.6 to 80.6% with most studies reported in the 20 to 50% range. The pooled prevalence of SCIs in HbSS and HbSß0 SCD patients is 29.5%. SCIs occur more often in patients with the HbSS and HbSß0 genotype in comparison with other SCD genotypes, as SCIs are found in 9.2% of HbSC and HbSß+ patients. Control subjects showed a mean pooled prevalence of SCIs of 9.8%. Data from included studies showed a statistically significant association between increasing mean age of the study population and mean SCI prevalence. Thirty-three studies examined the risk factors for SCIs. The majority of the risk factors show no clear association with prevalence, since more or less equal numbers of studies give evidence for and against the causal association. CONCLUSIONS: This systematic review and meta-analysis shows SCIs are common in patients with SCD. No clear risk factors for their development were identified. Larger, prospective and controlled clinical, neuropsychological and neuroimaging studies are needed to understand how SCD and SCIs affect cognition.

Cost of health care for paediatric patients with sickle cell disease: An analysis of resource use and costs in a European country.

BACKGROUND: While multiple studies have examined the cost of health care for one aspect of sickle cell disease care, few have focussed on the overall cost of comprehensive care for sickle cell disease. METHODS: We conducted a retrospective cohort study of children with sickle cell disease treated in a comprehensive care centre from 1 January 2015 to 31 December 2016. Health care utilisation of included patients was based upon data from two main sources. The clinical practice guideline was used to determine the expected resource use of routine comprehensive care (planned elective care), and the financial claims database was used to estimate real-world resource use associated with acute and inpatient care (additional care). RESULTS: A total of 125 children with sickle cell disease were analysed. Expenditures for these patients averaged €5049 [standard deviation (SD) €1634] per child per year. Total yearly costs per patient varied considerably, ranging from €669 to €84 010, and less than 15% of patients were responsible for 50% of the health care costs. The majority (37%) of costs was associated with inpatient hospital care, which increased by age group, 27% with diagnostics, 19% with treatment, 11% with outpatients' visits and 6% with emergency care. CONCLUSION: We have described real-world resource use and expenditures for children with sickle cell disease in a European comprehensive care centre. It seems that costs of a comprehensive approach with effective management in the outpatient setting is favourable when compared to episodic health care.

Rapid and reproducible characterization of sickling during automated deoxygenation in sickle cell disease patients.

In sickle cell disease (SCD), sickle hemoglobin (HbS) polymerizes upon deoxygenation, resulting in sickling of red blood cells (RBCs). These sickled RBCs have strongly reduced deformability, leading to vaso-occlusive crises and chronic hemolytic anemia. To date, there are no reliable laboratory parameters or assays capable of predicting disease severity or monitoring treatment effects. We here report on the oxygenscan, a newly developed method to measure RBC deformability (expressed as Elongation Index - EI) as a function of pO2 . Upon a standardized, 22 minute, automated cycle of deoxygenation (pO2 median 16 mmHg ± 0.17) and reoxygenation, a number of clinically relevant parameters are produced in a highly reproducible manner (coefficients of variation <5%). In particular, physiological modulators of oxygen affinity, such as, pH and 2,3-diphosphoglycerate showed a significant correlation (respectively R = -0.993 and R = 0.980) with Point of Sickling (PoS5% ), which is defined as the pO2 where a 5% decrease in EI is observed during deoxygenation. Furthermore, in vitro treatment with antisickling agents, including GBT440, which alter the oxygen affinity of hemoglobin, caused a reproducible left-shift of the PoS, indicating improved deformability at lower oxygen tensions. When RBCs from 21 SCD patients were analyzed, we observed a significantly higher PoS in untreated homozygous SCD patients compared to treated patients and other genotypes. We conclude that the oxygenscan is a state-of-the-art technique that allows for rapid analysis of sickling behavior in SCD patients. The method is promising for personalized treatment, development of new treatment strategies and could have potential in prediction of complications.

Somatic thrombopoietin (THPO) gene mutations in childhood myeloid leukemias.

We report, for the first time, a non-syndromic infant with a reversible myeloproliferative disease that harbors a germline hereditary thrombopoietin (THPO) gene mutation, a condition that is known to induce familial thrombocytosis at increasing age. In order to investigate whether somatic THPO gene mutations play a role in sporadic pediatric myeloproliferative diseases, we performed a mutation screening of a large representative cohort of pediatric acute myeloid leukemia, myeloid leukemia of Down syndrome, and juvenile myelomonocytic leukemia samples and show that gain-of-function THPO mutations are extremely rare in sporadic pediatric myeloproliferative diseases.