Gender-Related Differences in Sickle Cell Disease in a Pediatric Cohort: A Single-Center Retrospective Study

Sex-disaggregated analysis of acute kidney injury in hospitalized children with sickle cell anemia in Uganda

A growing body of research is categorizing sex differences in both sickle cell anemia (SCA) and acute kidney injury (AKI); however, most of this work is being conducted in high-resource settings. Here, we evaluated risk factors and clinical parameters associated with AKI and AKI severity, stratified by sex, in a cohort of children hospitalized with SCA and vaso-occlusive pain crisis (VOC). The purpose of this study was to explore sex disparities in a high-risk, vulnerable population. This study was a secondary analysis of data collected from a cohort of Ugandan children between 2 and 18 yr of age prospectively enrolled. A total of 185 children were enrolled in the primary study; 41.6% were female and 58.4% were male, with a median age of 8.9 yr. Incident or worsening AKI (P = 0.026) occurred more frequently in female compared with male children, despite no differences in AKI on admission. Female children also had altered markers of renal function including higher creatinine levels at admission (P = 0.03), higher peak creatinine (P = 0.006), and higher urine neutrophil gelatinase-associated lipocalin (NGAL) at admission (P = 0.003) compared with male children. Female children had elevated total (P = 0.045) and conjugated bilirubin at admission (P = 0.02) compared with male children and higher rates of hematuria at admission (P = 0.004). Here, we report sex differences in AKI in children with SCA and VOC, including increased incidence and worsening of AKI in female pediatric patients, in association with an increase in biological indicators of poor renal function including creatinine, estimated glomerular filtration rate, and NGAL.NEW & NOTEWORTHY In this study, we report an increased risk of developing acute kidney injury (AKI) during hospitalization, worsening AKI, and death among females with sickle cell anemia (SCA) hospitalized with an acute pain crisis compared with males. The sex differences in AKI were not explained by socioeconomic differences, severity of pain, or disease severity among females compared with males. Together, these data suggest that female children with SCA may be at increased risk of AKI.

Bone Disease among Children with Sickle Cell Disease: A Scoping Review of Incidence and Interventions

Background

Children with sickle cell disease (SCD) are more likely to have deficient serum levels of vitamin D for bone metabolism. However, appropriate interventions are essential to prevent its progression and alleviate symptoms.

Purpose

The aim of this study is to determine interventions for managing bone disease in children with SCD.

Methods

This study uses a scoping review. A literature review was conducted using PubMed, CINAHL, ScienceDirect, Scopus, and Google Scholar search engines. The study was eligible for inclusion if it included articles published from 2013 to 2023, full-text, and original study design. Study quality was assessed using the Joanna Briggs Institute (JBI) appraisal tool.

Results

This review identified six studies and 114 children with SCD, including 57 boys (50%) and 57 girls (50%). The majority of SCD types experienced were HbSS (86.84%), HbS-B0 Thal (7.01%), HbSC (5.27%), and the HbSS Arab-Indian haplotype (0.88%). Bone disease problems that often arise in children with SCD include Avascular Necrosis (AVN) (78.08%), Osteonecrosis of the Femoral Head (ONFH) (18.42%), and other bone problems (3.50%). Meanwhile, four types of intervention findings were used in managing bone disease among children with SCD: 1). Surgical procedures 53 (41.09%) included total hip arthroplasty (THA), Osteotomy, and Multiple epiphyseal drilling with Autologous Bone Marrow Implantation (AMBI); 2). Invasive procedures 67 (51.93%) included intravenous bisphosphonates, hydroxyurea (HU), and core decompression (CD) with bone marrow aspirate concentrate injection: 3). Oral pharmacological or Vitamin D3 (cholecalciferol) 4 (3.10%); 4). Non-pharmacology or physical therapy 5 (3.88%).

Conclusion

Our findings highlight that surgical, invasive, pharmacological, and physical therapy interventions positively impact increasing bone mineral density (BMD) and functional improvement of bone disease among children with SCD. The interventions provided excellent functional outcomes with minimal complications and no life-threatening side effects.

Effects of hydroxyurea on fertility in male and female sickle cell disease patients. A systemic review and meta-analysis

BACKGROUND

Evidence supports the benefits of hydroxyurea (HU) in adults with sickle cell disease (SCD), but reservations remain due to long-term concerns of fertility. Retrospective analysis of clinical records of SCD patients (haemoglobin SS genotype) have identified gender-related differences in disease progression. This could inform risk stratification during SCD at diagnosis with the possibility to guide therapeutic decisions.

METHODS

This systemic review and meta-analysis evaluated fertility parameters in both children (aged ≥ 6 years) and adults with SCD receiving HU therapy. Studies were sourced from PubMed and EMBASE from inception to July 2023. A total of 160 potentially relevant articles were identified.

RESULTS

Four studies were included that evaluated the effects of HU on sperm parameters in males. A further 4 studies assessed anti-mullerian hormone (AMH) levels and ovarian reserves in females. Differences from baseline values were used to identify compromised fertility. Amongst males, HU treatment negatively impacted the concentration of spermatozoa (MD = -15.48 million/mL; 95% CI: [-20.69, -10.26]; p< 0.001), which continued following treatment cessation (MD = -20.09 million/mL; 95% CI: [-38.78, -1.40]; P = 0.04). HU treatment also led to lower total sperm counts (MD = -105.87 million; 95% CI: [-140.61, -71.13]; P< 0.001) which persisted after treatment (MD = -53.05 million; 95% CI: [-104.96, -1.14]; P = 0.05). Sperm volume, initial forward motility and morphology were unaffected by HU treatment. In females, HU treatment decreased the mean AMH levels 1.83 (95% CI [1.42, 2.56]. A total of 18.2.% patients treated with HU showed reduced ovarian reserves.

INTERPRETATION & CONCLUSIONS

This systemic review and meta-analysis suggest that the use of HU for SCD impacts seminal fluid parameters in males and can diminish AMH levels and ovarian reserves in females.

End Organ Affection in Sickle Cell Disease

Sickle cell disease is an orphan disease affecting ethnic minorities and characterized by profound systemic manifestations. Although around 100,000 individuals with SCD are living in the US, the exact number of individuals is unknown, and it is considered an orphan disease. This single-gene disorder leads to red blood cell sickling and the deoxygenation of hemoglobin, resulting in hemolysis. SCD is associated with acute complications such as vaso-occlusive crisis, infections, and chronic target organ complications such as pulmonary disease and renal failure. While genetic therapy holds promise to alter the fundamental disease process, the major challenge in the field remains the target end organ damage and ways to mitigate or reverse it. Here, we provide an overview of the clinical manifestations and pathogenesis with a focus on end-organ damage and current therapeutic options, including recent FDA-approved stem cell and gene editing therapies.

Emergency Department Utilization by Pediatric Patients With Sickle Cell Disease in Basrah, Iraq

Background Patients with sickle cell disease (SCD) often present in the Emergency Department (ED) with acute and debilitating pain and other SCD-related complications. Objectives The objective is to analyze the causes of ED visits of pediatric patients with SCD, assess the burden of ED admission due to SCD in relation to other pediatric diseases, the treatment given, and the outcomes. Methods A prospective analytical study was conducted on children and adolescents with SCD, 1-14 years old who had been admitted to the ED at Basrah Maternity and Children Hospital over a six-month period. Patient's sociodemographic and clinical data, drug history, length of ED stay, complications, outcome, and readmissions were recorded.  Results A total of 422 patients with SCD were admitted to ED during the study period representing 4.10% of the total admitted cases; 276(65.40%) of them were recruited in this study, and their mean age was 7.84 ±3.47 years. The main cause for ED admission was pain (73.91%), followed by infection (10.14%) and hemolytic crisis (6.15%). The mean duration of stay at ED was 6.11±1.87 hours. All admitted SCD patients had received analgesia; non-steroidal anti-inflammatory drugs (NSAIDs) were the commonest (80.4%), followed by acetaminophen (39.5%), and opioid narcotic (18.5%). Readmission within 30-days was reported in 82(29.71%) patients and was associated with the number of ED visits/last year (B=0.151, P=0.023), length of stay at ED (B=0.140, P=0.034) and severe disease (B=0.253, P<0.001). Conclusions Acute painful episodes were the main cause of ED admission. Although most patients with pain did receive NSAIDs, only a small percentage of them did receive opioids. About one-third of patients have been readmitted within 30 days, and readmission was associated with the number of ED visits/last year, disease severity, and length of ED stay. These findings can help in establishing local guidelines for managing such patients in the ED especially pain management.

A mesomelic skeletal dysplasia, Kantaputra-like, not related to HOXD cluster region, and with phenotypic gender differences

Mesomelic skeletal dysplasia is a heterogeneous group of skeletal disorders that has grown since the molecular basis of these conditions is in the process of research and discovery. Here, we report a Brazilian family with eight affected members over three generations with a phenotype similar to mesomelic Kantaputra dysplasia. This family presents marked shortening of the upper limbs with hypotrophy of the lower limbs and clubfeet without synostosis. Array-based CNV analysis and exome sequencing of four family members failed to show any region or gene candidate. Interestingly, males were more severely affected than females in this family, suggesting that gender differences could play a role in the phenotypic expressivity of this condition.

Ultrasound Imaging in Subjects with Sickle Cell Disease: The Saudi Arabia Experiences

Background

Abdominal organ sonography is a crucial part of the workup for treating sickle cell disease (SCD) patients.

Objective

The main objective of this study was to evaluate the abdominal organs in SCD patients using ultrasonography.

Methodology

A non-interventional descriptive cross-sectional study was carried out in Asir region Saudi Arabia from April 2019 to July 2020. The study was conducted in 78 patients with sickle cell disease (SCD). Data were gathered using a data collection sheet included demographic information, clinical information including medication types, and complications linked to SCD. Furthermore, the study evaluated abdominal ultrasound findings pertaining to the liver, gall bladder, spleen, and kidneys. The data were analyzed using Statistical Package for Social Sciences (SPSS).

Results

More than half of the study participants 43 (55.1%) were females. About 53.8% of the study participants received blood transfusions, and (11.5%) receive extra-vaccine. Concerning ultrasound findings, hepatomegaly was found in seventeen (21.8%), focal liver lesions in four (5.1%), gallstones in five (6.4%), splenomegaly in fifteen (19.3%), and the presence of splenic focal lesions was found in seven (9.0%). The most frequent complication associated with SCD was osteomyelitis sepsis in six cases (7.7%). The study revealed a significant correlation between the type of crisis and type of medication used and the size of the spleen (P-value <0.01), and no notable correlation was found between the types of crises and the size of the liver (P-value >0.05).

Conclusion

Abdominal sonography in SCD patients revealed a wide range of alterations in the liver, gallbladder, and spleen. The most frequently observed complications in SCD were hepatomegaly, splenomegaly, localized lesions in both organs, and the presence of gallstones.

Pathophysiological characterization of the Townes mouse model for sickle cell disease

A deeper pathophysiologic understanding of available mouse models of sickle cell disease (SCD), such as the Townes model, will help improve preclinical studies. We evaluated groups of Townes mice expressing either normal adult human hemoglobin (HbA), sickle cell trait (HbAS), or SCD (HbS), comparing younger versus older adults, and females versus males. We obtained hematologic parameters in steady-state and hypoxic conditions and evaluated metabolic markers and cytokines from serum. Kidney function was evaluated by measuring the urine protein/creatinine ratio and urine osmolality. In vivo studies included von Frey assay, non-invasive plethysmography, and echocardiography. Histopathological evaluations were performed in lung, liver, spleen, and kidney tissues. HbS mice displayed elevated hemolysis markers and white blood cell counts, with some increases more pronounced in older adults. After extended in vivo hypoxia, hemoglobin, platelet counts, and white blood cell counts decreased significantly in HbS mice, whereas they remained stable in HbA mice. Cytokine analyses showed increased TNF-alpha in HbS mice. Kidney function assays revealed worsened kidney function in HbS mice. The von Frey assay showed a lower threshold to response in the HbS mice than controls, with more noticeable differences in males. Echocardiography in HbS mice suggested left ventricular hypertrophy and dilatation. Plethysmography suggested obstructive lung disease and inflammatory changes in HbS mice. Histopathological studies showed vascular congestion, increased iron deposition, and disruption of normal tissue architecture in HbS mice. These data correlate with clinical manifestations in SCD patients and highlight analyses and groups to be included in preclinical therapeutic studies.

Echocardiographic Evaluation in Paediatric Sickle Cell Disease Patients: A Pilot Study

Cardiovascular involvement has a great impact on morbidity and mortality in sickle cell disease (SCD). Currently, few studies are available regarding the paediatric setting and, moreover, current guidelines for the echocardiogram screening program in the asymptomatic paediatric population are controversial. We performed a retrospective observational monocentric study on 64 SCD patients (37 male and 27 female, median age 10) at the Bambino Gesù Childrens' Hospital, who had undergone a routine transthoracic echocardiogram. In total, 46 (72%) patients had at least one cardiac abnormality. Left atrial dilatation (LAD) was present in 41 (65%) patients and left ventricular hypertrophy (LVH) was found in 29 (45%) patients. Patients with LAD showed lower median haemoglobin levels (p = 0.009), and a higher absolute reticulocyte count (p = 0.04). LVH was negatively correlated with the median haemoglobin value (p = 0.006) and positively with the reticulocyte count (p = 0.03). Moreover, we found that patients with cardiac anomalies had higher transfusion needs and a lower frequency of pain crises. In our setting, cardiac involvement has a high prevalence in the paediatric cohort and seems to be associated with specific laboratory findings, and with a specific clinical phenotype characterized by complications related to high haemodynamic load.

Significance of the mathematically calculated red cell indices in patients with qualitative and quantitative hemoglobinopathies

Background

Hemoglobinopathies represent a set of inherited red blood cell (RBCs) disorders, characterized by abnormal hemoglobin molecule. They include qualitative and quantitative hemoglobinopathies, with a structurally abnormal globin chain in the first and defective production in the later. This study assessed, for the first time, the significance of the mathematically calculated RBC indices to identify patients with hemoglobinopathies from normal subjects or iron deficiency anemia (IDA) and to differentiate various types of hemoglobinopathies from each other.

Subjects and methods

The study was a comparative hospital based and included 167 participants with hemoglobinopathies (group 1) and 49 participants with IDA (group 2) as an active comparator. Another 50 healthy volunteers (group 3) were also included. All participants were subjected to medical history, clinical examination, CBC, and HPLC. Next, 10 RBC indices were mathematically calculated from the CBC for each participant.

Results

Gender analysis shows that females represent 36.8% in thalassemia group, 42% in sickle cell disease (SCD) group, and 71.4% in IDA group. The receiver operating characteristic (ROC) curve shows that Ehsani index (EI) is the most reliable screening tool for thalassemics because of showing the highest Youden index and specificity of 41.88% and 88.89%, respectively, followed by Shine and Lal index (SL), with Youden index (YI) value, specificity, and sensitivity equal to 39.78%, 69.70%, and 70.09%, respectively. Similar results were found for IDA. For SCD, SL index is the most suitable screening tool. In conclusion, the mathematically calculated RBC indices are available, cheap, reliable, and sensitive tools for screening patients with hemoglobinopathies.

Bone loss is ameliorated by fecal microbiota transplantation through SCFA/GPR41/ IGF1 pathway in sickle cell disease mice

Bone loss is common in sickle cell disease (SCD), but the molecular mechanisms is unclear. Serum insulin-like growth factor 1 (IGF1) was low in SCD subjects and SCD mice. To determine if decreased IGF1 associated with low bone mass in SCD is due to reduced SCFA production by gut microbiota, we performed reciprocal fecal microbiota transplantation (FMT) between healthy control (Ctrl) and SCD mice. uCT and histomorphometry analysis of femur showed decreased bone volume/total volume (BV/TV), trabecular number (Tb.N), osteoblast surface/bone surface (Ob.S/BS), mineralizing surface/ bone surface (MS/BS), inter-label thickness (Ir.L.Th) in SCD mice were significantly improved after receiving Ctrl feces. Bone formation genes Alp, Col1, Runx2, and Dmp1 from SCD mice were significantly decreased and were rescued after FMT from Ctrl feces. Transplantation of Ctrl feces increased the butyrate, valerate, and propionate levels in cecal content of SCD mice. Decreased G-coupled protein receptors 41 and 43 (GPR41 and GPR43) mRNA in tibia and lower IGF1 in bone and serum of SCD mice were partially restored after FMT from Ctrl feces. These data indicate that the healthy gut microbiota of Ctrl mice is protective for SCD bone loss through regulating IGF1 in response to impaired bacterial metabolites SCFAs.

The impact of Hydroxyurea on the rates of Vaso-occlusive crises in patients with sickle cell disease in Saudi Arabia: a single-center study

BACKGROUND

Vaso-occlusive crises (VOCs) are acute and common painful complication of sickle cell disease (SCD), and are the main reason behind the frequent emergency department visits among SCD patients. Hydroxyurea (HU) is an old and commonly used medication that demonstrated its effectiveness in reducing the risk of VOCs and the incidence of hospitalization. Although multiple studies have examined the impact of HU on the rates of VOCs, few have explored its effectiveness among SCD patients in Saudi Arabia.

METHODS

This was a single-center retrospective cohort study in which the electronic medical records of patients with SCD who have not had any previous exposure to HU prior to the initiation of HU treatment for ≥12 months were recruited. Paired t-test was conducted to examine the difference in the rates of VOCs, and levels of hemoglobin (Hgb), hematocrit (HCT), and platelet counts (PLT Ct) prior to the initiation of HU therapy and 12 months later. Multiple linear regression was conducted to examine whether age, gender, use of opioid analgesics, Hgb, HCT, and PLT Ct levels predict higher or lower rates of VOCs.

RESULTS

One hundred and fifty-six patients met the inclusion criteria and were included in the analysis. About 51% of the patients were males, and their mean age was 12.69 years. The mean HU dosage was 16.52 mg/kg/day, and the mean reduction in the rate of VOCs was 1.36 events per patient per year (95% CI [1.03-1.70], p < 0.0001) after the initiation of HU. Females were more likely to have greater reduction in the rates of VOCs in comparison to their male counterparts (β-estimate = 12.85, 95% CI [0.759-24.93], p = 0.0374).

CONCLUSION

The use of HU results in a significant reduction in the rates of VOCs and emergency department visits. Future studies with robust research designs should be conducted to further examine the impact of HU on VOCs, hospitalization, and length of stay as well as compare HU to other newly approved medications for SCD, such as crizanlizumab.

Clinical characteristics and risk factors of relative systemic hypertension and hypertension among sickle cell patients in Cameroon

Increased blood pressure (BP) has been associated with higher risk of stroke and mortality in Sickle Cell Disease (SCD). We investigated risk factors associated with Relative Systemic Hypertension (RSH) or systemic hypertension in SCD patients in Cameroon. Using R, Multivariate multinomial logistic regression modeling was used to examine the effects of the demographic, anthropometric, clinical, and laboratory factors to determine risk factors. A total of 815 individuals with SCD, including 380 (46.6%) males were analyzed. At baseline, the median age [interquartile range] was 18.0 [12.0-25.0] years, ranging from 3 to 66 years. Approximately three-quarters of the patients (n = 645; 79.1%) had normal BP, 151 (18.5%) had RSH and 19 (2.3%) had hypertension. Age (P < 0.001) and gender (P = 0.022) were significantly different across the BP categories. Weight (P < 0.001), height (P < 0.001), BMI (P < 0.001), pulse pressure (P = 0.020), history of stroke (P = 0.012), hemoglobin level (P = 0.002), red blood cell count (P = 0.031), creatinine (P < 0.001), and (estimated glomerular filtration rate) eGFR (P = 0.002) was also significantly different across the three BP categories. After adjustment, the significantly associated factors of RSH in the SCD patients were age [OR = 1.03, (95% CI = 1.01-1.06), P < 0.010], male gender [OR = 1.54, (95% CI = 1.04-2.27), P = 0.029], BMI [OR = 1.10, (95% CI = 1.04-1.17), P = 0.001]. After adjustment, the independent variables significantly associated factors of Hypertension in the SCD patients were age [OR = 1.05, (95% CI = 1.01-1.10), P = 0.034], male gender [OR = 3.31, (95% CI = 1.04-10.52), P = 0.042], BMI [OR = 1.14, (95% CI = 1.01-1.29), P = 0.027]. Creatinine was significantly associated with RSH [OR =1.31 (1.05-1.63), P = 0.016]. SCD patients with RSH or hypertension maybe at increased risk of renal dysfunction. We found relatively high prevalence of RSH and hypertension (20.8%) in SCD patients in Cameroon. Tailored Interventions that consider major risk factors (age, gender, and BMI) may lower BP pressure and prevent severe complications.

Factors associated with blood pressure variation in sickle cell disease patients: a systematic review and meta-analyses

OBJECTIVES

Blood pressure (BP) values ≥120/70 mmHg considerably increase the risk of pulmonary hypertension and renal dysfunction in Sickle Cell Disease (CSD) patients and ultimately increased morbidity and mortality. This has led to the development of the term relative systemic hypertension (RSH). RSH was defined as Systolic BP 120-139 mm Hg or diastolic BP 70-89 mm Hg, whereas systemic hypertension is defined as Systolic BP ≥ 140 mm Hg or diastolic BP ≥ 90 mm Hg. Systematic identification of BP variations and risk factors in SCD patients could promote effective management. This review aimed to identify factors associated with BP variation among SCD patients.

METHODS

We searched PubMed, Scopus, Web of Science, and Google Scholar up to December 2020 with no geographical or language restrictions. Two reviewers independently screened and summarized data from eligible studies.

RESULTS

Advancing age, gender, higher body weight, hemoglobin, eGFR, triglycerides, greater hematocrit, higher blood viscosity, history of blood transfusion, and targeted variants in DRD2 and MIR4301 genes were independently associated with the risk of hypertension in SCD patients.

CONCLUSION

Interventions that consider these risk factors may potentially contribute to lower BP pressure in SCD patients and prevent the development of severe complications.

Hospital Use and Mortality in Transition-Aged Patients With Sickle Cell Disease

OBJECTIVES

Childhood mortality in sickle cell disease (SCD) has decreased, but the transition period is associated with poor outcomes and higher mortality rates. We analyzed recent US hospitalizations and mortality trends in the transition-aged population and evaluated for differences between patients with and without SCD.

METHODS

Nationwide Inpatient Sample database was used to analyze hospitalizations among individuals aged 16 to 24 years from 2003 to 2017. Diagnoses were coded by using International Classification of Diseases, Ninth Revision, Clinical Modification and International Classification of Diseases, 10th Revision, Clinical Modification. We performed bivariate analyses to assess associations between sociodemographic characteristics and SCD hospitalizations, joinpoint regression analysis to describe mortality rate trends in SCD hospitalizations, and adjusted survey logistic regression to assess associations between patient characteristics and in-hospital mortality among transition-aged SCD and non-SCD-related hospitalizations.

RESULTS

There were 37 344 532 hospital encounters of patients aged 16 to 24 years during 2003-2017; both SCD and non-SCD hospitalizations increased with age. Female patients accounted for 78% of non-SCD and 54.9% of SCD hospitalizations. Although there was a +3.2% average annual percent change in SCD hospitalizations, total SCD in-hospital mortality rates did not have a statistically significant increase in average annual percent change over the study period. Patients with SCD aged 19 to 21 and 22 to 24 were more likely to suffer in-hospital mortality than those aged 16 to 18 (odds ratio = 2.09 and 2.71, respectively); the increased odds in mortality by age were not seen in our non-SCD population.

CONCLUSIONS

Transition-aged hospitalizations increase with age, but SCD hospitalizations have disparate age-related mortality rates. Hospital-based comprehensive care models are vital to address the persistent burden of early adulthood mortality in SCD.

A systematic literature review of frequency of vaso-occlusive crises in sickle cell disease

BACKGROUND AND PURPOSE

Sickle cell disease (SCD) is a collection of rare inherited blood disorders affecting approximately 100,000 people in the U.S. and 20-25 million people globally. Individuals with SCD experience recurrent episodes of severe and unpredictable pain that are caused by vaso-occlusive crises (VOCs), a hallmark of the disease. VOCs are the primary cause of hospitalization in SCD, result in missed workdays and school days, and decrease quality of life (QoL). Although VOCs cause significant burden in the lives of individuals with SCD, there is no synthesis on the frequency of VOCs in the real world. This systematic literature review sought to identify literature describing the frequency of VOCs experienced by individuals with SCD in real-world settings.

METHODS

MEDLINE and 6 congresses were searched (date range: January 1, 2000 to June 30, 2020). Studies were reviewed independently by two researchers. Studies assessing frequency or prevalence of VOCs or VOC-related outcomes were included.

RESULTS

Of 1438 studies identified in the search, 52 met pre-specified inclusion and exclusion criteria. Reported frequency of VOCs varied widely ranging from a mean or median of 0 VOCs/year to 18.2 VOCs/year. The proportion of patients experiencing ≥ 3 VOCs/year ranged from 4 to 67% and the proportion of patients experiencing ≥ 5 VOCs/year ranged from 18 to 59%. Measures of VOC severity were limited, with 13 studies considering frequency of complicated VOCs and only 1 study reporting duration of VOC episodes.

CONCLUSIONS

This is the first study to systematically assess published evidence pertaining to VOCs in real-world settings. Reported VOC frequency in real-world settings varied widely, with a majority of studies only considering VOCs managed in an inpatient or outpatient setting. Studies that considered VOCs managed at home reported a higher frequency of VOCs, suggesting that many studies may underestimate the frequency of VOCs. This systematic literature review (SLR) highlights the need for consistent reporting of (1) self-reported VOCs, including those managed at home, (2) definitions of VOCs, (3) complicated VOCs, and (4) duration of VOC episodes in literature.

Developmental Profile of Sleep and Its Potential Impact on Daytime Functioning from Childhood to Adulthood in Sickle Cell Anaemia

Young individuals with sickle cell anaemia (SCA) experience sleep disturbances and often experience daytime tiredness, which in turn may impact on their daytime functioning and academic attainment, but there are few longitudinal data.

METHODS

Data on sleep habits and behaviour were taken on the same day as an in-hospital polysomnography. This study assesses the developmental sleep profiles of children and young adults aged 4-23 years old with SCA. We examined retrospective polysomnography (PSG) and questionnaire data.

RESULTS

A total of 256 children with a median age of 10.67 years (130 male) were recruited and 179 returned for PSG 1.80-6.72 years later. Later bedtimes and a decrease in total sleep time (TST) were observed. Sleep disturbances, e.g., parasomnias and night waking, were highest in preschool children and young adults at their first visit. Participants with lower sleep quality, more movement during the night and increased night waking experienced daytime sleepiness, potentially an indicator of lower daytime functioning. Factors influencing sleep quantity included age, hydroxyurea prescription, mean overnight oxygen saturation, sleep onset latency, periodic limb movement, socioeconomic status and night waking.

CONCLUSION

Sleep serves an important role for daytime functioning in SCA; hence, quantitative (i.e., PSG for clinical symptoms, e.g., sleep-disordered breathing, nocturnal limb movement) and qualitative (i.e., questionnaires for habitual sleep behaviour) assessments of sleep should be mutually considered to guide interventions.

Clusters of pain trajectories among patients with sickle cell disease hospitalized for vaso-occlusive crisis: a data-driven approach

BACKGROUND

Vaso-occlusive crises (VOC) are the hallmark of sickle cell disease (SCD), with higher severity among hospitalized patients. Clustering hospitalizations with similar pain trajectories could identify vulnerable patient subgroups. Aims were to (1) identify clusters of hospitalizations based on pain trajectories; (2) identify factors associated with these clusters; and (3) determine the association between these clusters and 30-day readmissions.

METHODS

We retrospectively included 350 VOC hospitalizations from 2013-2016 among 59 patients. Finite mixture modeling identified clusters of hospitalizations from intercepts and slopes of pain trajectories during the hospitalization. Generalized estimating equations for multinomial and logistic models were used to identify factors associated with clusters of hospitalizations based on pain trajectories and 30-day readmissions, respectively, while accounting for multiple hospitalizations per patient.

RESULTS

Three clusters of hospitalizations based on pain trajectories were identified: slow (n=99), moderate (n=207), and rapid (n=44) decrease in pain scores. In multivariable analysis, SCD complications, female gender, and affective disorders were associated with clusters with slow or moderate decrease in pain scores (compared to rapid decrease). Although univariate analysis found that the cluster with moderate decrease in pain scores was associated with lower odds of 30-day readmissions compared to the cluster with slow decrease, it was non-significant in multivariable analysis. SCD complications were associated with higher odds of 30-day readmissions and older age was associated with lower odds of 30-day readmissions.

CONCLUSIONS

Our results highlight variability in pain trajectories among patients with SCD experiencing VOC and provide a novel approach for identifying subgroups of patients that could benefit from more intensive follow-up.

Locomotor mal-performance and gait adaptability deficits in sickle cell mice are associated with vascular and white matter abnormalities and oxidative stress in cerebellum

Patients with sickle cell disease (SCD) can develop strokes and as a result, present neurologic and neurocognitive deficits. However, recent studies show that even without detectable cerebral parenchymal abnormalities on imaging studies, SCD patients can have significant cognitive and motor dysfunction, which can present as early as during infancy. As the cerebellum plays a pivotal role in motor and non-motor functions including sensorimotor processing and learning, we examined cerebellar behavior in humanized SCD mice using the Erasmus ladder. Homozygous (sickling) mice had significant locomotor malperformance characterized by miscoordination and impaired locomotor gait/stepping pattern adaptability. Conversely, Townes homozygous mice had no overall deficits in motor learning, as they were able to associate a conditioning stimulus (high-pitch warning tone) with the presentation of an obstacle and learned to decrease steptimes thereby increasing speed to avoid it. While these animals had no cerebellar strokes, these locomotor and adaptive gait/stepping patterns deficits were associated with oxidative stress, as well as cerebellar vascular endothelial and white matter abnormalities and blood brain barrier disruption, suggestive of ischemic injury. Taken together, these observations suggest that motor and adaptive locomotor deficits in SCD mice mirror some of those described in SCD patients and that ischemic changes in white matter and vascular endothelium and oxidative stress are biologic correlates of those deficits. These findings point to the cerebellum as an area of the central nervous system that is vulnerable to vascular and white matter injury and support the use of SCD mice for studies of the underlying mechanisms of cerebellar dysfunction in SCD.

Metabolomic Profiling of Plasma and Erythrocytes in Sickle Mice Points to Altered Nociceptive Pathways

Few data-driven metabolomic approaches have been reported in sickle cell disease (SCD) to date. We performed a metabo-lipidomic study on the plasma and red blood cells of a steady-state mouse model carrying the homozygous human hemoglobin SS, compared with AS and AA genotypes. Among the 188 metabolites analyzed by a targeted quantitative metabolomic approach, 153 and 129 metabolites were accurately measured in the plasma and red blood cells, respectively. Unsupervised PCAs (principal component analyses) gave good spontaneous discrimination between HbSS and controls, and supervised OPLS-DAs (orthogonal partial least squares-discriminant analyses) provided highly discriminant models. These models confirmed the well-known deregulation of nitric oxide synthesis in the HbSS genotype, involving arginine deficiency and increased levels of dimethylarginines, ornithine, and polyamines. Other discriminant metabolites were newly evidenced, such as hexoses, alpha-aminoadipate, serotonin, kynurenine, and amino acids, pointing to a glycolytic shift and to the alteration of metabolites known to be involved in nociceptive pathways. Sharp remodeling of lysophosphatidylcholines, phosphatidylcholines, and sphingomyelins was evidenced in red blood cells. Our metabolomic study provides an overview of the metabolic remodeling induced by the sickle genotype in the plasma and red blood cells, revealing a biological fingerprint of altered nitric oxide, bioenergetics and nociceptive pathways.