Bedside Lung Ultrasound During Acute Chest Syndrome in Sickle Cell Disease

Lung ultrasound (LU) is increasingly used to assess pleural and lung disease in intensive care unit (ICU) and emergency unit at the bedside. We assessed the performance of bedside chest radiograph (CR) and LU during severe acute chest syndrome (ACS), using computed tomography (CT) as the reference standard. We prospectively explored 44 ACS episodes (in 41 patients) admitted to the medical ICU. Three imaging findings were evaluated (consolidation, ground-glass opacities, and pleural effusion). A score was used to quantify and compare loss of lung aeration with each technique and assess its association with outcome. A total number of 496, 507, and 519 lung regions could be assessed by CT scan, bedside CR, and bedside LU, respectively. Consolidations were the most common pattern and prevailed in lung bases (especially postero-inferior regions). The agreement with CT scan patterns was significantly higher for LU as compared to CR (κ coefficients of 0.45 ± 0.03 vs 0.30 ± 0.03, P < 0.01 for the parenchyma, and 0.73 ± 0.08 vs 0.06 ± 0.09, P < 0.001 for pleural effusion). The Bland and Altman analysis showed a nonfixed bias of -1.0 (P = 0.12) between LU score and CT score whereas CR score underestimated CT score with a fixed bias of -5.8 (P < 0.001). The specificity for the detection of consolidated regions or pleural effusion (using CT scan as the reference standard) was high for LU and CR, whereas the sensitivity was high for LU but low for CR. As compared to others, ACS patients with an LU score above the median value of 11 had a larger volume of transfused and exsanguinated blood, greater oxygen requirements, more need for mechanical ventilation, and a longer ICU length of stay. LU outperformed CR for the diagnosis of consolidations and pleural effusion during ACS. Higher values of LU score identified patients at risk of worse outcome. Abstract source Full text Full text (PMC)
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Associations of Prolonged QTc in Sickle Cell Disease

Sudden death is a leading cause of mortality in sickle cell disease, implicating ventricular tachyarrhythmias. Prolonged QTc on an electrocardiogram (ECG), commonly seen with myocardial ischemia, is a known risk for polymorphic ventricular tachycardia (VT). We hypothesized that prolonged QTc is associated with mortality in sickle cell disease. ECG were analyzed from a cohort of 224 sickle patients (University of Illinois at Chicago, UIC) along with available laboratory, and echocardiographic findings, and from another cohort of 38 patients (University of Chicago, UC) for which cardiac MRI and free heme values were also measured. In the UIC cohort, QTc was potentially related to mortality with a hazard ratio (HR) of 1.22 per 10ms, (P = 0.015), and a HR = 3.19 (P = 0.045) for a QTc>480ms. In multivariate analyses, QTc remained significantly associated with survival after adjusting for inpatient ECG status (HR 1.26 per 10ms interval, P = 0.010) and genotype status [HR 1.21 per 10ms interval, P = 0.037). QTc trended toward association with mortality after adjusting for both LDH and hydroxyurea use (HR 1.21 per 10ms interval, P = 0.062) but was not significant after adjusting for TRV. In univariate analyses, QTc was related to markers of hemolysis including AST (P = 0.031), hemoglobin (P = 0.014), TR velocity (P = 0.036), higher in inpatients (P<0.001) and those with an SS compared to SC genotype (P<0.001) in the UIC cohort as well as to free heme in the UC cohort (P = 0.002). These findings support a relationship of prolonged QTc with hemolysis and potentially mortality in sickle cell disease. Abstract source Full text Full text (PMC)
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Associations between environmental factors and hospital admissions for sickle cell disease

Sickle cell disease is an increasing global health burden. This inherited disease is characterized by a remarkable phenotypic heterogeneity, which can only partly be explained by genetic factors. Environmental factors are likely to play an important role but studies of their impact on disease severity are limited and their results are often inconsistent. This study investigated associations between a range of environmental factors and hospital admissions of young patients with sickle cell disease in London and in Paris between 2008 and 2012. Specific analyses were conducted for subgroups of patients with different genotypes and for the main reasons for admissions. Generalized additive models and distributed lag non-linear models were used to assess the magnitude of the associations and to calculate relative risks. Some environmental factors significantly influence the numbers of hospital admissions of children with sickle cell disease, although the associations identified are complicated. Our study suggests that meteorological factors are more likely to be associated with hospital admissions for sickle cell disease than air pollutants. It confirms previous reports of risks associated with wind speed (risk ratio: 1.06/standard deviation; 95% confidence interval: 1.00-1.12) and also with rainfall (1.06/standard deviation; 95% confidence interval: 1.01-1.12). Maximum atmospheric pressure was found to be a protective factor (0.93/standard deviation; 95% confidence interval: 0.88-0.99). Weak or no associations were found with temperature. Divergent associations were identified for different genotypes or reasons for admissions, which could partly explain the lack of consistency in earlier studies. Advice to patients with sickle cell disease usually includes avoiding a range of environmental conditions that are believed to trigger acute complications, including extreme temperatures and high altitudes. Scientific evidence to support such advice is limited and sometimes confusing. This study shows that environmental factors do explain some of the variations in rates of admission to hospital with acute symptoms in sickle cell disease, but the associations are complex, and likely to be specific to different environments and the individual's exposure to them. Furthermore, this study highlights the need for prospective studies with large numbers of patients and standardized protocols across Europe. Abstract source Full text Full text (PMC)
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Association of Sickle Cell Trait With Hemoglobin A1c in African Americans

IMPORTANCE: Hemoglobin A1c (HbA1c) reflects past glucose concentrations, but this relationship may differ between those with sickle cell trait (SCT) and those without it. OBJECTIVE: To evaluate the association between SCT and HbA1c for given levels of fasting or 2-hour glucose levels among African Americans. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study using data collected from 7938 participants in 2 community-based cohorts, the Coronary Artery Risk Development in Young Adults (CARDIA) study and the Jackson Heart Study (JHS). From the CARDIA study, 2637 patients contributed a maximum of 2 visits (2005-2011); from the JHS, 5301 participants contributed a maximum of 3 visits (2000-2013). All visits were scheduled at approximately 5-year intervals. Participants without SCT data, those without any concurrent HbA1c and glucose measurements, and those with hemoglobin variants HbSS, HbCC, or HbAC were excluded. Analysis of the primary outcome was conducted using generalized estimating equations (GEE) to examine the association of SCT with HbA1c levels, controlling for fasting or 2-hour glucose measures. EXPOSURES: Presence of SCT. MAIN OUTCOMES AND MEASURES: Hemoglobin A1c stratified by the presence or absence of SCT was the primary outcome measure. RESULTS: The analytic sample included 4620 participants (mean age, 52.3 [SD, 11.8] years; 2835 women [61.3%]; 367 [7.9%] with SCT) with 9062 concurrent measures of fasting glucose and HbA1c levels. In unadjusted GEE analyses, for a given fasting glucose, HbA1c values were statistically significantly lower in those with (5.72%) vs those without (6.01%) SCT (mean HbA1c difference, -0.29%; 95% CI, -0.35% to -0.23%). Findings were similar in models adjusted for key risk factors and in analyses using 2001 concurrent measures of 2-hour glucose and HbA1c concentration for those with SCT (mean, 5.35%) vs those without SCT (mean, 5.65%) for a mean HbA1c difference of -0.30% (95% CI, -0.39% to -0.21%). The HbA1c difference by SCT was greater at higher fasting (P = .02 for interaction) and 2-hour (P = .03) glucose concentrations. The prevalence of prediabetes and diabetes was statistically significantly lower among participants with SCT when defined using HbA1c values (29.2% vs 48.6% for prediabetes and 3.8% vs 7.3% for diabetes in 572 observations from participants with SCT and 6877 observations from participants without SCT; P CONCLUSIONS AND RELEVANCE: Among African Americans from 2 large, well-established cohorts, participants with SCT had lower levels of HbA1c at any given concentration of fasting or 2-hour glucose compared with participants without SCT. These findings suggest that HbA1c may systematically underestimate past glycemia in black patients with SCT and may require further evaluation. Abstract source Full text
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Cerebral haemorrhagic risk in children with sickle-cell disease

AIM: To address risk of first or recurrent cerebral haemorrhage in children with sickle-cell disease (SCD) who are being managed with modern stroke prevention strategies. METHOD: A systematically followed SCD paediatric cohort was retrospectively studied over a 9-year period. Haemorrhagic risk was defined as intracranial haemorrhage occurrence or intracranial aneurysm diagnosis during the study period. Ischaemic risk was defined as cerebrovascular ischaemic event occurrence or transcranial Doppler/magnetic resonance imaging hallmarks of ischaemic risk finding during the study period. RESULTS: Among the 251 patients in the cohort, 36 patients were included in the ischaemic group. Seven patients were included in the haemorrhagic group, of which five also met the criteria for the ischaemic group. Age at first haemorrhagic symptom/hallmark of risk was older (10.4 vs 6.2 years old, p=0.036). Nine intracranial saccular aneurysms were found, mostly on the posterior circulation. Two patients had endovascular embolization. INTERPRETATION: The ratio of ischaemic to haemorrhagic risk was not modified with modern management compared with historical series. Intracranial aneurysm in children with SCD had specific characteristics, close to intracranial aneurysms described in adults with SCD. Data favoured concurrent development of intracranial SCD-associated anterior stenosis and posterior dilation, suggesting common pathophysiology and management strategies. Abstract source Full text
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Caries prevalence and impact on oral health-related quality of life in children with sickle cell disease: cross-sectional study

BACKGROUND: Children with sickle cell disease (SCD) may present oral conditions that can compromise children's health even more. However, there is still no consensus on the association between SCD and dental caries. The aim of this study was to assess caries prevalence in children with sickle cell disease (SCD), and the association of dental caries with socioeconomic factors, disease severity, and oral-health related to quality of life (OHRQoL). METHODS: The sample was comprised of 106 children with SCD aged 8 to 14 years who were attending the Center for Hematology (Hemominas) in Belo Horizonte, Brazil. They were matched to 385 healthy peers. Data collection included interviews with guardians concerning SCD characteristics, and previous social and oral examinations to determine the caries prevalence. Caries prevalence as measured through the Decayed, Missing and Filled (dmft and DMFT) indices. OHRQoL was evaluated through the Brazilian versions of the Child Perceptions Questionnaires (CPQ8-10, and CPQ11-14 short-form version). Statistical analyses were performed using the chi-square test or Fisher`s exact test and the Mann Whitney test, as well as linear regression. RESULTS: The DMFT index was 1.3 (SD: 2.1) in younger children with SCD and 1.5 (SD: 1.9) in SCD teens. Younger children with SCD had lower caries experience compared to healthy peers (p = .03). The experience of dental caries among teens with SCD was similar to healthy peers (p > 0.05). In addition, we did not see a significant difference on the mean overall scores of CPQ8-10 between SCD younger children and controls. There was no statistically significant difference in the mean overall scores of teens CPQ11-14 between SCD and the control group. Socioeconomic variables were not associated with dental caries in the participants with SCD. However, SCD severity was associated with higher DMFT indexes (p < 0.05). CONCLUSIONS: Younger children with SCD had a low experience of dental caries. The dental caries experience in teenagers with SCD was similar to their healthy peers. OHRQoL was similar between SCD participants and controls. Abstract source Full text Full text (PMC)
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Care Coordination for Children With Sickle Cell Disease: A Longitudinal Study of Parent Perspectives and Acute Care Utilization

INTRODUCTION: Care coordination (CC), a core element of the medical home, has the potential to reduce fragmented care and improve patient experience for children with sickle cell disease (SCD). This study aimed to (1) assess CC for pediatric SCD and (2) determine its association with acute care utilization-emergency department encounters and hospitalizations. It was hypothesized that CC would reduce acute care utilization. METHODS: A longitudinal study of 101 children with SCD was conducted. Parents completed a survey instrument on enrollment. Utilization chart review was conducted 9 months post survey. Outcome variables were emergency department encounters and hospitalizations. Independent variables were parent-reported CC, satisfaction with communication between healthcare providers, and satisfaction with communication between healthcare providers and non-medical providers (e.g., schools, child care centers). Multivariate negative binomial regression was conducted to assess associations between CC and acute care utilization. Data were collected in 2011-2013 and analyzed in 2015. RESULTS: One third of children had emergency department encounters and 30% had hospitalizations. At enrollment, 25% of parents reported receiving CC help and 20% reported need for extra CC. Most parents were satisfied with communication between physicians but only two thirds were satisfied with communication between their healthcare providers and non-medical providers. No significant associations were found between CC measures and acute care utilization. CONCLUSIONS: Although parents report multiple CC deficiencies, no associations were found between CC and acute care utilization. Population-based studies are warranted to more definitively determine the association between CC and acute care utilization for children with SCD. Abstract source Full text Full text (PMC)
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Birth Weights in Sickle Cell Disease Pregnancies: A Cohort Study

Pregnancy in women with Sickle Cell Disease (SCD) has been linked with an increased incidence of adverse foetal outcomes when compared to women without haemoglobinopathies (HbAA). There's a paucity of data into foetal outcomes for infants born to women with SCD. Customised growth charts have been demonstrated to be better than population-based growth charts at identifying unhealthy small babies. We analysed the mean birth weight and customised birth weight centiles of infants born to mothers with SCD versus mothers with HbAA genotype, to quantify the risk of having a smaller baby. Birth weight and birth weight centiles were analysed for 88 women with SCD (50 HbSS; 38 HbSC) and 176 controls (HbAA). Statistically significant differences were seen in the mean birth weight (P value = 0.004) and the mean birth weight centiles (P value = 0.016). We conclude that SCD is a risk factor for having a smaller baby. Abstract source Full text Full text (PMC)
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Biochemical surrogate markers of hemolysis do not correlate with directly measured erythrocyte survival in sickle cell anemia

Hemolysis is a key feature of sickle cell anemia (HbSS). Direct quantitation of hemolysis could be used as an objective outcome in clinical trials of new therapeutics for HbSS and would also enable better human studies of the pathogenesis of complications of HbSS that are ostensibly hemolysis-related, such as pulmonary hypertension. However, contemporary human studies in HbSS have used only surrogate markers of hemolysis rather than direct measurements of RBC survival. We directly quantified hemolysis in HbSS by measuring survival of an age cohort of RBCs labeled with a stable isotope, administered orally as 15 N-glycine, a metabolic precursor of heme. The atomic excess of 15 N in heme extracted from blood was monitored by mass spectrometry over time. We performed 13 labeling experiments in 11 individuals with HbSS. Mean RBC survival was 31.9 days (range 14.1-53.6). Both HbF level, a known determinant of hemolysis, and absolute reticulocyte count (ARC), an index of the marrow's response to hemolysis, correlated with directly measured RBC survival (r = 0.61, P < 0.002; r = -0.84, P < 0.001). However, commonly used biochemical surrogates of hemolysis (LDH, AST, bilirubin, and plasma free hemoglobin) did not correlate with directly measured RBC survival. These biochemical surrogates should be interpreted cautiously, at best, in clinical trials and human physiologic studies in HbSS. ARC was the best correlate of total hemolysis, but only 70% of the variation in RBC survival was reflected in this marker. If greater accuracy is required in human studies, 15 N-glycine RBC labeling can directly and accurately quantify hemolysis. Abstract source Full text Full text (PMC)
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Association of circulating transcriptomic profiles with mortality in sickle cell disease

Sickle cell disease (SCD) complications are associated with increased morbidity and risk of mortality. We sought to identify a circulating transcriptomic profile predictive of these poor outcomes in SCD. Training and testing cohorts consisting of adult patients with SCD were recruited and prospectively followed. A pathway-based signature derived from grouping peripheral blood mononuclear cell transcriptomes distinguished 2 patient clusters with differences in survival in the training cohort. These findings were validated in a testing cohort in which the association between cluster 1 molecular profiling and mortality remained significant in a fully adjusted model. In a third cohort of West African children with SCD, cluster 1 differentiated SCD severity using a published scoring index. Finally, a risk score composed of assigning weights to cluster 1 profiling, along with established clinical risk factors using tricuspid regurgitation velocity, white blood cell count, history of acute chest syndrome, and hemoglobin levels, demonstrated a higher hazard ratio for mortality in both the training and testing cohorts compared with clinical risk factors or cluster 1 data alone. Circulating transcriptomic profiles are a powerful method to risk-stratify severity of disease and poor outcomes in both children and adults, respectively, with SCD and highlight potential associated molecular pathways Abstract source Full text
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