Health outcomes and services in children with sickle cell trait, sickle cell anemia, and normal hemoglobin

Immunization adherence among children with sickle cell disease and sickle cell trait: Results of a population-based study

INTRODUCTION

Despite the importance of timely vaccine completion for protection from infectious disease, there is limited knowledge of the immunization adherence rates of children with sickle cell disease (SCD).

METHODS

This is a retrospective cohort study comparing the immunization rates of children with SCD to those with sickle cell trait between 2008 and 2019 in Georgia. Completion rates for each vaccine and the proportion of children with up-to-date status at 24 and 35 months were calculated and compared between the cohorts. Chi-square tests with odds ratios (OR) for differences and 95% confidence intervals (CIs) were reported on the overall up-to-date rates and rates for individual vaccines at 24 and 35 months for the two cohorts.

RESULTS

Children with SCD had higher up-to-date rates than children with sickle cell trait at 24 and 35 months. At 35 months, the overall up-to-date rates (OR = 1.17; 95% CI, 1.04-1.31; p = .004) and the four-dose pneumococcal conjugate vaccine series (OR = 1.36; 95% CI, 1.18-1.57; p < .001) were significantly different between the groups. Both cohorts had the highest completion rates for the hepatitis B series and the lowest rates for the varicella vaccine. Doses of diphtheria, tetanus, and acellular pertussis vaccine; varicella; and pneumococcal conjugate vaccines were most commonly missed by children in both cohorts.

CONCLUSIONS

Children with SCD have better immunization coverage than children with sickle cell trait, but there is an opportunity for improvement. Policymakers and healthcare professionals should focus on increasing access to care coordination services among children with SCD to ensure on-time and preventive healthcare services.

Poverty and the wellbeing of children with sickle cell disease: The mediating role of parenting stress

BACKGROUND

Living in poverty in the midst of caring for a child with sickle cell disease (SCD) presents with challenges that may be overwhelming for caregivers. Prior research has shown a relationship between poverty and poor outcomes in children; however, no study has investigated the mediating role of parenting stress on health-related quality of life (HRQOL) for such children.

PROCEDURE

A total of 150 patients, ages 8-17 years and their parents, were enrolled and completed measures of parenting stress (caregivers) and HRQOL (patients). Caregivers also completed a demographic information questionnaire, which was used to determine poverty status. The Sobel test was used to analyze the association between poverty and HRQOL by way of parenting stress.

RESULTS

The series of linear regression results show poverty was a significant predictor for decreased HRQOL (B = -7.01, p = .05) among pediatric patients with SCD. Moreover, the regression coefficient measuring the indirect effect of the model measuring the mediating role of parenting stress was statistically significant (B = -1.05, p = .05).

CONCLUSION

The current study found an association between poverty status and HRQOL scores by way of parenting stress. Findings highlight the need for appropriate resource allocation to caregivers in addition to pediatric patients living with SCD.

Sickle Cell Anemia Associated With Increased In-Hospital Mortality in Post-Cardiac Arrest Patients

Introduction Sickle cell anemia (SCA) is a hemoglobinopathy that arises from a point mutation in the beta-globin gene, which causes the polymerization of deoxygenated hemoglobin that leads to a wide variety of clinical complications. Deaths in patients with SCA most commonly arise from renal, cardiovascular disease, infections, and stroke. In-hospital cardiac arrest has been found to be more common in older patients and those on ventilatory life support, among others. This study aims to provide more insight into how SCA affects the risk of in-hospital mortality in post-cardiac arrest patients. Methods The National Inpatient Survey database years 2016 to 2019 was utilized. The International Classification of Diseases, Tenth Revision, Procedure Coding System (ICD-10 PCS) codes for cardiopulmonary resuscitation were used to identify in-hospital cardiac arrest (IHCA) patients. ICD-10 Clinical Modification (CM) codes were used to identify SCA and other medical comorbidities. Categorical data was compared using Person's chi-square test, and continuous variables were compared using the independent samples t-test. Multinomial logistic regression was used to study the effects of SCA on post-arrest in-hospital mortality controlling for age, Charlson comorbidity score, and demographic variables. Binomial logistic regression models for dichotomous variables were utilized in the subgroup and secondary outcomes analysis. Results In patients with IHCA, patients who had SCA were found to have a significantly increased risk of in-hospital mortality adjusted for baseline characteristics and Charlson comorbidity score (OR: 1.16, 95% CI: 1.02-1.32, p=0.0025). Patient characteristics most strongly associated with an increased risk of in-hospital mortality in this cohort were found to be Black race (OR: 1.92, 95% CI: 1.87-1.97, p<0.001) and self-payer status (OR: 2.14, 95% CI: 2.06-2.22, p<0.001). Subgroup analysis revealed only patients with sickle cell disease had a statistically significant increased risk of in-hospital mortality in this cohort (OR: 4.41, 95% CI: 3.5-5.55, p<0.001), and patients with sickle cell trait did not. Conclusion In patients with IHCA, SCA is associated with an increased risk of in-hospital mortality. This risk was confined to patients with sickle cell disease and not patients with sickle cell trait.

Allogeneic hematopoietic stem cell transplantation to cure sickle cell disease: A review

Sickle cell disease (SCD) had first been mentioned in the literature a century ago. Advancement in the molecular basis of the pathophysiology of the disease opens the door for various therapeutic options. Though life-extending treatments are available for treating patients with SCD, allogeneic hematopoietic stem cell transplantation (HSCT) is the only option as of yet. A major obstacle before HSCT to cure patients with SCD is the availability of donors. Matched sibling donors are available only for a small percentage of patients. To expand the donor pool, different contrasting approaches of allogeneic HSCT like T-cell replete and deplete have been tested. None of those tested approaches have been without the risk of GvHD and graft rejection. Other limitations such as transplantation-related infections and organ dysfunction caused by the harsh conditioning regimen need to be addressed on a priority basis. In this review, we will discuss available allogeneic HSCT approaches to cure SCD, as well as recent advancements to make the approach safer. The center of interest is using megadose T-cell-depleted bone marrow in conjugation with donor-derived CD8 veto T cells to achieve engraftment and tolerance across MHC barriers, under reduced intensity conditioning (RIC). This approach is in phase I/II clinical trial at the MD Anderson Cancer Centre and is open to patients with hemoglobinopathies.

A perspective on the sickle cell disease international COVID-19 registry

To understand the risks and outcomes of COVID-19 in the sickle cell disease (SCD) population, our team established a rapid reporting registry to collect data on the course of COVID-19 illness in individuals with SCD. The registry includes cases reported voluntarily by providers. All data are collected through an online case report form available at covidsicklecell.org. The registry helped to recognize patients with SCD as a population at risk of severe COVID-19 illness and to identify comorbidities that put them at higher risk. In this report, we present data on 1045 reported COVID-19 cases based during a two-year long data collection period. Data include 590 (56.5%) children and 455 (43.5%) adults; 51.2% of total population were female. Most individuals (63.1%) had HbSS genotype. Majority of individuals experienced mild symptoms (62.2% of children, 55.6% of adults). We also present a perspective on setting up the registry and experiences through its growth.

Influenza immunization coverage of children with sickle cell disease

OBJECTIVES

To assess receipt of annual flu immunization among children living with sickle cell disease (SCD).

METHODS

Receipt of flu immunization (2014-2019) by SCD status was assessed among all Michigan children <18 years of age using the statewide immunization registry. Logistic regression was used to estimate the odds of annual flu immunization by SCD status and age.

RESULTS

Annual flu immunization coverage was higher among children with SCD (46.9%; n = 751) than without (23.2%; n = 2,012,846). The annual adjusted odds of flu immunization for those with SCD were 2.8 (95% CI: 2.5-3.1) times higher than for those without SCD; there were no significant differences by age among children with SCD. Among those without SCD, adolescents aged 13-17 were 2.2 (95% CI: 2.2-2.2) times less likely to receive annual flu immunization than children 6-35 months.

CONCLUSIONS

Children with SCD had higher annual flu immunization rates than those without SCD, but >50% remain unimmunized.

Comorbidities are risk factors for hospitalization and serious COVID-19 illness in children and adults with sickle cell disease

Patients with sickle cell disease (SCD) are at high risk of developing serious infections, therefore, understanding the impact that severe acute respiratory syndrome coronavirus 2 infection has on this population is important. We sought to identify factors associated with hospitalization and serious COVID-19 illness in children and adults with SCD.We established the international SECURE-SCD Registry to collect data on patients with SCD and COVID-19 illness. We used multivariable logistic models to estimate the independent effects of age, sex, genotype, hydroxyurea, and SCD-related and -nonrelated comorbidities on hospitalization, serious COVID-19 illness, and pain as a presenting symptom during COVID-19 illness. As of 23 March 2021, 750 COVID-19 illness cases in patients with SCD were reported to the registry. We identified history of pain (relative risk [RR], 2.15; P < .0001) and SCD heart/lung comorbidities (RR, 1.61; P = .0001) as risk factors for hospitalization in children. History of pain (RR, 1.78; P = .002) was also a risk factor for hospitalization in adults. Children with history of pain (RR, 3.09; P = .009), SCD heart/lung comorbidities (RR, 1.76; P = .03), and SCD renal comorbidities (RR, 3.67; P < .0001) and adults with history of pain (RR 1.94, P = .02) were at higher risk of developing serious COVID-19 illness. History of pain and SCD renal comorbidities also increased risk of pain during COVID-19 in children; history of pain, SCD heart/lung comorbidities, and female sex increased risk of pain during COVID-19 in adults. Hydroxyurea showed no effect on hospitalization and COVID-19 severity, but it lowered the risk of presenting with pain in adults during COVID-19.

Health services use by children identified as heterozygous hemoglobinopathy mutation carriers via newborn screening

Background

Newborn screening (NBS) for sickle cell disease incidentally identifies heterozygous carriers of hemoglobinopathy mutations. In Ontario, Canada, these carrier results are not routinely disclosed, presenting an opportunity to investigate the potential health implications of carrier status. We aimed to compare rates of health services use among children identified as carriers of hemoglobinopathy mutations and those who received negative NBS results.

Methods

Eligible children underwent NBS in Ontario from October 2006 to March 2010 and were identified as carriers or as screen-negative controls, matched to carriers 5:1 based on neighbourhood and timing of birth. We used health care administrative data to determine frequencies of inpatient hospitalizations, emergency department (ED) visits, and physician encounters through March 2012, using multivariable negative binomial regression to compare rates of service use in the two cohorts. We analyzed data from 4987 carriers and 24,935 controls.

Results

Adjusted incidence rate ratios (95% CI) for service use in carriers versus controls among children < 1 year of age were: 1.11 (1.06–1.17) for ED visits; 0.97 (0.89–1.06) for inpatient hospitalization; and 1.02 (1.00–1.04) for physician encounters. Among children ≥1 year of age, adjusted rate ratios were: 1.03 (0.98–1.07) for ED visits; 1.14 (1.03–1.25) for inpatient hospitalization and 0.92 (0.90–0.94) for physician encounters.

Conclusions

While we identified statistically significant differences in health services use among carriers of hemoglobinopathy mutations relative to controls, effect sizes were small and directions of association inconsistent across age groups and health service types. Our findings are consistent with the assumption that carrier status is likely benign in early childhood.

COVID-19 in individuals with sickle cell disease/trait compared with other Black individuals

In the United States, COVID-19 has disproportionately affected Black persons. Sickle cell disease (SCD) and sickle cell trait (SCT) are genetic conditions that occur predominantly among Black individuals. It is unknown if individuals with SCD/SCT are at higher risk of severe COVID-19 illness compared with Black individuals who do not have SCD/SCT. The objective of our study was to compare COVID-19 outcomes, including the disease manifestations, hospitalization, and death, among individuals with SCD/SCT vs Black individuals who do not have SCD/SCT. We leveraged electronic health record data from a multisite research network to identify Black patients with COVID-19 who have SCD/SCT and those who do not have SCD/SCT. During the study period of 20 January 2020 to 20 September 2020, there were 312 patients with COVID-19 and SCD and 449 patients with COVID-19 and SCT. There were 45 517 Black persons who were diagnosed with COVID-19 but who did not have SCD/SCT. After 1:1 propensity score matching (based on age, sex, and other preexisting comorbidities), patients with COVID-19 and SCD remained at a higher risk of hospitalization (relative risk [RR], 2.0; 95% CI, 1.5-2.7) and development of pneumonia (RR, 2.4; 95% CI, 1.6-3.4) and pain (RR, 3.4; 95% CI, 2.5-4.8) compared with Black persons without SCD/SCT. The case fatality rates for those with SCD compared with Black persons without SCD/SCT were not significantly different. There also were no significant differences in COVID-19 outcomes between individuals with SCT and Black persons without SCD/SCT within the matched cohorts.

Correction of murine sickle cell disease by allogeneic haematopoietic cell transplantation with anti-3rd party veto cells

Despite advances in gene therapy allogeneic hematopoietic stem cell transplants (HSCT) remains the most effective way to cure sickle cell disease (SCD). However, there are substantial challenges including lack of suitable donors, therapy-related toxicity (TRM) and risk of graft-versus-host disease (GvHD). Perhaps the most critical question is when to do a transplant for SCD. Safer transplant protocols for HLA-disparate HSCT is needed before transplants are widely accepted for SCD. Although risk of GvHD and TRM are less with T-cell-deplete HSCT and reduced-intensity conditioning (RIC), transplant rejection is a challenge. We have reported graft rejection of T cell-depleted non-myeloablative HSCT can be overcome in wild type fully mis-matched recipient mice, using donor-derived anti-3rd party central memory CD8-positive veto cells combined with short-term low-dose rapamycin. Here, we report safety and efficacy of this approach in a murine model for SCD. Durable donor-derived chimerism was achieved using this strategy with reversal of pathological parameters of SCD, including complete conversion to normal donor-derived red cells, and correction of splenomegaly and the levels of circulating reticulocytes, hematocrit, and hemoglobin.

Host genetic effects in pneumonia

Given the coronavirus disease 2019 (COVID-19) pandemic, investigations into host susceptibility to infectious diseases and downstream sequelae have never been more relevant. Pneumonia is a lung disease that can cause respiratory failure and hypoxia and is a common complication of infectious diseases, including COVID-19. Few genome-wide association studies (GWASs) of host susceptibility and severity of pneumonia have been conducted. We performed GWASs of pneumonia susceptibility and severity in the Vanderbilt University biobank (BioVU) with linked electronic health records (EHRs), including Illumina Expanded Multi-Ethnic Global Array (MEGAEX)-genotyped European ancestry (EA, n= 69,819) and African ancestry (AA, n = 15,603) individuals. Two regions of large effect were identified: the CFTR locus in EA (rs113827944; OR = 1.84, p value = 1.2 × 10-36) and HBB in AA (rs334 [p.Glu7Val]; OR = 1.63, p value = 3.5 × 10-13). Mutations in these genes cause cystic fibrosis (CF) and sickle cell disease (SCD), respectively. After removing individuals diagnosed with CF and SCD, we assessed heterozygosity effects at our lead variants. Further GWASs after removing individuals with CF uncovered an additional association in R3HCC1L (rs10786398; OR = 1.22, p value = 3.5 × 10-8), which was replicated in two independent datasets: UK Biobank (n = 459,741) and 7,985 non-overlapping BioVU subjects, who are genotyped on arrays other than MEGAEX. This variant was also validated in GWASs of COVID-19 hospitalization and lung function. Our results highlight the importance of the host genome in infectious disease susceptibility and severity and offer crucial insight into genetic effects that could potentially influence severity of COVID-19 sequelae.

Hemoglobin SE Disease Presenting as a High-Altitude Massive Splenic Infarction Complicated by Hemorrhagic Conversion and Splenectomy

Hemoglobin SE (HbSE) disease is a hemoglobinopathy resulting from the combination of hemoglobin S (HbS) and hemoglobin E (HbE) genotypes. It may present as a vaso-occlusive crisis (VOC) in the setting of an acute stressor. Herein, we present a case of undiagnosed HbSE disease presenting as a massive splenic infarct in the setting of high-altitude exposure. A 55-year-old female of South Asian descent presented with acute left upper quadrant abdominal pain after hiking in the Swiss Alps four days previously. Laboratory testing revealed that she had hemolytic anemia, and computed tomography (CT) imaging showed a greater than 50% splenic infarction. After the initiation of anticoagulation, she experienced a hemorrhagic conversion of the initial splenic infarct resulting in acute hemodynamic decompensation. She initially underwent vascular intervention with arterial plugging, coiling, and embolization but ultimately required a splenectomy and partial colectomy upon developing a large splenic hematoma. Hemoglobin electrophoresis was consistent with hemoglobin SE disease. Hemoglobin variants, especially combined heterozygosity, are rare and have the potential to present as a vaso-occlusive crisis in the setting of acute chemical and physiological stresses. Only 43 cases of hemoglobin SE disease have been previously reported and one other occurrence in the setting of high altitude. Conservative management is recommended when a diagnosis of sickle cell trait (SCT) is definite, in comparison with cardioembolic phenomena, in which antiplatelet and anticoagulant therapy should be initiated. Hemoglobin SE disease is a rare heterozygous hemoglobinopathy resulting from the combination of hemoglobin variants geographically separated by thousands of miles. Currently, there are no strict guidelines supporting anticoagulation for the management of VOC in hemoglobinopathies. Splenic infarct in HbSE disease should be managed similarly to SCT/sickle cell disease (SCD) with fluids and analgesia, and anticoagulation should be limited to confirmed thromboembolic events and with the insight of an anticoagulant specialist.

Safety of quadrivalent meningococcal conjugate vaccine in infants and toddlers 2 to 23-months old

INTRODUCTION

The quadrivalent meningococcal conjugate vaccine MenACWY-CRM is recommended for 2-23 month-old infants/toddlers at increased risk for meningococcal disease. This study adds to the current knowledge of MenACWY-CRM safety among this age group in a clinical care setting.

METHODS

Kaiser Permanente Southern California members aged 2-23 months who received MenACWY-CRM between July 2014 and June 2017 were included. Electronic health records were searched for emergency department (ED) and hospitalization encounters, and diagnoses associated with these visits up to 6 months after each dose.

RESULTS

There were 138 infants/toddlers who received MenACWY-CRM, with 59.4% being African American and 66.7% receiving only one dose. Most infants either had a high-risk condition (i.e., anatomic/functional asplenia or DiGeorge syndrome) (42.0%), or a travel indication (54.3%). The incidence rate of ED visits was 0.6/person-year (95% confidence interval [CI]: 0.5-0.8), 0.4/person-year (CI: 0.3-0.5) for hospitalizations, and 0.1/person-year (CI: 0.1-0.3) for ED to hospital transfers. Overall, 29.0% of recipients had an incident diagnosis in the ED or hospital setting. Fever and acute upper respiratory infections were the most common diagnoses, with 46 out of 47 diagnoses occurring among infants with high-risk conditions.

CONCLUSIONS

Data from this descriptive observational study do not suggest safety concerns associated with MenACWY-CRM when used as part of clinical care of 2-23 month-old infants/toddlers indicated for vaccination.