Global distribution of the sickle cell gene and geographical confirmation of the malaria hypothesis

History, Advances, and Challenges of Sickle Cell Disease Treatment

Sickle cell disease (SCD) is marked by red blood cells that deform into a sickle shape, causing severe health complications. Historic neglect and slow therapeutic progress have left many, especially African descendants, vulnerable. Recent treatment strides include novel drugs and gene therapy, promising improved management. Nonetheless, challenges persist with treatment adoption because of cost, adverse effects, and accessibility. Advancements hold hope for enhanced life quality and longevity for SCD patients.

Sickle cell disease in Cameroon: Taking out the "neglect" and highlighting key opportunities for sustainable control

Sickle Cell Disease (SCD) is a serious genetic disorder with astounding regional differences in childhood survival. Alarmingly, over 90% of children with SCD in SSA die before their fifth birthday. In Cameroon, approximately 7,000 children are born with SCD annually; however, most of them go undiagnosed until their fourth birthday, resulting into untold pain and suffering. Despite this, little is known about the barriers to optimal care and treatment for SCD in Cameroon. Here, we assess these barriers, and consider opportunities that could be leveraged, for a sustainable control of SCD in Cameroon. We conducted a qualitative study, with documentary analysis of key national and international policy documents related to SCD management in Cameroon; semi-structured interviews; and focus group discussions, used for data collection. Key informants were selected purposively, and met at the central level of the health system (in Yaoundé) and the operational level (Mfou health district). These were policy makers, health workers, parents with SCD children and teenagers with SCD. Several critical gaps exist which hinder SCD control in Cameroon. These include lack of a national sickle cell disease strategy, no proportional allocation of funds for SCD in the national budget, and gaps in service delivery. These are translated into healthcare providers having little knowledge on SCD, absence of SCD-specific indicators in the health information system, challenges accessing essential medicines, and limited awareness raising in communities on SCD. Still, several opportunities exist which could be leveraged for improving SCD care in Cameroon. These include the possibility of integrating SCD screening and care into well-established primary healthcare services like vaccination, antenatal care, and non-communicable disease clinics. In the light of such limited resource settings, considering opportunities for integration in existing health programs could go a long way to reduce morbidities and mortalities from SCD over the coming years.

Newborn Screening for Sickle Cell Disease in Catalonia between 2015 and 2022-Epidemiology and Impact on Clinical Events

In 2015, Catalonia introduced sickle cell disease (SCD) screening in its newborn screening (NBS) program along with standard-of-care treatments like penicillin, hydroxyurea, and anti-pneumococcal vaccination. Few studies have assessed the clinical impact of introducing NBS programs on SCD patients. We analyzed the incidence of SCD and related hemoglobinopathies in Catalonia and the change in clinical events occurring after introducing NBS. Screening 506,996 newborns from 2015 to 2022, we conducted a retrospective multicenter study including 100 screened (SG) and 95 unscreened (UG) SCD patients and analyzed SCD-related clinical events over the first six years of life. We diagnosed 160 cases of SCD, with an incidence of 1 in 3169 newborns. The SG had a significantly lower median age at diagnosis (0.1 y vs. 1.68 y, p < 0.0001), and initiated penicillin prophylaxis (0.12 y vs. 1.86 y, p < 0.0001) and hydroxyurea treatment earlier (1.42 y vs. 4.5 y, p < 0.0001). The SG experienced fewer median SCD-related clinical events (vaso-occlusive crisis, acute chest syndrome, infections of probable bacterial origin, acute anemia requiring transfusion, acute splenic sequestration, and pathological transcranial Doppler echography) per year of follow-up (0.19 vs. 0.77, p < 0.0001), a reduced number of annual emergency department visits (0.37 vs. 0.76, p < 0.0001), and fewer hospitalizations (0.33 vs. 0.72, p < 0.0001). SCD screening in Catalonia's NBS program has effectively reduced morbidity and improved affected children's quality of life.

Gene Therapies for Sickle Cell Disease

Background: Sickle cell disease (SCD) is a prevalent autosomal recessive hemoglobinopathy affecting millions worldwide, particularly individuals of African ancestry. Sickle cell disease is a lifelong condition associated with a negative impact on quality of life and mortality, causing complications such as painful vaso-occlusive episodes, acute chest syndrome, stroke, long-term anemia, and end-organ damage. Currently, there are 4 U.S. Food and Drug Administration (FDA)-approved drugs, including hydroxyurea, l-glutamine, voxelotor, and crizanlizumab, which work to alleviate symptoms and prevent complications associated with SCD, albeit without addressing the underlying cause of SCD. Allogeneic hematopoietic stem cell transplant (HSCT) has shown promise as a curative approach to SCD but is limited by donor availability and associated complications. This paper aims to review the efficacy and safety of exagamglogene autotemcel and lovotibeglogene autotemcel for managing patients with SCD, including their place in therapy, cost, and accessibility in clinical care. Data Sources: The authors searched PubMed and Medline from 2017 to 2024, for primary literature on both exagamglogene autotemcel and lovotibeglogene autotemcel. Results: The authors identified relevant studies and summarized the data on the two gene therapies. Conclusion: Exagamglogene autotemcel and lovotibeglogene autotemcel are two management strategies that address the underlying cause of SCD and provide curative potential for patients with SCD.

Exercise and training in sickle cell disease: Safety, potential benefits, and recommendations

Sickle cell disease (SCD) is a genetic disorder characterized by complex pathophysiological mechanisms leading to vaso-occlusive crisis, chronic pain, chronic hemolytic anemia, and vascular complications, which require considerations for exercise and physical activity. This review aims to elucidate the safety, potential benefits, and recommendations regarding exercise and training in individuals with SCD. SCD patients are characterized by decreased exercise capacity and tolerance. Acute intense exercise may be accompanied by biological changes (acidosis, increased oxidative stress, and dehydration) that could increase the risk of red blood cell sickling and acute clinical complications. However, recent findings suggest that controlled exercise training is safe and well tolerated by SCD patients and could confer benefits in disease management. Regular endurance exercises of submaximal intensity or exercise interventions incorporating resistance training have been shown to improve cardiorespiratory and muscle function in SCD, which may improve quality of life. Recommendations for exercise prescription in SCD should be based on accurate clinical and functional evaluations, taking into account disease phenotype and cardiorespiratory status at rest and in response to exercise. Exercise programs should include gradual progression, incorporating adequate warm-up, cool-down, and hydration strategies. Exercise training represents promising therapeutic strategy in the management of SCD. It is now time to move through the investigation of long-term biological, physiological, and clinical effects of regular physical activity in SCD patients.

Gene-environmental influence of space and microgravity on red blood cells with sickle cell disease

A fundamental question in human biology and for hematological disease is how do complex gene-environment interactions lead to individual disease outcome? This is no less the case for sickle cell disease (SCD), a monogenic disorder of Mendelian inheritance, both clinical course, severity, and treatment response, is variable amongst affected individuals. New insight and discovery often lie between the intersection of seemingly disparate disciplines. Recently, opportunities for space medicine have flourished and have offered a new paradigm for study. Two recent Nature papers have shown that hemolysis and oxidative stress play key mechanistic roles in erythrocyte pathogenesis during spaceflight. This paper reviews existing genetic and environmental modifiers of the sickle cell disease phenotype. It reviews evidence for erythrocyte pathology in microgravity environments and demonstrates why this may be relevant for the unique gene-environment interaction of the SCD phenotype. It also introduces the hematology and scientific community to methodological tools for evaluation in space and microgravity research. The increasing understanding of space biology may yield insight into gene-environment influences and new treatment paradigms in SCD and other hematological disease phenotypes.

A clinical evaluation program to monitor neurocognitive risk in children and adolescents with sickle cell disease

Objective: Sickle cell disease (SCD) is an inherited hematologic disorder that impacts approximately 100,000 Americans. This disease is associated with progressive organ damage, cerebral vascular accident, and neurocognitive deficits. Recent guidelines from the American Society of Hematology (ASH) recommend cognitive screening with a psychologist to help manage cerebrovascular risk and cognitive impairment in this population. SCD patients benefit from neuropsychology services and several institutions already have programs in place to monitor cognitive risk. Program Description: We describe a longitudinal neurocognitive evaluation program at our institution that serves all patients with SCD, regardless of disease severity or referral question. The Sickle Cell Assessment of Neurocognitive Skills (SCANS) program was established in 2012. We outline the program's theoretical framework, timepoints for evaluation, test battery, logistics, patient demographics, integration with research programming, and multidisciplinary collaboration to support optimal outcomes. Program Outcomes: Our program has provided 716 targeted neuropsychological evaluations for patients over the last decade. Nearly 26% of patients in the program have been followed longitudinally. The most common diagnoses generated across cross-sectional and longitudinal evaluations include cognitive disorder (n = 191), attention-deficit/hyperactivity disorder (n = 75), and specific learning disorder (n = 75). Approximately 87% of patients who participated in SCANS during late adolescence successfully transitioned from pediatric to adult care. Conclusion: We discuss considerations for developing programming to meet the needs of this population, including tiered assessment models, timing of evaluations, scope, and reimbursement. Program models that utilize prevention-based tiered models or targeted evaluations can assist with serving large volumes of patients.

Hydroxyurea in the sickle cell disease modern era

INTRODUCTION

Sickle cell disease is an inherited disorder characterized by hemoglobin S polymerization leading to vaso-occlusion and hemolytic anemia. These result in a variety of pathological events, causing both acute and chronic complications. Millions around the world are affected by sickle cell disease with predominance in sub-Saharan Africa. Hydroxyurea was the first drug approved for use in sickle cell disease to reduce the occurrence of painful crises and blood transfusions in patients with frequent, moderate to severe painful crises.

AREAS COVERED

With the development of new therapeutics, the role of hydroxyurea is evolving. This narrative review aims to provide clinical data, safety information, and supplementary evidence for the role of hydroxyurea in the current era of sickle cell disease. A comprehensive literature search of databases, including PubMed and Cochrane Library, was conducted from 1963 to 2024.

EXPERT OPINION

Even though new medications have been approved for sickle cell disease, hydroxyurea remains the gold standard. Hydroxyurea is not only a disease modifier but it has additional clinical benefits, it is affordable, and its longevity has prompted expanded research in areas such as underutilization and pharmacogenomics. As the treatment landscape evolves, hydroxyurea's long-standing record of efficacy and safety continues to support its role as a key agent in disease management.

Prevalence, patterns, and factors associated with abnormal lung function among children with sickle cell disease in Uganda: a cross-sectional study

BACKGROUND

Pulmonary complications are common among children with sickle cell disease (SCD). However, there is little literature on associated lung function abnormalities in Uganda. We aimed to determine the prevalence, patterns, and factors associated with abnormal lung function among children with SCD in a tertiary care hospital in Uganda.

METHOD

A cross-sectional study was conducted among children aged 6 to 18 years at the SCD clinic (SCC) of Mulago National Super-Specialized Hospital between January 2020 and April 2021. Data on sociodemographic and clinical characteristics was collected using a standardized questionnaire. Laboratory investigations, including a complete blood count and serum lactate dehydrogenase (LDH), were done. Spirometry was performed following the ATS/ERS standards. Multivariable modified Poisson regression analysis was performed to determine factors associated with abnormal lung function.

RESULTS

A total of 332 participants were enrolled. The mean age was 11.7 ± 3.4 years, and 184 (55.4%) were female. Overall, 126 (37.9%) participants had abnormal lung function: 67/126 (53.2%) restrictive, 57/126 (45.2%) obstructive, and 2/126 (1.6%) mixed-ventilatory patterns. Factors associated with abnormal lung function were; serum LDH level > 600UL (aIRR: 1.89 95% CI: 1.2 - 7.4, p = 0.049), a history of acute chest syndrome (aIRR: 1.55, 95% CI: 1.06-2.25, p = 0.024), wasting (aIRR: 1.33, 95%CI: 1.02 - 1.72, p = 0.032), and use of charcoal for household cooking (aIRR: 1.49, 95% CI: 1.03-2.15, p = 0.035).

CONCLUSION

More than one-third of children with SCD in Uganda have lung function abnormalities. Strategies to improve nutrition, reduce exposure to charcoal smoke, and monitoring serum LDH levels may be important in preventing or managing abnormal lung function in this population. The identification of reversible and irreversible airway obstruction in children with sickle cell disease also highlights the need for targeted interventions to address these specific patterns of abnormal lung function.

A suite of selective pressures supports the maintenance of alleles of a Drosophila immune peptide

The innate immune system provides hosts with a crucial first line of defense against pathogens. While immune genes are often among the fastest evolving genes in the genome, in Drosophila , antimicrobial peptides (AMPs) are notable exceptions. Instead, AMPs may be under balancing selection, such that over evolutionary timescales multiple alleles are maintained in populations. In this study, we focus on the Drosophila antimicrobial peptide Diptericin A, which has a segregating amino acid polymorphism associated with differential survival after infection with the Gram-negative bacteria Providencia rettgeri . Diptericin A also helps control opportunistic gut infections by common Drosophila gut microbes, especially those of Lactobacillus plantarum . In addition to genotypic effects on gut immunity, we also see strong sex-specific effects that are most prominent in flies without functional diptericin A . To further characterize differences in microbiomes between different diptericin genotypes, we used 16S metagenomics to look at the microbiome composition. We used both lab reared and wild caught flies for our sequencing and looked at overall composition as well as the differential abundance of individual bacterial families. Overall, we find flies that are homozygous for one allele of diptericin A are better equipped to survive a systemic infection from P. rettgeri , but in general have a shorter lifespans after being fed common gut commensals. Our results suggest a possible mechanism for the maintenance of genetic variation of diptericin A through the complex interactions of sex, systemic immunity, and the maintenance of the gut microbiome.

The effect on the equilibrium sickle cell allele frequency of the probable protection conferred by malaria and sickle cell gene against other infectious diseases

If a mutated gene with heterozygous advantage against malaria, e.g., hemoglobin S (HbS) gene, is introduced in a small tribe, the gene (allele) frequency (fgene) increases until it reaches a steady state value (feq) where the total mortality from malaria and sickle cell disease is a minimum. This is a classic example of balanced-polymorphism named malaria hypothesis. In a previous in silico study, assuming realistic initial conditions, it has been shown that the feq is around 14%, far less than the fgene observed in certain parts of Africa, 24%. It seems that the malaria hypothesis, per se, could not explain such a high fgene, unless it is assumed that malaria and HbS gene can provide protection against other diseases. Using Monte-Carlo simulation, the current study was conducted to examine the effect on feq of five scenarios was examined. The studied scenarios consisted of different combinations of mortality of other diseases and the possible amounts of protections conferred by malaria and HbS gene against the diseases. Taking into account other diseases causing mortality in the population makes the fgene rate of change steeper over generations. feq is an increasing function of the amount of protection conferred by HbS gene against other diseases. The effect of protection provided by malaria against other diseases on feq, is however, variable-depending on the amount of protection conferred by HbS gene against other diseases, it may increase or decrease feq. If malaria and HbS gene provide protections of 1.5-fold and threefold against other diseases, respectively, the feq is around 24%, the amount reported in certain tribes of Africa. Under certain scenarios, the feq attained is even higher.

Food insecurity and quality of life in patients with sickle cell disease

Little is known about the relationship between quality of life (QOL) and food insecurity (FI) among patients with sickle cell disease (SCD). We hypothesized FI is associated with lower QOL in children and young adults with SCD. Overall (N = 99), 22% screened positive for FI. Supplemental Nutrition Assistance Program (SNAP) enrollment was 50 and 71% among people from food secure and FI households, respectively. A higher FI score was correlated with lower overall QOL (r = -0.22, p = .03), specifically lower QOL in worry and communication domains. Interventions for FI beyond SNAP may be important for QOL among people living with SCD.

Pregnancy Outcomes Among Women With Sickle Cell Disease in Bahrain: A Case-Control Study

Objectives The study sought to evaluate and compare the maternal and fetal outcomes of pregnancy in women with sickle cell disease (SCD) versus healthy pregnant women in Bahrain. The objective was to update the available data in order to come up with a strategy to implement a multidisciplinary management program, which will enhance pregnancy outcomes for the SCD patient population. Materials and methods This retrospective case-control study was conducted in the Obstetrics and Gynecology Department at Salmaniya Medical Complex (SMC) in Bahrain. The study group consisted of all pregnant women with homozygous SCD (HbSS) who delivered at SMC between January 1, 2019, and December 31, 2021. The control group comprised pregnant women who delivered at SMC during the same period but did not have SCD or trait. Data for the study were collected from the healthcare system records at SMC, specifically the I-Seha electronic medical record system and the labor room registry book. A thorough review and analysis of the data were conducted, encompassing 217 cases of SCD and 200 controls. The variables examined included nationality, age, gravidity, parity, gestational age, reason for admission, antenatal/postnatal complications (such as urinary tract infection, pneumonia, acute chest syndrome, thromboembolism, premature rupture of membranes, hypertension, pre-eclampsia, and intrauterine growth restriction), type of delivery, birth weight, newborn outcome, and postnatal complications. Results Pregnant women with SCD experienced significantly higher rates of antenatal hospitalization compared to controls - 69.6% were admitted at least twice versus only 16.5%. Vaso-occlusive crises were the primary reason for admission in over half of SCD patients, with 22.6% having one episode, 11.1% having two, and 20.3% having more than two during pregnancy. Low hemoglobin levels also necessitated admission in 11.1% of SCD women, while no controls required hospitalization for this. The burden of maternal morbidity was substantially greater in the SCD group, with only 20.3% free of complications versus 94% in controls. SCD women had elevated rates of blood transfusions, acute chest syndrome, and urinary tract infections. Adverse pregnancy outcomes were also more common, including higher risks of preterm birth, low birth weight, and intrauterine growth restriction. Despite these increased maternal and fetal risks, there was no significant difference in the incidence of hypertensive disorders between groups. Interestingly, our data showed a significantly lower incidence of gestational diabetes in the SCD group compared to controls (8.3% vs. 18%). Tragically, one maternal death occurred in the SCD group, although the overall maternal mortality did not differ significantly. Conclusion SCD poses substantial risks for mother and fetus. Careful monitoring with a multidisciplinary team and patient education are crucial. Early detection can reduce morbidity and mortality. Further research is needed on interventions to improve outcomes.

Venous Thromboembolism in Individuals with Sickle Cell Disease: A Narrative Review

Sickle cell disease (SCD) is an inherited hemoglobinopathy characterized by vaso-occlusion, hemolysis of red blood cells (RBC), and a predisposition for venous thromboembolism (VTE). The sickling and hemolysis of RBC culminate in coagulation system abnormalities, platelet activation, endothelial dysfunction, and impaired blood flow manifesting as a prothrombotic state. In addition, individuals with SCD are often exposed to extrinsic risk factors for VTE including recurrent hospitalizations, central venous catheters, and acute medical illnesses. The diagnosis is often challenging as symptoms may mimic other complications of SCD, and there is little data to guide diagnostic algorithms involving probability scoring in the SCD population. Non-anticoagulant strategies aimed at reducing disease severity may aid in lowering the risk of VTE, but data is limited. Furthermore, high quality evidence regarding anticoagulation in prevention and treatment of SCD is severely lacking, resulting in heterogeneity in clinical practice. In this narrative review we aim to review the prothrombotic pathophysiology of SCD, to describe the risk factors, high risk of mortality, and types of VTE in SCD, to develop an approach to the diagnosis of VTE in SCD, and to understand the limited available evidence for the prevention and treatment of VTE in SCD.

Variant Effect Prediction in the Age of Machine Learning

Over the years, many computational methods have been created for the analysis of the impact of single amino acid substitutions resulting from single-nucleotide variants in genome coding regions. Historically, all methods have been supervised and thus limited by the inadequate sizes of experimentally curated data sets and by the lack of a standardized definition of variant effect. The emergence of unsupervised, deep learning (DL)-based methods raised an important question: Can machines learn the language of life from the unannotated protein sequence data well enough to identify significant errors in the protein "sentences"? Our analysis suggests that some unsupervised methods perform as well or better than existing supervised methods. Unsupervised methods are also faster and can, thus, be useful in large-scale variant evaluations. For all other methods, however, their performance varies by both evaluation metrics and by the type of variant effect being predicted. We also note that the evaluation of method performance is still lacking on less-studied, nonhuman proteins where unsupervised methods hold the most promise.

More evidence for widespread antagonistic pleiotropy in polymorphic disease alleles

Introduction

Many loci segregate alleles classified as "genetic diseases" due to their deleterious effects on health. However, some disease alleles have been reported to show beneficial effects under certain conditions or in certain populations. The beneficial effects of these antagonistically pleiotropic alleles may explain their continued prevalence, but the degree to which antagonistic pleiotropy is common or rare is unresolved. We surveyed the medical literature to identify examples of antagonistic pleiotropy to help determine whether antagonistic pleiotropy appears to be rare or common.

Results

We identified ten examples of loci with polymorphisms for which the presence of antagonistic pleiotropy is well supported by detailed genetic or epidemiological information in humans. One additional locus was identified for which the supporting evidence comes from animal studies. These examples complement over 20 others reported in other reviews.

Discussion

The existence of more than 30 identified antagonistically pleiotropic human disease alleles suggests that this phenomenon may be widespread. This poses important implications for both our understanding of human evolutionary genetics and our approaches to clinical treatment and disease prevention, especially therapies based on genetic modification.

Antioxidant supplementation for sickle cell disease

BACKGROUND

Sickle cell disease (SCD) refers to a group of genetic disorders characterized by the presence of an abnormal haemoglobin molecule called haemoglobin S (HbS). When subjected to oxidative stress from low oxygen concentrations, HbS molecules form rigid polymers, giving the red cell the typical sickle shape. Antioxidants have been shown to reduce oxidative stress and improve outcomes in other diseases associated with oxidative stress. Therefore, it is important to review and synthesize the available evidence on the effect of antioxidants on the clinical outcomes of people with SCD.

OBJECTIVES

To assess the effectiveness and safety of antioxidant supplementation for improving health outcomes in people with SCD.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 15 August 2023.

SELECTION CRITERIA

We included randomized and quasi-randomized controlled trials comparing antioxidant supplementation to placebo, other antioxidants, or different doses of antioxidants, in people with SCD.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data, assessed the risk of bias and certainty of the evidence, and reported according to Cochrane methodological procedures.

MAIN RESULTS

The review included 1609 participants in 26 studies, with 17 comparisons. We rated 13 studies as having a high risk of bias overall, and 13 studies as having an unclear risk of bias overall due to study limitations. We used GRADE to rate the certainty of evidence. Only eight studies reported on our important outcomes at six months. Vitamin C (1400 mg) plus vitamin E (800 mg) versus placebo Based on evidence from one study in 83 participants, vitamin C (1400 mg) plus vitamin E (800 mg) may not be better than placebo at reducing the frequency of crisis (risk ratio (RR) 1.18, 95% confidence interval (CI) 0.64 to 2.18), the severity of pain (RR 1.33, 95% CI 0.40 to 4.37), or adverse effects (AE), of which the most common were headache, nausea, fatigue, diarrhoea, and epigastric pain (RR 0.56, 95% CI 0.31 to 1.00). Vitamin C plus vitamin E may increase the risk of SCD-related complications (acute chest syndrome: RR 2.66, 95% CI 0.77 to 9.13; 1 study, 83 participants), and increase haemoglobin level (median (interquartile range) 90 (81 to 96) g/L versus 93.5 (84 to 105) g/L) (1 study, 83 participants) compared to placebo. However, the evidence for all the above effects is very uncertain. The study did not report on quality of life (QoL) of participants and their caregivers, nor on frequency of hospitalization. Zinc versus placebo Zinc may not be better than placebo at reducing the frequency of crisis at six months (rate ratio 0.62, 95% CI 0.17 to 2.29; 1 study, 36 participants; low-certainty evidence). We are uncertain whether zinc is better than placebo at improving sickle cell-related complications (complete healing of leg ulcers at six months: RR 2.00, 95% CI 0.60 to 6.72; 1 study, 34 participants; very low-certainty evidence). Zinc may be better than placebo at increasing haemoglobin level (g/dL) (MD 1.26, 95% CI 0.44 to 1.26; 1 study, 36 participants; low-certainty evidence). The study did not report on severity of pain, QoL, AE, and frequency of hospitalization. N-acetylcysteine versus placebo N-acetylcysteine (NAC) 1200 mg may not be better than placebo at reducing the frequency of crisis in SCD, reported as pain days (rate ratio 0.99 days, 95% CI 0.53 to 1.84; 1 study, 96 participants; low-certainty evidence). Low-certainty evidence from one study (96 participants) suggests NAC (1200 mg) may not be better than placebo at reducing the severity of pain (MD 0.17, 95% CI -0.53 to 0.87). Compared to placebo, NAC (1200 mg) may not be better at improving physical QoL (MD -1.80, 95% CI -5.01 to 1.41) and mental QoL (MD 2.00, 95% CI -1.45 to 5.45; very low-certainty evidence), reducing the risk of adverse effects (gastrointestinal complaints, pruritus, or rash) (RR 0.92, 95% CI 0.75 to 1.14; low-certainty evidence), reducing the frequency of hospitalizations (rate ratio 0.98, 95% CI 0.41 to 2.38; low-certainty evidence), and sickle cell-related complications (RR 5.00, 95% CI 0.25 to 101.48; very low-certainty evidence), or increasing haemoglobin level (MD -0.18 g/dL, 95% CI -0.40 to 0.04; low-certainty evidence). L-arginine versus placebo L-arginine may not be better than placebo at reducing the frequency of crisis (monthly pain) (RR 0.71, 95% CI 0.26 to 1.95; 1 study, 50 participants; low-certainty evidence). However, L-arginine may be better than placebo at reducing the severity of pain (MD -1.41, 95% CI -1.65 to -1.18; 2 studies, 125 participants; low-certainty evidence). One participant allocated to L-arginine developed hives during infusion of L-arginine, another experienced acute clinical deterioration, and a participant in the placebo group had clinically relevant increases in liver function enzymes. The evidence is very uncertain whether L-arginine is better at reducing the mean number of days in hospital compared to placebo (MD -0.85 days, 95% CI -1.87 to 0.17; 2 studies, 125 participants; very low-certainty evidence). Also, L-arginine may not be better than placebo at increasing haemoglobin level (MD 0.4 g/dL, 95% CI -0.50 to 1.3; 2 studies, 106 participants; low-certainty evidence). No study in this comparison reported on QoL and sickle cell-related complications. Omega-3 versus placebo Very low-certainty evidence shows no evidence of a difference in the risk of adverse effects of omega-3 compared to placebo (RR 1.05, 95% CI 0.74 to 1.48; 1 study, 67 participants). Very low-certainty evidence suggests that omega-3 may not be better than placebo at increasing haemoglobin level (MD 0.36 g/L, 95% CI -0.21 to 0.93; 1 study, 67 participants). The study did not report on frequency of crisis, severity of pain, QoL, frequency of hospitalization, and sickle cell-related complications.

AUTHORS' CONCLUSIONS

There was inconsistent evidence on all outcomes to draw conclusions on the beneficial and harmful effects of antioxidants. However, L-arginine may be better than placebo at reducing the severity of pain at six months, and zinc may be better than placebo at increasing haemoglobin level. We are uncertain whether other antioxidants are beneficial for SCD. Larger studies conducted on each comparison would reduce the current uncertainties.

Burden and outcome of respiratory morbidities among children and adolescents with sickle cell disease-A retrospective review of emergency presentations in some Nigerian tertiary institutions

BACKGROUND

Despite the huge burden of sickle cell disease (SCD) among Nigerian children, the burden and outcome of respiratory illnesses remain undocumented. Thus, we aimed to describe the spectrum and outcome of respiratory illnesses among SCD childrenand adolescentadmissions in ten Nigerian tertiary hospitals.

METHOD

A retrospective review of the SCD admission records of children and adolescents with a confirmed diagnosis of respiratory illnesses from 2012 to 2021 in ten tertiary health facilities across five geopolitical zones in Nigeria was conducted. The data, collectedbetween March and June 2023, included the age, sex, diagnosis, complications, duration and outcome of hospitalization.

RESULTS

Of the 72,333 paediatric admissions, 7,256 (10.0%) had SCD; the proportion of SCD from the total admission ranged from 2.1 to 16.3% in the facilities. Of the 7,256 children and adolescents with SCD, 1,213 (16.7%) had respiratory morbidities. Lower respiratory disease was the most common (70.0%) respiratory entity and the majority were pneumonia (40.1.0%), followed by acute chest syndrome (26.7%). Seventeen (1.4%) patients died; all had lower respiratory diseases [(acute chest syndrome ACS (11, 64.7%), pneumonia; 5, 29.4%, and asthma (1, 5.9%). Based on the proportion of deaths among overall SCD, the 17 death cases contributed 9.4% (95% CI 5.9 to 14.5). Factors associated with deaths included duration of hospitalization less than 72 hours and lower respiratory tract diseases.

CONCLUSION

Sickle cell disease is a major contributor to hospitalization among Nigerian children and adolescents, with high respiratory morbidity and mortality. Pneumonia and acute chest syndrome were associated with mortality, andthe highest risk of death within the first 72 hours.

Morbidity pattern and impact of hydroxyurea therapy among sickle cell patients in Raipur district of Chhattisgarh

Background

Sickle cell disease (SCD) is a disorder marked by a single-point mutation in the beta-globin gene. Hydroxyurea is a globally accepted disease-modifying agent that sounds to be effective in managing clinically and probably preventing complications of SCD. The current study aims to document the morbidity pattern and impact of Hydroxyurea therapy in the Outpatient Department of Sickle Cell Institute, Raipur.

Materials and Methods

This cross-sectional study was conducted among randomly selected sixty-five patients (adults and children above six years). After obtaining informed consent, relevant data were collected in a predesigned pretested questionnaire. The appropriate statistical exercise was applied for the interpretation of results and inferences.

Results

Acute febrile illness 54 (83%) and 53 (81.5%) reported pain crisis observed to have the most common morbidity among the study subjects, followed by 55.4% (36), 33 (50.8%) jaundice and difficulty breathing, respectively. Joint pain was the most commonly observed complaint, particularly at the knee joint (76.9%). Other complaints such as hand-foot syndrome (24.6%), epistaxis (27.7%), and acute chest syndrome (21.5%). Vaso-occlusive crisis (72.4%), difficulty in walking (60.0%) and eyesight (35.4%), leg ulcers (9.2%), and dactylitis (3.1%) were also documented as clinical manifestations among study participants. Less than half (44.46%) had an awareness about SCD. Hydroxyurea therapy was highly significant in improving the patient's clinical picture (P < 0.01), especially following the frequency of hospitalization and the requirement for blood transfusion.

Conclusion

Pain crisis is the most common morbidity among study participants with a low level of knowledge about SCD with febrile illness. Hydroxyurea therapy was found to be quite effective as a disease-modifying therapy, especially for reducing the frequency of blood transfusion and lowering hospitalization rates among SCD patients.

Interplay between α-thalassemia and β-hemoglobinopathies: Translating genotype-phenotype relationships into therapies

α-Thalassemia represents one of the most important genetic modulators of β-hemoglobinopathies. During this last decade, the ongoing interest in characterizing genotype-phenotype relationships has yielded incredible insights into α-globin gene regulation and its impact on β-hemoglobinopathies. In this review, we provide a holistic update on α-globin gene expression stemming from DNA to RNA to protein, as well as epigenetic mechanisms that can impact gene expression and potentially influence phenotypic outcomes. Here, we highlight defined α-globin targeted strategies and rationalize the use of distinct molecular targets based on the restoration of balanced α/β-like globin chain synthesis. Considering the therapies that either increase β-globin synthesis or reactivate γ-globin gene expression, the modulation of α-globin chains as a disease modifier for β-hemoglobinopathies still remains largely uncharted in clinical studies.

The gene "degrees of kevin bacon" (dokb) regulates a social network behaviour in Drosophila melanogaster

Social networks are a mathematical representation of interactions among individuals which are prevalent across various animal species. Studies of human populations have shown the breadth of what can spread throughout a social network: obesity, smoking cessation, happiness, drug use and divorce. 'Betweenness centrality' is a key property of social networks that indicates an individual's importance in facilitating communication and cohesion within the network. Heritability of betweenness centrality has been suggested in several species, however the genetic regulation of this property remains enigmatic. Here, we demonstrate that the gene CG14109, referred to as degrees of kevin bacon (dokb), influences betweenness centrality in Drosophila melanogaster. We identify strain-specific alleles of dokb with distinct amino acid sequences and when the dokb allele is exchanged between strains, flies exhibit the betweenness centrality pattern dictated by the donor allele. By inserting a GAL4 reporter into the dokb locus, we confirm that dokb is expressed in the central nervous system. These findings define a novel genetic entry point to study social network structure and thereby establish gene-to-social structure relationships. While dokb sequence homology is exclusive to Diptera, we anticipate that dokb-associated molecular pathways could unveil convergent neural mechanisms of social behaviour that apply in diverse animal species.

Roth Spots: A Rare Finding in Sickle Cell Anemia

White-centered, flame-shaped retinal hemorrhages, also known as Roth spots, occur in several diseases, most often in subacute bacterial endocarditis. Other conditions such as leukemia, hypertensive retinopathy, and pre-eclampsia are other causes. Here, we present the case of a 32-year-old female with sickle cell anemia (HbSS) who was treated at the hospital after experiencing a sickle cell crisis. Fundus examination was performed to rule out sickle cell retinopathies, suggesting the presence of Roth spots in the retina which are rarely seen in sickle cell disease.

Hemoglobin C Disorder in Anemic Patients Referred to the National Center for Thalassemia and Genetic Counseling in Damascus

Background: Hemoglobinopathies are common inherited blood disorders in our Mediterranean area. The main structural hemoglobin variants are hemoglobin S and hemoglobin C, due to their prevalence. We conducted this retrospective study to investigate and characterize hemoglobin C patients referred to the National Center for Thalassemia and Genetic Counseling and the management of hemoglobin C disease in Damascus. Materials and Methods: The study included patients referred to the National Center for Thalassemia and Genetic Counseling in Damascus between 2000 and 2022 for hemoglobin C detection. Gender, age, geographical origin, hemoglobin electrophoresis profile, and blood transfusion were considered for hemoglobin C patient classification. Blood transfusion in five consecutive years and linear regression with hemoglobin S and C values were determined. Results: 30 (14 males and 16 females) out of 624 patients between 3 and 46 years old (mean ± SD: 17.3 ± 9.7 years) showed hemoglobin C disease. Only eight patients (one male and seven females) received blood transfusions, and the remaining patients (13 males and 9 females) did not receive any transfusion. Only one patient with 100% hemoglobin C was detected; 19 showed HbSC, and 10 had HbAC. There was a significant correlation between hemoglobin S and geographical origin (P-value=0). Conclusion: A Homozygote hemoglobin C patient has mild hemolytic anemia, whereas the hemoglobin C 100% patient has only a one-time blood transfusion (he was 17 years old) in our study. The inherited combination of hemoglobin C and S is less severe than hemoglobin S alone. There is a significant relationship between hemoglobin S and geographical origin (p-value=0).

[Sickle cell disease in French Guiana: assessing 30 years of neonatal screening (1992-2021)]

Background

Sickle cell disease is one of the most common genetic diseases in France. In French Guiana, neonatal screening was introduced in 1992, at the same time as other screening programs for childhood diseases. The aim of this study is to describe the organization of newborn screening for sickle cell disease in French Guiana.

Materials and methods

We used several data sources: data collected from hospital records since 2005, activity reports from the national neonatal screening program and data from screening campaigns organized by the Drepaguyane association between 2010 and 2021 on 1,300 subjects. Blood samples from newborns are collected by capillary or venous sampling and absorbed on blotting paper (Guthrie) at the same time as those for other neonatal screenings. The dried papers are sent to the inter-regional laboratory in Lille, for further processing. In Saint-Laurent-du-Maroni, in order to reduce the proportion of people lost to follow-up, a double screening is carried out and the results are returned before discharge from the maternity hospital. All data were entered into an anonymous Excel file. The data were analyzed using STATA software.

Results

Among the 175,593 screened neonates between 1992 and 2021, screening detected 823 infants with sickle cell disease and 17,950 heterozygotes. Sickle cell genotypes include 493 SS (60%), 302 SC (37%) and 28 S-Beta-thalassemia (3%). The incidence of sickle cell disease was 1/213, 95% CI [1/236-1/204], and that of heterozygotes 1/10, IC 95% [1/12-1/8]. The majority of these children (52%) were from the Maroni region. The delay between screening and test results was 7 days. Only pathological results (homozygous, heterozygous) were communicated to parents and/or the attending physician by post. These data confirm the upward trend in the number of children screened for sickle cell disease in French Guiana. Data from screening campaigns organized by the Drepaguyane association have enabled to describe the distribution of the various abnormal hemoglobin fractions, and to confirm that HbS is more frequent in Western French Guiana. In Cayenne, in 2021, the active file comprised 699 patients, including 266 children under 18 years old.

Discussion and conclusion

This study provides valuable data on 30 years of neonatal screening for sickle cell disease in French Guiana, and on the evolution of sickle cell disease patients. It confirms that French Guiana is the French territory with the highest incidence of sickle cell disease. This incidence continues to rise over time. The study reveals the improvement in the organization of sickle cell disease management in French Guiana between 1992, when screening was introduced, and the present day. It highlights the role of patient associations in the fight against this disease, by organizing awareness and screening campaigns. These data will be used to guide public health policies in the pursuit of improved care and primary prevention.

Population-enriched innate immune variants may identify candidate gene targets at the intersection of cancer and cardio-metabolic disease

Both cancer and cardio-metabolic disease disparities exist among specific populations in the US. For example, African Americans experience the highest rates of breast and prostate cancer mortality and the highest incidence of obesity. Native and Hispanic Americans experience the highest rates of liver cancer mortality. At the same time, Pacific Islanders have the highest death rate attributed to type 2 diabetes (T2D), and Asian Americans experience the highest incidence of non-alcoholic fatty liver disease (NAFLD) and cancers induced by infectious agents. Notably, the pathologic progression of both cancer and cardio-metabolic diseases involves innate immunity and mechanisms of inflammation. Innate immunity in individuals is established through genetic inheritance and external stimuli to respond to environmental threats and stresses such as pathogen exposure. Further, individual genomes contain characteristic genetic markers associated with one or more geographic ancestries (ethnic groups), including protective innate immune genetic programming optimized for survival in their corresponding ancestral environment(s). This perspective explores evidence related to our working hypothesis that genetic variations in innate immune genes, particularly those that are commonly found but unevenly distributed between populations, are associated with disparities between populations in both cancer and cardio-metabolic diseases. Identifying conventional and unconventional innate immune genes that fit this profile may provide critical insights into the underlying mechanisms that connect these two families of complex diseases and offer novel targets for precision-based treatment of cancer and/or cardio-metabolic disease.

Sickle cell trait in São Tomé e Príncipe: a population-based prevalence study in women of reproductive age

BACKGROUND

Sickle Cell Disorder is Africa's most prevalent genetic disease. Yet, it remains a neglected condition, with high mortality under-five, and a lack of population-based studies in the region. This is the first of its kind in São Tomé e Príncipe, aiming to estimate the prevalence of sickle cell trait and other haemoglobin variants in women of reproductive age and its associated factors.

METHODS

We conducted a cluster survey in 35 neighbourhoods. Haemoglobin was assessed through point-of-care capillary electrophoresis or high-performance liquid chromatography, and sociodemographic data through questionnaires. The weighted prevalence of sickle cell trait (HbAS) and HbC carriers was estimated with a 95% confidence interval (95% CI). We calculated weighted prevalence ratios (95% CI) through robust Poisson regression for its association with age and individual and collective genetic heritage.

FINDINGS

The prevalence of sickle cell trait in women of reproductive age in São Tomé e Príncipe (n = 376) was 13.45% (95% CI: 9.05-19.00). The prevalence of HbC carriers was 8.00% (95% CI: 4.71-12.00). Older age and speaking Forro or Angolar were positively associated with having sickle cell trait.

INTERPRETATION

The prevalence of sickle cell trait in São Tomé e Príncipe ranks high in the West African region. The country should follow international guidelines, implementing newborn screening and comprehensive healthcare management.

Caught between pity, explicit bias, and discrimination: a qualitative study on the impact of stigma on the quality of life of persons living with sickle cell disease in three African countries

PURPOSE

Sickle cell disease (SCD) is an inherited blood disorder characterized by unpredictable episodes of acute pain and numerous health complications. Individuals with SCD often face stigma from the public, including perceptions that they are lazy or weak tending to exaggerate their pain crisis, which can profoundly impact their quality of life (QoL).

METHODS

In a qualitative phenomenological study conducted in Cameroon, Ghana, and Tanzania, we explored stakeholders' perceptions of SCD-related stigma using three analytical frameworks: Bronfenbrenner's Ecological Systems Theory; The Health Stigma and Discriminatory Framework; and A Public Health Framework for Reducing Stigma.

RESULTS

The study reveals that SCD-related stigma is marked by prejudice, negative labelling and social discrimination, with derogatory terms such as sickler, ogbanje (one who comes and goes), sika besa (money will finish), ene mewu (I can die today, I can die tomorrow), vampire (one who consumes human blood), and Efiewura (landlord-of the hospital), commonly used to refer to individuals living with SCD. Drivers of stigma include frequent crises and hospitalizations, distinct physical features of individuals living with SCD, cultural misconceptions about SCD and its association with early mortality. Proposed strategies for mitigating stigma include public health education campaigns about SCD, integrating SCD into school curricula, healthcare worker training and community engagement.

CONCLUSION

The results highlight the importance of challenging stigmatizing narratives on SCD and recognizing that stigmatization represents a social injustice that significantly diminishes the QoL of individuals living with SCD.

Adverse pregnancy, fetal and neonatal outcomes in women with sickle cell disease in a Middle Eastern country

BACKGROUND

Sickle cell disease in pregnancy is associated with high maternal and fetal mortality. However, studies reporting pregnancy, fetal, and neonatal outcomes in women with sickle cell disease are extremely limited.

OBJECTIVES

The objectives of the study are to determine whether women with sickle cell disease have a greater risk of adverse pregnancy, fetal, and neonatal outcomes than women without sickle cell disease and identify the predictors of adverse pregnancy, fetal, and neonatal outcomes in women with sickle cell disease.

DESIGN

A retrospective pair-matched case-control study was conducted to compare 171 pregnant women with sickle cell disease to 171 pregnant women without sickle cell disease in Muscat, Sultanate of Oman.

METHODS

All pregnant Omani women with sickle cell disease who delivered between January 2015 and August 2021 at Sultan Qaboos University Hospital and Royal Hospital, who were either primipara or multipara and who had a gestational age of 24-42 weeks, were included as patients, whereas women who had no sickle cell disease or any comorbidity during pregnancy, who delivered within the same timeframe and at the same hospitals, were recruited as controls. The data were retrieved from electronic medical records and delivery registry books between January 2015 and August 2021.

RESULTS

Women with sickle cell disease who had severe anemia had increased odds of (χ2 = 58.56, p < 0.001) having adverse pregnancy outcomes. Women with sickle cell disease had 21.97% higher odds of delivering a baby with intrauterine growth retardation (χ2 = 17.80, unadjusted odds ratio = 2.91-166.13, p < 0.001). Newborns born to women with sickle cell disease had 3.93% greater odds of being admitted to the neonatal intensive care unit (χ2 = 16.80, unadjusted odds ratio = 1.97-7.84, p < 0.001). In addition, the children born to women with sickle cell disease had 10.90% higher odds of being born with low birth weight (χ2 = 56.92, unadjusted odds ratio = 5.36-22.16, p < 0.001). Hemoglobin level (odds ratio = 0.17, p < 0.001, 95% confidence interval = 0.10-3.0), past medical history (odds ratio = 7.95, p < 0.001, 95% confidence interval = 2.39-26.43), past surgical history (odds ratio = 17.69, p < 0.001, 95% confidence interval = 3.41-91.76), and preterm delivery (odds ratio = 9.48, p = 0.005, 95% confidence interval = 1.95-46.23) were identified as predictors of adverse pregnancy, fetal, and neonatal outcomes in women with sickle cell disease.

CONCLUSION

As pregnant women with sickle cell disease are at increased risk for pregnancy, fetal, and neonatal adverse outcomes; improved antenatal surveillance and management may improve the outcomes.

Blood rheology and vascular function in sickle cell trait and sickle cell disease: From pathophysiological mechanisms to clinical usefulness

Sickle cell disease (SCD) is an autosomal recessive disorder. Although the molecular mechanisms at the origin of SCD have been well characterized, its clinical expression is highly variable. SCD is characterized by blood rheological abnormalities, increased inflammation and oxidative stress, and vascular dysfunction. Individuals with only one copy of the mutated β-globin gene have sickle cell trait (SCT) and are usually asymptomatic. The first part of this review focuses on the biological responses of SCT carriers during exercise and on the effects of combined SCT and diabetes on vascular function, several biomarkers and clinical complications. The second part of the review focuses on SCD and shows that the magnitude of red blood cell (RBC) rheological alterations is highly variable from one patient to another, and this variability reflects the clinical and hematological variability: patients with the less deformable RBCs have high hemolytic rate and severe anemia, and are prone to develop leg ulcers, priapism, cerebral vasculopathy, glomerulopathy or pulmonary hypertension. In contrast, SCD patients characterized by the presence of more deformable RBCs (but still rigid) are less anemic and may exhibit increased blood viscosity, which increases the risk for vaso-occlusive events. Several genetic and cellular factors may modulate RBC deformability in SCD: co-existence of α-thalassemia, fetal hemoglobin level, oxidative stress, the presence of residual mitochondria into mature RBCs, the activity of various non-selective cationic ion channels, etc. The last part of this review presents the effects of hydroxyurea and exercise training on RBC rheology and other biomarkers in SCD.

Pathogenic Variant Frequencies in Hereditary Haemorrhagic Telangiectasia Support Clinical Evidence of Protection from Myocardial Infarction

Hereditary haemorrhagic telangiectasia (HHT) is a vascular dysplasia inherited as an autosomal dominant trait, due to a single heterozygous loss-of-function variant, usually in ACVRL1 (encoding activin receptor-like kinase 1 [ALK1]), ENG (encoding endoglin [CD105]), or SMAD4. In a consecutive single-centre series of 37 positive clinical genetic tests performed in 2021-2023, a skewed distribution pattern was noted, with 30 of 32 variants reported only once, but ACVRL1 c.1231C>T (p.Arg411Trp) identified as the disease-causal gene in five different HHT families. In the same centre's non-overlapping 1992-2020 series where 110/134 (82.1%) HHT-causal variants were reported only once, ACVRL1 c.1231C>T (p.Arg411Trp) was identified in nine further families. In a 14-country, four-continent HHT Mutation Database where 181/250 (72.4%) HHT-causal variants were reported only once, ACVRL1 c.1231C>T (p.Arg411Trp) was reported by 12 different laboratories, the adjacent ACVRL1 c.1232G>A (p.Arg411Gln) by 14, and ACVRL1 c.1120C>T (p.Arg374Trp) by 18. Unlike the majority of HHT-causal ACVRL1 variants, these encode ALK1 protein that reaches the endothelial cell surface but fails to signal. Six variants of this type were present in the three series and were reported 6.8-25.5 (mean 8.9) times more frequently than the other ACVRL1 missense variants (all p-values < 0.0039). Noting lower rates of myocardial infarction reported in HHT, we explore potential mechanisms, including a selective paradigm relevant to ALK1's role in the initiating event of atherosclerosis, where a plausible dominant negative effect of these specific variants can be proposed. In conclusion, there is an ~9-fold excess of kinase-inactive, cell surface-expressed ACVRL1/ALK1 pathogenic missense variants in HHT. The findings support further examination of differential clinical and cellular phenotypes by HHT causal gene molecular subtypes.

Biology of Anemia: A Public Health Perspective

Our goal is to present recent progress in understanding the biological mechanisms underlying anemia from a public health perspective. We describe important advances in understanding common causes of anemia and their interactions, including iron deficiency (ID), lack of other micronutrients, infection, inflammation, and genetic conditions. ID develops if the iron circulating in the blood cannot provide the amounts required for red blood cell production and tissue needs. ID anemia develops as iron-limited red blood cell production fails to maintain the hemoglobin concentration above the threshold used to define anemia. Globally, absolute ID (absent or reduced body iron stores that do not meet the need for iron of an individual but may respond to iron supplementation) contributes to only a limited proportion of anemia. Functional ID (adequate or increased iron stores that cannot meet the need for iron because of the effects of infection or inflammation and does not respond to iron supplementation) is frequently responsible for anemia in low- and middle-income countries. Absolute and functional ID may coexist. We highlight continued improvement in understanding the roles of infections and inflammation in causing a large proportion of anemia. Deficiencies of nutrients other than iron are less common but important in some settings. The importance of genetic conditions as causes of anemia depends upon the specific inherited red blood cell abnormalities and their prevalence in the settings examined. From a public health perspective, each setting has a distinctive composition of components underlying the common causes of anemia. We emphasize the coincidence between regions with a high prevalence of anemia attributed to ID (both absolute and functional), those with endemic infections, and those with widespread genetic conditions affecting red blood cells, especially in sub-Saharan Africa and regions in Asia and Oceania.

Wilson's Disease in a 17-Year-Old Male With Sickle Cell Trait: A Report of a Rare Case

This case report describes the atypical presentation of Wilson's disease in a 17-year-old male with sickle cell trait AS pattern. The patient initially presented with fever, generalized weakness, and joint pain, leading to an inconclusive diagnosis and unsuccessful initial treatment. A comprehensive re-evaluation revealed vitamin-A deficiency, adenoid hypertrophy, splenomegaly, and acalculous cholecystitis. Elevated copper levels in the 24-hour urine test confirmed the diagnosis of Wilson's disease. Treatment was modified to include amikacin, prednisolone, and Zinconia®, with analgesics for joint pain management. This case emphasizes the need for a thorough diagnostic approach and consideration of overlapping conditions in complex presentations, contributing to improved patient outcomes.

Cystatin C-derived estimated glomerular filtration rate in children with sickle cell anaemia

BACKGROUND

Sickle cell disease is the most common inherited blood disorder in humans and constitutes a major public health burden. It is a multisystemic condition with long-term renal complications. Early detection of sickle cell nephropathy and initiation of appropriate interventions are associated with improved survival and quality of life. This study aimed to compare the cystatin C-derived estimated glomerular filtration rate (GFR) of the study groups and also, to correlate the clinical features of chronic kidney disease (CKD) with decreased GFR in children with sickle cell anaemia (SCA).

METHODS

This hospital-based cross-sectional analytic study recruited 86 SCA subjects in steady-state and 86 age and sex-matched healthy HbAA controls aged 1-14 years who attended the Paediatric Haematology and Outpatient clinics of Federal Medical Centre Bida over six months. Data were collected using a semi-structured questionnaire, and participants' length/height, weight, and blood pressure were measured using standard procedures. Blood samples were drawn for serum cystatin C assay via the sandwich enzyme-linked immunosorbent assay (ELISA) technique. Filler's equation was used to calculate the glomerular filtration rate.

RESULTS

There was a significant difference in the mean cystatin C-derived GFR between the two groups, i.e. 116 ± 30mL/min/1.73m2 vs. 106 ± 24mL/min/1.73m2 for the SCA and control groups, respectively (p = 0.017). The prevalence of supernormal GFR (i.e. GFR > 140mL/min/1.73m2) and decreased GFR (i.e. GFR < 90mL/min/1.73m2) was 19.8% and 22.1%, respectively, in children with SCA. There was no significant association between the age at diagnosis of SCA, blood transfusions, blood pressure, packed cell volume and presence of peripheral oedema with decreased GFR in the study subjects.

CONCLUSIONS

Supernormal GFR is common in children with SCA and there is no significant association between clinical features of CKD with decreased GFR. Regular evaluation of renal function is, however, recommended in children with SCA for early detection and treatment of renal complications in order to halt the progression to end-stage kidney disease (ESKD).

Comparison of new computational methods for spatial modelling of malaria

BACKGROUND

Geostatistical analysis of health data is increasingly used to model spatial variation in malaria prevalence, burden, and other metrics. Traditional inference methods for geostatistical modelling are notoriously computationally intensive, motivating the development of newer, approximate methods for geostatistical analysis or, more broadly, computational modelling of spatial processes. The appeal of faster methods is particularly great as the size of the region and number of spatial locations being modelled increases.

METHODS

This work presents an applied comparison of four proposed 'fast' computational methods for spatial modelling and the software provided to implement them-Integrated Nested Laplace Approximation (INLA), tree boosting with Gaussian processes and mixed effect models (GPBoost), Fixed Rank Kriging (FRK) and Spatial Random Forests (SpRF). The four methods are illustrated by estimating malaria prevalence on two different spatial scales-country and continent. The performance of the four methods is compared on these data in terms of accuracy, computation time, and ease of implementation.

RESULTS

Two of these methods-SpRF and GPBoost-do not scale well as the data size increases, and so are likely to be infeasible for larger-scale analysis problems. The two remaining methods-INLA and FRK-do scale well computationally, however the resulting model fits are very sensitive to the user's modelling assumptions and parameter choices. The binomial observation distribution commonly used for disease prevalence mapping with INLA fails to account for small-scale overdispersion present in the malaria prevalence data, which can lead to poor predictions. Selection of an appropriate alternative such as the Beta-binomial distribution is required to produce a reliable model fit. The small-scale random effect term in FRK overcomes this pitfall, but FRK model estimates are very reliant on providing a sufficient number and appropriate configuration of basis functions. Unfortunately the computation time for FRK increases rapidly with increasing basis resolution.

CONCLUSIONS

INLA and FRK both enable scalable geostatistical modelling of malaria prevalence data. However care must be taken when using both methods to assess the fit of the model to data and plausibility of predictions, in order to select appropriate model assumptions and parameters.

Sickle cell anemia and pregnancy: Profile of hemodynamic changes in sickle cell pregnant women in Kinshasa

Pregnancy is accompanied by hormonal changes. These relate mainly to progesterone and placenate growth factor. Hemodynamic changes are also observed. in a sickle cell pregnant woman, all these changes have a direct effect on hypoxia. This is responsible for the polymerization of HbS. The latter causes the sickling of sickle red blood cells. sickling of red blood cells is responsible for hemolysis and vasoocclusion, two major acute manifestations during pregnancy in a sickle cell patient.

Biomarker of Anopheles exposure in Ghanaian children with haemoglobin S and C

Heterozygous carriers of haemoglobin S and C (HbAS and HbAC) have a reduced risk of severe malaria but are not protected from Plasmodium falciparum infection, suggesting that the protection involves acquired immunity. During a blood meal, female Anopheles mosquitoes inject saliva that can elicit a host antibody response, which can serve as a proxy for exposure to Plasmodium infection. Previous studies have shown that the peptide gSG6-P1 of An. gambiae saliva is antigenic and highly Anopheles specific. Here, we used plasma samples from 201 Ghanaian children with wild-type haemoglobin (HbAA), HbAS, and HbAC to evaluate antibody levels against gSG6-P1 as a serological biomarker of Anopheles exposure and, therefore of P. falciparum infection risk. Malaria antigen (PfCSP, GLURP, Pfs230, and HB3VAR06)-specific IgG levels, demographic data, and data regarding P. falciparum infection and malaria control practices were also analysed. Children with active P. falciparum infection had higher antibody levels against all antigens, and those with HbAS and HbAC had significantly higher antibody levels against Pfs230. Pfs230-specific IgG correlated negatively with gSG6-P1-specific IgG in children with HbAC. Our results highlight the importance of studying the role of haemoglobinopathies in malaria transmission to improve control interventions.

Glaucoma in Black Individuals: How Far Have We Come and Where Do We Go From Here?

PURPOSE

To provide updates on the key scientific discoveries made and sociological theories put forth that have allowed for a better understanding of the disproportionate burden of glaucoma among Black individuals, and to provide insights into future directions for this important field of work.

DESIGN

Perspective with a scoping review of the literature.

METHODS

Review, synthesis, and critical appraisal of selected literature on the impact of glaucoma in Black Americans. Important studies within and outside of ophthalmology are considered to allow for a greater understanding of the historical, sociopolitical, and encompassing medical contexts surrounding this complex issue.

RESULTS

A historical overview of key epidemiologic studies highlights the repeated and unequivocal demonstration of increased risk of glaucoma in Black individuals. To begin to understand this multi-layered racial disparity, a historical review of race as a social-legal construct is provided. A careful examination of genetic ancestry is considered as a partial means by which increased glaucoma risk is conferred among Black individuals. The growing body of work examining social determinants as an important driver for racial disparities in glaucoma is also reviewed. Finally, the pitfalls and dangers of race-based medicine are highlighted through illustrative cases before providing insights to future directions.

CONCLUSIONS

Though our understanding of the disparities in glaucoma in Black individuals has grown over the past decades, gaps persist, particularly due to deficient data driven by a lack of studies in this disproportionately burdened group. Though the use of race as a variable may become increasingly less relevant with the rise of precision medicine, it remains a crucial, though flawed concept that continues to be our best means by which to measure, investigate, and intervene upon these disparities in our efforts to achieve health equity.

Plasmodium knowlesi (Pk) Malaria: A Review & Proposal of Therapeutically Rational Exchange (T-REX) of Pk-Resistant Red Blood Cells

Plasmodium knowlesi (Pk) causes zoonotic malaria and is known as the "fifth human malaria parasite". Pk malaria is an emerging threat because infections are increasing and can be fatal. While most infections are in Southeast Asia (SEA), especially Malaysia, travelers frequently visit this region and can present with Pk malaria around the world. So, clinicians need to know (1) patients who present with fever after recent travel to SEA might be infected with Pk and (2) Pk is often misdiagnosed as P. malariae (which typically causes less severe malaria). Here we review the history, pathophysiology, clinical features, diagnosis, and treatment of Pk malaria. Severe disease is most common in adults. Signs and symptoms can include fever, abdominal pain, jaundice, acute kidney injury, acute respiratory distress syndrome, hyponatremia, hyperparasitemia, and thrombocytopenia. Dengue is one of the diseases to be considered in the differential. Regarding pathophysiologic mechanisms, when Pk parasites invade mature red blood cells (RBCs, i.e., normocytes) and reticulocytes, changes in the red blood cell (RBC) surface can result in life-threatening cytoadherence, sequestration, and reduced RBC deformability. Since molecular mechanisms involving the erythrocytic stage are responsible for onset of severe disease and lethal outcomes, it is biologically plausible that manual exchange transfusion (ET) or automated RBC exchange (RBCX) could be highly beneficial by replacing "sticky" parasitized RBCs with uninfected, deformable, healthy donor RBCs. Here we suggest use of special Pk-resistant donor RBCs to optimize adjunctive manual ET/RBCX for malaria. "Therapeutically-rational exchange transfusion" (T-REX) is proposed in which Pk-resistant RBCs are transfused (instead of disease-promoting RBCs). Because expression of the Duffy antigen on the surface of human RBCs is essential for parasite invasion, T-REX of Duffy-negative RBCs-also known as Fy(a-b-) RBCs-could replace the majority of the patient's circulating normocytes with Pk invasion-resistant RBCs (in a single procedure lasting about 2 h). When sequestered or non-sequestered iRBCs rupture-in a 24 h Pk asexual life cycle-the released merozoites cannot invade Fy(a-b-) RBCs. When Fy(a-b-) RBC units are scarce (e.g., in Malaysia), clinicians can consider the risks and benefits of transfusing plausibly Pk-resistant RBCs, such as glucose-6-phosphate dehydrogenase deficient (G6PDd) RBCs and Southeast Asian ovalocytes (SAO). Patients typically require a very short recovery time (<1 h) after the procedure. Fy(a-b-) RBCs should have a normal lifespan, while SAO and G6PDd RBCs may have mildly reduced half-lives. Because SAO and G6PDd RBCs come from screened blood donors who are healthy and not anemic, these RBCs have a low-risk for hemolysis and do not need to be removed after the patient recovers from malaria. T-REX could be especially useful if (1) antimalarial medications are not readily available, (2) patients are likely to progress to severe disease, or (3) drug-resistant strains emerge. In conclusion, T-REX is a proposed optimization of manual ET/RBCX that has not yet been utilized but can be considered by physicians to treat Pk malaria patients.

Simultaneous adjunctive treatment of malaria and its coevolved genetic disorder sickle cell anemia

Effective treatments for genetic disorders that coevolved with pathogens require simultaneous betterment of both conditions. Hydroxyurea (HU) offers safe and efficacious treatment for sickle cell anemia (SCA) by reducing clinical complications, transfusions, and death rates. Despite concerns that the HU treatment for SCA would increase infection risk by the human malaria Plasmodium falciparum, (the genetic driver of the sickle mutation), HU instead reduced clinical malaria. We used physiologically relevant drug exposures that mimic in vivo pharmacokinetics in humans. Under these conditions, we showed that HU and other ribonucleotide reductase (RNR) inhibitors have significant, intrinsic killing activity in vitro against schizont stages of P falciparum in both normal and sickle red blood cells. Long-term in vitro selection with HU increased the expression of Pfrnr genes but showed a low risk of eliciting stably resistant parasites or compromising the potency of current antimalarial drugs. Additive activity devoid of antagonism by HU was observed with a wide spectrum of commonly used antimalarial treatments. These data endorse broad, safe, and long-term use of HU for SCA in malaria-endemic countries and provide a novel biological model for the treatment of a genetic disorder with simultaneous, adjunct therapy of a life-threatening infection needed in a global health setting.

Phylogenomics reveals the history of host use in mosquitoes

Mosquitoes have profoundly affected human history and continue to threaten human health through the transmission of a diverse array of pathogens. The phylogeny of mosquitoes has remained poorly characterized due to difficulty in taxonomic sampling and limited availability of genomic data beyond the most important vector species. Here, we used phylogenomic analysis of 709 single copy ortholog groups from 256 mosquito species to produce a strongly supported phylogeny that resolves the position of the major disease vector species and the major mosquito lineages. Our analyses support an origin of mosquitoes in the early Triassic (217 MYA [highest posterior density region: 188-250 MYA]), considerably older than previous estimates. Moreover, we utilize an extensive database of host associations for mosquitoes to show that mosquitoes have shifted to feeding upon the blood of mammals numerous times, and that mosquito diversification and host-use patterns within major lineages appear to coincide in earth history both with major continental drift events and with the diversification of vertebrate classes.

Prevalence and Risk Factors of Neonatal Hyperbilirubinemia in a Semi-Rural Area of the Democratic Republic of Congo: A Cohort Study

Neonatal hyperbilirubinemia (NH) is a frequent condition that, if left untreated, can lead to neurological disability and death. We assessed the prevalence of NH and associated neonatal and maternal risk factors in 362 mothers and 365 newborns in a semi-rural area of the Democratic Republic of Congo. In addition, we explored the knowledge and practices of mothers regarding this condition. We collected demographic data, anthropometric data, and obstetric and medical anamneses. We examined newborns at birth and at 24, 48, and 72 hours and measured bilirubin at birth in umbilical cord and capillary blood and thereafter in capillary blood. Hemoglobin, hematocrit, ABO group, Rhesus factor, glucose-6-phosphate dehydrogenase (G6PD) deficiency, Hemoglobin S (HbS), and malaria were assessed in mothers and newborns. Among 296 newborns (all time points available), 5.7% developed NH (95% CI: 3.4-9.0) between 24 and 72 hours according to National Institute for Health and Care Excellence (NICE) UK guidelines. There was a significantly higher risk in newborns with G6PD deficiency (homo- and hemizygous adjusted Odd Ratio [aOR]: 21.0, 95% CI: 4.1-105.9), preterm births (aOR: 6.1, 95% CI: 1.4-26.9), newborns with excessive birth weight loss (aOR: 5.8, 95% CI: 1.4-23.2), and hyperbilirubinemia at birth (aOR: 14.8, 95% CI: 2.7-79.6). Newborns with feto-maternal ABO incompatibility and G6PD deficiency had significantly higher bilirubin at birth than others. More than 60% of mothers had adequate knowledge of NH, but compliance with phototherapy in the absence of symptoms was low. Although risk factors for NH are common in this area, prevalence was not high, suggesting a need for better case definition. Implementation of point-of-care devices for diagnosis and awareness programs on risk prevention could help reduce neonatal morbidity and mortality associated with hyperbilirubinemia in these areas.

Genetic Variation and Sickle Cell Disease Severity: A Systematic Review and Meta-Analysis

Importance

Sickle cell disease (SCD) is a monogenic disorder, yet clinical outcomes are influenced by additional genetic factors. Despite decades of research, the genetics of SCD remain poorly understood.

Objective

To assess all reported genetic modifiers of SCD, evaluate the design of associated studies, and provide guidelines for future analyses according to modern genetic study recommendations.

Data Sources

PubMed, Web of Science, and Scopus were searched through May 16, 2023, identifying 5290 publications.

Study Selection

At least 2 reviewers identified 571 original, peer-reviewed English-language publications reporting genetic modifiers of human SCD phenotypes, wherein the outcome was not treatment response, and the comparison was not between SCD subtypes or including healthy controls.

Data Extraction and Synthesis

Data relevant to all genetic modifiers of SCD were extracted, evaluated, and presented following STREGA and PRISMA guidelines. Weighted z score meta-analyses and pathway analyses were conducted.

Main Outcomes and Measures

Outcomes were aggregated into 25 categories, grouped as acute complications, chronic conditions, hematologic parameters or biomarkers, and general or mixed measures of SCD severity.

Results

The 571 included studies reported on 29 670 unique individuals (50% ≤ 18 years of age) from 43 countries. Of the 17 757 extracted results (4890 significant) in 1552 genes, 3675 results met the study criteria for meta-analysis: reported phenotype and genotype, association size and direction, variability measure, sample size, and statistical test. Only 173 results for 62 associations could be cross-study combined. The remaining associations could not be aggregated because they were only reported once or methods (eg, study design, reporting practice) and genotype or phenotype definitions were insufficiently harmonized. Gene variants regulating fetal hemoglobin and α-thalassemia (important markers for SCD severity) were frequently identified: 19 single-nucleotide variants in BCL11A, HBS1L-MYB, and HBG2 were significantly associated with fetal hemoglobin (absolute value of Z = 4.00 to 20.66; P = 8.63 × 10-95 to 6.19 × 10-5), and α-thalassemia deletions were significantly associated with increased hemoglobin level and reduced risk of albuminuria, abnormal transcranial Doppler velocity, and stroke (absolute value of Z = 3.43 to 5.16; P = 2.42 × 10-7 to 6.00 × 10-4). However, other associations remain unconfirmed. Pathway analyses of significant genes highlighted the importance of cellular adhesion, inflammation, oxidative and toxic stress, and blood vessel regulation in SCD (23 of the top 25 Gene Ontology pathways involve these processes) and suggested future research areas.

Conclusions and Relevance

The findings of this comprehensive systematic review and meta-analysis of all published genetic modifiers of SCD indicated that implementation of standardized phenotypes, statistical methods, and reporting practices should accelerate discovery and validation of genetic modifiers and development of clinically actionable genetic profiles.

Understanding Sickle cell disease: Causes, symptoms, and treatment options

Sickle cell disease (SCD) is a hereditary blood disorder characterized by the production of abnormal hemoglobin molecules that cause red blood cells to take on a crescent or sickle shape. This condition affects millions of people worldwide, particularly those of African, Mediterranean, Middle Eastern, and South Asian descent. This paper aims to provide an overview of SCD by exploring its causes, symptoms, and available treatment options. The primary cause of SCD is a mutation in the gene responsible for producing hemoglobin, the protein that carries oxygen in red blood cells. This mutation has abnormal hemoglobin called hemoglobin S, which causes red blood cells to become stiff and sticky, leading to various health complications. Patients with SCD may experience recurrent pain, fatigue, anemia, and increased infection susceptibility. Treatment options for SCD focus on managing symptoms and preventing complications. This includes pain management with analgesics, hydration, and blood transfusions to improve oxygen delivery. Hydroxyurea, a medication that increases the production of fetal hemoglobin, is commonly used to reduce the frequency and severity of pain crises. Additionally, bone marrow or stem cell transplants can cure select individuals with severe SCD. Finally, understanding the causes, symptoms, and treatment options for SCD is crucial for healthcare professionals, patients, and their families. It enables early diagnosis, effective symptom management, and improved quality of life for individuals with this chronic condition.

Gene Therapy for Hemoglobinopathies

β-Thalassemia and sickle cell disease are autosomal recessive disorders of red blood cells due to mutations in the adult β-globin gene, with a worldwide diffusion. The severe forms of hemoglobinopathies are fatal if untreated, and allogeneic bone marrow transplantation can be offered to a limited proportion of patients. The unmet clinical need and the disease incidence have promoted the development of new genetic therapies based on the engineering of autologous hematopoietic stem cells. Here, the steps of ex vivo gene therapy development are reviewed along with results from clinical trials and recent new approaches employing cutting edge gene editing tools.

A Journey from Blood Cells to Genes and Back

I was attracted to hematology because by combining clinical findings with the use of a microscope and simple laboratory tests, one could often make a diagnosis. I was attracted to genetics when I learned about inherited blood disorders, at a time when we had only hints that somatic mutations were also important. It seemed clear that if we understood not only what genetic changes caused what diseases but also the mechanisms through which those genetic changes contribute to cause disease, we could improve management. Thus, I investigated many aspects of the glucose-6-phosphate dehydrogenase system, including cloning of the gene, and in the study of paroxysmal nocturnal hemoglobinuria (PNH), I found that it is a clonal disorder; subsequently, we were able to explain how a nonmalignant clone can expand, and I was involved in the first trial of PNH treatment by complement inhibition. I was fortunate to do clinical and research hematology in five countries; in all of them, I learned from mentors, from colleagues, and from patients.

Sickle Cell Disease: From Genetics to Curative Approaches

Sickle cell disease (SCD) is a monogenic blood disease caused by a point mutation in the gene coding for β-globin. The abnormal hemoglobin [sickle hemoglobin (HbS)] polymerizes under low-oxygen conditions and causes red blood cells to sickle. The clinical presentation varies from very severe (with acute pain, chronic pain, and early mortality) to normal (few complications and a normal life span). The variability of SCD might be due (in part) to various genetic modulators. First, we review the main genetic factors, polymorphisms, and modifier genes that influence the expression of globin or otherwise modulate the severity of SCD. Considering SCD as a complex, multifactorial disorder is important for the development of appropriate pharmacological and genetic treatments. Second, we review the characteristics, advantages, and disadvantages of the latest advances in gene therapy for SCD, from lentiviral-vector-based approaches to gene-editing strategies.

Impact and burden of sickle cell disease in critically ill obstetric patients in a high dependency unit in Sierra Leone-a registry based evaluation

INTRODUCTION

Sickle cell disease (SCD) in pregnancy is associated with worse maternal and neonatal outcomes. There is limited available data describing the burden and outcomes of critically ill obstetric patients affected by SCD in low-income settings.

OBJECTIVES

We aimed to define SCD burden and impact on mortality in critically-ill obstetric patients admitted to an urban referral hospital in Sierra Leone. We hypothesized that SCD burden is high and independently associated with increased mortality.

METHODS

We performed a registry-based cross-sectional study from March 2020 to December 2021 in the high-dependency unit (HDU) of Princess Christian Maternity Hospital PCMH, Freetown. Primary endpoints were the proportion of patients identified in the SCD group and HDU mortality. Secondary endpoints included frequency of maternal direct obstetric complications (MDOCs) and the maternal early obstetric warning score (MEOWS).

RESULTS

Out of a total of 497 patients, 25 (5.5%) qualified to be included in the SCD group. MEOWS on admission was not different between patients with and without SCD and SCD patients had also less frequently reported MDOCs. Yet, crude HDU mortality in the SCD group was 36%, compared to 9.5% in the non SCD group (P < 0.01), with an independent association between SCD group exposure and mortality when accounting for severity on admission (hazard ratio 3.40; 95%CI 1.57-7.39; P = 0.002). Patients with SCD had a tendency to longer HDU length of stay.

CONCLUSIONS

One out of twenty patients accessing a HDU in Sierra Leone fulfilled criteria for SCD. Despite comparable severity on admission, mortality in SCD patients was four times higher than patients without SCD. Optimization of intermediate and intensive care for this group of patients should be prioritized in low-resource settings with high maternal mortality.

Hemoglobinopathies, merozoite surface protein-2 gene polymorphisms, and acquisition of Epstein Barr virus among infants in Western Kenya

BACKGROUND

Epstein Barr virus (EBV)-associated endemic Burkitt's Lymphoma pediatric cancer is associated with morbidity and mortality among children resident in holoendemic Plasmodium falciparum regions in western Kenya. P. falciparum exerts strong selection pressure on sickle cell trait (SCT), alpha thalassemia (-α3.7/αα), glucose-6-phosphate dehydrogenase (G6PD), and merozoite surface protein 2 (MSP-2) variants (FC27, 3D7) that confer reduced malarial disease severity. The current study tested the hypothesis that SCT, (-α3.7/αα), G6PD mutation and (MSP-2) variants (FC27, 3D7) are associated with an early age of EBV acquisition.

METHODS

Data on infant EBV infection status (< 6 and ≥ 6-12 months of age) was abstracted from a previous longitudinal study. Archived infant DNA (n = 81) and mothers DNA (n = 70) samples were used for genotyping hemoglobinopathies and MSP-2. The presence of MSP-2 genotypes in maternal DNA samples was used to indicate infant in-utero malarial exposure. Genetic variants were determined by TaqMan assays or standard PCR. Group differences were determined by Chi-square or Fisher's analysis. Bivariate regression modeling was used to determine the relationship between the carriage of genetic variants and EBV acquisition.

RESULTS

EBV acquisition for infants < 6 months was not associated with -α3.7/αα (OR = 1.824, P = 0.354), SCT (OR = 0.897, P = 0.881), or G6PD [Viangchan (871G > A)/Chinese (1024 C > T) (OR = 2.614, P = 0.212)] and [Union (1360 C > T)/Kaiping (1388G > A) (OR = 0.321, P = 0.295)]. There was no relationship between EBV acquisition and in-utero exposure to either FC27 (OR = 0.922, P = 0.914) or 3D7 (OR = 0.933, P = 0.921). In addition, EBV acquisition in infants ≥ 6-12 months also showed no association with -α3.7/αα (OR = 0.681, P = 0.442), SCT (OR = 0.513, P = 0.305), G6PD [(Viangchan (871G > A)/Chinese (1024 C > T) (OR = 0.640, P = 0.677)], [Mahidol (487G > A)/Coimbra (592 C > T) (OR = 0.948, P = 0.940)], [(Union (1360 C > T)/Kaiping (1388G > A) (OR = 1.221, P = 0.768)], African A (OR = 0.278, P = 0.257)], or in utero exposure to either FC27 (OR = 0.780, P = 0.662) or 3D7 (OR = 0.549, P = 0.241).

CONCLUSION

Although hemoglobinopathies (-α3.7/αα, SCT, and G6PD mutations) and in-utero exposure to MSP-2 were not associated with EBV acquisition in infants 0-12 months, novel G6PD variants were discovered in the population from western Kenya. To establish that the known and novel hemoglobinopathies, and in utero MSP-2 exposure do not confer susceptibility to EBV, future studies with larger sample sizes from multiple sites adopting genome-wide analysis are required.

Evolutionary psychiatry: foundations, progress and challenges

Evolutionary biology provides a crucial foundation for medicine and behavioral science that has been missing from psychiatry. Its absence helps to explain slow progress; its advent promises major advances. Instead of offering a new kind of treatment, evolutionary psychiatry provides a scientific foundation useful for all kinds of treatment. It expands the search for causes from mechanistic explanations for disease in some individuals to evolutionary explanations for traits that make all members of a species vulnerable to disease. For instance, capacities for symptoms such as pain, cough, anxiety and low mood are universal because they are useful in certain situations. Failing to recognize the utility of anxiety and low mood is at the root of many problems in psychiatry. Determining if an emotion is normal and if it is useful requires understanding an individual's life situation. Conducting a review of social systems, parallel to the review of systems in the rest of medicine, can help achieve that understanding. Coping with substance abuse is advanced by acknowledging how substances available in modern environments hijack chemically mediated learning mechanisms. Understanding why eating spirals out of control in modern environments is aided by recognizing the motivations for caloric restriction and how it arouses famine protection mechanisms that induce binge eating. Finally, explaining the persistence of alleles that cause serious mental disorders requires evolutionary explanations of why some systems are intrinsically vulnerable to failure. The thrill of finding functions for apparent diseases is evolutionary psychiatry's greatest strength and weakness. Recognizing bad feelings as evolved adaptations corrects psychiatry's pervasive mistake of viewing all symptoms as if they were disease manifestations. However, viewing diseases such as panic disorder, melancholia and schizophrenia as if they are adaptations is an equally serious mistake in evolutionary psychiatry. Progress will come from framing and testing specific hypotheses about why natural selection left us vulnerable to mental disorders. The efforts of many people over many years will be needed before we will know if evolutionary biology can provide a new paradigm for understanding and treating mental disorders.

Evolutionary Selection of APOEɛ4 Encourages Increased Focus on Immunity in Alzheimer's Disease

Smith and Ashford present a compelling hypothesis on evolution of APOE alleles, namely that ɛ4 prevalence is mediated by immune selection pressure against enteric pathogens. While the ɛ3 allele is more prevalent today, it outcompetedɛ4 only relatively recently, as immune selection pressure for more effective immune responses to such pathogens was alleviated with transition to agrarian from hunter-gatherer lifestyles. Smith and Ashford's hypothesis is intriguing in itself, but the implications for APOE ɛ4 function in Alzheimer's disease are even more so and encourage greater focus on specific aspects of immunity in accounting for both ɛ4-mediated and general Alzheimer's disease risk.