Implementing neonatal screening for haemoglobinopathies in the Netherlands

Screening for sickle cell disease: focus on newborn investigations

Drepanocytosis is a genetic disease relevant for its epidemiological, clinical and socio-economic aspects. In our country the prevalence is highly uneven with peaks in former malaria areas, but migration flows in recent years have led to significant changes. In this document we review the screening programs currently existing in Italy with particular emphasis on newborn screening, which in other countries around the world, including within Europe, is at most universal and mandatory. The essential laboratory issues are reviewed, from sampling aspects (cord blood or peripheral), to the analytical (analytical methods dedicated to neonatal screening and adult carrier detection) and post analytical (reporting, informative) ones. An economic analysis based on data collected in the province of Modena is also proposed, clearly showing that neonatal screening is also beneficial from an economic point of view.

The association between obstructive sleep apnea and stroke in sickle-cell disease children

INTRODUCTION

The prevalence of stroke in SCD patients was reported to be around 4%; however, the pediatric category was among the higher risk group for stroke compared to young and middle age adults. Furthermore, the risk of OSA increases in SCD children. The objective of this study is to calculate the prevalence of stroke in children with SCD with and without obstructive sleep apnea.

METHOD

This is a cross-sectional study held at two major tertiary hospitals in Jeddah, Saudi Arabia. Inclusion criteria included patients aged between 2 and 18 at the time of enrollment with confirmed SCD. The primary outcome of the study was at least one documented episode of stroke over the last 3 years. OSA was assessed using PSQ.

RESULTS

A total of 150 children with SCD were included in the study. The mean age was 9.6 (±4.3). Most of the sample (85.3%) were sickle-cell anemia with HbSS. Children who were positive for OSA were at higher odds of having a stroke [OR 2.97; 95% CI 1.13-7.75 (P = 0.02)]. The relationship between OSA and stroke was not significant in the multivariant analysis.

CONCLUSION

Patients who had OSA had a higher prevalence of stroke compared to non-OSA patients by 16% with almost three times higher odds. The difference was statistically significant in bivariant but not multivariant analysis. The rate of hospitalization, emergency visit, and blood transfusion were not affected by OSA status. Screening for OSA in high-risk patients such as SCD children and early management could prevent the risk of SCD complications.

Health-Related Quality of Life of Children and Adolescents with Sickle Cell Disease in the Middle East and North Africa Region: A systematic review

Sickle cell disease (SCD) can significantly impair the health-related quality of life (HRQOL) of children and adolescents. This review aimed to assess current evidence regarding the HRQOL of children and adolescents with SCD in the Middle East and North Africa region. A systematic search of various databases was conducted to identify relevant articles, including MEDLINE^® (National Library of Medicine, Bethesda, Maryland, USA), Scopus^® (Elsevier, Amsterdam, the Netherlands), Cumulative Index to Nursing and Allied Health Literature^®, Masader (Oman Virtual Science Library, Muscat, Oman) and EBSCOhost (EBSCO Information Services, Ipswich, Massachusetts, USA). A total of 533 articles were identified; however, only 10 were eligible for inclusion in the final analysis. Results from these studies showed that children and adolescents with SCD had compromised HRQOL compared to their healthy peers, particularly in terms of physical, psychosocial, familial, financial and academic functioning. Therefore, interventions are necessary to improve overall HRQOL outcomes for this population.

A demographic prevalence of β Thalassemia carrier and other hemoglobinopathies in adolescent of Tharu population

BACKGROUND AND AIMS

Hemoglobinopathies and thalassemias are the commonest single gene disorders in India. In Terai region of India, Hemoglobinopathies and thalassemias are the most common in the Tharu community. Therefore, in this study, we aim to evaluate the Hb variant analysis of hemoglobinopathies and thalassemias in a Tharu population in Lakhimpur Kheri Districts of Uttar Pradesh, India.

MATERIALS AND METHODS

Total 493 individuals were recruited in this study. The demographic details and blood samples were collected from different location at Kheri district during mega health camp. Hb variant analysis was performed by high performance liquid chromatography (HPLC) system beta thalassemia short program in BIO-RAD VARIANT.

RESULTS

Out of 493, 108 (21.9%) individual suffers with abnormal haemoglobinopathies. In which β-thalassemia trait is the commonest haemoglobinopathy (12.98%), followed by HbE trait (7.50%), and compound heterozygous HbS/β-Thalassemia trait (1.42%) in overall population. The HbF was significantly greater in HbS heterozygous (1.45 ± 1.41), whereas mean HbA2 was significantly greater in β-Thalassemia trait (5.17 ± 1.36).

CONCLUSION

The high incidence of hemoglobinopathies and thalassemias were observed in Tharu community in Lakhimpur Kheri districts of Uttar Pradesh, Indian.

Recent advances in screening and diagnosis of hemoglobinopathy

Introduction: Hemoglobinopathies are important causes of inherited disorders with substantial mortality and morbidity across the world. Therefore, proper utilization of available screening and diagnostic techniques are important for its diagnosis and management.Areas covered: In this review, the authors attempt to summarize clinical presentations, give a brief account of existing techniques, and discuss evolving and advanced techniques for detection and screening of the condition. As prevention of the disease condition is an important community measure to control the disease, techniques involving newborn screening, antenatal diagnosis, and point of care tests have been described in addition to more advanced molecular and protein diagnostics. The literature search in this area is covered between 1980 and 2018 with PubMed as the main source along with authors' own research in this area.Expert opinion: Screening and detection of hemoglobinopathy is best accomplished by a hierarchical approach with the optimum blend of old and newer techniques. Starting with point of care techniques through the commonly used HPLC and high voltage capillary electrophoresis, or modern and high throughput molecular biology and mass spectroscopic techniques can be used depending on specific situations. Every country needs to optimize its techniques depending on the frequency of the problem and available resources.

Results of a multicenter universal newborn screening program for sickle cell disease in Italy: A call to action

BACKGROUND

Sickle cell disease (SCD) is a chronic multisystem disorder requiring comprehensive care that includes newborn screening (NBS) as the first step of care. Italy still lacks a national SCD NBS program and policy on blood disorders. Pilot single-center screening programs and a regional targeted screening have been implemented so far, but more evidence is needed in order to impact health policies.

POPULATION AND METHODS

NBS was offered to parents of newborns in gynecology clinics in Padova and Monza, tertiary care university hospitals in northern Italy. High-performance liquid chromatography (HPLC) was performed as the first test on samples collected on Guthrie cards. Molecular analysis of the beta-globin gene was performed on positive samples.

RESULTS

A total of 5466 newborns were enrolled; for 5439, informed consents were obtained. A similar family origin was seen in the two centers (65% Italians, 9% mixed couples, 26% immigrants). Compared with SCD NBS programs in the United States and Europe, our results show a similar incidence of SCD patients and carriers. All SCD patients had a Sub-Saharan family background; HbS carriers were 15% Caucasians (Italian, Albanians) and 10% from other areas (North Africa-India-South America); carriers of other hemoglobin variants were mainly (47%) from other areas.

CONCLUSIONS

Our results demonstrate the feasibility of a multicentric NBS program for SCD, give information on HbS epidemiology in two Northern Italian Areas, and support previous European recommendation for a universal NBS program for SCD in Italy: a high incidence of patients and carriers has been detected, with a high percentage of Caucasian carriers, impossible to identify in a targeted NBS.

Evaluation of Technical Issues in a Pilot Multicenter Newborn Screening Program for Sickle Cell Disease

A multicenter pilot program for universal newborn screening of Sickle cell disease (SCD) was conducted in two centres of Northern Italy (Padova and Monza). High Performance Liquid Chromatography (HPLC) was performed as the first test on samples collected on Guthrie cards and molecular analysis of the β-globin gene (HBB) was the confirmatory test performed on the HPLC-positive or indeterminate samples. 5466 samples of newborns were evaluated. Of these, 5439/5466 were submitted to HPLC analysis and the molecular analysis always confirmed in all the alteration detected in HPLC (62/5439 newborns); 4/5439 (0.07%) were SCD affected, 37/5439 (0.68%) were HbAS carriers and 21/5439 (0.40%) showed other hemoglobinopathies. Stored dried blood spots were adequate for HPLC and β-globin gene molecular analysis. Samples were suitable for analysis until sixteen months old. A cut-off of A₁ percentage, in order to avoid false negative or unnecessary confirmation tests, was identified. Our experience showed that several technical issues need to be addressed and resolved while developing a multicenter NBS program for SCD in a country where there is no national neonatal screening (NBS) program for SCD and NBS programs occur on a regional basis.

Newborn Screening for Sickle Cell Disease in Europe

The history of newborn screening (NBS) for sickle cell disease (SCD) in Europe goes back almost 40 years. However, most European countries have not established it to date. The European screening map is surprisingly heterogenous. The first countries to introduce sickle cell screening on a national scale were France and England. The French West Indies started to screen their newborns for SCD as early as 1983/84. To this day, all countries of the United Kingdom of Great Britain and Northern Ireland have added SCD as a target disease to their NBS programs. The Netherlands, Spain and Malta also have national programs. Belgium screens regionally in the Brussels and Liège regions, Ireland has been running a pilot for many years that has become quasi-official. However, the Belgian and Irish programs are not publicly funded. Italy and Germany have completed several pilot studies but are still in the preparatory phase of national NBS programs for SCD, although both countries have well-established concepts for metabolic and endocrine disorders. This article will give a brief overview of the situation in Europe and put a focus on the programs of the two pioneers of the continent, England and France.

Newborn Screening for Sickle Cell Disease and Other Hemoglobinopathies: A Short Review on Classical Laboratory Methods-Isoelectric Focusing, HPLC, and Capillary Electrophoresis

Sickle cell disease (SCD) and other hemoglobinopathies are a major health concern with a high burden of disease worldwide. Since the implementation of newborn screening (NBS) for SCD and other hemoglobinopathies in several regions of the world, technical progress of laboratory methods was achieved. This short review aims to summarize the current practice of classical laboratory methods for the detection of SCD and other hemoglobinopathies. This includes the newborn screening technologies of high-performance liquid chromatography (HPLC), capillary electrophoresis (CE), and isoelectric focusing (IEF).

New approach to accurate interpretation of sickle cell disease newborn screening by applying multiple of median cutoffs and ratios

BACKGROUND

The main goal of newborn screening (NBS) for sickle cell disease (SCD) is to detect affected neonates so that specific preventive care can be implemented. High-performance liquid chromatography (HPLC) used for NBS has high sensitivity and specificity, but we lack guidelines for quantitative hemoglobin (Hb) fraction interpretation. The purpose of this study was to determine cutoff values to standardize quantitative interpretation in SCD NBS for different clinical situation such as, red blood cell transfusion or beta-thalassemia, which can be real screening pitfalls.

METHODS

Retrospective study of 75,026 samples from the neonatal screening program analyzed in our laboratory. Precise HbA and HbS percentages at birth were recorded and median values established for each gestational age, allowing percentage results to be expressed in normal gestation-specific multiples of the median (MoM). Three threshold values of clinical interest were determined.

RESULTS

High levels of HbA (>2.5 MoM) allowed identification of newborns who received transfusions. Low levels of HbS (≤0.7 MoM) allowed detection of the association between HbS and other mutations of the beta-globin gene (i.e., HbHope, β0-thalassemia, etc.). An HbA/HbS ratio <0.5 to distinguish healthy carriers from SCD with S/β+-thalassemia. The screening accuracy for each threshold was established. The screening accuracy of low-level HbA, which is determinant in identifying the subgroup of patients at risk of β-thalassemia, will be determined prospectively.

CONCLUSIONS

This new approach introduces tools for a quantitative interpretation in SCD NBS by HPLC methods and could allow standardization of interpretation between centers.

Population Screening for Hemoglobinopathies

Hemoglobinopathies are the most common single-gene disorders in the world. Their prevalence is predicted to increase in the future, and low-income hemoglobinopathy-endemic regions need to manage most of the world's affected persons. International organizations, governments, and other stakeholders have initiated national or regional prevention programs in both endemic and nonendemic countries by performing population screening for α- and β-thalassemia, HbE disease, and sickle cell disease in neonates, adolescents, reproductive-age adults (preconceptionally or in the early antenatal period), and family members of diagnosed cases. The main aim of screening is to reduce the number of affected births and, in the case of sickle cell disease, reduce childhood morbidity and mortality. Screening strategies vary depending on the population group, but a few common screening test methods are universally used. We discuss the salient features of population-screening programs around the globe as well as current and proposed screening test methodologies.

The Prevalence of Sickle Cell Disease and Its Implication for Newborn Screening in Germany (Hamburg Metropolitan Area)

Sickle cell disease is among hereditary diseases with evidence that early diagnoses and treatment improves the clinical outcome. So far sickle cell disease has not been included in the German newborn screening program despite immigration from countries with populations at risk. To determine the birth prevalence we tested 17,018 newborns. High pressure liquid chromatography and subsequent molecular-genetic testing were used for the detection and confirmation of hemoglobin variants. The frequency of sickle cell disease-consistent genotypes was one in 2,385 newborns. Duffy-blood group typing showed evidence that affected children were likely of Sub-Saharan ancestry. An inclusion of sickle cell disease into the German newborn screening seems reasonable.

Universal screening for hemoglobinopathies in today's multi-ethnic societies: How and when

Increasing multi-ethnicity in countries endemic or non-endemic for hemoglobinopathies has brought fundamental changes to the screening strategies for these traits. While in the past pre-screening on microcytosis was a reasonable method to economize upon follow up analysis, selecting low mean corpuscular volume means today missing all those normocytic carriers of common traits associated with severe conditions. Therefore, blood count should not be considered as a pre-selection tool but as additional information to be used for the interpretation of the provisional results, obtained by routine high throughput separation and measurement of the hemoglobin (Hb) fractions. Moreover, the moment of screening should be well planned depending on the social and cultural situation. Screening for genetic diseases in a modern multi-ethnic society should be offered to couples seeking progeny when both partners are more likely to be equally concerned with the good health of their children. In several societies screening before marriage and changing partner choice is culturally accepted. However, new generations are bound to disagree with these more or less imposed conditions and may decide not to renounce the choice of their partner asking for other preventive methods. In addition, a carrier state during pre-marital screening may in some cultures stigmatize the carrier, mostly the female with adverse social consequences. Therefore, screening for hemoglobinopathies early in pregnancy is the most sensible alternative in modern countries. Adding hemoglobinopathies to the routine rhesus screening using a simple separation of the Hb fractions on dedicated devices (high performance liquid chromatography or capillary electrophoresis) will virtually identify all female carriers of all common traits responsible for the severe conditions mainly sickle cell disease and thalassemia major in time for partner analysis, counseling and primary prevention.

Feasibility of a newborn screening and follow-up programme for sickle cell disease among South Gujarat (India) tribal populations

OBJECTIVES

To evaluate the feasibility of a newborn screening and follow-up programme for sickle cell disease (SCD) among tribal populations of south Gujarat, India.

METHODS

A total of 5467 newborn babies were screened over 2 years using High-performance liquid chromatography, with diagnosis by molecular analysis. The SCD babies were followed-up clinically and haematologically regularly for 1.5 to 5 years to describe the course of the disease.

RESULTS

Thirty-three babies (0.60%) were sickle homozygous, 13 (0.23%) were-sickle-β-thalassaemia, 687 (12.5%) were sickle heterozygous, and 4736 were unaffected. The parents of SCD babies were educated and counselled for home care. There were 32 babies (69.5%) who could be clinically and haematologically followed-up; 7 babies (21.8%) presented with severe clinical complications, whereas 18 (56.2%) babies were asymptomatic till the last follow-up. The variation in clinical presentation was seen in spite of the presence of ameliorating factors, such as high fetal haemoglobin, Xmn-I polymorphism, and α-thalassaemia.

CONCLUSION

In addition to demonstrating the possibility of establishing a newborn screening programme for sickle cell disorders among tribal populations, this study has shown that the disease is not always mild among tribal groups in India, as previously believed. There is a need, therefore, for increasing awareness among these tribal groups about the disease, and for regular monitoring of affected babies to reduce morbidity and mortality and to understand the natural course of the disease.

Newborn screening for sickle cell disease: technical and legal aspects of a German pilot study with 38,220 participants

Sickle cell disease (SCD) does not occur in the indigenous German population, but with the increasing number of immigrants from countries at high risk for hemoglobinopathies, the question emerges whether or not a newborn screening program (NBS) for SCD disease should be initiated in Germany anyhow. We have recently shown that in Berlin, a city with a very large immigrant population, the incidence of SCD is considerable, but our findings are insufficient to make a decision for the country as a whole. In this paper we will show that a large body of epidemiological data can be generated in a relatively short period of time, with a very high degree of precision and at relatively little expense--a result that might motivate other working groups to start such a pilot project locally. We examined previously collected dried blood cards that were up to six months old, using high performance liquid chromatography (HPLC) as first method and capillary electrophoresis (CE) as second method. A single, part-time laboratory technician processed 38,220 samples in a period of 162 working days. The total costs per sample including all incidentals (as well as labor costs) were EUR 1.44.

Genetic epidemiology and preventive healthcare in multiethnic societies: the hemoglobinopathies

Healthy carriers of severe Hemoglobinopathies are usually asymptomatic and only efficiently detected through screening campaigns. Based upon epidemiological data, screenings have been offered for decades to populations of endemic Southern Europe for primary prevention of Thalassemia Major, while for many populations of the highly endemic African and Asian countries prevention for Sickle Cell Disease and Thalassemia Major is mainly unavailable. The massive migrations of the last decades have brought many healthy carriers of these diseases to live and reproduce in non-endemic immigration areas changing the epidemiological pattern of the local recessive diseases and bringing an urgent need for treatment and primary prevention in welfare countries. Nonetheless, no screening for an informed reproductive choice is actively offered by the healthcare systems of most of these welfare countries. As a consequence more children affected with severe Hemoglobinopathies are born today in the immigration countries of Northern Europe than in the endemic Southern European area. Following the Mediterranean example, some countries like the UK and The Netherlands have been offering early pregnancy carrier screening at different levels and/or in specific areas but more accessible measures need to be taken at the national level in all immigration countries. Identification of carriers using simple and inexpensive methods should be included in the Rhesus and infectious diseases screening which is offered early in pregnancy in most developed countries. This would allow identification of couples at risk in time for an informed choice and for prenatal diagnosis if required before the first affected child is born.

Incidence of sickle cell disease in an unselected cohort of neonates born in Berlin, Germany

Sickle cell disease (SCD) does not occur in the indigenous German population. However, with the increasing numbers of immigrants its prevalence is steadily rising. Nevertheless, robust epidemiological data is not available for Germany and, consequently, the German newborn screening (NBS) program does not include SCD. Between 1 September 2011 and 30 November 2012, an unselected cohort of 34,084 Berlin newborns was tested for SCD. The results of 14 newborns were consistent with SCD and 265 babies were identified as hemoglobin S (Hb S) carriers. These data indicate a 95% probability that the incidence of SCD in Berlin is at least 2.5/10,000.

Organizing national responses for rare blood disorders: the Italian experience with sickle cell disease in childhood

Background

Sickle cell disease (SCD) is the most frequent hemoglobinopathy worldwide but remains a rare blood disorder in most western countries. Recommendations for standard of care have been produced in the United States, the United Kingdom and France, where this disease is relatively frequent because of earlier immigration from Africa. These recommendations have changed the clinical course of SCD but can be difficult to apply in other contexts. The Italian Association of Pediatric Hematology Oncology (AIEOP) decided to develop a common national response to the rising number of SCD patients in Italy with the following objectives: 1) to create a national working group focused on pediatric SCD, and 2) to develop tailored guidelines for the management of SCD that could be accessed and practiced by those involved in the care of children with SCD in Italy.

Methods

Guidelines, adapted to the Italian social context and health system, were developed by 22 pediatric hematologists representing 54 AIEOP centers across Italy. The group met five times for a total of 128 hours in 22 months; documents and opinions were circulated via web.

Results

Recommendations regarding the prevention and treatment of the most relevant complications of SCD in childhood adapted to the Italian context and health system were produced.

For each topic, a pathway of diagnosis and care is detailed, and a selection of health management issues crucial to Italy or different from other countries is described (i.e., use of alternatives for infection prophylaxis because of the lack of oral penicillin in Italy).

Conclusions

Creating a network of physicians involved in the day-to-day care of children with SCD is feasible in a country where it remains rare. Providing hematologists, primary and secondary care physicians, and caregivers across the country with web-based guidelines for the management of SCD tailored to the Italian context is the first step in building a sustainable response to a rare but emerging childhood blood disorder and in implementing the World Health Organization’s suggestion “to design (and) implement … comprehensive national integrated programs for the prevention and management of SCD".

Prenatal diagnosis of β-thalassemia in Guangxi Zhuang Autonomous Region, China

PURPOSE

The aim of this study was to establish a comprehensive prenatal diagnosis service and to control the birth of thalassemia children in Guangxi Zhuang Automonous Region, China.

METHODS

Prenatal diagnosis was performed in 1,058 couples with 'at risk' β-thalassemia from Guangxi Zhuang Automonous Region. Fetal samplings were collected by chorionic villus sampling in the first trimester, by amniocentesis in the second trimester and by cordocentesis in the third trimester. DNA analysis was carried out using polymerase chain reaction, reverse dot blot assay, multiplex ligation-dependent probe amplification method and DNA sequencing. Automated high-performance liquid chromatography system was used to analyze the fetal hemoglobin in pregnancies in case mutations were unidentified.

RESULTS

A total of 12 different β-thalassemia mutations were characterized from 2,116 parents. The most common mutation for β-thalassemia was CD41-42 (-CTTT) followed by CD17 (A→T). Prenatal testing revealed 315 normal fetuses, 500 carriers and 253 β-thalassemia major fetuses. The couples having fetuses with β-thalassemia major were counselled to terminate the pregnancies. Postnatal follow-up confirmed all pregnancies.

CONCLUSION

Our prenatal diagnosis strategy proved to be highly effective in reducing severe thalassemia in pregnant populations.

Non-invasive prenatal diagnosis of beta-thalassemia and sickle-cell disease using pyrophosphorolysis-activated polymerization and melting curve analysis

OBJECTIVE

The aim of this study was to develop a pyrophosphorolysis-activated polymerization (PAP) assay for non-invasive prenatal diagnosis (NIPD) of β-thalassemia major and sickle-cell disease (SCD). PAP is able to detect mutations in free fetal DNA in a highly contaminating environment of maternal plasma DNA.

METHODS

Pyrophosphorolysis-activated polymerization primers were designed for 12 informative SNPs, genotyped by melting curve analysis (MCA) in both parents. The PAP assay was tested in a series of 13 plasma DNA samples collected from pregnant women. A retrospective NIPD was performed in a couple at risk for SCD.

RESULTS

All PAP reactions were optimized and able to detect <3% target gDNA in a background of >97% wildtype gDNA. In all 13 cases, the paternal allele was detected by PAP in maternal plasma at 10 to 18 weeks of gestation. For the couple at risk, PAP showed presence of the normal paternal SNP allele in maternal plasma, which was confirmed by results of the chorionic villus sampling analysis.

CONCLUSIONS

In contrast to other methods used for NIPD, the combined PAP and MCA analysis detecting the normal paternal allele is also applicable for couples at risk carrying the same mutation, provided that a previously born child is available for testing to determine the linkage to the paternal SNPs.

Relationship between neonatal screening results by HPLC and the number of α-thalassaemia gene mutations; consequences for the cut-off value

Objectives

To evaluate the relationship between FAST peak percentage by adapted Bio-Rad Vnbs analysis using the valley-to-valley integration and genotypes with the aim to improve differentiation between severe α-thalassaemia forms (HbH disease) and the milder disease types.

Method

DNA analysis for α-thalassaemia was performed on 91 dried blood spot samples presenting normal and elevated FAST peak levels, selected during three years of Dutch national newborn screening.

Results

Significant differences were found between samples with and without α-thalassaemia mutations, regardless of the genetic profiles. No significant difference was demonstrated between HPLC in -α/αα and -α/-α, between -α/-α and –/αα and between –/αα and –/-α genotypes.

Conclusion

This study confirms that the percentage HbBart's, as depicted by the FAST peak, is only a relative indication for the number of α genes affected in α-thalassaemia. Based on the data obtained using the modified Bio-Rad Vnbs software, we adopted a cut-off value of 22.5% to discriminate between possible severe α-thalassaemia or HbH disease and other α-thalassaemia phenotypes. Retrospectively, if this cut-off value was utilized during this initial three-year period of neonatal screening, the positive predictive value would have been 0.030 instead of 0.014.