The population genetics of the haemoglobinopathies

Controversies in the pathophysiology of leg ulcers in sickle cell disease

Patients with sickle cell disease (SCD) often experience painful vaso-occlusive crises and chronic haemolytic anaemia, as well as various acute and chronic complications, such as leg ulcers. Leg ulcers are characterized by their unpredictability, debilitating pain and prolonged healing process. The pathophysiology of SCD leg ulcers is not well defined. Known risk factors include male gender, poor social conditions, malnutrition and a lack of compression therapy when oedema occurs. Leg ulcers typically start with spontaneous pain, followed by induration, hyperpigmentation, blister formation and destruction of the epidermis. SCD is characterized by chronic haemolysis, increased oxidative stress and decreased nitric oxide bioavailability, which promote ischaemia and inflammation and consequently impair vascular function in the skin. This cutaneous vasculopathy, coupled with venostasis around the ankle, creates an ideal environment for local vaso-occlusive crises, which can result in the development of leg ulcers that resemble arterial ulcers. Following the development of the ulcer, healing is hindered as a result of factors commonly observed in venous ulceration, including venous insufficiency, oedema and impaired angiogenesis. All of these factors are modulated by genetic factors. However, our current understanding of these genetic factors remains limited and does not yet enable us to accurately predict ulceration susceptibility.

Whole exome sequencing and rare variant association study to identify genetic modifiers, KLF1 mutations, and a novel double mutation in Thai patients with hemoglobin E/beta-thalassemia

OBJECTIVES

Clinical manifestations of patients with Hemoglobin E/beta-thalassemia vary from mild to severe phenotypes despite exhibiting the same genotype. Studies have partially identified genetic modifiers. We aimed to study the association between rare variants in protein-coding regions and clinical severity in Thai patients.

METHODS

From April to November 2018, a case-control study was conducted based on clinical information and DNA samples collected from Thai patients with hemoglobin E/beta-thalassemia over the age of four years. Cases were patients with severe symptoms, while patients with mild symptoms acted as controls. Whole exome sequencing and rare variant association study were used to analyze the data.

RESULTS

All 338 unrelated patients were classified into 165 severe and 173 mild cases. Genotypes comprised 81.4% of hemoglobin E/beta-thalassemia, 2.7% of homozygous or compound heterozygous beta-thalassemia, and 0.3% of (δβ)⁰ thalassemia Hb E while 15.7% of samples were not classified as beta-thalassemia. A novel cis heterozygotes of IVS I-7 (A > T) and codon 26 (G > A) was identified. Six genes (COL4A3, DLK1, FAM186A, PZP, THPO, and TRIM51) showed the strongest associations with severity (observed p-values of <0.05; significance lost after correction for multiplicity). Among known modifiers, KLF1 variants were found in four mild patients and one severe patient.

CONCLUSION

No rare variants were identified as contributors to the clinical heterogeneity of hemoglobin E/beta-thalassemia. KLF1 mutations are potential genetic modifiers. Studies to identify genetic factors are still important and helpful for predicting severity and developing targeted therapy.

The Spectrum of α-Thalassemia Mutations in Syrian Patients

α-Thalassemia (α-thal) is a globally prevalent genetic disorder of hemoglobin (Hb) structure where the rate of α-globin chain synthesis is reduced or absent due to the presence of α-globin mutation(s). The aim of this study is to define the spectrum of α-globin gene mutations and evaluate their allele frequency in a group of α-thal carriers. A total of 55 individuals with possible α-thal patients were referred from the thalassemia centers in Syria. They have unexplained hypochromia and microcytosis. All patients were genetically tested for 21 common α-globin gene mutations using reverse hybridization kit. Seven different α-globin gene mutations and 13 different genotypes were detected in 55 patients. The two most frequently encountered mutations were -α3.7 deletion (47.1%) and --MED mutation (21.4%). The most commonly observed genotype was -α3.7/αα (40%), followed by --MED/αα genotype (21.8%). We determined the most common α thalassemia mutations in the Syrian patients. α-Thalassemia mutations with deletions were mostly observed in our study.

Evaluation of craniofacial anthropometry of children with β-thalassemia major in the eastern Anatolia: a case-control study

OBJECTIVE

The present study aims to compare β-thalassemia major patients and healthy individuals in terms of anthropometric characteristics and changes in craniofacial profile.

SUBJECTS AND METHOD

Craniofacial anthropometric measurements were performed on a total of 422 subjects (199 β-thalassemia major patients and 223 healthy individuals) by using a millimetric caliper and tape measure on 19 anthropometric parameters (8 horizontal, 10 vertical, and 1 head circumference) in cranial, facial, nasal, orolabial, and orbital zones.

RESULTS

The difference between the orbital, nasal, and orolabial zone parameters of healthy subjects and β-thalassemia major patients was found to be statistically significant (p < 0.05). There was no statistically significant difference between the groups in terms of head circumference in the cranial zone and total facial height in facial zone (n-gn) values (p˃0.05). In intragroup comparison between females and males with β-thalassemia, statistically significant differences were found in forehead width (ft-ft), forehead height (tr-gl), right eye width (R ex-ex), and upper lip height (sn-stm) (p < 0.05).

CONCLUSION

Understanding the craniofacial profile changes in β-thalassemia major patients and increasing our knowledge about the relationship between the course and severity of disease and the level of these changes would contribute to the advancements in diagnoses to be made in facial and jaw zones of these patients and in the treatment plans.

CLINICAL RELEVANCE

We believe that the analysis and results of the craniofacial anthropometric data obtained in the study will contribute to the diagnosis and treatment processes of patients with β-thalassemia major in areas of expertise such as craniofacial surgery, orthodontics, and hemato-oncology.

Human NCR3 gene variants rs2736191 and rs11575837 alter longitudinal risk for development of pediatric malaria episodes and severe malarial anemia

BACKGROUND

Plasmodium falciparum malaria is a leading cause of pediatric morbidity and mortality in holoendemic transmission areas. Severe malarial anemia [SMA, hemoglobin (Hb) < 5.0 g/dL in children] is the most common clinical manifestation of severe malaria in such regions. Although innate immune response genes are known to influence the development of SMA, the role of natural killer (NK) cells in malaria pathogenesis remains largely undefined. As such, we examined the impact of genetic variation in the gene encoding a primary NK cell receptor, natural cytotoxicity-triggering receptor 3 (NCR3), on the occurrence of malaria and SMA episodes over time.

METHODS

Susceptibility to malaria, SMA, and all-cause mortality was determined in carriers of NCR3 genetic variants (i.e., rs2736191:C > G and rs11575837:C > T) and their haplotypes. The prospective observational study was conducted over a 36 mos. follow-up period in a cohort of children (n = 1,515, aged 1.9-40 mos.) residing in a holoendemic P. falciparum transmission region, Siaya, Kenya.

RESULTS

Poisson regression modeling, controlling for anemia-promoting covariates, revealed a significantly increased risk of malaria in carriers of the homozygous mutant allele genotype (TT) for rs11575837 after multiple test correction [Incidence rate ratio (IRR) = 1.540, 95% CI = 1.114-2.129, P = 0.009]. Increased risk of SMA was observed for rs2736191 in children who inherited the CG genotype (IRR = 1.269, 95% CI = 1.009-1.597, P = 0.041) and in the additive model (presence of 1 or 2 copies) (IRR = 1.198, 95% CI = 1.030-1.393, P = 0.019), but was not significant after multiple test correction. Modeling of the haplotypes revealed that the CC haplotype had a significant additive effect for protection against SMA (i.e., reduced risk for development of SMA) after multiple test correction (IRR = 0.823, 95% CI = 0.711-0.952, P = 0.009). Although increased susceptibility to SMA was present in carriers of the GC haplotype (IRR = 1.276, 95% CI = 1.030-1.581, P = 0.026) with an additive effect (IRR = 1.182, 95% CI = 1.018-1.372, P = 0.029), the results did not remain significant after multiple test correction. None of the NCR3 genotypes or haplotypes were associated with all-cause mortality.

CONCLUSIONS

Variation in NCR3 alters susceptibility to malaria and SMA during the acquisition of naturally-acquired malarial immunity. These results highlight the importance of NK cells in the innate immune response to malaria.

Behind the scene of the prevalence of anaemia: an extended way of reporting

OBJECTIVE

To develop the methods for an extended reporting of anaemia and to measure the status of the key contextual underlying factors of anaemia.

DESIGN

Statistical appraisal of Hb v. key influencers of anaemia in Bangladesh – the intake of animal source food (ASF), concentration of Fe in the drinking groundwater (GWI) and the prevalence of congenital Hb disorder (CH) are conducted. The primary data of the National Micronutrient Survey 2011–2012 and the British Geological Survey 2001 are analysed to assess the intake of ASF and the GWI concentration, respectively. The prevalence of thalassaemia from a national survey is used to appraise the CH. ASF is evaluated relative to the 97·5th percentile intake and group scores are assigned. Association of the GWI and Hb is examined by the linear fit and the mspline fit and the group scores are allocated. Group score is allocated for the prevalence of thalassaemia. Inflammation-adjusted ferritin is considered to report Hb.

SETTING

A nationwide survey in Bangladesh.

PARTICIPANTS

Preschool children (6–59 months), school-age children (6–14 years) and non-pregnant non-lactating women (NPNLW, 15–49 years).

RESULTS

The extended reporting to the prevalence of anaemia in Bangladeshi preschool children, school children and women is – anaemia 33 % (ASF: 2·08; GWI: 1·75; CH: 2), anaemia 19 % (ASF: 1·98; GWI: 1·56; CH: 2) and anaemia 26 % (ASF: 2·16; GWI: 1·58; CH: 2), respectively.

CONCLUSION

The extended reporting of anaemia is a useful tool to understand the status of the key influencers of anaemia, to design the context-customised intervention and to monitor the intervention.

Hydroxyurea treatment is associated with lower malaria incidence in children with sickle cell anemia in sub-Saharan Africa

Realizing Effectiveness Across Continents with Hydroxyurea (REACH, NCT01966731) provides hydroxyurea at maximum tolerated dose (MTD) for children with sickle cell anemia (SCA) in sub-Saharan Africa. Beyond reducing SCA-related clinical events, documented treatment benefits include ∼50% reduction in malaria incidence. To identify associations and propose mechanisms by which hydroxyurea could be associated with lower malaria rates, infections were recorded across all clinical sites (Angola, Democratic Republic of Congo, Kenya, and Uganda). Hazard ratios (HR) with 95% confidence intervals (CIs) for baseline demographics, and time-varying laboratory and clinical parameters were estimated in a modified Cox gap-time model for repeated events. Over 3387 patient-years of hydroxyurea treatment, 717 clinical malaria episodes occurred in 336 of 606 study participants; over half were confirmed by blood smear and/or rapid diagnostic testing with 97.8% Plasmodium falciparum. In univariate analysis limited to 4 confirmed infections per child, malaria risk was significantly associated with absolute neutrophil count (ANC), splenomegaly, hemoglobin, and achieving MTD; age, malaria season, MTD dose, fetal hemoglobin, α-thalassemia, and glucose-6-phosphate dehydrogenase deficiency had no effect. In multivariable regression of confirmed infections, ANC was significant (HR, 1.37 per doubled value; 95% CI, 1.10-1.70; P = .0052), and ANC values <3.0 × 109/L were associated with lower malaria incidence. Compared with nonpalpable spleen, 1- to 4-cm splenomegaly also was associated with higher malaria risk (HR, 2.01; 95% CI, 1.41-2.85; P = .0001). Hydroxyurea at MTD is associated with lower malaria incidence in SCA through incompletely defined mechanisms, but treatment-associated mild myelosuppression with ANC <3.0 × 109/L is salutary. Splenomegaly is an unexplained risk factor for malaria infections among children with SCA in Africa.

Labile plasma iron and echocardiographic parameters are associated with cardiac events in β-thalassemic patients

BACKGROUND AND AIM

Notwithstanding the improvement in therapies, patients affected by thalassemia major (TM) and intermedia (TI) are still at high risk of cardiac complications. This study aimed at evaluating the incidence and predictive factors for developing cardiac events in adult β-TM and TI patients.

POPULATION AND METHODS

Data on diagnosis and clinical history were collected retrospectively; prospective data on new-onset cardiac failure and arrhythmias, echocardiographic parameters, biochemical variables including non-transferrin-bound iron (NTBI) and labile plasma iron (LPI), magnetic resonance imaging (MRI) T2* measurement of hepatic and cardiac iron deposits, and iron chelation therapy were recorded during a 6-year follow-up.

RESULTS

Thirty-seven patients, 29 TM and 8 TI, were included. At baseline, 8 TM patients and 1 TI patient had previously experienced a cardiac event (mainly heart failure). All patients were on chelation therapy and only 3 TM patients had mild-to-severe cardiac siderosis. During follow-up, 11 patients (29.7%) experienced a new cardiac event. The occurrence of cardiac events was correlated to high LPI levels (OR 12.0, 95% CI 1.56-92.3, p .017), low mean pre-transfusion haemoglobin (OR 0.21, 95% C.I. 0.051-0.761, p .21) and echocardiographic parameters suggestive of myocardial hypertrophy. Multivariate analysis disclosed high LPI and left ventricle mass index (LVMI) as independent variables significantly associated with cardiac events. Cardiac iron deposits measured by MRI T2* failed to predict cardiac events.

CONCLUSION

LPI, Hb levels and echocardiographic parameters assessing cardiac remodelling are associated with cardiac events in adult TM and TI patients. LPI might represent both a prognostic marker and a potential target for novel treatment strategies. Further studies are warranted to confirm our findings on larger populations.

A rare and novel mutation in a beta-globin gene of thalassemia patient of Pakistan: A case report

Introduction

Thalassemia is a genetically complex disorder that evolves from a mutation in the beta chain of hemoglobin. Much work has been done on the common mutations, but some rare mutations have been found that impact and diversify the disease spectrum.

Case presentation

Our case report is on a young adult who presented with anemia, gall stones, and off-and-on transfusion dependency. A detailed workup revealed that the patient was suffering from thalassemia intermedia. The interesting finding was that the patient, product of non-consanguineous marriage was homozygous for beta thalassemia mutation on genetic analysis. A detailed genetic analysis of the parents revealed them as carriers for the same mutation. It was found that patient was homozygous for a rare and novel mutation -88(C > A)[HBB:c.-138C  >  A] on whole gene sequencing.

Discussion

The area of genomics in thalassemia is rapidly growing, and our case report aims to update the current knowledge of thalassemia's genomic information in Pakistan. The mutation found in our patient was -88(C > A)[HBB:c.-138C  >  A], and the data provided by the National Library of Medicine for this mutation as Allele ID: 380597 and variant type of single nucleotide variant shows that only ten such cases exist in the world with this rare mutation. Our case would be the 11th case in the world and 1st in Pakistan according to the literature, reporting above mentioned mutation.

Conclusion

Further translational study is required to accurately utilize genomic data as an instrument of precision treatment in thalassemia patients, especially in underdeveloped countries like Pakistan.

Celocentesis for Early Prenatal Diagnosis in Couples at-Risk for β-Thalassemia and Sicilian (δβ)0-Thalassemia

The procedures commonly used for prenatal diagnosis (PND) of thalassemia are villocentesis or amniocentesis, respectively, at the 11th and 16th weeks of gestation. Their main limitation is essentially due to the late gestation week in which diagnosis is performed. The celomic cavity is accessible between the 7th and 9th weeks of gestation and it has been demonstrated that it contains embryonic erythroid precursor cells as a source of fetal DNA for earlier invasive PND of thalassemia and other monogenic diseases. In this study, we report the use of celomatic fluids obtained from nine women with high-risk pregnancies for Sicilian (δβ)⁰-thalassemia [(δβ)⁰-thal] deletion (NG_000007.3: g.64336_77738del13403) and β-thalassemia (β-thal). Fetal cells were isolated by a micromanipulator, and nested polymerase chain reaction (PCR) and short tandem repeats (STRs) analysis were performed. Prenatal diagnosis was successfully performed in all examined cases. One fetus was a compound heterozygote for (δβ)⁰- and β-thal, three fetuses were found to be carriers of β-thal, four fetuses carriers of a Sicilian δβ deletion, and one fetus without parental mutations. Accidentally, a rare case of paternal triploidy was observed. The genotypic analysis, carried out both by amniocentesis and on abortive tissue or after birth, showed concordance with results obtained on fetal celomic DNA. Our results unequivocally show that fetal DNA can be obtained by nucleated fetal cells present in the celomatic fluid and demonstrate, for the first time, that PND of Sicilian (δβ)⁰-thal and β-thal is feasible at an earlier time in pregnancy than other procedures.

A Comparison of Arc of Motion, Radiological Parameters of the Wrist and Patient Rated Wrist Evaluation between Adult Transfusion Dependent Thalassemics and Normal Subjects

Background: Bony deformities and arthropathies have been noticed in thalassemia patients. The aim of this study is to compare the arc of motion and radiological parameters of the wrist and patient rated wrist evaluation (PRWE) between adult transfusion-dependent thalassemics and normal subjects.

Methods: An observational cross-sectional study was done in the department of orthopaedics over a period of 2 years where a total of 30 skeletally mature thalassemia major patients (group A) were assessed. The data was then compared with the data of demographically matched 30 healthy adults (group B). Arc of motion of the dominant wrist that included flexion, extension, radial and ulnar deviation, pronation and supination was measured using a handheld goniometer for both groups. Radiographs of the dominant wrist were obtained in both groups and used to determine the radial height, radial articular angle and carpal slip. PRWE was used to assess the function of the wrist. A p-value of <0.05 was considered statistically significant.

Results: Clinical abnormalities at the wrist joint were found in 80% of thalassaemia patients. There was a statistically significant increase in ulnar deviation, wrist extension and decrease in wrist flexion in group A compared to group B. Radiological abnormalities were found in 100% of thalassaemia patients. All the radiological parameters were significantly increased in group A compared to group B. There were no differences in PRWE scores between both groups.

Conclusion: Clinical and radiological changes of wrist joint occur in skeletally mature thalassaemia major patients due to shortened ulna compared to healthy adults. This may be due to disease itself, bone marrow expansion, osteopenia, drug (chelating agent) or iron toxicity. Understanding the changes at the wrist in patients with thalassemia major is important to increasing the life expectancy of these patients.

Level of Evidence: Level IV (Diagnostic)

Insights into the genetic architecture of haematological traits from deep phenotyping and whole-genome sequencing for two Mediterranean isolated populations

Haematological traits are linked to cardiovascular, metabolic, infectious and immune disorders, as well as cancer. Here, we examine the role of genetic variation in shaping haematological traits in two isolated Mediterranean populations. Using whole-genome sequencing data at 22× depth for 1457 individuals from Crete (MANOLIS) and 1617 from the Pomak villages in Greece, we carry out a genome-wide association scan for haematological traits using linear mixed models. We discover novel associations (p < 5 × 10^–9) of five rare non-coding variants with alleles conferring effects of 1.44–2.63 units of standard deviation on red and white blood cell count, platelet and red cell distribution width. Moreover, 10.0% of individuals in the Pomak population and 6.8% in MANOLIS carry a pathogenic mutation in the Haemoglobin Subunit Beta (HBB) gene. The mutational spectrum is highly diverse (10 different mutations). The most frequent mutation in MANOLIS is the common Mediterranean variant IVS-I-110 (G>A) (rs35004220). In the Pomak population, c.364C>A (“HbO-Arab”, rs33946267) is most frequent (4.4% allele frequency). We demonstrate effects on haematological and other traits, including bilirubin, cholesterol, and, in MANOLIS, height and gestation age. We find less severe effects on red blood cell traits for HbS, HbO, and IVS-I-6 (T>C) compared to other b+ mutations. Overall, we uncover allelic diversity of HBB in Greek isolated populations and find an important role for additional rare variants outside of HBB.

De novo mutation rates at the single-mutation resolution in a human HBB gene-region associated with adaptation and genetic disease

Although it is known that the mutation rate varies across the genome, previous estimates were based on averaging across various numbers of positions. Here, we describe a method to measure the origination rates of target mutations at target base positions and apply it to a 6-bp region in the human hemoglobin subunit beta (HBB) gene and to the identical, paralogous hemoglobin subunit delta (HBD) region in sperm cells from both African and European donors. The HBB region of interest (ROI) includes the site of the hemoglobin S (HbS) mutation, which protects against malaria, is common in Africa, and has served as a classic example of adaptation by random mutation and natural selection. We found a significant correspondence between de novo mutation rates and past observations of alleles in carriers, showing that mutation rates vary substantially in a mutation-specific manner that contributes to the site frequency spectrum. We also found that the overall point mutation rate is significantly higher in Africans than in Europeans in the HBB region studied. Finally, the rate of the 20A→T mutation, called the “HbS mutation” when it appears in HBB, is significantly higher than expected from the genome-wide average for this mutation type. Nine instances were observed in the African HBB ROI, where it is of adaptive significance, representing at least three independent originations; no instances were observed elsewhere. Further studies will be needed to examine mutation rates at the single-mutation resolution across these and other loci and organisms and to uncover the molecular mechanisms responsible.

Uncertain crisis time affects psychosocial dimensions in beta-thalassemia patients during Covid-19 pandemic: A cross-sectional study

Psychosocial variables are key factors influencing the delicate equilibrium of chronic patients during crisis time. In this study, we explored distress, anxiety, depression, loneliness, coping strategies, and changes in life habits in 43 beta-thalassemia patients and 86 controls during Covid-19 pandemic. Patients showed higher anxiety levels and a predominant transcendent coping profile compared to controls. Patients significantly differed from controls in outdoor habits. Social isolation and habits changes in uncertain life-threaten situations as Covid-19 pandemic are particularly detrimental in fragile beta-thalassemia patients. Structured support interventions are needed to promote well-being in the Covid-19 era.

Pregnancy outcome in women with transfused beta-thalassemia in France

Because of chronic anemia, hypogonadotropic hypogonadism, and iron chelation, pregnancy in homozygous and heterozygous compound beta-thalassemia patients stays a challenge. Pregnancies of transfused beta-thalassemia women registered in the French National Registry, conducted between 1995 and 2015, are described. These pregnancies were compared with pregnancies in healthy women and to data previously published in the literature. Fifty-six pregnancies of 37 women were studied. There were 5 twin pregnancies. Assisted reproductive technologies (ART) were used in 9 pregnancies. Median term at delivery was 39 amenorrhea weeks, and median weight at birth was 2780 g. Cesarean section was performed in 53.6% of the pregnancies. There were 6 thromboembolic events, 6 serious infections, 6 pregnancy-induced hypertensions (PIH), 6 intrauterine growth retardations (IUGR), 5 severe hemorrhages, 4 gestational diabetes, 3 alloimmunizations, 2 heart diseases, and 1 pre-eclampsia. There were 5 infections and 4 osteoporosis in the first year of post-partum. ART and cesarean sections were more often used in the beta-thalassemia group, compared to control subjects. Thromboembolic events, PIH, hemorrhage at delivery, and IUGR were more frequent in the beta-thalassemia group. Time to delivery was not different, but infant weight at birth was significantly smaller in the beta-thalassemia group. In the post-partum period, global maternal complications were more frequent in the beta-thalassemia group. Pregnancy in transfused beta-thalassemia women is safe with rare obstetrical and fetal complications. Cesarean section remains often chosen, and infant weight at birth remains smaller than that in the general population, despite delivery at full term.

Haplotype heterogeneity and low linkage disequilibrium reduce reliable prediction of genotypes for the ‑α 3.7I form of α-thalassaemia using genome-wide microarray data

Background: The -α ^3.7I-thalassaemia deletion is very common throughout Africa because it protects against malaria. When undertaking studies to investigate human genetic adaptations to malaria or other diseases, it is important to account for any confounding effects of α-thalassaemia to rule out spurious associations.

Methods: In this study, we have used direct α-thalassaemia genotyping to understand why GWAS data from a large malaria association study in Kilifi Kenya did not identify the α-thalassaemia signal. We then explored the potential use of a number of new approaches to using GWAS data for imputing α-thalassaemia as an alternative to direct genotyping by PCR.

Results: We found very low linkage-disequilibrium of the directly typed data with the GWAS SNP markers around α-thalassaemia and across the haemoglobin-alpha ( HBA) gene region, which along with a complex haplotype structure, could explain the lack of an association signal from the GWAS SNP data. Some indirect typing methods gave results that were in broad agreement with those derived from direct genotyping and could identify an association signal, but none were sufficiently accurate to allow correct interpretation compared with direct typing, leading to confusing or erroneous results.

Conclusions: We conclude that going forwards, direct typing methods such as PCR will still be required to account for α-thalassaemia in GWAS studies.

A Systematic Review and Meta-Analysis on the Epidemiology of Hepatitis B and Hepatitis C Virus among Beta-Thalassemia Major Patients in Pakistan

Beta-thalassemia major patients are the leading consumers of blood transfusions in Pakistan and, therefore, have a greater risk of acquiring transfusion-transmitted infections, most notably hepatitis B and C virus (HBV and HCV). The present study includes a comprehensive review on the status of HBV and HCV in beta-thalassemia major patients in Pakistan. For this purpose, we examined original articles assessing the epidemiology of HBV and HCV in transfusion-dependent thalassemia patients.

We searched 10 major subscription databases from January through February 2020, that is, Medline, PakMediNet, CINAHL, Scopus, PubMed, Web of Science, Embase, Science Direct, Google Scholar, and Directory of Open Access Journals. The World Health Organization resources were also explored for relevant reports. The search criteria included published articles up to December 31, 2019, with no language restrictions. Articles identified were introduced into the Endnote version X9 software and then screened for relevance and duplication. The results were stated as the pooled prevalence for the overall study and also for region-wise subgroups.

A total of 33 studies conducted from 1995 to 2019 were included in the review. All 33 articles yielded information on HCV prevalence, while 19 of them provided information on HBV prevalence. The overall sample size was 8,554 that tested the prevalence of HCV in thalassemia patients. The sample size from the 19 studies that tested the prevalence of HBV was 6,184. The overall pooled prevalence of HBV was computed to be 4.13%, while the pooled prevalence of HCV was 29.79%. The majority of the studies were obtained from the Punjab Province (33.33%), followed by Khyber Pakhtunkhwa Province (24.24%).

The total sample size of 33 studies was less than 10% of the total number of estimated thalassemic patients, that is, 100,000. Further studies or a national baseline survey are imperative to confirm the actual frequency of HBV and HCV in thalassemia patients across the country.

Malaria in Europe: A Historical Perspective

Endemic malaria, which claimed 229 million new cases and 409,000 deaths in 2019 mainly in Africa, was eradicated from Europe by the mid-20th century. Historical descriptions of intermittent tertian and quartan fever reported in texts of Hippocrates in Greece and Celsus in Italy suggest malaria. A few paleomicrobiology investigations have confirmed the presence of malarial parasite Plasmodium falciparum in 1st, 2nd, and 5th century infected individuals in diverse regions of Italy, and Plasmodium sp. later in Bavaria. The causative Plasmodium pathogens, discovered in the 19th century in Algeria, were controversially used as therapeutic agents in the European pharmacopeia more than two centuries after effective quinine-based treatments had been introduced in Europe. How Europe managed to eradicate malaria and what the history of malaria was in Europe are of medical interest, and this review traces research pathways for a renewed understanding of malaria eradication in Europe through combined historical and paleomicrobiological investigations.

Hemoglobin F (HbF) inducers; History, Structure and Efficacies

Inherited beta-thalassemia is a major disease caused by irregular production of hemoglobin through reducing beta-globin chains. It has been observed that increasing fetal hemoglobin (HbF) production improves symptoms in the patients. Therefore, an increase in the level of HbF has been an operative approach for treating patients with beta-thalassemia. This review represents compounds with biological activities and pharmacological properties that can promote the HBF level and therefore used in the β-thalassemia patients' therapy. Various natural products with different mechanisms of action can be helpful in this medication cure. Clinical trials were efficient in improving the signs of patients. Association of in vivo, and in vitro studies of HbF induction and γ-globin mRNA growth displays that in vitro experiments could be an indicator of the in vivo response. The current study shows that; (a) HbF inducers can be grouped in several classes based on their chemical structures and mechanism of actions; b) According to several clinical trials, well-known drugs such as hydroxyurea and decitabine are useful HbF inducers; (c) The cellular biosensor K562 carrying genes under the control of the human γ-globin and β-globin gene promoters were applied during the researches; d) New natural products and lead compounds were found based on various studies as HbF inducers.

Sickle Cell Trait Modulates the Proteome and Phosphoproteome of Plasmodium falciparum-Infected Erythrocytes

The high prevalence of sickle cell disease in some human populations likely results from the protection afforded against severe Plasmodium falciparum malaria and death by heterozygous carriage of HbS. P. falciparum remodels the erythrocyte membrane and skeleton, displaying parasite proteins at the erythrocyte surface that interact with key human proteins in the Ankyrin R and 4.1R complexes. Oxidative stress generated by HbS, as well as by parasite invasion, disrupts the kinase/phosphatase balance, potentially interfering with the molecular interactions between human and parasite proteins. HbS is known to be associated with abnormal membrane display of parasite antigens. Studying the proteome and the phosphoproteome of red cell membrane extracts from P. falciparum infected and non-infected erythrocytes, we show here that HbS heterozygous carriage, combined with infection, modulates the phosphorylation of erythrocyte membrane transporters and skeletal proteins as well as of parasite proteins. Our results highlight modifications of Ser-/Thr- and/or Tyr- phosphorylation in key human proteins, such as ankyrin, β-adducin, β-spectrin and Band 3, and key parasite proteins, such as RESA or MESA. Altered phosphorylation patterns could disturb the interactions within membrane protein complexes, affect nutrient uptake and the infected erythrocyte cytoadherence phenomenon, thus lessening the severity of malaria symptoms.

Trends in sickle cell trait and disease screening in the Republic of Uganda, 2014-2019

OBJECTIVE

Sickle cell disease is an important public health issue that is increasingly recognised as a substantial contributor to morbidity and early childhood mortality in sub-Saharan Africa. We aimed to provide information from large-scale, long-term sickle cell screening efforts in Africa.

METHODS

We used nationally representative data from the centralised public health laboratory database in Uganda to examine epidemiological trends in sickle cell screening over a five-year period, comparing age and geographic adjustments to prevalence among different testing cohorts of children aged 0-24 months, and calculating screening coverage within high-burden districts.

RESULTS

A total of 324 356 children aged 0-24 months were screened for sickle cell trait and disease from February 2014 to March 2019. A high national burden of sickle cell disease (0.9%) was confirmed among a cohort of samples co-tested with HIV. In the cohort of samples referred specifically for sickle cell testing, the overall prevalence of sickle cell disease was 9.7% and particularly elevated in high-burden districts where focused screening occurred. The majority of children were screened before age 4 months, but the sickle-specific cohort had a larger proportion of affected children tested between age 5-9 months, coincident with onset of disease signs and symptoms. Successful screening coverage of sickle cell disease births was achieved in several high-burden districts.

CONCLUSIONS

Examination and analysis of national sickle cell screening trends in Uganda documents the successes of focused screening strategies as an important step towards universal screening. With this evidence and increased healthcare provider knowledge, Uganda can optimise sickle cell diagnosis and management across the country.

Haplotype heterogeneity and low linkage disequilibrium reduce reliable prediction of genotypes for the ‑α3.7I form of α-thalassaemia using genome-wide microarray data

Background: The -α3.7I-thalassaemia deletion is very common throughout Africa because it protects against malaria. When undertaking studies to investigate human genetic adaptations to malaria or other diseases, it is important to account for any confounding effects of α-thalassaemia to rule out spurious associations. Methods: In this study we have used direct α-thalassaemia genotyping to understand why GWAS data from a large malaria association study in Kilifi Kenya did not identify the α-thalassaemia signal. We then explored the potential use of a number of new approaches to using GWAS data for imputing α-thalassaemia as an alternative to direct genotyping by PCR. Results: We found very low linkage-disequilibrium of the directly typed data with the GWAS SNP markers around α-thalassaemia and across the haemoglobin-alpha (HBA) gene region, which along with a complex haplotype structure, could explain the lack of an association signal from the GWAS SNP data. Some indirect typing methods gave results that were in broad agreement with those derived from direct genotyping and could identify an association signal, but none were sufficiently accurate to allow correct interpretation compared with direct typing, leading to confusing or erroneous results. Conclusions: We conclude that going forwards, direct typing methods such as PCR will still be required to account for α-thalassaemia in GWAS studies.

A study of red blood cell alloimmunization and autoimmunization among 200 multitransfused Egyptian β thalassemia patients

The development of hemolytic erythrocyte alloantibodies and autoantibodies complicates transfusion therapy in thalassemia patients. These antibodies ultimately increase the need for blood and intensify transfusion complications. There is a scanty data on the frequency of RBC alloimmunization and autoimmunization in Egyptian β thalassemia patients as pretransfusion antibody screening is not routinely performed. We studied the frequency of alloimmunization and autoimmunization among 200 multiply transfused β thalassemia patients and investigated the factors that possibly affect antibody formation. Of the 200 patients in our study, 94 were males and 106 females, with the age range of 2–37 years. Alloantibodies were detected in 36 (18%) of the patients, while autoantibodies were detected in 33 (16.5%). The dominant alloantibodies were directed against Kell (33%) and Rh (24.4%) groups. Alloimmunization had a significant relationship with treatment duration and the frequency of transfusion (P = 0.007, 0.001, respectively). The presence of autoantibodies was significantly related to age (P = 0.001), total number of transfused units (P = 0.000) and splenectomy (P = 0.000). The high prevalence of alloimmunization in the study population disclosed the need for providing phenotypically matched cells for selective antigens especially for Kell and Rh subgroups to reduce risk of alloimmunization and increase the efficiency of blood transfusion.

Determinants of Anemia Among Children Aged 6 to 59 Months in Dilla Town, Southern Ethiopia: A Facility Based Case Control Study

Background. Globally, anemia is a widespread public health problem associated with increased risk of morbidity and mortality. Under 5 children have greater risk of anemia. The level of burden and the risk factors for anemia vary in different settings. Identifying local factors will have important implications for health intervention programs aimed to tackle the burden. Our study aims to investigate the determinants of anemia among under 5 children in the study area. Methods. Facility based unmatched case control study was conducted among 413 (137 cases and 276 controls) children of Dilla town. Cases were children who had hemoglobin level of less than 11 g/dl and controls were children aged 6 to 59 months with hemoglobin ≥11 g/dl. Quota and simple random sampling was used for cases and controls respectively. Data on socio-demographic, dietary diversity score, food security, anthropometry, hemoglobin level, malaria infection and intestinal parasites were collected. Data were analyzed with SPSS version 25. Bi-variate and multivariate binary logistic regression analysis was used to identify independent determinants of anemia. P-value less than .05 were used to declare statistical significance. Result. In the multivariate analysis, having more than 1 under 5 children in the households (AOR = 3.03, 95%CI = 1.35-6.81), intestinal parasitosis (AOR = 4.42, 95%CI = 2.07-9.44), food insecurity (AOR = 2.75, 95% CI = 1.39-5.45), and stunting (AOR = 6.09, 95% CI = 2.53-14.67) were determinants of anemia among children aged 6 to 59 months. Conclusion. Some of the identified factors are modifiable that could be targeted to reduce childhood anemia. Family planning education, provision of anti-helminthic drugs and ensuring household food security will be beneficial to tackle anemia.

Evaluation of electrocardiographic markers of cardiac arrhythmic events and their correlation with cardiac iron overload in patients with β-thalassemia major

Iron overload is associated with an increased risk of atrial and ventricular arrhythmias. Data regarding the relationship between electrocardiographic parameters of atrial depolarisation and ventricular repolarisation with cardiac T2* MRI are scarce. Therefore, we aimed to investigate these electrocardiographic parameters and their relationship with cardiac T2* value in patients with β-thalassemia major. In this prospective study, 52 patients with β-thalassemia major and 52 age- and gender-matched healthy patients were included. Electrocardiographic measurements of QT, T peak to end interval, and P wave intervals were performed by one cardiologist who was blind to patients' data. All patients underwent MRI for cardiac T2* evaluation. Cardiac T2* scores less than 20 ms were considered as iron overload. P wave dispersion, QTc interval, and the dispersions of QT and QTc were significantly prolonged in β-thalassemia major patients compared to controls. Interestingly, we found prolonged P waves, QT and T peak to end dispersions, T peak to end intervals, and increased T peak to end/QT ratios in patients with T2* greater than 20 ms. No significant correlation was observed between electrocardiographic parameters and cardiac T2* values and plasma ferritin levels. In conclusion, our study demonstrated that atrial depolarisation and ventricular repolarisation parameters are affected in β-thalassemia major patients and that these parameters are not correlated with cardiac iron load.

Utility of screening tools to differentiate beta thalassemia trait and iron-deficiency anemia - do they serve a purpose in blood donors?

Background

The aim of this study was to estimate the prevalence of the beta thalassemia trait (BTT) and differentiate it from iron-deficiency anemia (IDA) among blood donors.

Methods

A total of 1,000 samples from blood donors were subjected to complete hemogram with red blood cell indices. Further, Mentzer index (MI) was calculated for samples with mean corpuscular volume (MCV) below 80 fL and mean corpuscular hemoglobin (MCH) below 27 pg. Samples with Mentzer index <12 were subjected to naked-eye single-tube red cell osmotic fragility test (NESTROFT) followed by hemoglobin electrophoresis in positive cases. Serum ferritin was assessed in NESTROFT-negative cases.

Results

The prevalence of BTT among blood donors was 3.7% and that of microcytosis among donors was 8.6%. The prevalence of BTT among microcytic donors was 41.8% while that among those with IDA was 11.6%. A value of MI <13 was highly sensitive in the diagnosis of BTT. MI >13 was found to have both high specificity and high sensitivity for diagnosing IDA.

Conclusion

A moderately high prevalence of BTT was observed among blood donors. Presently, no screening program is mandatory for screening of BTT among blood donors. Indices like MCV, MCH, and Mentzer Index were thus found to be effective to screen for BTT and IDA among blood donors, and NESTROFT was a cost-effective mass screening method to differentiate BTT and IDA.

Molecular spectrum of α-thalassemia mutations in Erbil province of Iraqi Kurdistan

α-Thalassemia is a globally prevalent genetic disorder of hemoglobin (Hb) structure where the rate of α-globin chain synthesis is reduced or absent based on the underlying α-globin mutation(s). This study aimed to define the spectrum of α-globin gene mutations and assess their relative frequency within a group of α-thalassemia carriers. A total of 96 young subjects with unexplained hypochromia and microcytosis were recruited. They were referred from the premarital hemoglobinopathy screening and genetic counseling center in Erbil. All subjects were genetically tested for 21 common α-globin gene mutations using multiplex PCR and reverse hybridization. Six different α-globin gene mutations and nine different genotypes were detected in 84 carrier subjects. Their mean Hb was 12.9 (± 1.29) g/dL, of whom 49 subjects (58.3%) had a normal Hb level. The two most frequently encountered mutations were -α^3.7 deletion (62.86%) and α2^-5nt mutation (20%). Deletions were encountered in 71.43% of the mutated alleles. The most commonly observed genotype was -α^3.7/αα (46.43%), followed by -α^3.7/-α^3.7 and α^-5ntα/αα genotypes (10.72% each). Carriers of α^poly-A1α/αα and -α^3.7/-α^-5ntα genotypes showed significantly lower Hb, mean cell volume, and mean cell Hb values comparing to carriers of most other genotypes. In our population, the spectrum of α-globin mutations was confined to a limited number of mutations with deletions being mostly observed.

The safety and effectiveness of genetically corrected iPSCs derived from β-thalassaemia patients in nonmyeloablative β-thalassaemic mice

BACKGROUND

β-Thalassaemia is a clinically common cause of hereditary haemolytic anaemia stemming from mutations in important functional regions of the β-globin gene. The rapid development of gene editing technology and induced pluripotent stem cell (iPSC)-derived haematopoietic stem cell (HSC) transplantation has provided new methods for curing this disease.

METHODS

Genetically corrected β-thalassaemia (homozygous 41/42 deletion) iPSCs that were previously established in our laboratory were induced to differentiate into HSCs, which were transplanted into a mouse model of IVS2-654 β-thalassaemia (B6;129P2-Hbb^tm2Unc/J mice) after administration of an appropriate nonmyeloablative conditioning regimen. We also investigated the safety of this method by detecting the incidence of tumour formation in these mice after transplantation.

RESULTS

The combination of 25 mg/kg busulfan and 50 mg/(kg day) cyclophosphamide is an ideal nonmyeloablative protocol before transplantation. Genetically corrected β-thalassaemic HSCs survived and differentiated in nonmyeloablated thalassaemia mice. No tumour formation was observed in the mice for 10 weeks after transplantation.

CONCLUSION

Our study provides evidence that the transplantation of genetically corrected, patient-specific iPSCs could be used to cure genetic diseases, such as β-thalassaemia major.

Human genetics and malaria resistance

Malaria has been the pre-eminent cause of early mortality in many parts of the world throughout much of the last five thousand years and, as a result, it is the strongest force for selective pressure on the human genome yet described. Around one third of the variability in the risk of severe and complicated malaria is now explained by additive host genetic effects. Many individual variants have been identified that are associated with malaria protection, but the most important all relate to the structure or function of red blood cells. They include the classical polymorphisms that cause sickle cell trait, α-thalassaemia, G6PD deficiency, and the major red cell blood group variants. More recently however, with improving technology and experimental design, others have been identified that include the Dantu blood group variant, polymorphisms in the red cell membrane protein ATP2B4, and several variants related to the immune response. Characterising how these genes confer their effects could eventually inform novel therapeutic approaches to combat malaria. Nevertheless, all together, only a small proportion of the heritable component of malaria resistance can be explained by the variants described so far, underscoring its complex genetic architecture and the need for continued research.

Antibodies against the erythroferrone N-terminal domain prevent hepcidin suppression and ameliorate murine thalassemia

Erythroferrone (ERFE) is produced by erythroblasts in response to erythropoietin (EPO) and acts in the liver to prevent hepcidin stimulation by BMP6. Hepcidin suppression allows for the mobilization of iron to the bone marrow for the production of red blood cells. Aberrantly high circulating ERFE in conditions of stress erythropoiesis, such as in patients with β-thalassemia, promotes the tissue iron accumulation that substantially contributes to morbidity in these patients. Here we developed antibodies against ERFE to prevent hepcidin suppression and to correct the iron loading phenotype in a mouse model of β-thalassemia [Hbb(th3/+) mice] and used these antibodies as tools to further characterize ERFE's mechanism of action. We show that ERFE binds to BMP6 with nanomolar affinity and binds BMP2 and BMP4 with somewhat weaker affinities. We found that BMP6 binds the N-terminal domain of ERFE, and a polypeptide derived from the N terminus of ERFE was sufficient to cause hepcidin suppression in Huh7 hepatoma cells and in wild-type mice. Anti-ERFE antibodies targeting the N-terminal domain prevented hepcidin suppression in ERFE-treated Huh7 cells and in EPO-treated mice. Finally, we observed a decrease in splenomegaly and serum and liver iron in anti-ERFE-treated Hbb(th3/+) mice, accompanied by an increase in red blood cells and hemoglobin and a decrease in reticulocyte counts. In summary, we show that ERFE binds BMP6 directly and with high affinity, and that antibodies targeting the N-terminal domain of ERFE that prevent ERFE-BMP6 interactions constitute a potential therapeutic tool for iron loading anemias.

Nationwide carrier detection and molecular characterization of β-thalassemia and hemoglobin E variants in Bangladeshi population

Background

ß-thalassemia is one of the most common inherited blood disorders in the world and a major deterrent to the public health of Bangladesh. The management of thalassemia patients requires lifelong frequent blood transfusion and the available treatment options are unsatisfactory. A national policy on thalassemia prevention is mandatory in Bangladesh. However, precise and up-to-date information on the frequency of ß-thalassemia carriers are missing due to lack of accurate diagnostic approaches, limited access to information and absence of national screening program. This study aims to determine the nationwide carrier frequency of hemoglobin E (HbE) and β- thalassemia and mutation spectrum among the carriers using molecular, hematological and biochemical methods.

Methods

The study enrolled a total of 1877 individuals (60.1% male and 39.9% female) aged between 18 and 35 years. Total sample size and its division-wise breakdown were calculated in proportion to national and division-wise population. Venous blood was collected and subjected to CBC analysis and Hb-electrophoresis for each participant. Serum ferritin was measured to detect coexistence of iron deficiency anemia with thalassemia carrier. DNA-based High Resolution Melting (HRM) curve analysis was performed for confirmation of carrier status by mutation detection.

Results

Of 11.89% (95% CI, 10.43–13.35) carriers of β-globin gene mutations, 8.68% (95% CI, 7.41–9.95) had HbE trait (ETT) and 2.24% (95% CI, 1.57–2.91) had beta-thalassemia trait (BTT). Among eight divisions, Rangpur had the highest carrier frequency of 27.1% (ETT-25%, BTT-2.1%), whereas Khulna had the lowest frequency of 4.2% (ETT-4.2% only). Moreover, α- thalassemia, HbD trait, HbE disease, hereditary persistence of HbF were detected in 0.11, 0.16, 0.43 and 0.16% participants, respectively. HRM could identify two individuals with reported pathogenic mutations in both alleles who were erroneously interpreted as carriers by hematological indices. Finally, a total of nine different mutations including a novel mutation (c.151A > G) were detected in the β-globin gene.

Conclusions

Since carrier frequency for both HbE and β-thalassemia is alarmingly high in Bangladesh, a nationwide awareness and prevention program should be made mandatory to halt the current deteriorating situations. Mutation-based confirmation is highly recommended for the inconclusive cases with conventional carrier screening methods to avoid any faulty detection of thalassemia carriers.

Profiling of hydroxyurea-treated β-thalassemia/ serum proteome through nano-LC-ESI-MS/ MS in combination with microsol-isoelectric focusing

Advancements in proteomic tools offer a comprehensive solution to studying the complexity of diseases at molecular level. This study focusses on the clinical proteomic profiling of pre- and post-hydroxyurea (HU)-treated β-thalassemia patients in parallel with healthy individuals to better understand the role of HU in the treatment of β-thalassemia. The strategy encompasses sequential high-resolution protein fractionation using MicroSol-isoelectric focusing (ZOOM- IEF) followed by one-dimensional SDS-PAGE before nano-RP-LC-MS/ MS analysis of tryptic peptides. Protein identification was performed through Mascot search using NCBInr and SwissProt databases. Several different proteins were observed in pool serum samples of each of the three study groups. Approximately, 1250 proteins exclusive to each group were identified, and after removing the redundant and low sequence coverage proteins, the number was reduced to 576 (201 in healthy, 187 in HU-untreated and 188 in HU-treated group). Uniquely identified proteins in the HU-treated group regulate the focal adhesion, ECM-receptor interaction, PI3K-Akt signaling, Rap1 signaling, cAMP signaling, platelet activation, and Ca²⁺ signaling pathways in the HU-treated group. The proteomic profile presented here will add to the current state of understanding of molecular mechanisms involved in hydroxyurea treatment of β-thalassemia.

Evaluation of maxillary sinus volume and surface area in children with β-thalassaemia using cone beam computed tomography

OBJECTIVES

Among children with β-thalassaemia, skeletal changes and abnormalities, such as decreased volume or obliteration of the sinus, result primarily from hypertrophy and expansion of the erythroid marrow due to ineffective erythropoiesis. This study evaluated the volumes and surface areas of the maxillary sinuses of children with β-thalassaemia using cone beam computed tomography (CBCT), and compared these findings with corresponding measurements in age- and sex-matched control children.

METHODS

CBCT images were retrospectively evaluated for 16 children with β-thalassaemia, 19 children with a class I skeletal pattern (class I group), and 18 children with a class II skeletal pattern (class II group). After three-dimensional analyses and segmentation of each maxillary sinus, the volumes and surface areas were calculated.

RESULTS

The volumes and surface areas of the right (p > 0.05 and p > 0.05) and left maxillary sinuses (p > 0.05 and p > 0.05) and SNA angles (p > 0.05) were not significantly different among the groups. The ANB (p < 0.05) and SNGoMe (p < 0.05) angles were significantly greater and the SNB (p < 0.05) angle was significantly smaller in the class II and thalassaemia groups than in the class I group.

CONCLUSION

Children with thalassaemia tended to have lower maxillary sinus volumes and surface areas on both right and left sides, compared to those of children with class I and class II skeletal patterns; however, these differences were not statistically significant. In children with thalassaemia, a large intermaxillary discrepancy (ANB) indicated a tendency toward the class II skeletal pattern.

A Novel Pathogenic β-Thalassemia Mutation Identified at Codon 8 (HBB: c.27delG) in a Bangladeshi Family Acquired De Novo

In Bangladesh, the practice of β-thalassemia (β-thal) carrier screening and prenatal diagnosis (PND) by β-globin gene sequencing has been initiated to prevent the birth of affected children. The study aimed to describe a novel de novo mutation of the β-globin gene and its clinical implication. Out of 100 Bangladeshi β-thal carrier families, one patient with hematological and clinical features associated with β-thal and her parents were included. Molecular characterizations of β-globin gene mutations were performed by direct sequencing. A novel nucleotide deletion mutation at codon 8 in the first exon of the β-globin gene (HBB: c.27delG) was found in a 1-year-old child of the studied family in a heterozygous state along with common Hb E (HBB: c.79G>A). The mutation caused a frameshift to a new stop codon at codon 18 resulting in a β⁰-thal phenotype. The proband exhibited a β-thal intermedia (β-TI)-like genotype, however, showed β-thal major (β-TM)-like complications and was transfusion-dependent. Her mother had a profile consistent with the Hb E trait, while the father had normal hematological indices. Mutation analyses revealed the mother to be heterozygous for Hb E, while the father had a normal genotype. The novel mutation was assumed to be inherited de novo by the paternity test. The study documented a novel pathogenic mutation in the β-globin gene in a Bangladeshi family by β-globin gene sequencing.

Beta Thalassemia Major with Gaucher's Disease: A Rare Entity

Thalassemia is a genetic disorder due to deletion or mutation in the gene for alpha or beta chain of hemoglobin. Gaucher's disease (GD) is characterized by a deficiency of a lysosomal enzyme, glucocerebrosidase which occurs due to mutations in the GBA1 gene on chromosome 1. Thalassemia and GD have overlapping clinical manifestations and present with features such as anemia, hepatosplenomegaly, and skeletal involvement. This creates a diagnostic conundrum for physicians. We present a case of an 11-month-old female who presented with fever, increasing paleness, and labored breathing. She had a recent history of uncross-matched transfusion. The child showed signs of anemic failure. Physical exam findings strongly pointed towards hemolytic anemia due to thalassemia major. Genetic analysis confirmed homozygosity in Fr 8-9 mutation confirming beta thalassemia major. Bicytopenia along with visceromegaly indicated malaria or storage diseases. Enzyme analysis revealed low levels of beta-glucocerebrosidase with normal acid sphingomyelinase levels confirming GD. In our case, we report the association of beta thalassemia major with GD which is a rare entity. The report highlights the need for an independent assessment of disorders that have similar presentations to avoid missing an associated disorder.

Hemoglobin S and Glucose-6-Phosphate Dehydrogenase Deficiency Coinheritance in AS and SS Individuals in Malaria-Endemic Region: A Study in Calabar, Nigeria

BACKGROUND

Malaria placed a huge burden on human life and has been reported to be a key health problem affecting developing countries. This study was designed to assay for glucose-6-phosphate dehydrogenase (G6PD) status and malaria parasite density of individuals with sickle cell gene in University of Calabar Teaching Hospital, Calabar.

SUBJECTS AND METHODS

The methemoglobin method was used to determine the G6PD status. Thick blood films were used to ascertain the malaria parasite density while hemoglobin genotype was determined using cellulose acetate paper electrophoresis with tris ethylenediaminetetracetic acid borate buffer (pH 8.6). Thirty hemoglobin SS (HbSS) and 30 hemoglobin AS (HbAS) individuals were recruited for the study while 30 hemoglobin AA (HbAA) individuals were recruited as control.

RESULTS

The study showed a high frequency of G6PD deficiency (17.78%) in the study area while G6PD deficiency was significantly (P < 0.05) higher in HbAA individuals (33.33%) when compared to HbSS (10.00%) and HbAS (10.00%) individuals. The prevalence of malaria parasitemia and parasite density was comparable in the three hemoglobin variants. The distribution of malaria parasitemia and parasite density in both gender among the various hemoglobin variants showed no association (P > 0.05). G6PD deficiency distribution in both gender were found to be comparable (P > 0.05). The distribution of malaria parasitemia in the various hemoglobin variants in the G6PD-deficient individuals showed no significant difference (P > 0.5). However, the parasite density of the HbAS (3100 ± 1828.48 μL) and HbSS (2400 ± 1687.06 μL) were significantly lower than that of HbAA (4040 ± 1529.44 μL).

CONCLUSION

The result of this study supports the hypothesis that inheriting the G6PD deficiency gene and sickle cell gene (both in homozygous and heterozygous form) reduces the severity of malaria parasite infection and hence protects against severe acute malaria while having less effect on infection.

Increased risk of arterial thromboembolic events in transfusion-naïve thalassemia: a nationwide population-based study

Transfusion-naïve thalassemia minor/trait is often associated with decreased risk of coronary artery diseases. The present study aimed to evaluate the effect of transfusion-naïve thalassemia on the incidence of arterial thromboembolic events using the National Health Insurance Research Database, Taiwan (2001-2010). Data from patients with transfusion-naïve thalassemia (n=2356) frequency matched with non-thalassemia subjects (n=9424) according to sex, age, and index year at a ratio of 1:4 were included. The risk of arterial thromboembolic events, cerebrovascular ischemic events, arterial embolism/thrombosis, peripheral embolism, myocardial infarction, myocardial ischemia, and angina pectoris in transfusion-naïve thalassemia were analyzed using Cox proportional hazard regression models. The transfusion-naïve thalassemia group had significantly higher risk of arterial thromboembolic events (aHR=1.28, 95% CI 1.07 to 1.52) and myocardial ischemia (aHR=1.41, 95% CI 1.13 to 1.76) as compared with the non-thalassemia group. In addition, they also had a significantly higher cumulative incidence of arterial thromboembolic event and myocardial ischemia. Interestingly, a higher risk of arterial thromboembolic events (aHR=1.58, 95% CI 1.22 to 2.04) and myocardial ischemia (aHR=1.73, 95% CI 1.25 to 2.41) was observed in men with thalassemia as compared with those without. Furthermore, patients with comorbidities had an increased risk of arterial thromboembolic events than did those without comorbidities. The effect of thalassemia on arterial thromboembolic events may be mainly attributed to the influence of thalassemia on myocardial ischemia, as no significant differences were observed in other outcomes evaluated in the present study. In conclusion, the present study confirms the increased risk of arterial thromboembolic events, mainly attributed to the dramatic increase in myocardial ischemia, inminor patients with transfusion-naïve thalassemia.

Estimating the burden of α-thalassaemia in Thailand using a comprehensive prevalence database for Southeast Asia

Severe forms of α-thalassaemia, haemoglobin H disease and haemoglobin Bart’s hydrops fetalis, are an important public health concern in Southeast Asia. Yet information on the prevalence, genetic diversity and health burden of α-thalassaemia in the region remains limited. We compiled a geodatabase of α-thalassaemia prevalence and genetic diversity surveys and, using geostatistical modelling methods, generated the first continuous maps of α-thalassaemia mutations in Thailand and sub-national estimates of the number of newborns with severe forms in 2020. We also summarised the current evidence-base for α-thalassaemia prevalence and diversity for the region. We estimate that 3595 (95% credible interval 1,717–6,199) newborns will be born with severe α-thalassaemia in Thailand in 2020, which is considerably higher than previous estimates. Accurate, fine-scale epidemiological data are necessary to guide sustainable national and regional health policies for α-thalassaemia management. Our maps and newborn estimates are an important first step towards this aim.

Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).

Sickle cell disease: Clinical presentation and management of a global health challenge

Sickle cell disease is an autosomal recessive, multisystem disorder, characterised by chronic haemolytic anaemia, painful episodes of vaso-occlusion, progressive organ failure and a reduced life expectancy. Sickle cell disease is the most common monogenetic disease, with millions affected worldwide. In well-resourced countries, comprehensive care programs have increased life expectancy of sickle cell disease patients, with almost all infants surviving into adulthood. Therapeutic options for sickle cell disease patients are however, still scarce. Predictors of sickle cell disease severity and a better understanding of pathophysiology and (epi)genetic modifiers are warranted and could lead to more precise management and treatment. This review provides an extensive summary of the pathophysiology and management of sickle cell disease and encompasses the characteristics, complications and current and future treatment options of the disease.

Impact of Hemoglobin S Trait on Cell Surface Antibody Recognition of Plasmodium falciparum-Infected Erythrocytes in Pregnancy-Associated Malaria

Background

Sickle cell trait (HbAS) confers partial protection against malaria by reducing the adhesion of Plasmodium falciparum-infected erythrocytes to host receptors, but little is known about its potential protection against placental malaria.

Methods

Using flow cytometry, we assessed the recognition of HbAA and HbAS VAR2CSA-expressing infected erythrocytes, by plasma from 159 Beninese pregnant women with either HbAA (normal) or HbAS. Using multivariate linear models adjusted for gravidity, parasite infection at delivery, glucose-6-phosphate dehydrogenase deficiency, and α-thalassemia carriage, we observed significantly reduced cell surface antibody binding of HbAS-infected erythrocytes by plasma from HbAS compared with HbAA women (P < 10^–3).

Results

The difference in cell surface antibody binding was only observed when infected erythrocytes and plasma were associated according to the same hemoglobin genotype. Similar levels of VAR2CSA-specific antibody were measured by enzyme-linked immunosorbent assay in the 2 groups, suggesting that the altered interaction between VAR2CSA and HbAS women’s antibodies could reflect abnormal display of VAR2CSA on HbAS erythrocytes.

Conclusions

Our data stress the need for assessments of erythrocyte disorders such as the sickle cell trait in a population group when studying immunological responses to P falciparum.

Liver Iron Quantification with MR Imaging: A Primer for Radiologists

Iron overload is a systemic disorder and is either primary (genetic) or secondary (exogenous iron administration). Primary iron overload is most commonly associated with hereditary hemochromatosis and secondary iron overload with ineffective erythropoiesis (predominantly caused by β-thalassemia major and sickle cell disease) that requires long-term transfusion therapy, leading to transfusional hemosiderosis. Iron overload may lead to liver cirrhosis and hepatocellular carcinoma, in addition to cardiac and endocrine complications. The liver is one of the main iron storage organs and the first to show iron overload. Therefore, detection and quantification of liver iron overload are critical to initiate treatment and prevent complications. Liver biopsy was the historical reference standard for detection and quantification of liver iron content. Magnetic resonance (MR) imaging is now commonly used for liver iron quantification, including assessment of distribution, detection, grading, and monitoring of treatment response in iron overload. Several MR imaging techniques have been developed for iron quantification, each with advantages and limitations. The liver-to-muscle signal intensity ratio technique is simple and widely available; however, it assumes that the reference tissue is normal. Transverse magnetization (also known as R2) relaxometry is validated but is prone to respiratory motion artifacts due to a long acquisition time, is presently available only for 1.5-T imaging, and requires additional cost and delay for off-line analysis. The R2* technique has fast acquisition time, demonstrates a wide range of liver iron content, and is available for 1.5-T and 3.0-T imaging but requires additional postprocessing software. Quantitative susceptibility mapping has the highest sensitivity for detecting iron deposition; however, it is still investigational, and the correlation with liver iron content is not yet established. ^©RSNA, 2018.

Sickle Cell Anemia and Its Phenotypes

In the 100 years since sickle cell anemia (SCA) was first described in the medical literature, studies of its molecular and pathophysiological basis have been at the vanguard of scientific discovery. By contrast, the translation of such knowledge into treatments that improve the lives of those affected has been much too slow. Recent years, however, have seen major advances on several fronts. A more detailed understanding of the switch from fetal to adult hemoglobin and the identification of regulators such as BCL11A provide hope that these findings will be translated into genomic-based approaches to the therapeutic reactivation of hemoglobin F production in patients with SCA. Meanwhile, an unprecedented number of new drugs aimed at both the treatment and prevention of end-organ damage are now in the pipeline, outcomes from potentially curative treatments such as allogeneic hematopoietic stem cell transplantation are improving, and great strides are being made in gene therapy, where methods employing both antisickling β-globin lentiviral vectors and gene editing are now entering clinical trials. Encouragingly, after a century of neglect, the profile of the vast majority of those with SCA in Africa and India is also finally improving.

Pharmacoproteomics Profiling of Plasma From β-Thalassemia Patients in Response to Hydroxyurea Treatment

β-Thalassemia is a genetic disorder caused by defects in the β-globin gene resulting in the absence or reduced synthesis of adult hemoglobin (HbA). Hydroxyurea is an effective drug to increase fetal γ-globin (HbF) expression, replacing the missing adult β-globin. The mechanism of HbF induction by hydroxyurea and improvement in clinical symptoms are still poorly understood. In the present study we performed comparative analysis of plasma proteome in pre- and post-hydroxyurea-treated β-thalassemia major transfusion-dependent children (n = 10, mean age = 3.2 years) as well as responders versus nonresponders to hydroxyurea treatment. Plasma was collected before and after 6 months of hydroxyurea treatment, with patients subcategorized on the basis of their response to hydroxyurea. Among 400 identified proteins using a label-free quantitative proteomics approach, 28 proteins were found to be significantly different in pre- versus post-hydroxyurea-treated groups, with transferrin receptor protein-1 being most downregulated and hemopexin and haptoglobin the most upregulated proteins after treatment. In responder versus nonresponder comparison, 26 proteins were found to be differentially expressed, with carbonic anhydrase 1, hemoglobin subunit γ-1, and peroxiredoxin-2 showing the significant changes. The mechanism of hydroxyurea treatment in β-thalassemia patients appears to be complex, requiring a large sample size and a longer period of treatment to reveal its details.