Evaluation of beta-thalassemia in the fetus through cffDNA with multiple polymorphisms as a haplotype in the beta-globin gene

OBJECTIVE

Invasive biopsy during the pregnancy is associated with an abortion risk of approximately 1% for the fetus. Free fetal DNA in maternal plasma is an excellent source of genetic material for prenatal molecular diagnoses. This study was conducted to investigate beta-thalassemia mutation in the fetus through maternal blood with multiple polymorphisms as haplotypes in the beta-globin gene.

METHODS

In this study, a total of 33 beta-thalassemia carrier (minor) couples were genotyped by ARMS-PCR for IVSII-IG>A mutation. During pregnancy, 10mL of blood was collected from pregnant women, and DNA was extracted by the magnetic bead-based extraction, and fetal DNA was enriched with AMPure XP kit. Five polymorphisms in 4 haplotype groups were evaluated by the Sanger Sequencing method. Finally, results were compared with those of the invasion method.

RESULTS

Participants in study were 33 couples, mean age of the men was 26±5 years, and mean age of women was 23±4 years, and mean MCV, MCH, HbA2 blood parameters were 62.4±5.3, 19.6±3.1, 4.2±2.1 respectively. A total of 33 fetuses were genotyped for IVSII-IG>A mutation. Nine fetuses were affected, 10 fetuses were normal and 14 fetuses were carrier of beta-thalassemia. Sensitivity and specificity of Sanger Sequencing were equal to 88.8% and 91.6% respectively. Positive and negative predictive values were obtained as 80% and 95.6%, respectively.

CONCLUSION

Mutational status of the fetus can be assessed by determining inheritance of paternally-derived alleles based on detection of haplotype-associated SNP in maternal plasma. Magnetic-based DNA extraction and fetal DNA enrichment are very simple and easy to perform and have satisfactory accuracy.

Using LIBS as a diagnostic tool in pediatrics beta-thalassemia

Beta-thalassemia major is a common inherited single-gene disorder. Thalassemic patients are at risk of changes in some important trace elements. To detect alteration of iron, copper, zinc, and calcium serum levels in beta-thalassemia major patients, laser-induced breakdown spectroscopy (LIBS) was used. This study was conducted on 40 beta-thalassemia major and 40 healthy young patients (age: 12-18 years old; male:female = 1:1). Venous blood samples were collected from both groups and analyzed for the serum levels of iron, calcium, zinc, and copper by exposing the samples to LIBS. The intensities of the tested elements were detected using the Kestrel Spec computer software and analyzed with an SPSS 25 program. Thalassemic patients had significantly higher serum iron (p = < 0.001) and copper (p = < 0.005) while they had significantly lower serum zinc (p = < 0.005) and calcium (p= > 0.005) when compared with control. Also, thalassemic patients had significantly lower body weight and height as they were less than the 3rd percentile by 82.5% and p < 0.001. LIBS is a safe and efficient tool to detect alteration of some serum trace elements in beta-thalassemia patients.

Hepatocellular carcinoma in adult thalassemia patients: an expert opinion based on current evidence

Beta-thalassemia represents a heterogeneous group of haemoglobin inherited disorders, among the most common genetic diseases in the world, frequent in the Mediterranean basin. As beta-thalassemia patients' survival has increased over time, previously unknown complications are observed with increasing frequency. Among them, an increased risk of hepatocellular carcinoma (HCC) has been registered. Our aim is to reduce inequalities in diagnosis and treatment and to offer patients univocal recommendations in any institution.The members of the panel - gastroenterologists, radiologists, surgeons and oncologists -were selected on the basis of their publication records and expertise. Thirteen clinical questions, derived from clinical needs, and an integration of all the committee members' suggestions, were formulated. Modified Delphi approach involving a detailed literature review and the collective judgement of experts, was applied to this work.Thirteen statements were derived from expert opinions' based on the current literature, on recently developed reviews and on technological advancements. Each statement is discussed in a short paragraph reporting the current key evidence. As this is an emerging issue, the number of papers on HCC in beta-thalassemia patients is limited and based on anecdotal cases rather than on randomized controlled studies. Therefore, the panel has discussed, step by step, the possible differences between beta-thalassemia and non beta-thalassemia patients. Despite the paucity of the literature, practical and concise statements were generated.This paper offers a practical guide organized by statements describing how to manage HCC in patients with beta-thalassemia.

Seroprevalence of HBV, HCV and HIV-1 and Correlation with Molecular Markers among Multi-Transfused Thalassemia Patients in Western India

Background

Multitransfused β-thalassemia major patients are always at high risk of having Transfusion Transmitted Infections (TTIs). This study was aimed to determine the seroprevalence of HBsAg, Anti-HIV-1/2, and Anti-HCV among these patients and to correlate the same with NAT testing.

Methods

A total of 196 patients with β-thalassemia were included in the study. Patients were screened for the presence of viral markers by third-generation ELISA test as well as for viral DNA/RNA by NAT test.

Results

Among 196 multi-transfused Beta-thalassemia patients, the seroprevalence of anti-HCV was very high 100 (51.1%), however, anti-HIV1/2 was 6 (3.1%), and HBsAg were 3 (1.5%). Surprisingly similar patterns were observed in the prevalence of molecular markers, as HCV-RNA were 66 (33.7%) of the patients along with HIV-1 RNA were 8 (4.1%), and HBV-DNA were 5 (2.5%) patients. Overall eight (4.1%) patients were found to have coinfections, where two were positive for HBsAg/anti-HCV by ELISA along with 3 (1.5%) were positive for HBV-DNA/ HCV-RNA, 1 (0.5%) was positive for HIV-RNA/HBV-DNA, and 2 (1%) had coinfection of HIV-RNA/ HCV RNA by NAT testing

Conclusion

The prevalence of HCV infection among multi-transfused β-thalassemia patients is significantly higher than that of the HBV and HIV infections. This scenario should be controlled and monitored by doing regular follow-up testing schedules of such patients and also the administration of the booster dose of the HBV vaccine along with HCV treatment with antiviral DAAs.

Haplotype Analysis in Carriers of β-Globin Gene Mutation Facilitates Genetic Counseling in β-Thalassemia: A Cross-Sectional Study in Kerman Province, Iran

BACKGROUND

β-thalassemia is characterized by reduced synthesis of the hemoglobin beta chain that results in microcytic hypochromic anemia and reduced amounts of hemoglobin A (HbA) on hemoglobin analysis. β-thalassemias are caused by mutations in the β-globin gene, inherited in an autosomal recessive manner. Determining molecular defects in couples carrying β-thalassemia is a prerequisite for prenatal diagnosis of the disease. In this regards, database of β-globin gene haplotypes facilitates mutation detection of the gene and helps genetic counselors to reach the goals of β-thalassemia prevention program.

METHODS

In this cross-sectional study, 255 couples attended genetic counseling between December 2017 and January 2019 in Afzalipour Hospital, Kerman University of Medical Scinces, Kerman, Iran as suspicious of β-thalassemia carriers. Furthermore, they were investigated using amplification refractory mutations system-polymerase chain reaction and restriction fragment length polymorphism methods for mutation screening and haplotype analysis of polymorphic sites in β-globin gene cluster, respectively.

RESULTS

We identified 20 different types of β-globin gene mutation in 449 β-thalassemia carriers. Analysis of the pattern of Hind III/Gγ, Hinf I/5'β, Hinc II/3'Ψβ, Rsa I/5'β, AvaII/β and Hind III/Aγ polymorphic sites in 257 alleles of informative families revealed 17 different haplotypes. Haplotype 1 (77.24%) showed strong linkage with the most common mutation IVSI-5 while haplotype 5 (66.67%) was associated with the second frequent mutation IVSII-1.

CONCLUSION

To our knowledge, these β-globin haplotypes are reported for the first time which are different with those found in other parts of Iran. The current haplotypes pattern data makes the counseling of β-thalassemia carriers more straightforward and the process of mutation screening faster and more accurate.

HBG2 -158 (C>T) polymorphism and its contribution to fetal hemoglobin variability in Iraqi Kurds with beta-thalassemia minor

PURPOSE

Hemoglobin (Hb) F% is increased in up to half of beta-thalassemia (β-thal) carriers. Several polymorphisms have been linked to such variability in different populations, including HBG2 - 158(C>T) (Xmn I polymorphism) on chromosome 11. To determine the role of this polymorphism in such variability among Iraqi Kurds, the current study was initiated.

MATERIALS AND METHODS

A total of 102 consecutive patients diagnosed as β-thal minor were enrolled. The enrollees had their diagnosis based on peripheral blood counts and high-performance liquid chromatography to determine HbA2 and HbF. All enrollees had their DNA extracted by phenol-chloroform method and Xmn I polymorphism detected by restriction fragment length polymorphism-polymerase chain reaction.

RESULTS

The mean age (standard deviation [SD]) of the 102 enrollees was 25.4 (14.0) years, and the enrollees included 48 males and 54 females. Xmn I polymorphism was identified in heterozygous state in 46 (45.1%) patients and in homozygous state in one patient (0.98%). Thus, the minor allele frequency of this polymorphism was 0.235 in the studied group. There were no significant differences in red cell indices and HbA2% in carriers of the minor allele compared to noncarriers, while HbF% and absolute HbF concentrations were significantly higher in the former subgroup (P = 0.032 and 0.014, respectively). This polymorphism's contribution to HbF variability was found to be 5.8% in the studied sample. Furthermore, those with HbF ≥2% were 3.2 folds more likely to carry the minor allele.

CONCLUSIONS

Xmn I polymorphism is frequently encountered in Iraqi Kurds with β-thal minor, and it is significantly associated with higher fetal hemoglobin in these patients.

Comments to "PRevention of INCisional hernia after liver transplantation (PRINC trial): study protocol for a randomized controlled trial."

Prophylactic augmentation of the wound with mesh proposed by Kniepeiss et al is the world's first attempt to significantly reduce the risk of postoperative hernia in liver transplantation. Similar technique have been described 17 years ago in bariatric patients and confirmed by many studies in various clinical settings. The results of mesh hernia repair in patients on immunosuppressive therapy are not inferior from the data obtained from non- transplant surgery registers.To reduce the risk of using the mesh in patients scheduled for liver transplantation authors chose absorbable mesh, that maintains the mechanical strength of the wound for up to 18 months. Half of the incisional hernias have been diagnoses more than 3 years from the original procedure.For prevention of incisional hernias, there is no evidence to support the use of biologic/biosynthetic meshes.

Asymptomatic intracranial aneurysms in beta-thalassemia: a three-year follow-up report

Background

No information is currently available regarding the natural history of asymptomatic intracranial aneurysms in beta-thalassemia, raising several concerns about their proper management.

Methods

We performed a prospective longitudinal three-year-long MR-angiography study on nine beta-thalassemia patients (mean-age 40.3 ± 7.5, six females, 8 transfusion dependent) harboring ten asymptomatic intracranial aneurysms. In addition, we analyzed the clinical files of all adult beta-thalassemia patients (160 patients including those followed with MR-angiography, 121 transfusion dependent) referring to our Centers between 2014 and 2019 searching for history of subarachnoid hemorrhage or history of symptomatic intracranial aneurysms.

Results

At the end of the three-year-long follow-up, no patient showed any change in the size and shape of the aneurysms, none presented new intracranial aneurysms or artery stenoses, none showed new brain vascular-like parenchymal lesions or enlargement of the preexisting ones. Besides, in our database of all adult beta-thalassemia patients, no one had history of subarachnoid hemorrhage or history of symptomatic intracranial aneurysms.

Conclusions

Incidental asymptomatic intracranial aneurysms do not seem to be associated, in beta-thalassemia, with an increased risk of complications (enlargement or rupture) at least in the short term period, helping to optimize human and economic resources and patient compliance during their complex long-lasting management.

Molecular prevalence and genotypes of human pegivirus-1 (HPgV-1) and SENV-like viruses among multiply transfused patients with beta-thalassemia

Due to the high number of transfusions which patients with hereditary hemoglobinopathies (thalassemia, sickle cell disease) receive, they represent high risk of acquiring parenterally transmitted infectious diseases. In this respect, non pathogenic human commensal viruses, which also demonstrate parenteral transmission routes might also be acquired. One of the most widely spread parenterally-transmitted human commensal viruses include the Human Pegivirus-1 (HPgV-1, GBV-C) and Torque teno viruses (TTV) including its SEN virus-like (SENV) forms. The objective of this study was to evaluate the prevalence of HPgV-1 RNA and SENV-like viruses, among a group of patients with beta-thalassemia from a Blood Transfusion Center in the São Paulo State, Brazil. The prevalence of HPgV-1 RNA was 14.3 % (n = 6/42) and all of the positive samples were characterized as belonging to genotype 2 (83.3 % were referred to subgenotype 2A and 16.7 % to 2B). The prevalence of SENV-like viruses was 28.6 % (n = 12/42). SENV-like viruses of the genotypes SENV-H and SENV-A were classified during the performed phylogenetic analysis. Our study came as a continuation of a viral metagenomic survey among multiple transfused patients with beta-thalassemia. The obtained results shed a light on the prevalence and genotype distribution of commensal parenterally transmitted viruses like HPgV-1 and SENV in this specific population. However, more studies are needed to evaluate the clinical impact of these apparently non-pathogenic viruses in patients with thalassemia and their significance for the hemotherapy.

Effect of quercetin on oxidative stress and liver function in beta-thalassemia major patients receiving desferrioxamine: A double-blind randomized clinical trial

Background:

Blood transfusion therapy is lifesaving for beta-thalassemia major patients, yet it indirectly causes complications such as oxidative stress and liver dysfunction. In the present study, we investigated the effect of quercetin supplementation on oxidative stress and liver function in beta-thalassemia major patients.

Materials and Methods:

In this double-blind clinical trial, 84 beta-thalassemia patients who received desferrioxamine (DFO) were randomly assigned to two groups; the treatment group received 500 mg quercetin tablet daily for 12 weeks, and the control group received placebo. In addition to demographic and anthropometric assessment, malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were biochemically assessed to detect the effect of quercetin on oxidative stress and liver function, respectively. The data were analyzed using SPSS 21. P < 0.05 was considered statistically significant.

Results:

Before adjusting for confounding variables, within-group comparison showed that quercetin supplementation reduced ALT (P < 0.001) and TAC (P < 0.001) significantly. Between-group comparison using analysis of covariance analysis though showed that quercetin could significantly reduce ALT (P = 0.002), but there was an insignificant increase in SOD and TAC, and insignificant decrease in GPx, MDA, AST, and ALP (P > 0.05).

Conclusion:

According to our results, consumption of 500 mg quercetin supplement daily for 3 months along with DFO treatment might be able to alter liver function, but not the oxidative stress in beta-thalassemia major patients.

Comparative effectiveness of alendronate and zoledronic acid on bone mass improvement in transfusion-dependent thalassemia patients

Thalassemia, as the most prevalent genetic blood disorder, has many associated comorbidities including low bone mass. We studied the comparative effectiveness of alendronate (AL) and zoledronic acid (ZOL) on bone mass improvement in transfusion-dependent thalassemia (TDT) patients a year after treatment. Three hundred seventy-five TDT patients with low bone mass were enrolled in this study. After a year of treatment with either AL or ZOL, a second bone mineral density (BMD) test was ordered to compare the effectiveness of the two aforementioned drugs. Body mass index (BMI), physical activity, sun exposure, and biochemical laboratory data were also considered as associated factors in this study. The BMD test of both groups was almost the same at the baseline and it increased comparably after a year of treatment with AL and ZOL. However, there was a significant difference in lumbar spine BMD delta Z score between both groups of female patients. ZOL was more effective in increasing the lumbar spine BMD of female patients. The choice of bisphosphonates therapy (oral versus parenteral) should be individually selected by considering patient's preference, compliance and the physician's decision. Given the longer administration interval, and TDT patients' compliance issue, it is justified to recommend ZOL as the drug of choice for patients suffering from low bone mass.

Brain iron content in systemic iron overload: A beta-thalassemia quantitative MRI study

•

Iron overload is a life-threatening condition in beta-thalassemia.

•

Data on brain involvement in systemic iron overload are conflicting.

•

MRI quantification of brain tissue iron content is feasible in a voxel-based approach.

•

No iron tissue excess is evident in beta-thalassemia but in the choroid plexuses.

Objective

Multisystem iron poisoning is a major concern for long-term beta-thalassemia management. Quantitative MRI-based techniques routinely show iron overload in heart, liver, endocrine glands and kidneys. However, data on the brain are conflicting and monitoring of brain iron content is still matter of debate.

Methods

This 3T-MRI study applied a well validated high-resolution whole-brain quantitative MRI assessment of iron content on 47 transfusion-dependent (mean-age: 36.9 ± 10.3 years, 63% females), 23 non-transfusion dependent (mean-age: 29.2 ± 11.7 years, 56% females) and 57 healthy controls (mean-age: 33.9 ± 10.8 years, 65% females). Clinical data, Wechsler Adult Intelligence Scale scores and treatment regimens were recorded. Beside whole-brain R2* analyses, regional R2*-values were extracted in putamen, globus pallidum, caudate nucleus, thalamus and red nucleus; hippocampal volumes were also determined.

Results

Regional analyses yielded no significant differences between patients and controls, except in those treated with deferiprone that showed lower R2*-values (p<0.05). Whole-brain analyses of R2*-maps revealed strong age-R2* correlations (r²=0.51) in both groups and clusters of significantly increased R2*-values in beta-thalassemia patients in the hippocampal formations and around the Luschka foramina; transfusion treatment was associated with additional R2* increase in dorsal thalami. Hippocampal formation R2*-values did not correlate with hippocampal volume; hippocampal volume did not differ between patients and controls. All regions with increased R2*-values shared a strict anatomical contiguity with choroid plexuses suggesting a blooming effect as the likely cause of R2* increase, in agreement with the available histopathologic literature evidence.

Conclusion

According to our MRI findings and the available histopathologic literature evidence, concerns about neural tissue iron overload in beta-thalassemia appear to be unjustified.

Subclinical nephrotoxicity in patients with beta-thalassemia: role of urinary kidney injury molecule

We aimed to investigate the role of urinary kidney injury molecule-1 (KIM-1) in detection of subclinical nephrotoxicity in patients with Beta-thalassemia (β-TM) in relation to chelation therapy and to correlate the urinary KIM-1 level with other clinical and laboratory findings. We conducted a cross-sectional study on 66 thalassemic patients. Their ages range from 7 to 22 years. Routine kidney indices and novel urinary KIM/creatinine ratio (U_KIM-1/Cr) were measured. Estimated glomerular filtration rate (eGFR) was calculated. Results indicate that the level of serum creatinine was significantly higher in patients on deferasirox therapy than patients on deferoxamine and deferiprone therapy [median(IQR), 0.85(0.63-0.99), 0.50(0.34-0.58) and 0.44(0.36-0.45)] mg/dL, respectively, p < 0.001]. The median(IQR) level of eGFR was significantly lower in patients on deferasirox therapy than patients on deferoxamine and deferiprone therapy [63.3(56.5-92.1), 117.3(91.9-162) and 136.7(109.4-157.6)] ml/min/1.73 m², respectively, p < 0.001]. The mean level of U_KIM-1/Cr was significantly higher in patients on deferasirox therapy than patients on deferoxamine and deferiprone therapy (7.0 ± 1.9, 4.1 ± 1.7 and 4.2 ± 1.5) ng/mg creatinine, respectively, p < 0.001). We concluded that urinary KIM-1 is an early predictive biomarker for decline in eGFR in patients with β-TM on deferasirox therapy. The appropriate chelation therapy and good monitoring of those patients are intensely needed for early detection of renal dysfunction and timely intervention.

Investigation of correlation between H63D and C282Y mutations in HFE gene and serum Ferritin level in beta-thalassemia major patients

INTRODUCTION

Mutations in the HFE gene have been shown to be associated with hemochromatosis which is observed in beta-thalassemia major. In this study, we determined the HFE gene mutations (C282Y and H63D) among b-thalassemia major patients to investigate the effect of these mutations on serum Ferritin levels.

MATERIAL AND METHODS

In this cross-sectional study, a total of 105 b-thalassemia subjects with a history of regular blood transfusion were selected. They divided into two distinct groups according cut off 1000ng/ml of serum Ferritin levels. The HFE gene mutant allele detected by RFLP-PCR.

RESULTS

Of 105 thalassemia patients, 29 patients (14 male and 15 female) were heterozygote for H63D mutation, and just one male was homozygote, but for C282Y mutation just one heterozygote and one homozygote was detected, and overall 31% had coexistence of b-thal and HFE gene mutations. As expected, Ferritin levels significantly differed between groups (P=0.001).

CONCLUSION

The impact of detection of HFE mutations could prognosis the likelihood of iron overload in multi-transfused patients, and allowing early diagnosis and proper management to overcome complications of iron overload in beta-thalassemia patients.

Echocardiografic abnormalities in patients with sickle cell/β-thalassemia do not depend on the β-thalassemia phenotype

OBJECTIVES AND METHODS

We evaluated possible relationships between echocardiographic findings and clinical and laboratory parameters, in a cohort of Brazilian patients diagnosed with sickle cell/β-thalassemia, to better understand the cardiac involvement in this disease.

RESULTS

Left atrial (LA) and left ventricular (LV) dilation were found in 19.5 and 11% of patients, respectively; systolic left ventricular dysfunction was present in a single patient. There were no differences in masses and volumes of cardiac chambers comparing Sβ⁰ with Sβ⁺ patients, and no relationship between these parameters and specific complications of the disease. However, parameters of altered ventricular geometry were significantly correlated with serum creatinine, hepatic transaminases and bilirubin levels. Moreover, 3 patients presented stroke; they were significantly older [53 (41-56)×37.5 (18-70), p=0.048], had higher values of LV posterior wall diastolic thickness [10 (10-11)×8 (6-14), p=0.03], LV mass [226 (194-260)×147 (69-537), p=0.039] and LA/aortic ratio [1.545 (1.48-1.61)×1.26 (0.9-1.48), p=0.032].

CONCLUSIONS

Cardiac involvement in this disease does not appear to depend on the thalassemia phenotype. The presence of signs of myocardial remodeling in this group of patients was related to multi-organ impairment and rendered a higher propensity for stroke in older patients, suggesting the need for greater vigilance and control of associated factors.

Characterization of thalassemia major and diabetes mellitus patients at a reference center in Brazil

OBJECTIVE

This is a quantitative transversal study that aimed to analyze the sociodemographic and clinical characteristics of thalassemia major patients with and without diabetes mellitus.

METHOD

The cohort consisted of 31 thalassemia major patients from a reference center of treatment in Brazil in 2016. The data were obtained from an interview using a questionnaire containing demographic and clinical variables. The results show that 16.1% of the participants with thalassemia major had diabetes mellitus. The participants' ages ranged from 20 to 48 years, with an average of 35 years, mostly students and starting in the formal job market. The most commonly used treatment was the oral desferasirox and the transfusion treatment interval was 15-22 days.

RESULTS

Patients with thalassemia major and diabetes mellitus presented altered values of fasting glycemia, serum alanine transaminase, magnetic resonance imaging and bone densitometry.

CONCLUSION

It was concluded that knowledge of the characteristics of this population contributes in the proposal of effective educational strategies in light of the complexity of care and the progression of the disease.

No increased cerebrovascular involvement in adult beta-thalassemia by advanced MRI analyses

Beta-thalassemia-related anemia and chronic hypercoagulative state are supposed to cause cumulative cerebrovascular damage with consequent parenchymal/vascular changes and functional impairment. However, recent conventional MRI/MR-angiography investigations failed to show an increased cerebrovascular involvement in beta-thalassemia patients managed according to current treatment guidelines, in spite of significantly decreased full-scale IQ scores. We therefore investigated those patients and controls by means of advanced quantitative MRI analyses (based on magnetization transfer and diffusion tensor imaging) searching for signs of possible cerebrovascular injuries undetected by conventional MRI/MR-angiography. The 3 T-MRI study protocol included diffusion tensor imaging and 3D-multi-echo FLASH sequences for magnetization transfer analysis. Whole-brain voxel-based analyses showed that magnetization transfer, fractional anisotropy, and mean, radial and axial diffusivity do not differ between healthy controls and beta-thalassemia patients (considered as a whole group or as distinct transfusion dependent and non-transfusion dependent subgroups). No correlation emerged between all the considered MRI metrics and cognitive findings (full-scale IQ) or the main clinical and laboratory data. According to our findings, adult neurologically-asymptomatic beta-thalassemia patients (regardless of clinical severity) do not seem to present an increased disease-related cerebrovascular vulnerability compared to healthy controls downsizing the need of regular brain MRI monitoring, at least when the current treatment guidelines are followed.

Targeted deletion of BCL11A gene by CRISPR-Cas9 system for fetal hemoglobin reactivation: A promising approach for gene therapy of beta thalassemia disease

Hemoglobinopathies, such as β-thalassemia, and sickle cell disease (SCD) are caused by abnormal structure or reduced production of β-chains and affect millions of people worldwide. Hereditary persistence of fetal hemoglobin (HPFH) is a condition which is naturally occurring and characterized by a considerable elevation of fetal hemoglobin (HbF) in adult red blood cells. Individuals with compound heterozygous β-thalassemia or SCD and HPFH have milder clinical symptoms. So, HbF reactivation has long been sought as an approach to mitigate the clinical symptoms of β-thalassemia and SCD. Using CRISPR-Cas9 genome-editing strategy, we deleted a 200bp genomic region within the human erythroid-specific BCL11A (B-cell lymphoma/leukemia 11A) enhancer in KU-812, KG-1, and K562 cell lines. In our study, deletion of 200bp of BCL11A erythroid enhancer including GATAA motif leads to strong induction of γ-hemoglobin expression in K562 cells, but not in KU-812 and KG-1 cells. Altogether, our findings highlight the therapeutic potential of CRISPR-Cas9 as a precision genome editing tool for treating β-thalassemia. In addition, our data indicate that KU-812 and KG-1 cell lines are not good models for studying HbF reactivation through inactivation of BCL11A silencing pathway.

Beta-thalassemia: renal complications and mechanisms: a narrative review

OBJECTIVES

Beta-thalassemias are a group of recessively autosomal inherited disorders of hemoglobin synthesis, which, due to mutations of the beta-globin gene, lead to various degrees of defective beta-chain production, an imbalance in alpha/beta-globin chain synthesis, ineffective erythropoiesis, and anemia. Improved survival in thalassemic patients has led to the emergence of previously unrecognized complications, such as renal disease.

METHODS

A comprehensive literature review through PubMed was undertaken to summarize the published evidence on the epidemiology and pathophysiology of renal disease in thalassemia. Literature sources published in English since 1990 were searched, using the terms beta-thalassemia, renal disease.

RESULTS

Renal disease is considered to be the 4th cause of morbidity among patients with transfusion dependent thalassemia. Chronic anemia, hypoxia and iron overload are the main mechanisms implicated in development of renal injury, whereas several studies also suggested a contributive role of iron chelators.

DISCUSSION AND CONCLUSION

Kidney disease may develop through progressive renal tubular and glomerular damage; thus, its early recognition is important in order to prevent and/or reverse deterioration. This review will provide an insight on the involved mechanisms implicated in kidney disease in thalassemic patients and will discuss the updates on diagnosis and prevention of renal complications in thalassemia.

Investigation of RFLP Haplotypes β-Globin Gene Cluster in Beta-Thalassemia Patients in Central Iran

Introduction: Beta-thalassemia is one of the most prevalent inherited blood diseases among Iranians. The aim of this study was to elucidate the chromosomal background of beta-thalassemia mutations in Esfahan province, Iran. Materials and Methods: In this study, we investigated three frequent mutations (c.315+1G>A, c.93-21G>A and c.92+5G>C in β-globin gene, the frequency of RFLP haplotypes, and LD between markers at β-globin gene cluster) in 150 beta-thalassemia patients and 50 healthy individuals. The molecular and population genetic investigations were performed on RFLP markers HindIII in the c.315+1G>A of Gγ (HindIIIG) and Aγ (HindIIIA) genes, AvaII in the c.315+1G>A of β-globin gene and BamHI 3' to the β-globin gene. All statistical analyses were performed using Power Marker software and SISA server. Results: Fifty percent of beta-thalasemia patients were associated with these mutations. Haplotype I was the most prevalent haplotype among beta-thalassemia patients (39.33%) and normal individuals (46%). The commonest c.315+1G>A mutation in our population was tightly linked with haplotype III (43.75%) and haplotype I (31.25%). The second prevalent mutation, c.92+5G>C, was 90%, 6.66%, and 3.33% in linkage disequilibrium with haplotypes I, VII, and III, respectively. The c.93-21G>A mutation indicated a strong association with haplotype I (80%). Conclusion: Our study participants like beta-thalassemia patients from Kermanshah province was found to possess a similar haplotype background for common mutations. The emergence of most prevalent mutations on chromosomes with different haplotypes can be explained by gene conversion and recombination. High linkage of a mutation with specific haplotype is consistent with the hypothesis that chromosomes carrying beta-thalassemia mutations experienced positive selection pressure, probably because of the protection against malaria experienced by beta-thalassemia carriers.

Cardiac involvement by CMR in different genotypic groups of thalassemia major patients

Beta thalassemia major (β-TM) displays a great deal of phenotypic heterogeneity, not fully investigated in terms of cause-effect. We aimed to detect if different genotypic groups could be related to different levels of cardiac impairment, evaluated by cardiovascular magnetic resonance (CMR). We considered 671 β-TM patients (age 30.1 years, 52.9% females) consecutively enrolled in the Myocardial Iron Overload (MIO) in Thalassemia network. MIO was assessed by T2* technique. Biventricular function was quantified by cine images. Myocardial fibrosis was evaluated by late gadolinium enhancement (LGE) technique. Three groups of patients were identified: heterozygotes β⁺/β° (N = 279), homozygotes β ⁺ (N = 154), homozygotes β° (N = 238). Transfusional needs resulted significantly lower in homozygous β ⁺ TM patients when compared to the other groups. The homozygous β ⁺ group versus the heterozygous and homozygous β° groups showed higher global heart T2* values (P < 0.0001) and a lower number of patients with a global heart T2* value<20 ms (P < 0.001). The homozygotes β ⁺ showed a lower number of patients with a pathological left ventricular ejection fraction (LVEF) than the other two groups (P < 0.05). The β⁺/β ⁺ TM patients showed less MIO and a concordant better systolic heart function. These data support the knowledge of different genotypic groups in the management of β-TM patients.

News from Mars: Two-Tier Paradox, Intracellular PCR, Chimeric Junction Shift, Dark Matter mRNA and Other Remarkable Features of Mammalian RNA-Dependent mRNA Amplification. Implications for Alzheimer's Disease, RNA-Based Vaccines and mRNA Therapeutics

Molecular Biology, a branch of science established to examine the flow of information from "letters" encrypted into DNA structure to functional proteins, was initially defined by a concept of DNA-to-RNA-to-Protein information movement, a notion termed the Central Dogma of Molecular Biology. RNA-dependent mRNA amplification, a novel mode of eukaryotic protein-encoding RNA-to-RNA-to-Protein genomic information transfer, constitutes the extension of the Central Dogma in the context of mammalian cells. It was shown to occur in cellular circumstances requiring exceptionally high levels of production of specific polypeptides, e.g. globin chains during erythroid differentiation or defined secreted proteins in the context of extracellular matrix deposition. Its potency is reflected in the observed cellular levels of the resulting amplified mRNA product: At the peak of the erythroid differentiation, for example, the amount of globin mRNA produced in the amplification pathway is about 1500-fold higher than the amount of its conventionally generated counterpart in the same cells. The cellular enzymatic machinery at the core of this process, RNA-dependent RNA polymerase activity (RdRp), albeit in a non-conventional form, was shown to be constitutively and ubiquitously present, and RNA-dependent RNA synthesis (RdRs) appeared to regularly occur, in mammalian cells. Under most circumstances, the mammalian RdRp activity produces only short antisense RNA transcripts. Generation of complete antisense RNA transcripts and amplification of mRNA molecules require the activation of inducible components of the mammalian RdRp complex. The mechanism of such activation is not clear. The present article suggests that it is triggered by a variety of cellular stresses and occurs in the context of stress responses in general and within the framework of the integrated stress response (ISR) in particular. In this process, various cellular stresses activate, in a stress type-specific manner, defined members of the mammalian translation initiation factor 2α, eIF2α, kinase family: PKR, GCN2, PERK and HRI. Any of these kinases, in an activated form, phosphorylates eIF2α. This results in suppression of global cellular protein synthesis but also in activation of expression of select group of transcription factors including ATF4, ATF5 and CHOP. These transcription factors either function as inducible components of the RdRp complex or enable their expression. The assembly of the competent RdRp complex activates mammalian RNA-dependent mRNA amplification, which appears to be a two-tier process. Tier One is a "chimeric" pathway, named so because it results in an amplified chimeric mRNA molecule containing a fragment of the antisense RNA strand at its 5' terminus. Tier Two further amplifies one of the two RNA end products of the chimeric pathway and constitutes the physiologically occurring intracellular polymerase chain reaction, iPCR. Depending on the structure of the initial mRNA amplification progenitor, the chimeric pathway, Tier One, may result in multiple outcomes including chimeric mRNA that produces either a polypeptide identical to the original, conventional mRNA progenitor-encoded protein or only its C-terminal fragment, CTF. The chimeric RNA end product of Tier One may also produce a polypeptide that is non-contiguously encoded in the genome, activate translation from an open reading frame, which is "silent" in a conventionally transcribed mRNA, or initiate an abortive translation. In sharp contrast, regardless of the outcome of Tier One, the mRNA end product of Tier Two of mammalian mRNA amplification, the iPCR pathway, always produces a polypeptide identical to a conventional mRNA progenitor-encoded protein. This discordance is referred to as the Two-Tier Paradox and discussed in detail in the present article. On the other hand, both Tiers are similar in that they result in heavily modified mRNA molecules resistant to reverse transcription, undetectable by reverse transcription-based methods of sequencing and therefore constituting a proverbial "Dark Matter" mRNA, despite being highly ubiquitous. It appears that in addition to their other functions, the modifications of the amplified mRNA render it compatible, unlike the bulk of cellular mRNA, with phosphorylated eIF2α in translation, implying that in addition to being extraordinarily abundant due to the method of its generation, amplified mRNA is also preferentially translated under the ISR conditions, thus augmenting the efficiency of the amplification process. The vital importance of powerful mechanisms of amplification of protein-encoding genomic information in normal physiology is self-evident. Their malfunctions or misuse appear to be associated with two types of abnormalities, the deficiency of a protein normally produced by these mechanisms and the mRNA amplification-mediated overproduction of a protein normally not generated by such a process. Certain classes of beta-thalassemia exemplify the first type, whereas the second type is represented by overproduction of beta-amyloid in Alzheimer's disease. Moreover, the proposed mechanism of Alzheimer's disease allows a crucial and verifiable prediction, namely that the disease-causing intraneuronally retained variant of beta-amyloid differs from that produced conventionally by βAPP proteolysis in that it contains the additional methionine or acetylated methionine at its N-terminus. Because of its extraordinary evidential value as a natural reporter of the mRNA amplification pathway, this feature, if proven, would, arguably, constitute the proverbial Holy Grail not only for Alzheimer's disease but also for the mammalian RNA-dependent mRNA amplification field in general. Both examples are discussed in detail in the present article, which summarizes and systematizes our current understanding of the field and describes two categories of reporter constructs, one for the chimeric Tier of mRNA amplification, another for the iPCR pathway; both reporter types are essential for elucidating underlying molecular mechanisms. It also suggests, in light of the recently demonstrated feasibility of RNA-based vaccines, that the targeted intracellular amplification of exogenously introduced amplification-eligible antigen-encoding mRNAs via the induced or naturally occurring RNA-dependent mRNA amplification pathway could be of substantial benefit in triggering a fast and potent immune response and instrumental in the development of future vaccines. Similar approaches can also be effective in achieving efficient and sustained expression of exogenous mRNA in mRNA therapeutics.

The Effect of a Training Program Based on the PRECEDE-PROCEED Model on Lifestyle of Adolescents with Beta-Thalassemia: A Randomized Controlled Clinical Trial

Background: Lifestyle is a key issue in the concept of health promotion. Lifestyle includes all activities that encourage optimum physical, spiritual, and mental functions. The aim of this study was to determine the effect of a training program based on PRECEDE-PROCEED Model on lifestyle of adolescents with beta thalassemia. Materials and Methods: In this clinical trial study, 64 adolescents (age 16-20) who referred to the Thalassemia Center of Ahvaz (2015) were selected and randomly divided into two groups: experimental and control group. The components of the PRECEDE-PROCEED Model were used for planning, implementation and evaluation of the program. Changes in predisposing, reinforcing, enabling factors and lifestyle were immediately and a month after the intervention were assessed by a questionnaire based on PRECEDE-PROCEED Model and the Health-Promoting Lifestyle Profile. Results: The intervention had significantly positive effect on predisposing, enabling and reinforcing factors immediately and a month after the intervention (P < 0.05). Repeated measures analysis of variance showed a significant positive increase in the six dimensions of lifestyle score in the experimental group from baseline to one-month follow-up (P < 0.05). Conclusion: This study showed that the theory-based training program in adolescents suffered from beta thalassemia disease could improve the adolescent's awareness and attitude of healthy lifestyle.

The burden of psychiatric illnesses in adult patients with beta-thalassemia: a 5-year nationwide inpatient evaluation in the United States

Beta-thalassemia (ß-thalassemia) is a frequently inherited monogenic disorder worldwide with severe physical and mental health comorbidities. The aim of this study is to evaluate the burden of psychiatric disorders in adult patients hospitalized with ß-thalassemia in the United States (US). We utilized the discharge data from the National Inpatient Sample (NIS) from 2010 through 2014 to identify hospitalized ß-thalassemia patients who are 18 years and older. We assessed categorical and continuous variables using chi-square test and Student's t test respectively. The burden of psychiatric disorders was assessed using descriptive statistics and represented in terms of frequency (n) and percentage (%). A p value threshold of < 0.05 was considered clinically significant. All statistical analyses were performed using SPSS version 22.0 (IBM Corp., Armonk, NY, USA). Of the 10,046 ß-thalassemia patients studied, 24.4% (n = 2448) reported psychiatric disorders. Mood disorders (15.2%; inclusive of 10.3% depression), followed by anxiety (9.4%), and substance abuse disorder (6.5%; 4.3% drug abuse, 2.2% alcohol abuse) were most prevalent. Comorbid mental illnesses increased the length of stay by 44.6% and total costs by 23.4%. All-cause mortality rate was reported at 1.9% in overall ß-thalassemia patients. This study highlights higher rates of psychiatric disorders such as depression and anxiety and correlated increases in length of stay and cost in hospitalized ß-thalassemia patients. To improve medical outcomes and curtail unnecessary health-care costs, implementation of an integrated care model can be considered.

Gene correction of HBB mutations in CD34+ hematopoietic stem cells using Cas9 mRNA and ssODN donors

Background

β-Thalassemia is an inherited hematological disorder caused by mutations in the human hemoglobin beta (HBB) gene that reduce or abrogate β-globin expression. Although lentiviral-mediated expression of β-globin and autologous transplantation is a promising therapeutic approach, the risk of insertional mutagenesis or low transgene expression is apparent. However, targeted gene correction of HBB mutations with programmable nucleases such as CRISPR/Cas9, TALENs, and ZFNs with non-viral repair templates ensures a higher safety profile and endogenous expression control.

Methods

We have compared three different gene-editing tools (CRISPR/Cas9, TALENs, and ZFNs) for their targeting efficiency of the HBB gene locus. As a proof of concept, we studied the personalized gene-correction therapy for a common β-thalassemia splicing variant HBB^IVS1–110 using Cas9 mRNA and several optimally designed single-stranded oligonucleotide (ssODN) donors in K562 and CD34⁺ hematopoietic stem cells (HSCs).

Results

Our results exhibited that indel frequency of CRISPR/Cas9 was superior to TALENs and ZFNs (P < 0.0001). Our designed sgRNA targeting the site of HBB^IVS1–110 mutation showed indels in both K562 cells (up to 77%) and CD34⁺ hematopoietic stem cells—HSCs (up to 87%). The absolute quantification by next-generation sequencing showed that up to 8% site-specific insertion of the NheI tag was achieved using Cas9 mRNA and a chemically modified ssODN in CD34⁺ HSCs.

Conclusion

Our approach provides guidance on non-viral gene correction in CD34⁺ HSCs using Cas9 mRNA and chemically modified ssODN. However, further optimization is needed to increase the homology directed repair (HDR) to attain a real clinical benefit for β-thalassemia.

Electronic supplementary material

The online version of this article (10.1186/s40348-018-0086-1) contains supplementary material, which is available to authorized users.