Thalassemia and related hemoglobinopathies

A community based study on haemoglobinopathies and G6PD deficiency among particularly vulnerable tribal groups in hard-to-reach malaria endemic areas of Odisha, India: implications on malaria control

BACKGROUND

Haemoglobinopathies and G6PD deficiency are inherited disorders found mostly in malaria-endemic areas among different tribal groups of India. However, epidemiological data specific to Particularly Vulnerable Tribal Groups (PVTGs), important for planning and implementing malaria programmes, is limited. Therefore, the present community-based study aimed to assess the prevalence of haemoglobinopathies and G6PD deficiency among the 13 PVTGs found in the state of Odisha, reporting the maximum malaria cases in the country.

METHODS

This cross-sectional study was conducted from July 2018 to February 2019 in 12 districts, home to all 13 PVTGs, in an estimated sample size of 1461, selected two-stage sampling method. Detection of haemoglobinopathies was done by the variant analyser. Screening of G6PD deficiency was carried out using DPIP method followed by quantification using spectrophotometry. The PCR-RFLP technology was used to determine variant of G6PD deficiency and haplotype analysis of sickle cell, while ARMS-PCR and GAP-PCR was used for detecting the mutation pattern in β-thalassaemia and α-thalassaemia respectively. The diagnosis of malaria was done by Pf-PAN RDT as point of care, followed by nPCR for confirmation and Plasmodium species identification.

RESULTS

The prevalence of sickle cell heterozygotes (AS) was 3.4%, sickle cell homozygous (SS) 0.1%, β-thalassaemia heterozygotes 0.3%, HbS/β-thalassaemia compound heterozygote 0.07%, HbS-α-thalassaemia 2.1%, G6PD deficiency 3.2% and malaria 8.1%. Molecular characterization of βS revealed the presence of Arab-Indian haplotype in all HbS cases and IVS 1-5 G → C mutation in all β-thalassaemia cases. In case of α-thal, αα/α-3.7 gene deletion was most frequent (38%), followed by αα/α-4.2 (18%) and α-3.7/α-3.7 (4%). The frequency of G6PD Orissa (131C → G) mutation was found to be 97.9% and G6PD Mediterranean (563C → T) 2.1%. Around 57.4% of G6PD deficient individuals and 16% of the AS were found to be malaria positive.

CONCLUSION

The present study reveals wide spread prevalence of sickle cell anaemia, α-thalassaemia, G6PD deficiency and malaria in the studied population. Moderate to high prevalence of G6PD deficiency and malaria warrants G6PD testing before treating with primaquine (PQ) for radical cure of Plasmodium vivax. Screening and counselling for HbS is required for the PVTGs of Odisha.

Evaluation of the Function of a Rare Variant in the 3'-Untranslated Region of the β-Globin Gene

β-Thalassemia (β-thal) is an inherited genetic disease that occurs because of the absence or reduction of β-globin chain synthesis. Genetic changes occur in different regions of the β-globin gene, but these mutations are less reported in the 3' untranslated region (3'-UTR). The objective of the present investigation was to evaluate the functional effect of a rare variant in the 3'-UTR of the β-globin gene. A variant at the first nucleotide of the 3'-UTR of the β-globin gene (HBB: c.*1G > A) was identified by DNA sequencing in an individual with low hematological indices and a normal hemoglobin (Hb) electrophoresis pattern. To evaluate the functional effect of this variant, the normal and mutated 3'-UTR of the β-globin gene was synthesized separately and sub cloned in the psiCHEK2 vector. Next, using the calcium phosphate method, the psiCHEK2 vectors containing normal and mutated 3'-UTR were transfected separately into the HEK293T cell line. Finally, the transfected cell line was analyzed by dual luciferase assay. The ratio of Renilla to firefly for the mutant sample was 1.26 ± 0.06, while for normal samples it was 1.12 ± 0.04. The results of the luciferase assay showed that there was no significant difference in the functional effect between the mutant and wild type construct. Therefore, it was concluded that this variant might not reduce the expression of the β-globin gene. Future studies by globin chain synthesis or to evaluate the expression of the gene in erythroid cells, might be necessary to understand the regulatory function of this mutation.

New Insights into Hemolytic Anemias: Ultrastructural and Nanomechanical Investigation of Red Blood Cells Showed Early Morphological Changes

Several diseases are characterized by changes in the mechanical properties of erythrocytes. Hemolytic anemias are an example of these diseases. Among the hemolytic anemias, Sickle Cell Disease and Thalassemia are the most common, characterized by alterations in the structure of their hemoglobin. Sickle cell disease has a pathological origin in synthesizing abnormal hemoglobin, HbS. In contrast, thalassemia results in extinction or decreased synthesis of α and β hemoglobin chains. This work presents a detailed study of biophysical and ultrastructural early erythrocytes membrane alterations at the nanoscale using Atomic Force Microscopy (AFM). Cells from individuals with sickle cell anemia and thalassemia mutations were studied. The analysis methodology in the AFM was given by blood smear and exposure of the inner membrane for ghost analysis. A robust statistic was used with 65,536 force curves for each map, ten cells of each type, with three individuals for each sample group. The results showed significant differences in cell rigidity, adhesion, volume, and roughness at early morphological alterations, bringing new perspectives for understanding pathogenesis. The sickle cell trait (HbAS) results stand out. Significant alterations were observed in the membrane properties, bringing new perspectives for the knowledge of this mutation. This work presents ultrastructural and biomechanical signatures of sickle cell anemia and thalassemia genotypes, which may help determine a more accurate biophysical description and clinical prognosis for these diseases.

Clinical and Biochemical Assessment of Liver Function Test and Its Correlation with Serum Ferritin Levels in Transfusion-dependent Thalassemia Patients

Aims

The aim of our study was to correlate liver function tests with serum ferritin levels in multi-transfused thalassemia patients.

Methods 

This was a descriptive cross-sectional study conducted in the department of hematology, Khyber Medical University, from January 2018 to December 2018. Thalassemia patients of either sex dependent on transfusion ≥ 1 year and having a confirmatory report of the disease were included in our study. The nonprobability convenience sampling technique was used. The Pearson correlation coefficient was applied to observe the correlation between serum ferritin level and liver function tests. A p-value of ≤0.05 was considered statistically significant. SPSS version 23 (SPSS Inc., Chicago, Illinois) was used for data analysis.

Results

A total of 138 subjects of age range 2-23 years, with a mean age of 12.08 ± 6.02 years, were included in our study. The mean serum ferritin of patients in our study was 3278.64 ng/ml with the lowest of 285.2 ng/mL and the highest of 10940.2 ng/ml. With the increase in serum ferritin levels, a rapid increase in alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) levels was seen. When serum ferritin levels were correlated with total bilirubin level, the bilirubin level remains static with a further increase in serum ferritin levels.

Conclusion

It was deduced that iron deposition is the ultimate reason for increased liver enzymes. There was a positive correlation between serum ferritin and ALT, AST, and ALP while a weak connection was found between serum ferritin and bilirubin levels.

Monogenic diseases in India

Studies on monogenic diseases are considered valuable because they give insights and expand our knowledge on gene function and regulation. Despite all the current advancement in science and technology, a deep understanding and knowledge as to why only those particular genes are affected in a disease is still vague. We also lack profound illumination as to why only certain mutations are seen in a disease. Though useful from a research perspective, a majority of these diseases are lethal resulting in death of the affected individual. Unfortunately, in the fast - growing land of India, the incidence of monogenic diseases is very high with few counter-measures in place. This article encompasses a list of all monogenic diseases ever to be reported in India with special focus on five diseases which has been stated to have the highest incidence in India. Here, we discuss about the limited research carried out in India on these high incidence monogenic diseases, the other diseases related to those genes, the range of treatments available for these diseases in India in contrast to its availability around the world and the need to develop treatment strategies to reduce the mortality and morbidity due to these rare but daunting diseases.

Clinico-Haematological Profile of Hereditary Haemolytic Anaemias in a Tertiary Health Care Hospital in South India

INTRODUCTION

Hereditary haemolytic anaemia is a common inherited disorder causing varying degree of morbidity and mortality. This includes disorders due to haemoglobin defect, membrane defect, and enzyme defect. Among them haemoglobinopathies, a single gene disorder, constitutes the major part of the disorder and is distributed worldwide with an incidence of 5%. These inherited disorders pose a major public health problem and increase the burden both on the patient and the society. Presently, these disorders are not curable but can only be prevented. Improved awareness about these diseases among medical fraternity leading to diagnosis of carrier state, genetic counselling, and antenatal diagnosis may help in decreasing the prevalence of the disease.

AIM

To determine the prevalence of hereditary haemolytic anaemia and to correlate clinical and haematological features.

MATERIALS AND METHODS

The study was carried for duration five and half years (four years of retrospective and one and a half years prospective). All the patients diagnosed as hereditary haemolytic anaemia based on peripheral smear and special haematological investigation were included in the study. The clinical parameters and haematological parameters of all these patients were studied.

RESULTS

A total of 322 cases of hereditary haemolytic anaemia were diagnosed over a period of five and a half years. Of them thalassaemia syndrome constituted 165 cases (51.24%), sickle cell disorders 78 cases (24%), hereditary spherocytosis 43 cases (13.3%), G6PD deficiency 20 cases (6.29%) and HbE disorder 12 cases (3.7%). One case of hereditary elliptocytosis and one case of HbD Punjab was detected. Among thalassaemia syndromes beta thalassaemia was commonest clinically presenting disorder with a high morbidity. Sickle cell anaemia showed a higher level of HbF and a relatively milder clinical course. Hereditary spherocytosis had varied age at presentation. In G6PD deficiency drug induced haemolysis was the commonest clinical presentation. HbE disorders were from the north eastern states.

CONCLUSION

Haemoglobinopathies constitute the major group of hereditary haemolytic anaemia (74%). Genetic counselling is an important step in reducing the incidence of thalassaemia major.

Spectrum of Types of Thalassemias and Hemoglobinopathies: Study in a Tertiary Level Children Hospital in Bangladesh

Thalassemias and hemoglobinopathies are the most common hemolytic congenital disorders in Bangladesh as in many parts of the world. This study was done to find the common types of thalassemias and abnormal hemoglobin variants seen in Bangladeshi populations. A total of 4813 samples were analyzed for hemoglobin disorders out of which 2308 (49.95%) showed abnormalities. The samples were analyzed by Bio Rad D 10 Analyzer in 3914 (81.32%) cases, BIORAD VARIANTβ thalassemia short program using the principle of high performance liquid chromatography in 474 (9.85%) cases and by CAPILLARYS 2 FLEX PIERCING utilizing capillary electrophoresis in 425 (8.83%) cases. The samples were analyzed in the Department of Biochemistry and Molecular Biology of Dhaka Shishu (Children) Hospital, Dhaka, Bangladesh. The common hemoglobin disorders seen were β trait 863 (17.94%), Hb E trait 601 (12.50%), Hb E β thalassemia 524 (10.87%), β thalassemia major 192 (4.00 %), Hb E disease 99 (2.05%). Other Hb abnormalities detected were Hb D trait 17 (0.35%), Sickle cell trait 4 (0.08%), hereditary persistence of fetal hemoglobin (HPFH) 2 (0.04%), and Hb Lepore, δ β thalassemia, sickle cell β thalassemia, Sickle cell disease, compound heterozygote for HbE+D and Hb Q band one case each (0.02%).

Heart valve surgery in patients with homozygous sickle cell disease: A management strategy

Background:

Patients with the homozygous sickle cell disease have increased perioperative mortality. Some indications like heart valve surgery, may justify an exchange blood transfusion to reduce the proportion of hemoglobin S (HbS) and complications.

Subjects and Methods:

We report two female cases aged 20 and 27, of African origin with homozygous sickle cell anemia who underwent heart valve surgery to treat mitral valve regurgitation. This presentation describes the perioperative considerations including anesthesia and postoperative care.

Results:

A partial exchange blood transfusion decreased HbS levels from respectively, 90% and 84%, 9% to 27% and 34%, and simultaneously treated the anemia. Neither sickling crisis nor acidosis occurred in any patient, and no special postoperative complication occurred. Average hospital stay was 10 days. Currently, the two patients remain alive and free of cardiac symptoms.

Discussion:

Although the presence of sickle cell disorders is associated with increased risk of sickling and thus vaso-occlusive complications, they should not be taken as a contraindication for heart valve surgery. Nevertheless, monitoring of certain parameters such as venous, arterial oxygen content, pH, and body temperature is mandatory for a better outcome. Furthermore, preoperative exchange transfusion has a positive influence on the outcome of surgery and on the survival of patients undergoing heart valves surgery. Avoiding intraoperative hypoxia, hypothermia, and vaso-constrictive agents, minimizing HbS levels with preoperative exchange transfusion, and ensuring a stress-free environment with the judicious use of sedatives made surgery relatively safe in these cases.

Pulmonary Embolism and Infarct After Bilateral Cochlear Implantation in a Patient with Newly Diagnosed Sickle/β+ Thalassemia

OBJECTIVE

To heighten awareness of increased postoperative thromboembolic complications in patients with β-hemoglobinopathies.

PATIENT

A 42-year-old African American woman with previously undiagnosed β-hemoglobinopathies suffers from sensorineural hearing loss caused by bacterial meningitis and undergoes bilateral cochlear implantation.

INTERVENTION(S)

Diagnostic: hemoglobin electrophoresis. Therapeutic: cochlear implantation, anticoagulation.

MAIN OUTCOME MEASURE(S)

Risk of thromboembolic event.

RESULTS

Five days after surgery, the patient developed pulmonary embolism and infarct in the right lower lobe, which was treated with a 4-month course of anticoagulation. Hemoglobin electrophoresis showed that the patient had a previously undiagnosed rare β-hemoglobinopathy known as sickle/β+ thalassemia.

CONCLUSION

β-Hemoglobinopathies are associated with a higher incidence of thromboembolism; thus, they should be managed aggressively to prevent or treat perioperative thrombosis.

Prenatal diagnosis of sickle cell disease by the technique of PCR

Sickle cell disease (SCD) is prevalent in Central India and causes major morbidity and mortality. There is a lack of prenatal diagnostic facility near population affected with SCD. This is the pilot study in our region with the aim to establish prenatal diagnostic facility for the couples carrying sickle cell gene in Central India, in order to help them take an informed decision regarding fetus affected with SCD and also to calculate sensitivity of polymerase chain reaction (PCR) technique in our set up with follow up high performance liquid chromatography (HPLC) of baby's blood sample. Fetal sampling was done by chorionic villous biopsy. Extracted DNA was subjected to amplification refractory mutation system (ARMS-PCR) to detect sickle cell mutation (GAG → GTG) in the sixth codon of β globin gene. Follow-up HPLC was done to detect baby's Hb pattern. Prenatal diagnosis of sickle cell anemia was offered in total 37 cases out of which one (2.7 %) fetal sample was inadequate. Total 26 (70.27 %) fetuses had AS Hb genotype, 3 (8.11 %) had AA Hb genotype and 3 (8.11 %) had SS Hb genotype while remaining 4 (10.81 %) were given AA/AS Hb genotype. All couples with SS fetuses opted for MTP. Follow up HPLC was performed in 24 cases, out of which 18 (75 %) were correlated and 6 (25 %) were mismatched. In present study sensitivity of ARMS-PCR was 75 %. ARMS-PCR is a simple technique to be established initially for providing rapid prenatal diagnosis to the couples with known sickle cell mutation. The sensitivity of ARMS-PCR can be increased by using suitable techniques to detect maternal cell DNA contamination.

Comparison of discriminative indices for iron deficiency anemia and β thalassemia trait in a Brazilian population

To discriminate iron deficiency anemia (IDA) from β thalassemia trait (βTT), several indices obtained from modern blood count analyzers have been reported. Discrimination power of seven indices to differentiate between IDA and βTT, such as Green and King Index (GKI), RDW Index (RDWI), Srivastava Index (SRI), Mentzer Index (MI), Shine and Lal Index (SLI), Ehsani Index (EI), and Sirdah Index (SI), were evaluated. These indices were applied on 47 patients with βTT and on 289 patients with IDA, as confirmed by gold standard tests. Sensitivity, specificity, positive and negative predictive values, efficiency, area under receiver-operating characteristics curve (AUC), and Youden's Index (YI) were calculated. GKI and RDWI showed the highest reliability, as they had the largest AUCs (0.919, 0.912, respectively) and Youden's Index (70.4, 74.6, respectively). Conversely, SLI presented a less satisfactory performance (AUC = 0.786 and YI = 6.6). Data taken together suggest the superiority of GKI and RDWI to discriminate between IDA and βTT.

Newborn screening shows a high incidence of sickle cell anemia in Central India

There is limited data on the incidence of sickle cell anemia in Central India; we therefore conducted a study to estimate the incidence of this disease in Central India. Mothers who delivered a live baby at the Government Medical College, Nagpur, India were screened for the presence of the sickle cell hemoglobin {Hb S: [β6 (A3) Glu→Val, GAG>GTG]} using the solubility test within 48 hours of delivery. Infants of mothers who showed the presence of Hb S then underwent Hb analysis by high performance liquid chromatography (HPLC). A total of 8243 mothers was screened, 1178 of whom were positive. One thousand, one hundred and sixty-two infants of mothers with a positive solubility test underwent Hb analysis by HPLC; 530 infants were normal, while 536 were heterozygous for Hb S (sickle cell trait), 88 babies were homozygous for Hb S (sickle cell anemia), while another eight babies had other Hb abnormalities. The incidence of sickle cell anemia was highest in the Scheduled caste group (1:50). We concluded that the incidence of sickle cell anemia is high in central India.