Homozygous sickle cell disease in Central India & Jamaica: A comparison of newborn cohorts

Background & objectives:

Homozygous sickle cell (SS) disease in Central India runs a more severe clinical course than reports from other areas of India. The current study was undertaken to compare the disease in Central India (Nagpur) with that in Jamaica, both populations defined by newborn screening.

Methods:

The Nagpur cohort included infants born to sickling-positive mothers from May 2008 to 2012, examined by high-pressure liquid chromatography and DNA analysis. The Jamaican cohort screened 100,000 consecutive non-operative deliveries between June 1973 and December 1981, analyzed by haemoglobin (Hb) electrophoresis and confirmed by family studies and compatible HbA₂ levels.

Results:

In Nagpur, 103 SS patients were detected, but only 78 (76%) were followed up. In Jamaica, 311 cases were followed from birth and compliance with follow up remained 100 per cent up to 45 years. In the Nagpur cohort all had the Asian haplotype, and 82 per cent of Jamaicans had at least one Benin chromosome; none had the Asian haplotype. Compared to Jamaica, Nagpur patients had higher foetal Hb, less alpha-thalassaemia, later development of splenomegaly and less dactylitis. There were also high admission rates for febrile illness and marked anaemia. Invasive pneumococcal disease occurred in 10 per cent of Jamaicans but was not seen in Nagpur.

Interpretation & conclusions:

There were many differences between the disease in Nagpur, Central India and the African form observed in Jamaica. The causes of severe anaemia in Nagpur require further study, and reticulocyte counts may be recommended as a routine parameter in the management of SS disease. The role of pneumococcal prophylaxis needs to be determined in Nagpur patients. Future studies in India must avoid high default rates.

Genotypic-phenotypic heterogeneity of δβ-thalassemia and hereditary persistence of fetal hemoglobin (HPFH) in India

Large deletions in the β-globin gene cluster lead to increased HbF levels by delaying the γ- to β-globin switch process. However, these deletions when inherited as a homozygous condition or when co-inherited with β-thalassemia result in variable clinical phenotypes. Individuals or families with a clinically presenting child, where the parents had HbF levels ≥ 10%, were further screened for the presence of large β-globin cluster deletions. Six deletions in the β-globin gene cluster were screened by GAP-PCR, and the uncharacterized deletions were further analyzed by gene dosage or by multiplex ligation-dependent probe amplification (MLPA). Among 192 individuals suspected for the inheritance of large deletions, 138 were heterozygous for large deletions, 45 were compound heterozygous of a large β-globin cluster deletion and β-thalassemia, and 9 were found to be homozygous for deletions. Among the heterozygotes, the Asian Indian inversion-deletion was found to be the most common deletion (39.9%), followed by the HPFH-3 deletion (30.0%). Other deletions 49.3 kb, δβ-thalassemia (21.2%), and 32.6 kb deletion (4.4%) were also found to be prevalent in our population. Patients compound heterozygous or homozygous for HPFH-3 and 32.6 kb deletions showed a milder clinical presentation, as compared with the patients compound heterozygous or homozygous for the Asian Indian inversion-deletion and 49.3 kb δβ-thalassemia. This comprehensive study highlights the mutation spectrum of large β-globin cluster deletions and the clinical heterogeneity in the patients homozygous or compound heterozygous with β-thalassemia, thus asserting the need for molecular characterization of these deletions.

Prevalence of globin gene modifiers encountered in fetuses during antenatal diagnosis of hemoglobinopathies

INTRODUCTION

The hemoglobinopathies are the commonest group of single gene disorders in the Indian subcontinent. Although genetic modifiers are known to have a remarkable effect on phenotypic expression, the effects of the possible co-inheritance of different modifiers are not taken into account during prenatal diagnosis. The present study was undertaken to look for the frequency of globin gene modifiers like the types of β-globin gene mutations, α thalassemia, α gene triplication, and the Xmn1 polymorphism in fetuses during antenatal diagnosis of hemoglobinopathies.

MATERIALS AND METHODS

A total of 580 fetuses with different diagnoses were screened for the presence of genetic modifiers.

RESULTS

Twenty-two different β-globin gene mutations were identified of which 3.5% were milder mutations. Among the affected fetuses, 29.6% of the β-thalassemia major and 52.9% of the sickle cell anemia (SCA) fetuses had one genetic modifier while 3.7% of the β-thalassemia major and 41.1% of the SCA fetuses had co-inherited two modifiers. α-gene triplication was detected in 16 (3.5%) β-thalassemia/sickle cell heterozygous and normal fetuses of which 5 babies (2 β-thalassemia heterozygous and 3 normal) could be followed up. Of the 2 β-thalassemia heterozygous babies, one had a severe clinical presentation.

CONCLUSION

Many fetuses had one or two gene modifiers. However, the impact of these on ameliorating the severity of the disease could not be evaluated as all the fetuses with β thalassemia major or sickle cell disease were terminated. Parents having heterozygous fetuses with α gene triplication should be followed up periodically after birth for better management of these babies.

Differential role of Kruppel like factor 1 (KLF1) gene in red blood cell disorders

The master erythroid regulator KLF1,plays a pivotal role during erythroid lineage development by regulating the expression of many erythroid genes. Variations in the KLF1 gene are found to be associated with varied erythroid phenotypes. With the aim of determining the role of KLF1 gene variations in HbF induction and their genotype phenotype relationship, in this study, we screened 370 individuals with different hemoglobinopathy condition. Hematological analysis was carried out using automated blood cell counter and Variant II HPLC (Biorad). KLF1 gene mutations were screened using automated DNA sequencing. Expression analysis was carried out using q-RT PCR of KLF1, BCL11A and γ-globin after selective enrichment and culturing of CD 34 +ve cells into an erythroid lineage. Over all 14 KLF1 gene variations were identified, of which six variants were novel. The incidence of KLF1 gene mutations was found to be 8.1%. It was seen that KLF1 mutations contributed in borderline HbA₂ levels as 7.6% of our borderline HbA₂ cases showed presence of KLF1 variations. It also contributed in induction of HbF levels under stress erythropoietic conditions. Gene expression studies revealed inverse correlation of KLF1, BCL11A (reduced) with γ-globin gene expression (increased) in patients showing KLF1 gene mutations, thus indicating the role of KLF1 gene in regulating the γ-globin gene expression. The identification of genomic variants of the KLF1 may help in determining the functionally active domain of this protein and will facilitate in understanding the wide spectrum of phenotypes generated by these variants.

Effect of inherited red cell defects on growth of Plasmodium falciparum: An in vitro study

Background & objectives:

High prevalence of certain polymorphic alleles of erythrocytes in malaria endemic area has been linked to the resistance provided by these alleles against parasitic infestations. Numerous studies undertaken to demonstrate this correlation have generated conflicting results. This study was undertaken to investigate the abilities of various polymorphic erythrocytes to support in vitro growth of Plasmodium falciparum parasites.

Methods:

In this study under in vitro condition the ability of P. falciparum parasites to grow was assessed in the erythrocytes obtained from a total of 40 patients with various haemoglobinopathies, such as β-thalassaemia (β-Thal), sickle cell anaemia, erythroenzymopathy-like glucose-6-phosphate dehydrogenase deficiency and membranopathy-like hereditary spherocytosis.

Results:

Significantly reduced in vitro invasion and growth of parasites was seen in the cultures containing abnormal erythrocytes than in control cultures containing normal erythrocytes (P< 0.05). The mean per cent parasitaemia comparison was also carried out among the three polymorphic erythrocyte groups, i.e. β-Thal, sickle cell anaemia and enzyme-membranopathies.

Interpretation & conclusions:

Erythroenzymopathies and membranopathies were found to provide a more hostile environment for parasites, as the least parasitaemia was observed in these erythrocytes. The present in vitro study showed that P. falciparum did not grow well and did not invade well in erythrocytes obtained from common inherited red cell disorders.

Prenatal Diagnosis of HbE-β-Thalassemia: Experience of a Center in Western India

The clinical presentation of HbE-β-thalassemia is extremely variable, however, many cases are severe and transfusion dependent. We offered prenatal diagnosis to 108 couples, 20 of whom came prospectively. CVS was done in 93 cases (9.5-13 weeks of gestation) while amniocentesis/cordocentesis was done for 15 cases in the second trimester. Diagnosis was done by reverse dot blot hybridization, ARMS, DNA sequencing and in a few cases by HPLC analysis of fetal blood. The genetic combinations in the couples at-risk were the following: HbE trait/β-thal trait-95, HbE-thal/HbE trait-5, HbE homozygous/β-thal trait-3, HbE-thal/β-thal trait-3, HbE Lepore/β-thal trait-1, HbE trait/HbD^Punjab trait-1. IVS1-5(G>C) was the commonest β-thalassemia mutation followed by codon15(G>A), codon30(G>C), codons41/42(-CTTT), the 619 bp deletion and codon8/9(+G) in the β-thalassemic parent. However, several rare mutations seen in India like -90(C>T), -88(C>T),codon15(-T), IVS1-129(A>C), IVS1-130(G>C), IVSII-1(G>A), IVSII-837(C>T) and IVSII 848(C>A) were also encountered. Twenty-one fetuses were affected (HbE-β-thal-20, β-thal major-1) and all the couples opted for termination of the pregnancies. Couples with affected children wish to undergo prenatal testing for HbE-β-thal in subsequent pregnancies. More regional centers are needed for these services, particularly in West Bengal and the North-East where HbE is very common.

Phenotypic expression of HbO Indonesia in two Indian families and its interaction with sickle hemoglobin

BACKGROUND

Alpha globin chain variants are clinically significant since they directly influence the structure and function of the hemoglobin (Hb) molecules they constitute, either in combination with normal beta globin chains or with variant beta chains, thereby altering the morbidity and mortality associated with the resultant hemoglobinopathies. We describe here two unrelated families from Madhya Pradesh who had a nondeletional alpha-chain variant, HbO Indonesia (CD116 G → A). Members of one of the two families also had coinheritance of sickle hemoglobin (HbS).

AIMS

The aim was to study the phenotype of HbO Indonesia and its interaction with HbS.

MATERIALS AND METHODS

Hb electrophoresis, high-performance liquid chromatography (HPLC), covalent reverse dot blot hybridization, amplification refractory mutation system, multiplex polymerase chain reaction, and direct gene sequencing were used to identify and characterize the variant Hbs.

RESULTS

The abnormal Hb moved in HbS region in Hb electrophoresis at alkaline pH but gave an abnormal peak in HPLC with a retention time (RT) of 4.86-4.89 min. In two members of the family with coinheritance of HbS, it produced small additional abnormal Hb peaks (4.6% in heterozygous and 11.9% in homozygous member) in HPLC with a longer RT (5.15-5.17 min) possibly resulting from a combination of HbO Indonesia alpha chain with HbS beta chain.

CONCLUSIONS

It appears that depending on the zygosity of HbS, HbO Indonesia would subtract a variable amount of HbS beta chain from the total pool, thereby potentially reducing the clinical severity of HbS disease. HbO Indonesia per se does not cause anemia or alter the red cell indices.

Hemoglobin Agenogi--A rare abnormal beta globin chain variant

Haemoglobin (Hb) Agenogi is clinically asymptomatic, rare β-globin chain variant characterized by a substitution of glutamic acid by lysine at position 90 of β-chain. It elutes in the C-window on high-performance liquid chromatography (HPLC). We report a 10-year-old male with easy fatigability, lethargy, pallor, and mild splenomegaly. Hematological parameters revealed microcytic hypochromic anemia and mildly raised red blood cells count, suggestive of thalassemia trait. On HPLC, a predominant peak was observed in the C-window (82.6%) along with raised HbA 2 level (9.3%). Based on these findings, a possibility of HbC disease/β-thalassemia trait doubly heterozygous was considered. Family studies were advised. HPLC findings in father were suggestive of β-thalassemia trait, while both his mother and brother had an abnormal peak in the C-window of 42.7% and 40.8%, respectively, with elevated HbA 2 values of 5% and 4.9%, respectively. Direct DNA sequencing revealed intervening sequences 1-5 (G ; C) in father, confirming β-thalassemia trait. His mother and brother had heterozygous gene mutation at codon 90 of β-globin chain (G ; A) suggestive of Hb Agenogi. The child carried mutations for both β-thalassemia trait as well as Hb Agenogi.

A microplate reader-based method to quantify NADH-cytochrome b5 reductase activity for diagnosis of recessive congenital methaemoglobinemia

OBJECTIVES

Congenital methemoglobinemia due to NADH-cytochrome b5 reductase 3 (CYB5R3) deficiencies is an autosomal recessive disorder that occurs sporadically worldwide, A sensitive, accurate, and rapid analysis of NADH-CYB5R enzyme concentrations is necessary for the diagnosis of RCM. Here we present an alternative microplate method that is based on a standard 96-well microplate format and microplate reader that simplify the quantification of NADH-CYB5R activity.

METHODS

TECAN (Infinite 200 PRO series) microplate reader with Tecan's proven Magellan™ software measured the NADH-CYB5R enzyme activity in 250 normal controls and previously diagnosed 25 cases of RCM due to NADH-CYB5R deficiency in the Indian population using 96-well microplates using 200 μl of total reaction mixture and also compared with standard spectrophotometric assay. We have also studied stability of the hemolysate stored at 4 and -20°C temperature.

RESULTS AND DISCUSSION

Enzyme activity in all 25 samples ranged from 6.09 to 10.07 IU/g Hb (mean ± SD: 8.08 ± 1.99 IU/g Hb) where as normal control ranged (n = 250) between 13.42 and 21.58 IU/g Hb) (mean ± SD: 17.5 ± 4.08 IU/g of Hb). Data obtained from the microplate reader were compared with standard spectrophotometer method and found 100% concordance using both methods. Microplate method allows differentiating between normal, deficient and intermediate enzyme activity. It was observed that samples had significant loss of activity when stored at 4°C and retained stable activity at -20°C for 1 week time.

CONCLUSION

Our new method, incorporating a whole process of enzyme assay into a microplate format is readily applicable and allows rapid monitoring of enzyme assay. It is readily applicable to quantitative assay on pediatric sample as well as large number of samples for population screening.

Sickle Cell Disease in Central India: A Potentially Severe Syndrome

OBJECTIVES

To explore clinical, hematological and molecular features of homozygous sickle cell (SS) disease in central India.

METHODS

Focusing on the pediatric age group attending a clinic at the Akola Government Medical College, Akola, Maharashtra State, India, a cross-sectional assessment of 91 patients with sickle cell disease was performed during one week in March 2015.

RESULTS

Of the 91 patients, there were 49 with SS disease, 36 with sickle cell-beta thalassemia, and 6 with sickle cell-HbD Punjab. Alpha globin gene deletions occurred in only 8/49 (16 %) SS disease but fetal hemoglobin (HbF) levels were markedly elevated with mean and median of 24.4 %; all except 3 SS disease patients had the Xmn1(+/+) polymorphism consistent with the Asian haplotype. Among the 36 patients with sickle cell-beta thalassemia, 25 (69 %) had the severe beta(+) mutation, IVS1-5 G > C, and seven other molecular mutations, all beta(o) occurred in the other 11 patients. Many patients had a relatively severe clinical course. Comparison of SS disease and sickle cell-beta thalassemia showed no differences in the prevalence of dactylitis, bone pain crisis, acute chest syndrome, hemoglobin level, reticulocyte counts or hydroxyurea usage but patients with sickle cell-beta thalassemia had significantly more blood transfusions, and greater frequencies of splenomegaly and hepatomegaly.

CONCLUSIONS

Many patients in central India have relatively severe manifestations. This may result from lower frequencies of alpha thalassemia and more frequent severe sickle cell-beta(+) thalassemia. There is a need for assessment of the indications and policies for blood transfusion and for hydroxyurea.

Correlation between 'H' blood group antigen and Plasmodium falciparum invasion

The ABO blood group system is the most important blood group system in clinical practice. The relationship between Plasmodium falciparum and ABO blood groups has been studied for many years. This study was undertaken to investigate the abilities of different blood group erythrocytes to support in vitro growth of P. falciparum parasites. P. falciparum parasites of four different strains (3D7, 7G8, Dd2 and RKL9) were co-cultured with erythrocytes of blood group 'A', 'B', 'O' (n = 10 for each) and 'O(h)' (Bombay group) (n = 7) for 5 days. Statistically significant differences were observed on the fourth day among the mean percent parasitemias of 'O', non-'O' ('A' and 'B') and 'O(h)' group cultures. The parasitemias of four strains ranged from 12.23 to 14.66, 11.68 to 13.24, 16.89 to 22.3, and 7.37 to 11.27 % in 'A', 'B', 'O' and Bombay group cultures, respectively. As the expression of H antigen decreased from 'O' blood group to 'A' and 'B' and then to Bombay blood group, parasite invasion (percent parasitemia) also decreased significantly (p < 0.01) and concomitantly, indicating the association of parasite invasion with the amount of H antigen present on the surface of erythrocyte. Thus, the question arises, could H antigen be involved in P. falciparum invasion? To evaluate erythrocyte invasion inhibition, 'O' group erythrocytes were virtually converted to Bombay group-like erythrocytes by the treatment of anti-H lectins extracted from Ulex europaeus seeds. Mean percent parasitemia of lectin-treated cultures on the fourth day was significantly lower (p < 0.05) than that of non-treated cultures and was found to be similar with the mean percent parasitemia demonstrated by the Bombay group erythrocyte cultures, thus further strengthening the hypothesis.

A novel nine base deletion mutation in NADH-cytochrome b5 reductase gene in an Indian family with recessive congenital methemoglobinemia-type-II

Recessive hereditary methemoglobinemia (RCM) associated with severe neurological abnormalities is a very rare disorder caused by NADH- cytochrome b5 reductase (cb5r) deficiency (Type II). We report a case of 11 month old male child who had severe mental retardation, microcephaly and gross global developmental delay with methemoglobin level of 61.1%. The diagnosis of NADH-CYB5R3 deficiency was made by the demonstration of significantly reduced NADH-CYB5R3 activity in the patient and intermediate enzyme activity in both the parents. Mutation analysis of the CYB5R gene revealed a novel nine nucleotide deletion in exon 6 leading to the elimination of 3 amino acid residues (Lys173, Ser174 and Val 175). To confirm that this mutation was not an artifact, we performed PCR-RFLP analysis using the restriction enzyme Drd I. As the normal sequence has a restriction recognition site for Drd I which was eliminated by the deletion, a single band of 603-bp was seen in the presence of the homozygous mutation. Molecular modeling analysis showed a significant effect of these 3 amino acids deletion on the protein structure and stability leading to a severe clinical presentation. A novel homozygous 9 nucleotide deletion (p.K173–p.V175del3) is shown to be segregated with the disease in this family. Knowing the profile of mutations would allow us to offer prenatal diagnosis in families with severe neurological disorders associated with RCM — Type II.

ICSH recommendations for assessing automated high-performance liquid chromatography and capillary electrophoresis equipment for the quantitation of HbA2

Automated high performance liquid chromatography and Capillary electrophoresis are used to quantitate the proportion of Hemoglobin A2 (HbA2 ) in blood samples order to enable screening and diagnosis of carriers of β-thalassemia. Since there is only a very small difference in HbA2 levels between people who are carriers and people who are not carriers such analyses need to be both precise and accurate. This paper examines the different parameters of such equipment and discusses how they should be assessed.

Tyrosine kinase inhibitors: New class of antimalarials on the horizon?

Development of the antimalarial drug resistant strains has currently become a major public health challenge. There is an urgent need to develop new antimalarial drugs. Tyrosine kinase inhibitors (TKIs) are receiving increasing attention as anticancer therapy. It has revolutionarised the management of CML to say the least. TKIs are also increasingly being implicated in complicated but vital life cycle of malaria parasite. Hence we tested two commonly used but different classes of TKIs (imatinib and sorafenib) in-vitro for their antimalarial activity and possible synergistic activity with existing antimalarial drug. Antimalarial activity was tested with the help of modified WHO microtest technique in-vitro for five different Plasmodium falciparum laboratory strains (3D7, Dd2, 7G8, MRC2, PKL9). Imatinib and sorafenib showed a promising antimalarial activity with all the strains. These compounds caused dose dependent inhibition of parasite maturation. The isobologram analysis of the interactions of these TKIs with standard antimalarial drug, artesunate revealed distinct patterns of synergism, additivity and antagonism at different ratios. Imatinib showed worthwhile synergism with artesunate indicating imatinib and other tyrosine kinase inhibitors may have significant antimalarial activity and can be used in combination therapy.

Hemoglobinopathy screening by osmotic fragility test based on flow cytometer or naked eye

BACKGROUND

Diagnosis of hemoglobin (Hb) disorders is based mostly on abnormal red blood cell (RBC) indices, elevated levels of HbA2, HbF, or any other Hb on the Variant high performance liquid chromatography (HPLC) system, and confirmation by molecular methods. However, large scale population screening is of prime importance and requires a simple, accurate, and cost effective technique. We have tried to compare the sensitivity of the widely used Naked Eye Single Tube Red Cell Osmotic Fragility Test (NESTROFT) and the osmotic fragility described as % residual RBCs through flow cytometry for population screening.

METHODS

The count of residual red cells was measured sequentially in real-time using flow cytometry. NESTROFT was performed using a 0.36% buffered saline. HbA2 and HbF levels along with other abnormal Hbs were determined on the Variant HPLC System. Molecular studies were done to confirm the diagnosis.

RESULTS

The normal group showed a significantly lower percentage of residual RBCs (48.08 ± 11.87) as compared to cases (β thalassemia trait-82.97 ± 12.20, α thalassemia trait-72.58 ± 8.34, and HbS trait-85.00 ± 4.05). The sensitivity and specificity of NESTROFT was high for both β thalassemia traits (98.33 and 96.72%, respectively) and α thalassemia traits (100 and 96.72%, respectively) but very low sensitivity for HbS traits (54.84%).

CONCLUSION

Flow cytometric osmotic fragility was a more sensitive method to discriminate normal from the group of hemoglobinopathy carriers as compared to NESTROFT which missed majority of HbS carriers. However, in view of feasibility and cost effectiveness, NESTROFT could still be used for population screening of thalassemia. © 2014 International Clinical Cytometry Society.

Hemoglobinopathy Screening by Osmotic Fragility Test Based on Flow Cytometer or Naked Eye

BACKGROUND

Diagnosis of hemoglobin disorders is based mostly on abnormal red blood cell indices, elevated levels of HbA2, HbF or any other Hb on the Variant HPLC system and confirmation by molecular methods. However, large scale population screening is of prime importance and requires a simple, accurate and cost effective technique. We have tried to compare the sensitivity of the widely used NESTROFT and the osmotic fragility described as percentage residual RBCs through flow cytometry for population screening.

METHODS

The count of residual red cells was measured sequentially in real-time using flow cytometry. NESTROFT was performed using a 0.36% buffered saline. HbA2 and HbF levels along with other abnormal hemoglobins were determined on the Variant HPLC System. Molecular studies were done to confirm the diagnosis.

RESULTS

The normal group showed a significantly lower percentage of residual RBCs (48.08±11.87) as compared to cases (β thalassemia trait- 82.97±12.20, α thalassemia trait-72.58±8.34 and HbS trait- 85.00±4.05). The sensitivity and specificity of NESTROFT was high for both β thalassemia traits (98.33% and 96.72% respectively) and α thalassemia traits (100% and 96.72 % respectively) but very low sensitivity for HbS traits (54.84%).

CONCLUSION

Flow cytometric osmotic fragility was a more sensitive method to discriminate normals from the group of hemoglobinopathy carriers as compared to NESTROFT which missed majority of Hb S carriers. However, in view of feasibility and cost effectiveness, NESTROFT could still be used for population screening of thalassemia. This article is protected by copyright. All rights reserved.

Guidelines for screening, diagnosis and management of hemoglobinopathies

The β-thalassemias and sickle cell disorders are a major health burden in India. Diagnosis and management of these disorders both in adults and in newborns using appropriate approaches and uniform technology are important in different regions of a vast and diverse country as India. In view of a National Thalassemia Control Program to be launched soon, a need was felt for guidelines on whom to screen, cost-effective technologies that are to be used as well as for establishing prenatal diagnosis programs in regional centers. Newborn screening for sickle cell disorders is in its infancy in India and uniform approaches need to be followed. Also, included are guidelines for monitoring and managing patients who are now growing older and need comprehensive care as well as management of complications of the disease.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Clinical and hematological presentation among Indian patients with common hemoglobin variants

BACKGROUND

Co-inheritance of structural hemoglobin variants like HbS, HbD(Punjab) and HbE can lead to a variable clinical presentation and only few cases have been described so far in the Indian population.

METHODS

We present the varied clinical and hematological presentation of 22 cases (HbSD(Punjab) disease-15, HbSE disease-4, HbD(Punjab)E disease-3) referred to us for diagnosis.

RESULTS

Two of the 15 HbSD(Punjab) disease patients had moderate crisis, one presented with mild hemolytic anemia; however, the other 12 patients had a severe clinical presentation with frequent blood transfusion requirements, vaso occlusive crisis, avascular necrosis of the femur and febrile illness. The 4 HbSE disease patients had a mild to moderate presentation. Two of the 3 HbD(Punjab)E patients were asymptomatic with one patient's sibling having a mild presentation. The hemoglobin levels of the HbSD(Punjab) disease patients ranged from 2.3 to 8.5 g/dl and MCV from 76.3 to 111.6 fl. The hemoglobin levels of the HbD(Punjab)E and HbSE patients ranged from 10.8 to 11.9 and 9.8 to 10.0 g/dl whereas MCV ranged from 67.1 to 78.2 and 74.5 to 76.0 fl respectively.

CONCLUSIONS

HbSD(Punjab) disease patients should be identified during newborn screening programmes and managed in a way similar to sickle cell disease. Couple at risk of having HbSD(Punjab) disease children may be given the option of prenatal diagnosis in subsequent pregnancies.

Hydroxyurea could be a good clinically relevant iron chelator

Our previous study showed a reduction in serum ferritin of β-thalassemia patients on hydroxyurea therapy. Here we aimed to evaluate the efficacy of hydroxyurea alone and in combination with most widely used iron chelators like deferiprone and deferasirox for reducing iron from experimentally iron overloaded mice. 70 BALB/c mice received intraperitonial injections of iron-sucrose. The mice were then divided into 8 groups and were orally given hydroxyurea, deferiprone or deferasirox alone and their combinations for 4 months. CBC, serum-ferritin, TBARS, sTfr and hepcidin were evaluated before and after iron overload and subsequently after 4 months of drug therapy. All animals were then killed. Iron staining of the heart and liver tissue was done using Perl’s Prussian Blue stain. Dry weight of iron in the heart and liver was determined by atomic absorption spectrometry. Increased serum-ferritin, TBARS, hepcidin and dry weight of iron in the liver and heart showed a significant reduction in groups treated with iron chelators with maximum reduction in the group treated with a combination of deferiprone, deferasirox and hydroxyurea. Thus hydroxyurea proves its role in reducing iron from iron overloaded mice. The iron chelating effect of these drugs can also be increased if given in combination.

Comparison of in-vitro and in-vivo response to fetal hemoglobin production and γ-mRNA expression by hydroxyurea in Hemoglobinopathies

BACKGROUND

Hydroxyurea, which induces Fetal hemoglobin (HbF) synthesis, is the only drug widely used in different hemoglobinopathies; however, the response is very variable. We compared the efficacy of hydroxyurea in-vitro in erythroid cultures and in-vivo in the same patients with different hemoglobinopathies to induce HbF production and enhance γ-messenger RNA expression.

MATERIALS AND METHODS

A total of 24-patients with different Hemoglobinopathies were given hydroxyurea and their response was studied in-vivo and in-vitro on mononuclear cells collected from them simultaneously.

RESULTS

A total of 57.7% of patients (responders) showed no further crisis or transfusion requirements after hydroxyurea therapy with a mean increase in fetal cells (F-cells) of 63.8 ± 59.1% and γ-mRNA expression of 205.5 ± 120.8%. In-vitro results also showed a mean increase in F-cells of 27.2 ± 24.7% and γ-mRNA expression of 119.6% ± 65.4% among the treated cells. Nearly 19.0% of the partial-responders reduced their transfusion requirements by 50% with a mean increase in F-cells of 61.2 ± 25.0% and 28.4 ± 25.3% and γ-mRNA-expression of 21.0% ± 1.4% and 80.0% ± 14.1% in-vivo and in-vitro respectively. The non-responders (15.3%) showed no change in their clinical status and there was no significant increase in F-cells levels and γ-mRNA expression in-vivo or in-vitro.

CONCLUSION

Thus, this method may help to predict the in-vivo response to hydroxyurea therapy; however, a much larger study is required.

Clinical and molecular characterization of Hb Hofu in eastern India

INTRODUCTION

Hb Hofu (HBB:c. 380T>A) is a rare inherited hemoglobin abnormality with few case reports in the world literature.

METHODS

Screening for the sickle cell gene mutation and other hemoglobinopathies was carried out using the sickle slide test, Hb electrophoresis, and HPLC under an ongoing central government project.

RESULTS

We detected twelve Hb Hofu heterozygotes and three sickle Hb Hofu compound heterozygotes. The heterozygotes were asymptomatic except for one individual who had chronic kidney disease and moderate anemia. Only one HbS-Hofu case was symptomatic and presented with intermittent attacks of painful crisis. In the carrier state, the Hb Hofu eluted as a hump at the beginning of the HbA(0) window. But in HbS-Hofu cases, Hb Hofu eluted as a single peak in the HbA(0) window, with the HbA(2) levels being >4% consistently.

CONCLUSION

HbS-Hofu has a variable clinical presentation. The retention time of Hb Hofu on HPLC is very close to that of HbA(0) and often elutes in the A0 window. Thus, there is every possibility of the HbS-Hofu chromatogram to be misinterpreted as that of a sickle cell trait/transfused sickle cell-beta-thalassemia case. This is the first time where Hb Hofu has been detected by HPLC, which is the widely accepted screening technique for hemoglobinopathies around the world.

Attenuation of oxidative hemolysis of human red blood cells by the natural phenolic compound, allylpyrocatechol

The protecting ability of the Piper betle leaves-derived phenol, allylpyrocatechol (APC) against AAPH-induced membrane damage of human red blood cells (RBCs) was investigated. Compared to control, AAPH (50 mM) treatment resulted in significant hemolysis (55%, p < 0.01), associated with increased malondialdehyde (MDA) (2.9-fold, p < 0.001) and methemoglobin (6.1-fold, p < 0.001) levels. The structural deformation due to membrane damage was confirmed from scanning electron microscopy (SEM) images and Heinz bodies formation, while the cell permeability was evident from the K(+) efflux (28.7%, p < 0.05) and increased intracellular Na(+) concentration (8%, p < 0.05). The membrane damage, due to the reduction of the cholesterol/phospholipids ratio and depletion (p < 0.001) of ATP, 2,3-DPG by ˜44-54% and Na(+)-K(+) ATPase activity (43.7%), indicated loss of RBC functionality. The adverse effects of AAPH on all these biochemical parameters and the resultant oxidative hemolysis of RBCs were significantly reduced by pretreating the cells with APC (7 μM) or α-tocopherol (50 μM) for 1 h, prior to incubation with AAPH.

Molecular and clinical heterogeneity in pyruvate kinase deficiency in India

We studied the PK-LR gene in 10 unrelated Indian patients with congenital haemolytic anemia associated with erythrocyte pyruvate kinase deficiency. The patients had a variable presentation ranging from a very mild compensated hemolysis to severe anemia. Nine different mutations were detected among the 20 mutated alleles identified: one deletion (c.1042-1044del) p.Lys348del and eight single-nucleotide (nt) substitutions resulting in amino acid exchanges c.397A>G (p.Asn133Asp), c.992A>G (p.Asp331Gly), c.1072G>A (p.Gly358Arg), c.1076G>A (p.Arg359His), c.1219G>A (p.Glu407Lys), c.1241C>T (p.Pro414Leu), c.1436G>A (p.Arg479His) and c.1529G>A (p.Arg510Gln) were identified. Although all the exons, the flanking regions and the promoter region were sequenced in all cases, we failed to detect the second expected mutation in two subjects. Two mutations [c.397A>G; c.1241C>T] were novel. These novel missense mutations involved highly conserved amino acids. Two mutations were identified for the first time in the homozygous state globally (c1042-1044del; c.1072G>A) and two other mutations were identified for the first time in our population (c.1076G>A; c.1529G>A). This study along with our earlier report suggests that the most frequent mutations in India would appear to be c.1436G>A (18.33%), followed by c.992A>G (11.66%) and c.1456C>T (11.66%). Structural implications of amino acid substitutions were correlated with the clinical phenotypes seen.

Antenatal screening for identification of couples for prenatal diagnosis of severe hemoglobinopathies in surat, South gujarat

PURPOSE

Our aim was to identify couples at risk of having a homozygous or compound heterozygous child with a severe hemoglobinopathy by antenatal screening and prenatal diagnosis in Surat, South Gujarat.

METHOD

Pregnant women were screened for hemoglobinopathies by means of red cell indices, the solubility test, cellulose acetate electrophoresis tests, and confirmation by HPLC. Husbands of the pregnant women having hemoglobinopathies were counseled and screened for hemoglobinopathies. The couples at risk were again counseled and referred to the National Institute of Immunohematology, where mutations in parents and fetuses were identified by molecular analysis. After prenatal diagnosis, the continuing pregnancies were followed up and infants were tested at birth.

RESULTS

Out of 3,009 women, 37.04, 52.6, and 10.3 % were in the first, second, and third trimester of pregnancy, respectively. Among those having hemoglobinopathies, 102 (3.38 %) had the β-thalassemia trait, 46 (1.5 %) the Sickle cell trait, and 26 (0.86) had hemoglobin variants like Hb DPunjab, Hb E, Hb DIran, Hb QIndia, Hb JParis-I, and Hb OIndonesia. Out of the 14 couples at risk of having an affected child, 11 (78.5 %) couples opted for prenatal diagnosis. Three fetuses had homozygous β-thalassemia and hence the pregnancies were terminated. Follow up of normal or heterozygous fetuses confirmed the diagnosis.

CONCLUSION

During antenatal screening, we found many Hb variants of β and α globin chains. Late antenatal registration, non-cooperation of the husband for investigation, and refusal for prenatal diagnosis are the main hurdles in the hemoglobinopathy prevention program and awareness is necessary.

Variable haematological and clinical presentation of β-thalassaemia carriers and homozygotes with the Poly A (T→C) mutation in the Indian population

OBJECTIVES

To study the varied clinical and haematological profile of β-thalassaemia homozygotes, compound heterozygotes and heterozygotes with the Poly A (T→C) mutation and its implication in prenatal diagnosis.

MATERIALS AND METHODS

Forty individuals were included in the study. Peripheral smear examination, complete blood count and haemoglobin analysis were carried out. β-thalassaemia mutation analysis was carried out by reverse-dot-blot hybridization, amplification refractory mutation system and DNA sequencing of the β-globin gene.

RESULTS

Five of the six β-thalassaemia homozygotes with the Poly A (T→C) mutation and five individuals who were compound heterozygous for the Poly A (T→C) mutation along with another common Indian β-thalassaemia mutation showed a severe β-thalassaemia major phenotype, while one individual presented as a thalassaemia intermedia. Majority of the 28 heterozygous individuals with this mutation showed borderline HbA₂ (mean HbA₂ = 3.7 ± 0.4%) levels as compared to individuals with common β-thalassaemia mutations (mean HbA₂ = 5.2 ± 1.4%). The Mean Corpuscular Volume (MCV) levels in individuals heterozygous for the Poly A (T→C) mutation (mean MCV 70.0 ± 5.2 fl) were significantly higher than in individuals with other common β-thalassaemia mutations (mean MCV 60.7 ± 7.7 fl) (P < 0.001).

CONCLUSION

It is important to identify these often silent carriers of β-thalassaemia for prenatal diagnosis as homozygotes have a severe disease.