Role of Oxidative Stress and the Protective Effect of Fermented Papaya Preparation in Sickle Cell Disease.

Fermented papaya preparation (FPP) is the source of antioxidants that may help in reducing the complications associated with oxidative stress and may improve the quality of life in sickle cell disease patients. In this study, we assessed the in vitro effect of FPP on sickled red blood cells (RBCs) using oxidative stress markers and observed that FPP has the potential to reduce the oxidative stress. Scanning electron microscopy (SEM) and eosin 5' malaemide (E5'M) dye test showed that FPP protects red cell morphology against the oxidative stress. Liquid chromatography mass spectrometry (LCMS) analysis of FPP suggests the presence of essential amino acids, vitamin D3, and its derivatives. Fermented papaya preparation can be of benefit either in reducing oxidative stress parameters or in preventing pathophysiological events in the sickle cell disease patients.

G6PD A- is the major cause of G6PD deficiency among the Siddis of Karnataka, India.

Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human erythroenzymopathy affecting more than 400 million people worldwide. G6PD deficiency was reported in India more than 50 years ago and the prevalence rate varies from 5.7% to 27.9% in different caste and tribal groups.Aim: To study the prevalence of, and the mutations causing, G6PD deficiency among the Siddis of Karnataka.Subjects and methods: A total of 755 individuals were screened using the DPIP dye decolorisation method and the deficiency was further confirmed by quantitative assay. Molecular characterisation was performed by PCR-RFLP method and DNA sequencing. Biochemical characterisation was performed as per WHO criteria.Results: Of the 755 individuals, 71 individuals (9.4%) were found to be G6PD deficient with an enzyme activity ranging from 0.02 to 3.83 IU/gm Hb. Mutational analysis could be performed on 49 G6PD deficient individuals and 45 (91.8%) of them showed the presence of the G6PD A- variant while the remaining 4 (8.2%) had the G6PD Kerala-Kalyan mutation. Microsatellite analysis in G6PD A- individuals showed the presence of 166/195 bp, AC/CTT alleles.Conclusions: G6PD deficiencies among the Siddis are predominantly due to G6PD A- mutation. Furthermore, biochemical parameters and the microsatellite repeat markers in the Siddi A- chromosome confirmed they are African descendants with Indian admixture.

Red Cell Distribution Width (RDW): Normative Data in Indian Neonates.

Red cell distribution width (RDW) is altered because of prematurity and fetal growth restriction (FGR). We conducted a prospective observational study to determine normal RDW values in Indian neonates (N=964) with significant FGR. Mean RDW values in preterm neonates were higher than term neonates (P<0.0004). The RDW values in Indian neonates (with significant FGR) were higher than their western counterparts (P<0.0001). The mean RDW values for different gestational ages in Indian neonates are higher than those observed in other studies. This could be attributable to the FGR component among Indian neonates.

Potential involvement of ubiquitin-proteasome system dysfunction associated with oxidative stress in the pathogenesis of sickle cell disease.

The ubiquitin-proteasome system (UPS) is an important intracellular proteolytic pathway responsible for the degradation of proteins and oxidative damage; hence it plays a central role in maintaining homeostasis of red blood cells (RBCs). The present study investigated the levels of polyubiquitination, the function of proteasomes and effect of hydroxycarbamide (HC) therapy in RBCs from sickle cell disease (SCD) patients. Polyubiquitinated proteins were found to be elevated in untreated SCD (UT-SCD) patients compared to those in HC-treated SCD patients (HC-SCD) and controls. Activities of ß1 and ß2 subunits were a little higher in UT-SCD patients, and much higher proteolytic activities were observed in all three subunits (ß1, ß2 and ß5) of RBCs in HC-SCD patients compared to those of UT-SCD patients and controls, although the protein levels of these subunits remained approximately the same. It is notable that, despite HC therapy, some patients showed persistent complications and accumulation of polyubiquitinated proteins. The enhanced proteasomal activity among HC-treated patients might remove the polyubiquitinated protein and could be one of the important mechanisms of therapeutic action. These findings could be useful to understand the pathophysiology of SCD and its clinical heterogeneity and identify a suitable therapeutic target for the better management of these patients.

Genetic lesions in the UGT1A1 genes among Gilbert's syndrome patients from India.

The present study was undertaken to investigate genetic variations present in the coding regions of the UGT1A1 gene among the Gilbert's syndrome patients. Analysis of genetic variations was performed by direct DNA sequencing among the patients that do not have any polymorphic variations in the promoter regions of the UGT1A1 gene. We identified seven different sequence variations among Gilbert's Syndrome patients, of which four were novel. Out of seven variants, six missense and one silent single nucleotide substitutions were present in the UGT1A1 gene. In addition, molecular modeling of UGT1A1 (H55R, P152S and N212H) variants suggested a reduced activity of the enzyme. This study demonstrates that different variations present in the UGT1A1 gene and specifically, the H55R variation had a significant effect on bilirubin levels and could be genetic risk factors for hyperbilirubinemia.

Effect of Assorted Globin Haplotypes and α-Thalassemia on the Clinical Heterogeneity of Hb S-ß-Thalassemia.

Hemoglobinopathies and thalassemias are the most commonly encountered monogenic disorders of blood in humans, posing a major genetic and public health problem round the globe. Hb S (HBB: c.20A>T)-ß-thalassemia (ß-thal) is a compound aberrant heterozygosity with inconsistent phenotypic expression, which are poorly described and clinically mapped. Comprehensive genetic characterization of such a population is highly warranted for complete understanding of the clinical heterogeneity, disease prognosis and therapeutic management. In this study, Hb S-ß-thal (n = 60) patients, strictly defined by varying degrees of clinical presentations, were selected to evaluate their genotype-phenotype agreement. Furthermore, ß-globin (n = 120) and α-globin gene clusters (n = 60) were genetically characterized and statistically correlated with clinical terminologies to explain the clinical heterogeneity. Our results revealed the association of the Arab-Indian haplotypes with nine different frameworks of ß-thal together with the modulating role of α-thalassemia (α-thal). The study subjects, including carriers of ß-thal haplotype III [- - - - - - -] (8.0%), presented with varying severe patterns of clinical symptoms such as painful crisis, multiple infections and splenomegaly, as an outcome of significantly less Hb F and higher Hb S levels (p < 0.5). The study findings indicated that together with α-thal, ß-thal haplotypes and Hb F levels, may possibly provide a close justification to support the clinical heterogeneity in the study population.

Newborn Screening for Hemoglobinopathies and Red Cell Enzymopathies in Tripura State: A Malaria-Endemic State in Northeast India.

Hemoglobinopathies are a group of inherited single gene disorders. There are reports on hemoglobin (Hb) variants identified in the tribal and non-tribal populations of Tripura State in northeastern India. This study aimed to determine the spectrum of hemoglobinopathies and enzymopathies by newborn screening in Tripura State and assess the extent of neonatal jaundice. A total of 2400 cord blood samples were collected and analyzed by high performance liquid chromatography (HPLC). Further confirmation of any abnormal HPLC was done by DNA analysis. The samples were also screened for deficiency of enzymopathies, glucose-6-phosphate dehydrogenase (G6PD) deficiency and pyruvate kinase. Of 2400 cord blood samples screened, 225 (9.3%) were Hb E (HBB: c.79G>A) heterozygotes, 80 (3.3%) were Hb E homozygotes and one carried Hb E-ß-thalassemia (ß-thal). Other Hb abnormalities were also detected including 15 Hb S (HBB: c.20A>T) heterozygotes, two Hb D-Punjab (HBB: c.364G>C) heterozygotes and two compound heterozygotes for Hb D-Punjab and Hb E. Of the 80 homozygous Hb E babies, four were non-tribal and 76 babies were tribal, and 225 patients carried Hb E trait, 141 were tribal, while 84 were non-tribal. Of 40 G6PD deficient babies identified, 13 had coinherited Hb E and two babies had pyruvate kinase deficiency. α Genotyping was performed in 162 affected babies, 50 of them carried α gene deletions. Newborn screening programs for Hb E, other hemoglobinopathies and G6PD deficiency must be encouraged in the malaria-endemic northeastern region of India. Drug-induced hemolysis can also be avoided by screening for G6PD deficiency at birth.

Genetic Variations in Bilirubin Metabolism Genes and Their Association with Unconjugated Hyperbilirubinemia in Adults.

OBJECTIVE: The present study was undertaken to investigate the genotype and allele frequencies of the variants in the four bilirubin metabolism genes (UGT1A1, OATP2, HMOX1, and BLVRA) and their association with hyperbilirubinemia. MATERIAL AND METHODS: Genotyping of 17 genetic variants was performed in 115 adults with hyperbilirubinemia and 150 controls by PCR-RFLP, GeneScan analysis, and direct DNA sequencing. RESULTS: Genetic polymorphisms of the UGT1A1 promoter, specifically the T-3279G phenobarbital-responsive enhancer module and (TA)7 dinucleotide repeat, as well as the intron and coding region variants of the OATP2, HMOX1, and BLVRA genes, were significantly higher among the cases than the controls. Further, nearly 82% of the cases showed the presence of significantly four or more variants as compared to 37% of the controls (P < 0.0001) and the mean total serum bilirubin levels also increased according to the number of variants co-expressed. CONCLUSIONS: This study demonstrates that polymorphisms in the bilirubin metabolism genes had a significant effect on bilirubin levels and could be genetic risk factors for hyperbilirubinemia.

Haemoglobinopathies in tribal populations of India.

Haemoglobinopathies particularly haemoglobin S and E (HbS, HbE) and ß-thalassaemia are important challenges for tribal populations in India. The HbS, HbE and ß-thalassaemia genes are variably distributed across various tribal populations of India. HbE is mainly restricted in tribals of North-East, West Bengal, Odisha and those in Andaman and Nicobar islands. HbS has more extensive distribution in the country (10-40% trait frequency) and the homozygotes and double heterozygotes present with a wide array of morbidities. The morbidity varies greatly in different areas of the country due to differential co-inheritance of α-thalassaemia gene and interaction of various epistatic and environmental factors. Though substantial data on prevalence of these disorders exist, there is an urgent need to develop integrated hierarchical core facilities to manage the disease. Such centres will generate more data and will also explore areas of management which need more local attention. Newborn screening, genetic counselling, carrier detection, prenatal diagnosis along with management of cases should form the basic infrastructure of haemoglobinopathy management. Research in this areas should continue focusing on various challenges in care delivery, prevention and basic sciences on interaction of haemoglobinopathies with various other infections.

Sickle cell disease in tribal populations in India.

The sickle gene is widespread among many tribal population groups in India with prevalence of heterozygotes varying from 1-40 per cent. Co-inheritance of the sickle gene with ß-thalassaemia, HbD Punjab and glucose-6-phosphate dehydrogenase (G6PD) deficiency has also been reported. Most of the screening programmes in India now use high performance liquid chromatography (HPLC) analysis although the solubility test is also sensitive and cheap. Sickle cell disease (SCD) among tribal populations is generally milder than among non-tribal groups with fewer episodes of painful crises, infections, acute chest syndrome and need for hospitalization. This has partly been attributed to the very high prevalence of α-thalassaemia among these tribes as well as higher foetal haemoglobin levels. However, the clinical presentation is variable with many cases having a severe presentation. There is not much information available on maternal and perinatal outcome in tribal women with sickle cell disease. Newborn screening programmes for SCD have recently been initiated in Maharashtra, Gujarat, Orissa and Chattisgarh and monitoring these birth cohorts will help to understand the natural history of SCD in India. Prenatal diagnosis is acceptable by tribal families in India. The Indian Council of Medical Research and the National Rural Health Mission in different States are undertaking outreach programmes for better management and control of the disease.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency among tribal populations of India - Country scenario.

It is believed that the tribal people, who constitute 8.6 per cent of the total population (2011 census of India), are the original inhabitants of India. Glucose-6-phosphate-dehydrogenase (G6PD) deficiency is an X-linked genetic defect, affecting around 400 million people worldwide and is characterized by considerable biochemical and molecular heterogeneity. Deficiency of this enzyme is highly polymorphic in those areas where malaria is/has been endemic. G6PD deficiency was reported from India more than 50 years ago. t0 he prevalence varies from 2.3 to 27.0 per cent with an overall prevalence of 7.7 per cent in different tribal groups. Since the tribal populations live in remote areas where malaria is/has been endemic, irrational use of antimalarial drugs could result in an increased number of cases with drug induced haemolysis. Therefore, before giving antimalarial therapy, routine screening for G6PD deficiency should be undertaken in those tribal communities where its prevalence is high.

Wide spectrum of novel and rare hemoglobin variants in the multi-ethnic Indian population: A review.

The hemoglobin (Hb) variants are qualitative abnormalities due to production of structurally abnormal globin proteins. They are categorized based on the type of mutation present in the α1, α2, ß, Gγ, Aγ and δ globin genes. So far, more than 1550 Hb variants are reported in the database. They could lead to Hb polymerization, Hb instability, altered oxygen affinity and decreased oxygen-carrying capacity of Hb or have no clinical manifestations. In India, ethnic diversity, consanguinity, regional variations and migration result in the presence of different Hb variants. We have compiled all the variants of α, ß and δ globin chains in heterozygous, homozygous and in compound heterozygous forms reported from India in the last 52 years. Of the 63 rare and novel hemoglobin variants reported from India, 22 were α-globin chain variants, 37 were ß-globin chain variants and 4 were δ-globin chain variants. Twelve novel Hb variants (Hb J Rajappan, Hb Koya Dora, Hb Rampa, Hb Godavari, Hb Chandigarh, Hb D Agri, Hb Lucknow, Hb Vellore, Hb Midnapore, Hb Bijnor, Hb A2Tianhe and Hb A2Saurashtra) were identified among persons of Indian origin. Majority of them were picked up on HPLC. Some of the variants like Hb Titusville, Hb Shimonoseki, Hb Chandigarh, Hb D Agri, Hb Yaizu and Hb Vellore eluted in the HbS window whereas variants like HbD Iran, Hb St. Louis, Hb G Coushata, HbM Saskatoon, Hb Lucknow, Hb Grange-Blanche and Hb Tianshui showed falsely elevated HbA2. Hence, careful and systematic investigations are required to identify them.

Newborn Screening and Clinical Profile of Children With Sickle Cell Disease in a Tribal Area of Gujarat.

OBJECTIVE: To present the result of newborn sickle cell disease (SCD) screening and clinical profile of SCD newborns in a tribal area of Gujarat. METHODS: We screened all newborns of sickle cell trait (SCT) and SCD mothers for SCD using high-performance liquid chromatography (HPLC) within two days of birth at a secondary care hospital in a tribal area in Gujarat from 2014 to 2019. Newborns with SCD were registered under an information technology based platform for hospital-based comprehensive care. Neonates were followed prospectively every 3 months. If they missed the clinic visit, a medical counsellor visited them at home to collect the required information. RESULTS: Out of 2492 newborns screened, 87 (3.5%) were diagnosed with SCD. Among the 67 newborns screened for alpha-thalassemia deletion, 64 (95.4%) of babies had alpha-thalassemia deletion. We recorded total 554 clinic visits over the period of 221.5 person-years. The rates of acute febrile illness, painful crisis, hospitalization and severe anemia were 42.9, 14.9, 14.9 and 4.5 per 100 person-year, respectively. Two deaths were recorded, and 5 babies (5.7%) had severe SCD. CONCLUSION: We found a high prevalence of alpha thalassemia deletion among newborn SCD cohort in tribal area of Gujarat, and 70% babies had atleast one clinical complication on follow-up.

Restriction fragment length polymorphism (RFLP) of the X chromosome linked glucose-6-phosphate dehydrogenase (G6PD) locus in India.

STUDY: Haplotypes linked to glucose-6-phosphate dehydrogenase (G6PD) genotypes were defined by studying six intragenic restriction fragment length polymorphisms (RFLPs) in 141 G6PD deficient and 252 normal chromosomes. RESULTS: Only four of the 64 possible haplotypes were observed, indicating marked linkage disequilibrium. All the G6PD deficient mutations were associated with either haplotype I or VII, which are similar to the common G6PD B variant observed in the present study except the G6PD Namoru mutation which corresponded to mainly haplotype VIIa where a Nla III restriction site was created due to this mutation. CONCLUSION: The limited number and low haplotype diversity probably indicates a strong selective pressure on the G6PD gene.

Erythrocytes as a preferential target of oxidative stress in blood.

Red blood cells (RBC) are specifically differentiated to transport oxygen and carbon dioxide in the blood and they lack most organelles, including mitochondria. The autoxidation of hemoglobin constitutes a major source of reactive oxygen species (ROS). Nitric oxide, which is produced by endothelial nitric oxide synthase (NOS3) or via the hemoglobin-mediated conversion of nitrite, interacts with ROS and results in the production of reactive nitrogen oxide species. Herein we present an overview of anemic diseases that are closely related to oxidative damage. Because the compensation of proteins by means of gene expression does not proceed in enucleated cells, antioxidative and redox systems play more important roles in maintaining the homeostasis of RBC against oxidative insult compared to ordinary cells. Defects in hemoglobin and enzymes that are involved in energy production and redox reactions largely trigger oxidative damage to RBC. The results of studies using genetically modified mice suggest that antioxidative enzymes, notably superoxide dismutase 1 and peroxiredoxin 2, play essential roles in coping with oxidative damage in erythroid cells, and their absence limits erythropoiesis, the life-span of RBC and consequently results in the development of anemia. The degeneration of the machinery involved in the proteolytic removal of damaged proteins appears to be associated with hemolytic events. The ubiquitin-proteasome system is the dominant machinery, not only for the proteolytic removal of damaged proteins in erythroid cells but also for the development of erythropoiesis. Hence, despite the fact that it is less abundant in RBC compared to ordinary cells, the aberrant ubiquitin-proteasome system may be associated with the development of anemic diseases via the accumulation of damaged proteins, as typified in sickle cell disease, and impaired erythropoiesis.

Newborn Screening for Sickle Cell Disease Among Tribal Populations in the States of Gujarat and Madhya Pradesh in India: Evaluation and Outcome Over 6 Years.

Sickle cell disease (SCD) poses considerable public health problems in India. This study was undertaken to understand the clinical course of SCD among children identified during newborn screening programmes in Gujarat and Madhya Pradesh where the frequency of the HbS gene is high. A total of 8,916 newborn babies 8,411 from Gujarat and 505 from Madhya Pradesh were screened over 6 years (2010-2016) using HPLC and the diagnosis was confirmed by molecular analysis in a subset. A total of 128 babies (122 Gujarat, 6 Madhya Pradesh) were identified with sickle cell disease, of whom 87 (69 HbSS, 18 HbS-ß thalassemia) from Gujarat were followed for 0.5-6.6 years. Acute painful events, severe anemia and fever with infections were the major complications and 23 babies required hospitalization. Severe to moderate clinical presentation was found in 13.8% babies with SCD whereas, 86.2% babies had a milder presentation. Presence of ameliorating factors (α-thalassemia and Xmn 1 polymorphism) did not have a discernible effect on the clinical severity. Parents of babies with SCD were educated and counseled for home care. Distribution of mobile phones to 44 families having babies with SCD was beneficial as it allowed regular contact with patients and their families. Genetic counseling to the affected families has increased the awareness and acceptance for prenatal diagnosis and 18 couples opted for prenatal diagnosis in subsequent pregnancies. SCD is not always mild among tribal groups in India. Therefore, facilities for early diagnosis and prophylactic treatment in the tertiary care centers should be made available. The difficulties in regular follow up of the babies in remote rural areas have also been highlighted.

Clinical, hematologic and molecular variability of sickle cell-ß thalassemia in western India.

BACKGROUND: Sickle cell-ß thalassemia (HbS-ß thalassemia) is a sickling disorder of varying severity, which results from compound heterozygosity for sickle cell trait and ß thalassemia trait. The present study was undertaken to determine the genetic factors responsible for the clinical variability of HbS-ß thalassemia patients from western India. MATERIALS AND METHODS: Twenty-one HbS-ß thalassemia cases with variable clinical manifestations were investigated. The α and ß globin gene clusters were studied by molecular analysis. RESULTS: Thirteen patients showed milder clinical presentation as against eight patients who had severe clinical manifestations. Four ß thalassemia mutations were identified: IVS 1-5 (G→C), codon 15 (G→A), codon 30 (G→C) and codon 8/9 (+G). α thalassemia and XmnI polymorphism in homozygous condition (+/+) were found to be common among the milder cases. The ß(S) chromosomes were linked to the typical Arab-Indian haplotype (#31). Framework (FW) linkage studies showed that four ß thalassemia mutations were associated with different ß globin gene frameworks. Linkage of codon 15 (G→A) mutation to FW2 is being observed for the first time. CONCLUSION: The phenotypic expression of HbS-ß thalassemia is not uniformly mild and α thalassemia and XmnI polymorphism in homozygous condition (+/+) are additional genetic factors modulating the severity of the disease in the Indian subcontinent.

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

Multicenter Evaluation of HemoTypeSC as a Point-of-Care Sickle Cell Disease Rapid Diagnostic Test for Newborns and Adults Across India.

OBJECTIVES: Sickle cell anemia is the commonest genetic disorder in India, and the frequency of the sickle cell gene is very high in the remote tribal areas where facilities are generally limited. Therefore, a rapid and affordable point-of-care test for sickle cell disease is needed. METHODS: The diagnostic accuracy of HemoTypeSC was evaluated against automated high-performance liquid chromatography (HPLC) as the gold standard for its efficacy in a newborn screening program. RESULTS: A total of 1,559 individuals (980 newborns and 579 adults) from four participating centers were analyzed by both methods. HemoTypeSC correctly identified 209 of 211 total hemoglobin (Hb) SS cases, for a 99.1%/99.9% total HbSS sensitivity/specificity. Overall, HemoTypeSC exhibited sensitivity and specificity of 98.1% and 99.1% for all possible phenotypes (HbAA, HbAS, and HbSS) detected. HPLC is relatively expensive and not available in most laboratories in remote tribal areas. CONCLUSIONS: We conclude that the rapid, point-of-care testing device HemoTypeSC test is suitable for population and newborn screening for the HbS phenotype.