Evaluation of pharmacological efficacy and safety of hydroxyurea in sickle cell disease: Study of a pediatric cohort from Chhattisgarh, India.

Sickle cell disease (SCD) is a disease of abnormal hemoglobin associated with severe clinical phenotype and recurrent complications. Hydroxyurea (HU) is one of the US-FDA approved and commonly used drug for the treatment of adult SCD patients with clinical -severity. However, its use in the pediatric groups remains atypical. Despite a high prevalence of the disease in the state Chhattisgarh, there is a lack of evidence supporting its use in pediatric patients. This study aimed to evaluate the pharmacological and clinical efficacy and safety of HU in a large pediatric cohort with SCD from Central India. The study cohort consisted of 164 SCD (138 Hb SS and 26 Hb S beta-thalassemia) children (≤14 years of age) on HU therapy, who were monitored for toxicity, hematological and clinical efficacy at baseline (Pre-HU) and after 24 months (Post-HU). The results highlight the beneficial effects of HU at a mean dose of 18.7 ± 7.0 mg/kg/day. A significant improvement was observed, not only in physical and clinical parameters but also in hematological parameters which include fetal hemoglobin (Hb F), total hemoglobin, hematocrit, mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) levels, when evaluated against the baseline. We did not observe any significant adverse effects during the treatment period. Similar results were obtained on independent analysis of Hb SS and Hb Sß patients. These findings strengthen the beneficial effect of hydroxyurea in pediatric population also without any serious adverse effects and builds up ground for expanding its use under regular monitoring.

Hb F Levels in Indian Sickle Cell Patients and Association with the HBB Locus Variant rs10128556 (C>T), and the HBG XmnI (Arab-Indian) Variant.

The prevalence of sickle cell disease in India is very high. Hb F is one of the most powerful modulators of disease severity in sickle cell disease patients. It was traditionally thought that the disease is milder in Indian sickle cell disease patients predominantly due to the Arab-Indian haplotype characterized by the HBG XmnI [rs7482144 (G>A)] variant, which is associated with increased Hb F levels. In the current study, we investigated the Hb F levels in individuals with the rs10128556 (C>T) variant and also determined its linkage with the HBG XmnI variant. The present study was conducted on a cohort of 275 individuals, which consisted of 221 patients with sickle cell disease and 54 patients with sickle cell trait. Analysis of hemoglobin (Hb) fractions and variants was done on the high performance liquid chromatography (HPLC) system. Genotyping for rs10128556 was done by direct sequencing of the products. Mean Hb F levels in the sickle cell disease patients was 19.36 ± 6.79. The genotypic frequencies for rs10128556 were 82.0% (TT), 16.7% (CT) and 1.3% (CC) for sickle cell disease patients. The minor C allele resulted in 52.0% decrease in Hb F levels when homozygous and 7.0% decrease when heterozygous. The rs10128556 single nucleotide polymorphism (SNP) was in strong but not complete linkage with the HBG XmnI variant. In conclusion, the study determined for the first time the frequency and association of rs10128556 in Indian sickle cell disease patients with Hb F. It also established that it was not in complete linkage with the HBG XmnI variant in this high risk population.

A candidate transacting modulator of fetal hemoglobin gene expression in the Arab-Indian haplotype of sickle cell anemia.

Fetal hemoglobin (HbF) levels are higher in the Arab-Indian (AI) ß-globin gene haplotype of sickle cell anemia compared with African-origin haplotypes. To study genetic elements that effect HbF expression in the AI haplotype we completed whole genome sequencing in 14 Saudi AI haplotype sickle hemoglobin homozygotes-seven selected for low HbF (8.2% ± 1.3%) and seven selected for high HbF (23.5% ± 2.6%). An intronic single nucleotide polymorphism (SNP) in ANTXR1, an anthrax toxin receptor (chromosome 2p13), was associated with HbF. These results were replicated in two independent Saudi AI haplotype cohorts of 120 and 139 patients, but not in 76 Saudi Benin haplotype, 894 African origin haplotype and 44 AI haplotype patients of Indian origin, suggesting that this association is effective only in the Saudi AI haplotype background. ANTXR1 variants explained 10% of the HbF variability compared with 8% for BCL11A. These two genes had independent, additive effects on HbF and together explained about 15% of HbF variability in Saudi AI sickle cell anemia patients. ANTXR1 was expressed at mRNA and protein levels in erythroid progenitors derived from induced pluripotent stem cells (iPSCs) and CD34+ cells. As CD34+ cells matured and their HbF decreased ANTXR1 expression increased; as iPSCs differentiated and their HbF increased, ANTXR1 expression decreased. Along with elements in cis to the HbF genes, ANTXR1 contributes to the variation in HbF in Saudi AI haplotype sickle cell anemia and is the first gene in trans to HBB that is associated with HbF only in carriers of the Saudi AI haplotype. Am. J. Hematol. 91:1118-1122, 2016. © 2016 Wiley Periodicals, Inc.

MBL2 variations and malaria susceptibility in Indian populations.

Human mannose-binding lectin (MBL) encoded by the MBL2 gene is a pattern recognition protein and has been associated with many infectious diseases, including malaria. We sought to investigate the contribution of functional MBL2 gene variations to Plasmodium falciparum malaria in well-defined cases and in matched controls. We resequenced the 8.7 kb of the entire MBL2 gene in 434 individuals clinically classified with malaria from regions of India where malaria is endemic. The study cohort included 176 patients with severe malaria, 101 patients with mild malaria, and 157 ethnically matched asymptomatic individuals. In addition, 830 individuals from 32 socially, linguistically, and geographically diverse endogamous populations of India were investigated for the distribution of functional MBL2 variants. The MBL2 -221C (X) allelic variant is associated with increased risk of malaria (mild malaria odds ratio [OR] = 1.9, corrected P value [P(Corr)] = 0.0036; severe malaria OR = 1.6, P(Corr) = 0.02). The exon1 variants MBL2*B (severe malaria OR = 2.1, P(Corr) = 0.036; mild versus severe malaria OR = 2.5, P(Corr) = 0.039) and MBL2*C (mild versus severe malaria OR = 5.4, P(Corr) = 0.045) increased the odds of having malaria. The exon1 MBL2*D/*B/*C variant increased the risk for severe malaria (OR = 3.4, P(Corr) = 0.000045). The frequencies of low MBL haplotypes were significantly higher in severe malaria (14.2%) compared to mild malaria (7.9%) and asymptomatic (3.8%). The MBL2*LYPA haplotypes confer protection, whereas MBL2*LXPA increases the malaria risk. Our findings in Indian populations demonstrate that MBL2 functional variants are strongly associated with malaria and infection severity.

Variations in ncRNA gene LOC284889 and MIF-794CATT repeats are associated with malaria susceptibility in Indian populations.

BACKGROUND: There are increasing evidences on the role of non-coding RNA (ncRNA) as key regulator of cellular homeostasis. LOC284889 is an uncharacterized ncRNA gene on reverse strand to MIF mapped to 22q11.23. MIF, a lymphokine, regulates innate immune response by up-regulating the expression of TLR4, suppressing the p53 activity and has been shown to be involved in malaria pathogenesis. METHODS: In this study, the possible effect of MIF variations on malaria susceptibility was investigated by re-sequencing the complete MIF gene along with 1 kb each of 5' and 3' region in 425 individuals from malaria endemic regions of the Orissa and Chhattisgarh states of India. The subjects comprised of 160 cases of severe malaria, 101 of mild malaria and 164 ethnically matched asymptomatic controls. Data were statistically compared between cases and controls for their possible association with Plasmodium falciparum malarial outcome. RESULTS: It is the first study, which shows that the allele A (rs34383331T > A) in ncRNA is significantly associated with increased risk to P. falciparum malaria [severe: OR = 2.08, p = 0.002 and mild: OR = 2.09, P = 0.005]. In addition, it has been observed that the higher MIF-794CATT repeats (>5) increases malaria risk (OR = 1.61, p = 0.01). Further, diplotype (MIF-794CATT and rs34383331T > A) 5 T confers protection to severe malaria (OR = 0.55, p = 0.002) while 6A (OR = 3.07, p = 0.001) increases malaria risk. CONCLUSIONS: These findings support the involvement of ncRNA in malarial pathogenesis and further emphasize the complex genetic regulation of malaria outcome. In addition, the study shows that the higher MIF-794CATT repeats (>5) is a risk factor for severe malaria. The study would help in identifying people who are at higher risk to malaria and adapt strategies for prevention and treatment.

A standalone approach to utilize telomere length measurement as a surveillance tool in oral leukoplakia.

Oral squamous cell carcinoma (OSCC) is often preceded by a white patch on a surface of the mouth, called oral leukoplakia (OL). As accelerated telomere length (TL) shortening in dividing epithelial cells may lead to oncogenic transformation, telomere length measurement could serve as a predictive biomarker in OL. However, due to high variability and lack of a universal reference, there has been a limited translational application. Here, we describe an approach of evaluating TL using paired peripheral blood mononuclear cells (PBMC) as an internal reference and demonstrate its translational relevance. Oral brush biopsy and paired venous blood were collected from 50 male OL patients and 44 male healthy controls (HC). Relative TL was measured by quantitative PCR. TL of each OL or healthy sample was normalized to the paired PBMC sample (TL ratio). In OL patients, the mean TL ratio was significantly smaller not only in the patch but also in distal normal oral tissue, relative to healthy controls without a high-risk oral habit. Dysplasia was frequently associated with a subgroup that showed a normal TL ratio at the patch but significantly smaller TL ratio at a paired normal distal site. Our data suggest that evaluation of TL attrition using a paired PBMC sample eliminates the requirement of external reference DNA, makes data universally comparable and provides a useful marker to define high-risk OL groups for follow-up programs. Larger studies will further validate the approach and its broader application in other premalignant conditions.

Methylenetetrahydrofolate reductase polymorphisms as genetic markers to predict homocysteinemia and clinical severity in sickle cell disease.

Aim: The present study observed the relationship between the methylenetetrahydrofolate reductase genotypes and clinical outcome in children with sickle cell disorder. Methodology: A total of 249 children were recruited for the study and evaluated clinically for calculating severity score, homocysteine levels and C677T and A1298C genotyping. Results: The frequencies of variant genotypes were 28.1% CT/TT677 and 69.1% AC/CC1298. Plasma homocysteine was significantly elevated in variant groups (p < 0.001). Both the genotypes accorded significant association with homocysteinemia (p < 0.001). Vascular crisis (p = 0.04), frequency of hospitalization (p < 0.001) and severity score (p = 0.02) revealed association with C677T and not with A1298C. The CT/TT677 genotypes showed 3.39-times (p = 0.032) increase in a higher score for severity. Conclusion: C677T depicted significant association with clinical severity in study population.

Identification of therapeutic targets for inflammation in sickle cell disease (SCD) among Indian patients using gene expression data analysis.

Sickle cell disease (SCD) is life-threatening hemoglobinopathy prevalent in India, Sub-Saharan Africa and Middle East. Inflammation plays a pivotal role in disease process and involves intricate interaction among leukocytes, platelets, sickle erythrocytes and vascular endothelium. Available disease modifying therapies are hydroxyl-urea and blood transfusion. Therefore, it is of interest to develop improved pharmacological agents for SCD. We report up-regulated genes in steady state and vaso-occlusive crisis using analysis of gene expression data obtained by microarray experiment for SCD as potential targets. The association of these targets with inflammation in pathway analysis is also documented.

Polymorphism of CYP1A1 gene variants rs4646903 and rs1048943 relation to the incidence of cervical cancer in Chhattisgarh.

Cytochrome P450 CYP1A1 is a phase 1 xenobiotic metabolizing enzyme involved in the metabolism of toxins, endogenous hormones and pharmaceutical drugs. It is therefore possible that polymorphism of CYP1A1 gene producing functional changes in the enzyme may be susceptible factors in cervical carcinogenesis. This study was aimed to look association of CYP1A1m1 (T>C) and m2 (A>G) gene polymorphisms in Chhattisgarh population. In this case-control study, we analyzed leukocyte DNA from a total of 200 subjects form Chhattisgarh (100 cases and 100 controls). All subjects were genotyped for CYP1A1m1 (T>C) and m2 (A>G) using PCR-RFLP with statistical analysis by using SPSS version 16.0 and VassarStats (online). Among the two gene variants rs4646903 (T>C) and rs1048943 (A>G), individuals with AG and GG genotypes of CYP1A1m2 polymorphism have significantly higher and increased risk of cervical cancer (OR=2.0, 95%CI=1.04-3.84, p=0.035; OR=62.9, 95%CI=3.72-1063.83, p=0.004 respectively) and the association of CYP1A1m1 polymorphism did not show any significant relationship with cervical cancer patients (p=0.23). The 'G' allele showed strong association with the disease (p<0.0001). Thus, CYP1A1m2 polymorphism showed an increased risk in the population leading to cervical cancer. Our study suggested that the presence of 'C' allele of rs4646903 (T>C) showed no risk and 'G' allele of rs1048943 (A>G) might be a leading allele to cause increased cervical cancer susceptibility due to significant association of CYP1A1m2 gene polymorphism.

Association of TP53 gene codon 72 polymorphism with incidence of cervical cancer in Chhattisgarh

TP53 gene encoding polymorphisms is a risk allele in terms of carcinogenesis. Here, we studied the risk assessment and association of TP53 to understand the cancer biology and behaviour in cervical cancer patients and possible anticancer drug development interfering with p53 protein production. TP53 gene encodes a central protein of apoptosis pathway p53 and its allelic variant has been postulated to play a vital role in carcinogenesis in addition to a variety of neurodegenerative disorders. We undertook a case control study, to examine the possible association of TP53 gene codon 72 polymorphism in leukocyte DNA from a total of 200 subjects (100 controls and 100 cases). TP53 codon Arg72Pro (rs1042522) genotype was identified using allele specific PCR and RFLP with statistical analysis using Vassar Stats (online). In Chhattisgarh population, individuals with GC and GG genotypes of TP53 gene codon 72 polymorphism has a significantly higher risk of cervical cancer (OR=6.36, 95%CI=2.8-14.03 and OR=7.42, 95%CI=3.5-15.9) as compared to CC genotype (OR=1) which was taken as reference. The 'G' allele was found to confer a significant risk of cervical cancer (OR= 3.69, 95%CI= 2.40-5.5) compared to 'C' allele. The present case control study demonstrated the prevalence of the Arg/Arg (GG) genotype in women with cervical cancer among Chhattisgarh population.

A rare non-synonymous c.102C>G SNP in the IFNB1 gene might be a risk factor for cerebral malaria in Indian populations.

Interferon beta1 (IFNB1) is a type I interferon that is mainly known for its antiviral activity, but it also regulates a number of anti-inflammatory and immunomodulatory functions. Studies on mouse models of cerebral malaria have established that IFNB1 regulates severe malaria pathogenesis and increases overall survival against malaria. It down-regulates pro-inflammatory cytokines: TNF, IFNG and ICAM-1, resulting in decreased adherence of Plasmodium falciparum parasitized RBC to capillary wall, entry into the brain and delayed onset of death. Therefore, we hypothesized that variations in IFNB1 gene could regulate malarial pathogenesis. We re-sequenced the complete IFNB1 gene along with 900bp of 5' up-stream and 500bp of 3'-UTR in 437 individuals from malaria endemic regions of the Orissa and Chhattisgarh states of India. The subjects comprised of 173 cases of severe malaria, 101 of mild malaria, and 156 ethnically matched asymptomatic controls. Data were statistically compared between cases and controls for their possible association with P. falciparum malarial outcome. Two single nucleotide polymorphisms (SNPs): a synonymous c.153C>T (rs1051922) and a non-synonymous substitution c.102C>G (rs139262191, p.Ser34Arg) were identified. The genotype and allele distribution of c.153C>T did not differ significantly between the study groups [mild, χ(2)2=4.10, p-value<0.13 and severe χ(2)2=0.06, p-value<0.97]. Interestingly, the rare non-synonymous SNP (rs139262191) was observed only in malaria patients. The differences between all cases and controls did not reach statistical significance, however, a statistically significant difference was observed between the asymptomatic control group and the cerebral malaria group [OR=20.32, 95% CI=1.08-382.63, p-value=0.044]. Moreover, the genotypes between cerebral malaria positive and negative groups were not significantly different [OR=5.58, 95% CI=0.61-50.97, p-value=0.123]. Our findings suggest that the IFNB1 variant, p.Ser34Arg, might be a risk factor for cerebral malaria in Indian populations.

IL-4 haplotype -590T, -34T and intron-3 VNTR R2 is associated with reduced malaria risk among ancestral indian tribal populations.

BACKGROUND: Interleukin 4 (IL-4) is an anti-inflammatory cytokine, which regulates balance between T(H)1 and T(H)2 immune response, immunoglobulin class switching and humoral immunity. Polymorphisms in this gene have been reported to affect the risk of infectious and autoimmune diseases. METHODS: We have analyzed three regulatory IL-4 polymorphisms; -590C>T, -34C>T and 70 bp intron-3 VNTR, in 4216 individuals; including: (1) 430 ethnically matched case-control groups (173 severe malaria, 101 mild malaria and 156 asymptomatic); (2) 3452 individuals from 76 linguistically and geographically distinct endogamous populations of India, and (3) 334 individuals with different ancestry from outside India (84 Brazilian, 104 Syrian, and 146 Vietnamese). RESULTS: The -590T, -34T and intron-3 VNTR R2 alleles were found to be associated with reduced malaria risk (P<0.001 for -590C>T and -34C>T, and P = 0.003 for VNTR). These three alleles were in strong LD (r²>0.75) and the TTR2 (-590T, -34T and intron-3 VNTR R2) haplotype appeared to be a susceptibility factor for malaria (P = 0.009, OR = 0.552, 95% CI = 0.356 -0.854). Allele and genotype frequencies differ significantly between caste, nomadic, tribe and ancestral tribal populations (ATP). The distribution of protective haplotype TTR2 was found to be significant (χ²3 =  182.95, p-value <0.001), which is highest in ATP (40.5%); intermediate in tribes (33%); and lowest in caste (17.8%) and nomadic (21.6%). CONCLUSIONS: Our study suggests that the IL-4 polymorphisms regulate host susceptibility to malaria and disease progression. TTR2 haplotype, which gives protection against malaria, is high among ATPs. Since they inhabited in isolation and mainly practice hunter-gatherer lifestyles and exposed to various parasites, IL-4 TTR2 haplotype might be under positive selection.

Screening for the sickle cell gene in Chhattisgarh state, India: an approach to a major public health problem.

The aim of this study is to determine the feasibility of large-scale population screening for the sickle cell gene in high risk areas with limited resources. A programme designed to detect the sickle cell trait and sickle cell disease has screened 359,823 subjects among 2,087 (99.7%) of the villages in Raipur District, Chhattisgarh State, India between October 2007 and June 2010. Children aged 3-15 years were initially screened in the villages by solubility tests on fingerprick samples. Venipuncture was performed on subjects with positive solubility tests, and the samples were transferred to Raipur Medical College for alkaline haemoglobin electrophoresis. The sickle cell trait occurred in 33,467 (9.30%) and an SS phenotype in 747 (0.21%). The gene frequencies were not in Hardy-Weinberg equilibrium most likely due to a deficiency of the SS phenotype failing to enter the sampled population from either sickness or early death. Subjects with abnormal haemoglobin genotypes may factor this information into decisions regarding marriage and avoid the risks of having children with sickle cell disease. The techniques described may be a model for other developing societies with limited resources.