Project description:BACKGROUND:Gradual improvements in the management of sickle cell disease (SCD), have led to an increase in the number of women with SCD who reach the age of procreation. However, evidence on the iron status of pregnant women with sickle cell disease (PWSCD) remains inconclusive. We conducted the first systematic review on the prevalence, determinants and maternal/foetal outcomes of iron deficiency anaemia among PWSCD. METHODS:We searched MEDLINE, EMBASE, Global Health, Africa Index Medicus, the Cochrane library databases and reference lists of retrieved publications for studies describing the iron status of PWSCD. The literature search was done over a period of 1?month, with no language or date restrictions applied. Data were extracted on a Microsoft excel sheet. Two authors assessed all included studies for methodological quality and risk of bias. RESULTS:A total of 710 reports were identified for title and article screening. Five retained studies were conducted before or during the 90s and included 67 participants. After quality assessment, the observational studies were designated to have a "fair" quality assessment while the randomised control trial had an "unclear" quality assessment. The prevalence of iron deficiency anaemia among PWSCD varied by study design and diagnostic method. The overall prevalence ranged from 6.67-83.33%. None of the studies provided evidence on factors associated with iron deficiency anaemia and the randomized trial reported no difference in outcomes between PWSCD who had iron supplementation and those who did not. CONCLUSION:Evidence on factors associated with iron deficiency anaemia among PWSCD and maternal/foetal outcomes in PWSCD who have iron deficiency anaemia is poor. The studies included in this review suggests that iron deficiency anaemia may be highly prevalent in PWSCD but due to the very small sample sizes and varied study designs, this evidence is inconclusive. The review shows that there is a need for more studies with robust designs and adequate sample sizes to assess the disease burden of iron deficiency anaemia in PWSCD.
Project description:Under exchange conditions (no net increase in calcium), erythrocytes incubated in isoosmotic phosphate-buffered saline have an exchangeable calcium pool comprising about 10% of the total erythrocyte calcium. This pool reaches exchange equilibrium, for either inward-directed or outward-directed transfer of the 45Ca-exchange label, with a half-time of about 20 min. The uptake of Ca2+ requires phosphate, even under hypo-osmotic conditions, where the calcium loading expected as the cells swell is obtained only when phosphate is present. The phosphate requirement is not due to Ca2+ transport as a phosphate salt. This exchangeable-calcium pool is also present in sickle-cell-anemia erythrocytes, and comprises a similar proportion of total cellular calcium.
Project description:Background and aimsChildren with sickle cell disease (SCD) have an increased risk of multiple hemotransfusions and this can predispose them to elevated iron stores. The objectives of the study were to determine the extent of elevated iron stores and the associated risk factors in a population of steady-state SCD children in Ghana.MethodsThis cross-sectional study was conducted at the pediatric sickle cell clinic at the Komfo Anokye Teaching Hospital. Complete blood count and serum ferritin assay were performed for (n = 178) steady-state SCD children. Descriptive and multivariate logistic regression analysis were performed. Elevated iron stores were defined as serum ferritin levels >300 ng/ml. Statistical significance was considered at p < 0.05.ResultsThe mean (standard deviation) age of the participants was 9.61 (±4.34) years, and 51% of them were males. About 17% of SCD children had elevated iron stores and receiving at least three hemotransfusions during the last 12 months was strongly associated with elevated iron stores (p < 0.001). History of chronic hemotransfusion increased the odds of having elevated iron store (adjusted odds ratio [aOR] = 11.41; 95% confidence interval [CI] = 3.11-30.85; p < 0.001) but SCD patients on hydroxyurea treatment had reduced-odds of having elevated iron stores (aOR = 0.18; 95% CI = 0.06-0.602; p = 0.006). Moreover, red blood cell (Coef. = -0.84; 95% CI = -0.37, -1.32; p = 0.001), hemoglobin (Coef. = -0.83; 95% CI = -0.05, -1.61; p = 0.04), hematocrit (Coef. = -0.85; 95% CI = -0.08, -1.63; p = 0.03), mean cell volume (Coef. = 0.02; 95% CI = 0.01, 0.03; p = 0.001) and mean cell hemoglobin (Coef. = 0.04; 95% CI = 0.01, 0.07; p = 0.002) could significantly predict serum ferritin levels.ConclusionThe magnitude of elevated iron stores was high among children with SCD in steady-state. Red cell indices could provide invaluable information regarding the risk of elevated iron stores. SCD children who have a history of chronic hemotransfusion or had received at least three hemotransfusions in a year should be monitored for elevated iron stores.
Project description:IntroductionSickle cell disease (SCD) is the most common inherited disease worldwide. The greatest disease burden is seen in sub-Saharan Africa. Early diagnosis and improved care of people living with SCD have led to an increase in the number of women with SCD reaching the reproductive age. Iron deficiency anaemia remains the most common cause of anaemia in pregnancy, affecting 51%-63% of pregnancies in Africa. However, the unavailability of guidelines on supplementation of iron in this pregnant subpopulation often leaves clinicians in a fix. We propose to conduct the first systematic review and possibly a meta-analysis on the prevalence, associated factors and maternal/fetal outcomes of iron deficiency anaemia among pregnant women with SCD.Methods and analysisWe will search the following electronic databases for studies on the iron status of pregnant women with SCD: PubMed, MEDLINE, EMBASE, Google Scholar, African Journals Online, African Index Medicus, Popline and the Cochrane Library. After the selection of eligible studies from the search output, review of full text, data extraction and data synthesis will be performed. Studies obtained from the review shall be evaluated for quality, risk of bias and heterogeneity. Appropriate statistical methods shall be used to pool prevalence estimates for matching studies globally and in subpopulations. This protocol has been reported as per the 2015 guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols.Ethics and disseminationThere is no requirement for ethical approval as the proposed study will use published data. The findings of this study will be published in a peer-reviewed journal and will be presented at conferences.Trial registration numberCRD42018109803.
Project description:Haemolytic anaemia is variable among patients with sickle cell anaemia and can be estimated by reticulocyte count, lactate dehydrogenase, aspartate aminotransferase and bilirubin levels. Using principal component analysis of these measurements we computed a haemolytic score that we used as a subphenotype in a genome-wide association study. We identified in one cohort and replicated in two additional cohorts the association of a single nucleotide polymorphism in NPRL3 (rs7203560; chr16p13·3) (P = 6·04 × 10(-07) ). This association was validated by targeted genotyping in a fourth independent cohort. The HBA1/HBA2 regulatory elements, hypersensitive sites (HS)-33, HS-40 and HS-48 are located in introns of NPRL3. Rs7203560 was in perfect linkage disequilibrium (LD) with rs9926112 (r(2) = 1) and in strong LD with rs7197554 (r(2) = 0·75) and rs13336641 (r(2) = 0·77); the latter is located between HS-33 and HS-40 sites and next to a CTCF binding site. The minor allele for rs7203560 was associated with the -?(3·7) thalassaemia gene deletion. When adjusting for HbF and ? thalassaemia, the association of NPRL3 with the haemolytic score was significant (P = 0·00375) and remained significant when examining only cases without gene deletion? thalassaemia (P = 0·02463). Perhaps by independently down-regulating expression of the HBA1/HBA2 genes, variants of the HBA1/HBA2 gene regulatory loci, tagged by rs7203560, reduce haemolysis in sickle cell anaemia.
Project description:Sickle-cell anaemia (SCA) is a neglected chronic disorder of increasing global health importance, with India estimated to have the second highest burden of the disease. In the country, SCA is particularly prevalent in scheduled populations, which comprise the most socioeconomically disadvantaged communities. We compiled a geodatabase of a substantial number of SCA surveys carried out in India over the last decade. Using generalised additive models and bootstrapping methods, we generated the first India-specific model-based map of sickle-cell allele frequency which accounts for the district-level distribution of scheduled and non-scheduled populations. Where possible, we derived state- and district-level estimates of the number of SCA newborns in 2020 in the two groups. Through the inclusion of an additional 158 data points and 1.3 million individuals, we considerably increased the amount of data in our mapping evidence-base compared to previous studies. Highest predicted frequencies of up to 10% spanned central India, whilst a hotspot of ~12% was observed in Jammu and Kashmir. Evidence was heavily biased towards scheduled populations and remained limited for non-scheduled populations, which can lead to considerable uncertainties in newborn estimates at national and state level. This has important implications for health policy and planning. By taking population composition into account, we have generated maps and estimates that better reflect the complex epidemiology of SCA in India and in turn provide more reliable estimates of its burden in the vast country. This work was supported by European Union's Seventh Framework Programme (FP7//2007-2013)/European Research Council [268904 - DIVERSITY]; and the Newton-Bhabha Fund [227756052 to CH].
Project description:Oral iron promotes intestinal tumourigenesis in animal models. In humans, expression of iron transport proteins are altered in colorectal cancer. This study examined whether the route of iron therapy alters iron transport and tumour growth. Colorectal adenocarcinoma patients with pre-operative iron deficiency anaemia received oral ferrous sulphate (n = 15), or intravenous ferric carboxymaltose (n = 15). Paired (normal and tumour tissues) samples were compared for expression of iron loading, iron transporters, proliferation, apoptosis and Wnt signalling using immunohistochemistry and RT-PCR. Iron loading was increased in tumour and distributed to the stroma in intravenous treatment and to the epithelium in oral treatment. Protein and mRNA expression of proliferation and iron transporters were increased in tumours compared to normal tissues but there were no significant differences between the treatment groups. However, intravenous iron treatment reduced ferritin mRNA levels in tumours and replenished body iron stores. Iron distribution to non-epithelial cells in intravenous iron suggests that iron is less bioavailable to tumour cells. Therefore, intravenous iron may be a better option in the treatment of colorectal cancer patients with iron deficiency anaemia due to its efficiency in replenishing iron levels while its effect on proliferation and iron metabolism is similar to that of oral iron treatment.
Project description:The datasets contained in this article are simulated data with respect to Sickle Cell Anaemia (SCA) in order to examine the mathematical inheritance formation of the SCA disease. The simulation is done using Monte Carlos Simulation (MCS) Technique to complement the Physical Simulation Smith's Statistical (PSSS) package used as random number generator for birth simulation. One hundred and fifty-six (156) births for seven (7) generations were considered in the simulation alongside non-gestating reproductive females with fertile male adults while immigration and emigration are not permitted. These datasets can effectively serve as benchmarks for both health, and marital counselling institutions.
Project description:OBJECTIVE Increased serum ferritin levels and iron stores may be involved in the development of abnormal glucose tolerance in women presenting with obesity and/or polycystic ovary syndrome (PCOS). We aimed to study the determinants of serum ferritin levels in premenopausal women among indexes of insulin resistance, adiposity, hyperandrogenism, and genotypes pertaining to inflammation, oxidative stress, and iron metabolism. RESEARCH DESIGN AND METHODS A total of 257 premenopausal women, classified depending on the presence or absence of PCOS, obesity, and/or abnormal glucose tolerance, underwent a complete metabolic evaluation, serum ferritin, haptoglobin, and C-reactive protein (CRP) measurements, and genotyping for proinflammatory and prooxidant variants and mutations in the HFE gene. RESULTS Serum ferritin concentrations were increased in women presenting with PCOS and/or abnormal glucose tolerance, independent of obesity. A stepwise multivariate linear regression analysis (R(2) = 0.18, P < 0.0001) retained menstrual dysfunction (beta = 0.14, P = 0.035), free testosterone (beta = 0.14, P = 0.052), insulin sensitivity index (beta = -0.12, P = 0.012), the His63Asp variant in HFE (beta = 0.16, P = 0.008), and abnormal glucose tolerance (beta = 0.15, P = 0.015) as significant predictors of the logarithm of ferritin levels, whereas CRP, haptoglobin, waist-to-hip ratio, or variants in the TNFalpha, TNFRSF1B, IL6, IL6ST, IL6Ralpha, PON1, and HFE Cys282Tyr mutation exerted no influence. CONCLUSIONS Androgen excess (partly because of hyperandrogenemia and partly because of menstrual dysfunction), insulin resistance, abnormal glucose tolerance, and the HFE His63Asp variant correlate with ferritin levels in premenopausal women.
Project description:Serial phlebotomy was performed on sixty children with sickle cell anaemia, stroke and transfusional iron overload randomized to hydroxycarbamide in the Stroke With Transfusions Changing to Hydroxyurea trial. There were 927 phlebotomy procedures with only 33 adverse events, all of which were grade 2. Among 23 children completing 30 months of study treatment, the net iron balance was favourable (-8·7 mg Fe/kg) with significant decrease in ferritin, although liver iron concentration remained unchanged. Therapeutic phlebotomy was safe and well-tolerated, with net iron removal in most children who completed 30 months of protocol-directed treatment.