Percentage Of Fetal Hemoglobin Research Articles

A miniaturized wash-free microfluidic assay for electrical impedance-based assessment of red blood cell-mediated microvascular occlusion

The production of HbS — an abnormal hemoglobin (Hb) — in sickle cell disease (SCD) results in poorly deformable red blood cells (RBCs) that are prone to microcapillary occlusion, causing tissue ischemia and organ damage. Novel treatments, including gene therapy, may reduce SCD morbidity, but methods to functionally evaluate RBCs remain limited. Previously, we presented the microfluidic impedance red cell assay (MIRCA) for rapid assessment of RBC deformability, employing electrical impedance-based readout to measure RBC occlusion of progressively narrowing micropillar openings. We describe herein the design, development, validation, and clinical utility of the next-generation MIRCA assay, featuring enhanced portability, rapidity, and usability. It incorporates a miniaturized impedance analyzer and features a simplified wash-free operation that yields an occlusion index (OI) within 15 min as a new metric for RBC occlusion. We show a correlation between OI and percent fetal hemoglobin (%HbF), other laboratory biomarkers of RBC hemolysis, and SCD severity. To demonstrate the assay’s versatility, we tested RBC samples from treatment-naïve SCD patients in Uganda that yielded OI levels similar to those from hydroxyurea (HU)-treated patients in the U.S., highlighting the role of %HbF in protecting against microcapillary occlusion independent of other pharmacological effects. The MIRCA assay could also identify a subset of HU-treated patients with high occlusion risks, suggesting that they may require treatment adjustments including a second-line therapy to improve their outcomes. This work demonstrates the potential of the MIRCA assay for accelerated evaluation of RBC health, function, and therapeutic effect in an ex vivo model of the microcapillary networks.

Identifying Clinical Predictors of Proliferative Sickle Cell Retinopathy

Purpose To identify systemic and/or ophthalmologic predictors of proliferative sickle retinopathy. Methods Cross-sectional study comparing clinical, laboratory, and structural choriorretinal aspects between sickle cell disease patients with and without proliferative retinopathy. Patients underwent complete systemic and ophthalmologic evaluation. Enhanced depth spectral domain optical coherence tomography with choroidal binarization and optic coherence tomography angiography were performed and choriorretinal vascular components were compared. Results Forty-five eyes from 45 sickle cell patients were included. Ninety-one percent of patients were diagnosed with sickle cell retinopathy, 29% with proliferative retinopathy. Mean corpuscular volume, lactate dehydrogenase, and percentage of fetal hemoglobin were reduced in the subgroup of patients with proliferative retinopathy when compared with patients without proliferative retinopathy (p ≤ 0.001; p = 0.04; p ≤ 0.001, respectively). The best predictor of proliferative retinopathy was mean corpuscular volume (AUC = 0.842; p = 0.001), followed by the percentage of fetal hemoglobin (AUC = 0.763, p = 0.009) and lactate dehydrogenase (AUC curve = 0.706; p = 0.039). No differences were found between groups in the quantitative analysis of retinal vascularization using OCTA and choroidal vascularization using OCT (p ≥ 0.05). Conclusion Fetal hemoglobin and mean corpuscular volume may be good predictors of proliferative sickle retinopathy. The association between proliferative retinopathy and reduced levels of lactate dehydrogenase and mean corpuscular volume points to hypoxia and not hemolysis as a possible driving force in its pathophysiology.

Induction of fetal hemoglobin: Lentiviral shRNA knockdown of HBS1L in β0-thalassemia/HbE erythroid cells.

Imbalanced globin chain output contributes to thalassemia pathophysiology. Hence, induction of fetal hemoglobin in β-thalassemia and other β-hemoglobinopathies are of continuing interest for therapeutic approaches. Genome-wide association studies have identified three common genetic loci: namely β-globin (HBB), an intergenic region between MYB and HBS1L, and BCL11A underlying quantitative fetal hemoglobin production. Here, we report that knockdown of HBS1L (all known variants) using shRNA in early erythroblast obtained from β0-thalassemia/HbE patients triggers an upregulation of γ-globin mRNA 1.69 folds. There is modest perturbation of red cell differentiation assessed by flow cytometry and morphology studies. The levels of α- and β-globin mRNAs are relatively unaltered. Knockdown of HBS1L also increases the percentage of fetal hemoglobin around 16.7 folds when compared to non-targeting shRNA. Targeting HBS1L is attractive because of the potent induction of fetal hemoglobin and the modest effect on cell differentiation.

β-talasemia intermedia: triplicación de genes α/β talasemia heterocigota en España

Objectives. Check with hematological data that the diagnosis and clinical grade of β-thalassemia intermedia can be established when a triplication of genes alpha (αααanti 3.7) and heterozygous β-thalassemia are coherent. Methods. Retrospective study in which 73 patients of Caucasian origin participated, who simultaneously showed a tripling or quadrupling of the genes α and heterozygous β-thalassemia. Screening for the most frequent α-thalassemia mutations, as well as gene triplication (αααanti 3.7) was carried out by multiplex PCR followed by reverse hybridization and confirmed by MLPA. The molecular diagnosis of β-thalassemia was carried out by automatic sequencing according to the Sanger’s method. Results. Genotypes have been classified into three groups according to the number of α-globin genes and the severity of the alteration in the β-globin gene. All had a mutation in the β-globin gene (β0-thalassemia, severe β+-thalassemia, and mild β+-thalassemia). Group I patients who have inherited 6 α globin genes. Group II and group III have inherited 5 α globin genes. In group III, the patients were carriers of mutations affecting the β and δ globin genes. The most significant hematological parameters were hemoglobin levels, mean corpuscular volume, red deep width, and percentage of fetal hemoglobin. Conclusions. In group I, patients who have inherited of 6 α globin genes, either by homozygous triplication (ααα/ααα) or heterozygous quadruplication (αααα/αα), with heterozygous β-thalassemia results in severe to moderate anemia that may require transfusion therapy, being the severity of the β-globin gene mutation that would determine the clinical variation. Group II patients behaved phenotypically like mild thalassemia intermedia. Finally, group III patients behaved like a thalassemic trait since all were carriers of mutations that increase the overexpression of g genes.

Fetal hemoglobin levels in premature newborns. Should we reconsider transfusion of adult donor blood?

PurposeThe aim of this study was to assess the percent decrease in fetal hemoglobin (HbF) after transfusion of adult-derived donor packed red blood cell (pRBC) units in extremely low gestational age newborns (ELGANs). MethodsControl percent fetal hemoglobin (%HbF) levels were measured in newborn cord blood or peripheral blood samples in non-transfused patients prior to elective surgery. ELGANs were followed prospectively and %HbF was measured on residual post-test complete blood count (CBC) specimens. ELGAN %HbF values were compared to the control population and transfusions were recorded. ResultsInitial mean %HbF in ELGANs (n=16) was 92.2±1.3% (range 90.2-95.1%), which is similar to the control group (n=25). Mean levels dropped to 61.1±11.1% (range 34.2-73.2%) after a single pRBC transfusion (n=9) and to a mean of 35.6±6.3% after an additional transfusion (n=5). %HbF levels trended upwards if no additional transfusions were given, but levels still remained lower than expected for gestational age through discharge (n=85 samples). ConclusionsPercent fetal hemoglobin concentrations in ELGANs decrease precipitously after transfusion with adult donor pRBCs. Further studies are needed to evaluate the benefit of maintaining higher fetal hemoglobin concentrations in these patients and whether administration of HbF rather than adult donor pRBCs would improve patient outcomes.

Fetal-Maternal Hemorrhage in First-Trimester Intrauterine Hematoma

Objective: The objective of this study was to compare the frequency and percentage of fetal hemoglobin (HbF%) by flow cytometry of (1) first-trimester asymptomatic patients with intrauterine hematoma (IUH), (2) first-trimester pregnant patients with vaginal bleeding (VB), and (3) first-trimester asymptomatic pregnant women without hematoma. Methods: Prospective study involving pregnant women in the first trimester of pregnancy. Patients with ultrasound findings of asymptomatic hematoma and with VB were paired with asymptomatic pregnant women of same gestational age without hematoma (control group [CG]). Maternal blood HbF% was evaluated by flow cytometry. The groups were compared in terms of circulating fetal hemoglobin and HbF%. Results: Sixty-six patients were selected, 22 with hematoma, 17 with bleeding, and 27 in the CG. Fetal hemoglobin was detected in 15 patients with hematoma (68.2%) and 13 with bleeding (76.5%) and in 20 of the control (74.1%) (p = 0.830). The mean HbF% of each group was 0.054, 0.012, and 0.042 for hematoma, bleeding, and control, respectively, and differences were not significant (p = 0.141). There was a moderate negative correlation between the volume of hematoma and HbF% (r_Spearman = −0.527; p = 0.012). Conclusions: The fetal-maternal hemorrhage expressed by Hbf% in first-trimester pregnancies did not seem to differ between patients with and without ultrasound findings of IUH.

Effect of Hydroxyurea Treatment on the Inflammatory Markers Among Children With Sickle Cell Disease.

Background:Neutrophil-to-lymphocyte ratio (NLR) was introduced as a potential inflammatory marker in sickle cell disease (SCD). This study aimed to evaluate the impact of hydroxyurea (HU) treatment on the value of NLR and some inflammatory mediators in SCD.Methods:The hematological parameters and clinical events were analyzed in 35 children with SCD under HU treatment and followed up for 1 year and in 20 healthy controls. Enzyme-linked immunosorbent assay was performed for the evaluation of proinflammatory cytokines, including interleukin (IL) 6, IL-8, high-sensitivity C-reactive protein (hs-CRP), and tumor necrosis factor α (TNF-α).Results:Hydroxyurea significantly improves most of the hematological parameters in children with SCD. The percentages of hemoglobin fraction S, serum levels of TNF-α and IL-6 were significantly decreased when compared to baseline value but did not reach the value of the healthy control. The HU treatment led to a significant decrease in NLR compared to the baseline values and reached healthy control values. Neutrophil-to-lymphocyte ratio was positively correlated with hs-CRP, TNF-α, and IL-8 serum levels and negatively correlated with percentage of fetal hemoglobin and hematocrit values. The cutoff value of NLR to expect a response to HU among SCD was 3.0, with 76% specificity and 85% sensitivity (area under the curve: 0.85, P < .0001). In conclusion, hydroxyurea induced a decrease in NLR and inflammatory cytokines, which represent a biomarker of inflammation in SCD. The calculation of NLR is a straightforward and cheap method for SCD outcome prediction in young children.

The Effect of Patient Navigators on Laboratory Parameters of Hydroxyurea Adherence in Sickle Cell Anemia: The SHIP-HU Study

Background: Hydroxyurea (HU) therapy in adults with sickle cell anemia (SCA) increases total hemoglobin (Hb) and percent fetal hemoglobin (HbF) levels, reduces total white cell (WBC) and neutrophil (ANC) count, and increases the mean corpuscular volume (MCV). Case management and community health workers are both evidence-based health management strategies. Patient navigators (PN) are community health workers trained specifically in case management for patients with SCA. We therefore hypothesized that HU-eligible patients exposed to patient navigators (PN) would have improved laboratory characteristics reflecting improved uptake and adherence to HU. Methods: We enrolled 224 adult patients eligible for HU into the Start Healing in Patients with Hydroxyurea (SHIP-HU) Randomized Controlled Trial. All patients received care from trained physicians who implemented use of a standardized HU prescribing protocol using NIH guidelines. Pateints were randomized to either PN intervention (which included case management and education through home, telephone, and/or other visits from PNs) plus standard care by their treating physician (Experimental, E), or standard care by their physician alone (Control, C). Study physicians were blinded to study arm. At baseline, 6 months and 12 months we assessed: Complete Blood Count including WBC, ANC, total hemoglobin (Hb), platelet count (plt), mean corpuscular volume (MCV), and; HbF via HPLC and electrophoresis. Main analyses consisted of comparisons of the hematological variables between arms. Mixed model analysis of variance was used to analyze follow-up visits, controlling for site and baseline value of outcome variable. Any missing baseline values for subjects were imputed. Results: 206 of 224 patients had at least one lab value at follow-up. Patients had mean age 30.1, 45.6% were male, 82.5% had been prescribed HU at baseline. HbF was higher at the 6 month visit for group E vs. group C when controlled for baseline values. Neither WBC, ANC, Hb, Hb F, Plt, nor MCV were different between groups E and C at any other time point (Table). Conclusions: In our sample, there were no differences in hematological variables among patients who were exposed to PNs vs those who weren't. Several factors may have impacted these outcomes. HU was prescribed to 82.5% of enrolled patients at baseline, with higher % HbF than anticipated in study design. The intention to study change in % HbF as a singular marker for HU uptake and adherence did not assume high utilization of HU at baseline. We are currently analyzing data to enable comparisons between patients who were on HU at baseline and those who were not, which we believe will be able to speak to the true impact of the PN intervention. Future analyses will examine these and other factors influencing outcomes. Table Disclosures Smith: Novartis: Consultancy, Honoraria. Villella:Pfizer: Other: Site PI for the Rivipansel Clinical Trial; Emmaus: Membership on an entity's Board of Directors or advisory committees. Liles:Novartis: Other: PI on clinical trial Sickle cell ; Shire: Other: PI on clinical trial Sickle cell ; Imara: Other: PI on Clinical trial- Sickle cell.

Sickle-Cell Disease Patients' Attitudes Towards Their Treatment with Hydroxycarbamide

Hydroxyurea (HU) is approved in the EU and USA for prevention of vaso-occlusive crises (VOC) including acute chest syndromes (ACS) in patients over 2 years with sickle-cell disease (SCD). The major benefits of HU in SCD are directly related to its abilities to increase HbF, decrease sickling of red blood cells and hemolysis, leading to reduction of vaso-occlusive episodes, need for blood transfusions and consequently reduction of morbidity and mortality. Adherence to the treatment is paramount for effectiveness, but in spite of proven benefits, barriers to adherence persist.[1] ESCORT-HU study (European Sickle Cell Disease COhoRT - HydroxyUrea), is a multicentric, prospective, non-interventional European study designed to evaluate the safety profile of HU in real life. Patients were enrolled from January 2009 to June 2017 with a follow-up of up to 10 years. All interruptions and resumptions of HU treatment exceeding 15 days were recorded in this study. We hereby present the analysis of the group of patients who self-discontinued HU at least once during the study before informing their caregiver, with a view to identify potential barriers to long-term adherence. In total, 1906 patients were enrolled in ESCORT-HU from 63 centers in France, Germany, Greece and Italy. Of these, 619 patients (32%) stopped HU for over 15 days at least once, and around a third (11% of all patients) were due to patient's will. The mean duration of HU treatment before the first discontinuation was 4.8 ± 5.1 years. Data are summarized in table 1. Compared to the rest of the cohort, the 'treatment discontinuation' group had similar distribution by gender and indication for HU prescription, but a higher proportion of adults stopped HU more than 15 days. It is notable that the proportion of patients with SC genotype was higher in the 'treatment discontinuation' group (4.5% vs 1.7%). The patients in the 'treatment discontinuation' group had more frequent SCD symptoms before enrolment in the study (table 2). Hematological and clinical improvement compared to the baseline was observed in both groups. However, average mean Corpuscular Volume (MCV) and Fetal Hemoglobin percentage (HbF%) were lower and mean percentages of patients with SCD symptoms were higher over the three years of follow-up in the 'treatment discontinuation' group, suggesting that HU daily dose was insufficient (table 2). Sixty patients have no treatment resumption date reported which suggest a permanent interruption of their treatment. Among them 32% preferred to switch to another HU medicinal product and 13% have safety issue (table 3). Understanding and managing self-discontinuation of HU before taking medical advice is challenging for the physician. It is tempting to speculate that it may be due, at least in part, to lack of effectiveness potentially due to an underdosage of the treatment. Resistance to the treatment may also be suggested based on past literature data revealing a great variability in the response (determined by HbF%) to HU therapy. There is evidence that genetic modifiers affect individual response to HU.[2],[3] Finally, weariness from long-term use may also explain the patient's wish to discontinue HU. But treatment at optimal effective should be the primary goal of caregivers. [1]Smaldone A., Manwani D., Green NS, Greater number of perceived barriers to hydroxyurea associated with poorer health-related quality of life in youth with sickle cell disease, Pediatr Blood Cancer. 2019 [2] Steinberg MH, Voskaridou E, Kutlar A, Loukopoulos D, Koshy M, et al. (2003). Concordant fetal hemoglobin response to hydroxyurea in siblings with sickle cell disease. Am J Hematol 72: 121-126 [3] Ware RE, Despotovic JM, Mortier NA, Flanagan JM, He J, et al. (2011) Pharmacokinetics, pharmacodynamics, and pharmacogenetics of hydroxyurea treatment for children with sickle cell anemia. Blood 118: 4985-4991 Disclosures Galactéros: Addmedica: Membership on an entity's Board of Directors or advisory committees. Voskaridou:Celgene Corporation: Consultancy, Research Funding; Protagonist: Research Funding; Genesis: Consultancy, Research Funding; Acceleron: Consultancy, Research Funding; Addmedica: Membership on an entity's Board of Directors or advisory committees. Cannas:Addmedica: Membership on an entity's Board of Directors or advisory committees.

Methemoglobinemia: Infants at risk

Methemoglobin is formed when the iron center in hemoglobin is oxidized from ferrous iron to ferric iron. The functional consequence of this change is that hemoglobin is transformed to methemoglobin and cannot oxygenate tissues adequately, causing hypoxia and cyanosis. Infants have unique physiology that increases their risk of developing methemoglobinemia. Infants drink more water per body weight compared to children and adults, have lower NADH cyb5r reductase activity that converts methemoglobin to hemoglobin, and have a higher percentage of fetal hemoglobin, which is easier to convert to methemoglobin. A well-studied exposure to a chemical that can cause methemoglobinemia in infants is nitrate in well water. For the first part specifically about methemoglobin in infants, articles that were recent (2015-now) were given preference over articles that were older. Search terms included: methemoglobin, methemoglobinemia, infant, acquired, congenital, and methylene blue. For the latter half of the paper on nitrate and methemoglobinemia, preference was given to articles that described regionally important cases. In addition, search terms were: Minnesota, methemoglobinemia, nitrate, well water, drinking water, and infant. Acquired methemoglobinemia is rare, yet can still be seen in medical settings, and when an infant is exposed to nitrate in well water above 10mg/L. To prevent exposure, parents should have their water tested for nitrate before the baby comes home. Physicians should make it practice to ask what the source of drinking water is for newly pregnant women and urge them to test for nitrate and bacteria if using a well. Using bottled water to make formula is also an option, but the best option is still breastfeeding.

Low fetal hemoglobin percentage is associated with silent brain lesions in adults with homozygous sickle cell disease.

Silent white matter changes (WMCs) on brain imaging are common in individuals with sickle cell disease (SCD) and are associated with cognitive deficits in children. We investigated the factors predictive of WMCs in adults with homozygous SCD and no history of neurological conditions. Patients were recruited from a cohort of adults with homozygous SCD followed up at an adult sickle cell referral center for which steady-state measurements of biological parameters and magnetic resonance imaging scans of the brain were available. WMCs were rated by consensus, on a validated age-related WMC scale. The prevalence of WMCs was 49% (95% confidence interval [CI], 39%-60%) in the 83 patients without vasculopathy included. In univariable analysis, the patients who had WMCs were more likely to be older (P = .003) and to have hypertension (P = .02), a lower mean corpuscular volume (P = .005), a lower corpuscular hemoglobin concentration (P = .008), and a lower fetal hemoglobin percentage (%HbF) (P = .003). In multivariable analysis, only a lower %HbF remained associated with the presence of WMCs (odds ratio [OR] per 1% increase in %HbF, 0.84; 95% CI, 0.72-0.97; P = .021). %HbF was also associated with WMC burden (P for trend = .007). Multivariable ordinal logistic regression showed an inverse relationship between WMC burden (age-related WMC score divided into 4 strata) and HbF level (OR for 1% increase in %HbF, 0.89; 95% CI, 0.79-0.99; P = .039). Our study suggests that HbF may protect against silent WMCs, decreasing the likelihood of WMCs being present and their severity. It may therefore be beneficial to increase HbF levels in patients with WMCs.

The frequency of βS-globin haplotypes in the state of Paraná, Brazil, and clinical manifestations of sickle cell anemia

ABSTRACT Introduction: Haplotypes in the β S-globin cluster are named according to their geographical origin as Central African Republic (CAR), Benin (BEN), Senegal (SEN), Cameroon (CAM) and Arab-Indian. They are considered to have influence on the diversity of clinical manifestations in sickle cell anemia (HbSS). Objective: To identify β S haplotypes and genotypes, their frequencies and their probable association with clinical presentation in patients with sickle cell anemia in the state of Parana. Method: Longitudinal and descriptive study for the definition of haplotypes, and associative study for analysis of their influence on clinical severity. By polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), polymorphic regions of 100 HbSS patients were identified. The association of haplotypes with clinical manifestations was analyzed in a subset of 52 pediatric patients. Results: In the state of Parana, haplotype frequencies were: CAR: 76% BEN: 17.5% SEN: 0.5%, CAM: 0.5% and Atypical (Atp): 5.5%. Genotype frequencies were: CAR/CAR: 62%; CAR/BEN: 20%; CAR/Atp: 6%; CAR/ SEN: 1%; CAR/CAM: 1%; BEN/BEN: 6%; BEN/Atp: 3%, Atp/Atp: 1%. The average percentage of fetal hemoglobin (HbF) in CAR/CAR and CAR/BEN patients was higher than in other studies. Clinical manifestations were not influenced by β S haplotypes. Dactylitis and splenic sequestration occurred more frequently in children below 3 years of age. Conclusion: In this study, no association was found between haplotypes and clinical manifestations, probably given the almost absolute predominance of CAR and BEN haplotypes. However, this fact alerts to the possible influence of other polymorphisms and miscegenation in the Brazilian population.

The Impact of Cognitive Function on Adherence to Hydroxyurea Therapy in Patients with Sickle Cell Disease

Introduction:Cognitive impairment is a serious complication of sickle cell disease (SCD) that affects both children and adults. While it is known to adversely affect school performance and overall development in children, its functional impact in adults is not known. Importantly, poor disease self-management and adherence to hydroxyurea are major problems in SCD and are likely to be impacted by cognitive impairment. In the study presented herein, we hypothesized that lower cognitive function in areas of memory and executive function would be associated with worse adherence to hydroxyurea therapy in adults with SCD.Methods:We designed a cross-sectional study of patients with SCD from the University of Pittsburgh Medical Center Adult Sickle Cell Clinic. Patients who underwent neurocognitive testing between 2011 and 2016 as part of an ongoing neurocognitive study and whose adherence to hydroxyurea therapy has been monitored by a dedicated clinical nurse were included. Performance on four neurocognitive tests of verbal learning, memory and executive function - the Hopkins Verbal Learning Test-Revised (HVLT-R) retention, HVLT-R total recall, Delis-Kaplan Executive Function System Trail Making Condition 4 vs. 5, and Color Word Condition 3 - were selected a priori as explanatory variables. We explored the association between the four test scores and the most recent adherence data at the time of the study. Adherence measures included the laboratory biomarkers red blood cell corpuscular volume (MCV) and percentage of fetal hemoglobin (HbF) - whose values are expected to rise with hydroxyurea therapy - and the patient’s self-report of adherence categorized as "good" (≥ 80% adherence) or "less-than-good" (< 80% adherence). Differences between groups were compared by 2-sided t-test or chi-square tests where indicated.Results:Study participants (n=48) had a mean age of 35.2 years (range 22-60) and were predominantly female (58.3%). Fifty-two percent had higher than high-school level education, and 72.9% had a HbSS or HbS/β0 thalassemia phenotype. There were no statistically significant differences between the "good" adherence and "less-than-good" adherence groups with regard to these baseline characteristics. As expected, the mean MCV, an objective marker of hydroxyurea adherence, was significantly higher in the "good" adherence group (102.3 ± 15.0 vs. 89.1 ± 11.5 fL, p=0.005), corroborating the patients’ self-report. We observed a statistically significant positive correlation between the HVLT-R retention score and MCV that remained significant after adjustment for demographic characteristics (Pearson r=0.309, p=0.033) and a similar correlation with HVLT-R total recall (Pearson r=0.269, p=0.065). A similar trend between HVLT-R retention and HbF percentage was observed (Pearson r=0.260, p=0.081). The mean HVLT-R retention and HVLT-R total recall scores were higher in the "good" adherence group (80.1% ± 27% vs. 64.9% ± 33%, and 41.9% ± 14% vs.34.1% ± 13%, respectively), although the difference between the two groups did not reach statistical significance. There was no significant difference in performance on the Trail Making Condition 4 vs. 5 or the Color Word Condition 3 tests.Discussion:Our study suggests that adherence to hydroxyurea therapy in adult patients with SCD might be affected by impairment in episodic memory, as measured in our study through HVLT-R retention, with qualitatively similar patterns by HVLT-R total recall. Although more extensive investigation is warranted, these results suggest that a brief, targeted neurocognitive assessment should be considered as a component of any strategy aimed at improving adherence to hydroxyurea and other therapeutic interventions in patients with SCD. DisclosuresJonassaint:Sicklesoft: Other: officer of Sicklesoft. Kato:Mast Therapeutics: Consultancy; Bayer: Research Funding.

Albuminuria, serum antioxidant enzyme levels and markers of hemolysis and inflammation in steady state children with sickle cell anemia.

BackgroundOxidative stress is thought to be involved in the pathogenesis of microalbuminuria in Sickle cell anemia (SCA). Antioxidant enzymes such as glutathione peroxidase (GPx) and Cu-Zn superoxide dismutase (SOD) may play an important protective role. This study aimed to evaluate the association between albuminuria and these two antioxidant enzymes.MethodsWe consecutively recruited Steady state children aged between 2 and 18 years old with established diagnosis of homozygous SCA in two hospitals of Kinshasa/DR Congo. The relationship between Urinary Albumin Creatinine Ratio (UACR) and other variables of interest (age, systolic blood pressure, diastolic blood pressure, plasma GPx and Cu-Zn SOD, free plasmatic hemoglobin, LDH, indirect bilirubin, white blood cells (WBC), percentage of fetal hemoglobin, serum iron, ferritin, CRP) was analyzed by Bivariate correlation (Pearson’s correlation coefficient). Microalbuminuria was defined by urine albumin/creatinine ratio between 30 and 299 mg/g.ResultsSeventy Steady state Black African children with SCA (56% boys; average age 9.9 ± 4.3 years; 53% receiving hydroxyurea) were selected. Prevalence of microalbuminuria was 11.8%. LDH (r = 0.260; p = 0.033) and WBC count (r = 0.264; p = 0.033) were positively correlated with UACR whereas GPx (− 0.328; p = 0.007) and Cu-Zn SOD (− 0.210; p = 0.091) were negatively correlated with UACR.ConclusionsAlbuminuria is associated with decreased antioxidant capacity and increased levels of markers of hemolysis and inflammation. Therefore, strategies targeting the reduction of sickling and subsequent hemolysis, oxidative stress and inflammation could help preventing or at least delaying the progression of kidney disease in SCA children.

Hydroxyurea decreases hospitalizations in pediatric patients with Hb SC and Hb SB+ thalassemia.

PurposePatients with hemoglobin SC (Hb SC) and hemoglobin SB+ (Hb SB+) thalassemia suffer from frequent hospitalizations yet strong evidence of a clinical benefit of hydroxyurea (HU) in this population is lacking. Patients with recurrent hospitalizations for pain crisis are offered HU at our institution based on small cohort data and anecdotal benefit. This study identifies outcomes from a large cohort of patients with Hb SC and SB+ thalassemia who were treated with HU for 2 years.Materials and methodsA retrospective review was conducted of 32 patients with Hb SC and SB+ thalassemia who were treated with HU. We reviewed the number, and reasons for hospitalization in the 2 years prior to, and 2 years post-HU treatment as well as laboratory changes from baseline, over 1 year.ResultsPatients with Hb SC and SB+ thalassemia started on HU for frequent pain, had a significant reduction in hospitalizations over 2 years as compared to the 2 years prior to HU initiation (mean total hospitalizations/year: pre-HU: 1.6 vs post-HU 0.4 hospitalizations, P<0.001; mean pain hospitalizations/year: pre-HU 1.5 vs post-HU 0.3 hospitalizations, P<0.001). Patients demonstrated hematologic changes including an increase in percent fetal hemoglobin (%HbF) pre–post HU (4.5% to 7.7%, P=0.002), mean corpuscular volume (74 to 86 fL, P<0,0001), and decrease in absolute neutrophil count (5.0 to 3.2×109/L, P=0.007). Patients with higher doses of HU demonstrated the greatest reduction in hospitalizations but this was unrelated to absolute neutrophil count.ConclusionThis cohort of patients with Hb SC and SB+ thalassemia provides additional support for using HU in patients with recurrent hospitalizations for pain. A large randomized multicenter trial of HU to reduce pain admissions should be conducted to confirm these data and provide much needed evidence based recommendations for this population.

Effects of Sulforaphane Obtained from Broccoli Sprout Homogenate in Patients with Sickle Cell Disease (SCD)

BACKGROUNDSickle cell disease (SCD) is the most common hemoglobinopathy worldwide, characterized by chronic complications due to ongoing vaso-occlusion and hemolysis. Previous studies have shown that red cells from individuals with sickle cell disease (HbSS) have reduced NRF2 expression levels, which contribute to decreased oxidative stress capacity and increased hemolysis (Sangokoya, et al. 2010 Blood). Additionally, Macari and Lowry have shown that in vitro NRF2 activation of erythroid progenitors results in induction of anti-oxidant stress response genes, as well as increased percent fetal hemoglobin (HbF), which is known to prevent sickling (2011 Blood). Therefore, we hypothesize that NRF2 activation in SCD patients has potential therapeutic benefits by simultaneously inducing HbF and increasing the anti-oxidative stress capacity of red cells. We proposed to activate NRF2 by using sulforaphane (SFN), a well-known natural product enriched in broccoli sprouts. We conducted an open-label, dose-escalation clinical trial for SCD patients to investigate the safety and physiological effects of NRF2 activation by SFN through ingestion of a broccoli sprout homogenate (BSH).METHODSMale and female adult patients (> 18 years) with either HbSS or HbSߺ thalassemia were enrolled at the Duke Comprehensive Sickle Cell Center adult clinic. Exclusion criteria: RBC transfusion or a change in hydroxyurea dose in the last three months, ongoing pregnancy, diabetes, or renal insufficiency (BUN >21 mg/dL and/or creatinine >1.4 mg/dL). Inclusion criteria: Hematocrit (Hct) ≥ 20% and Hb > 6.0 g/dL. Recruited subjects were instructed to avoid additional SFN-containing foods before and during the study period. Subjects ingested a thawed preparation of BSH once daily for 21 days to allow for repopulation of red cells during therapy. Tolerability, toxicity, and physiological effects of NRF2 activation were determined at pre-treatment baseline (day 0), on the last day of ingestion (day 21), and after a wash-out period (day 49). Five patients were recruited for each dose (50g, 100g), with the smaller dose having elicited no safety concerns.RESULTSNo safety concerns were noted among the subjects at either dose. In both cohorts, there were no significant differences in the adverse events, pain scores, complete blood counts, complete metabolic profile, reticulocyte count, and LDH levels when comparing days 0 and 21. In the 50g cohort, there was an overall but not statistically significant increase of average HbF from 14.5% to 14.9% (p=0.0786) in all five patients from Day 0 to Day 21; analyses are incomplete for the higher dose. We also observed a trend of NRF2 mRNA target gene induction, including heme oxygenase-1 (HO-1), NAD(P)H dehydrogenase (quinone 1, NQO1), and globin mRNAs, at day 21 vs day 0, which returned to baseline levels at day 49. In the 50g cohort, we observed a 66% increase of ho-1 and 44% increase of nqo1 mRNA levels at day 21 vs. baseline. In the 100g cohort, we observed a 14% increase of ho-1 and 42% increase of nqo1mRNA levels at day 21 vs. baseline.CONCLUSIONOur pilot trial suggests that NRF2 activation by BSH may increase NRF2 expression programs and induce fetal hemoglobin. We aim to enroll more patients at escalating doses, as participants present a wide range of clinical variability and may show variable response. Additionally, the lack of statistical significance at the lowest doses along with a lack of safety concerns strongly compel us to pursue more potent NRF2 inducers to elicit more robust physiological changes for additional clinical trials. DisclosuresNo relevant conflicts of interest to declare.

Heme oxygenase-1 gene promoter polymorphism is associated with reduced incidence of acute chest syndrome among children with sickle cell disease

AbstractSickle cell disease is a common hemolytic disorder with a broad range of complications, including vaso-occlusive episodes, acute chest syndrome (ACS), pain, and stroke. Heme oxygenase-1 (gene HMOX1; protein HO-1) is the inducible, rate-limiting enzyme in the catabolism of heme and might attenuate the severity of outcomes from vaso-occlusive and hemolytic crises. A (GT)n dinucleotide repeat located in the promoter region of the HMOX1 gene is highly polymorphic, with long repeat lengths linked to decreased activity and inducibility. We examined this polymorphism to test the hypothesis that short alleles are associated with a decreased risk of adverse outcomes (hospitalization for pain or ACS) among a cohort of 942 children with sickle cell disease. Allele lengths varied from 13 to 45 repeats and showed a trimodal distribution. Compared with children with longer allele lengths, children with 2 shorter alleles (4%; ≤ 25 repeats) had lower rates of hospitalization for ACS (incidence rate ratio 0.28, 95% confidence interval, 0.10-0.81), after adjusting for sex, age, asthma, percentage of fetal hemoglobin, and α-globin gene deletion. No relationship was identified between allele lengths and pain rate. We provide evidence that genetic variation in HMOX1 is associated with decreased rates of hospitalization for ACS, but not pain. This study is registered at www.clinicaltrials.gov as #NCT00072761.

To assess the efficacy of hydroxyurea, in children with homozygous sickle cell disease, in the age group of 1 year to 18 years, at tertiary care hospital

Aims: To evaluate the increase in fetal hemoglobin percentage and MCV in children of sickle cell disease treated with hydroxyurea. To observe the safety of hydroxyurea in treated children. To arrive at the therapeutic dose of the drug to produce the beneficial effects.Settings and Design: A single blind randomized controlled trial of 12 months duration was designed to study the effect of hydroxyurea on sickle cell patients which aims to study the clinical and laboratory effects, in tertiary care hospital.Materials and Methods: Sixty children with severe sickle cell disease in the age group of 1-18 years were studied. Outcomes were measured in terms of decrease in number of vaso-occlusive crises, necessity of blood transfusions, laboratory parameters for different organ functions, blood cell counts and toxicity of hydroxyurea.Results: In patients of sickle, cell disease treated with hydroxyurea there was significant reduction in number and severity of vaso- occlusive crises and necessity of blood transfusions. Total hemoglobin, MCV and fetal hemoglobin percentage were raised significantly. Bone marrow suppression as reflected by the decrease in white blood cell and reticulocyte counts occurred but it was not below the defined toxicity levels. Serum bilirubin was decreased significantly. Conclusions: In the present study, we concluded that, hydroxyurea decreases number of vaso-occlusive crises and need for blood transfusions in children with severe sickle cell disease. It increases total, fetal hemoglobin concentration and MCV. It causes bone marrow suppression thereby decreasing white blood cell and reticulocyte count. However, this fall was never below defined toxicity levels. It causes no hematological, hepatic, renal or general toxicities when given on short-term basis. Overall, hydroxyurea has proved to be safe and efficacious in children between the age groups of 1-18 years.

Increased prevalence of osteonecrosis of the femoral head in children and adolescents with sickle‐cell disease

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Population pharmacokinetics and pharmacodynamics of hydroxyurea in sickle cell anemia patients, a basis for optimizing the dosing regimen

BackgroundHydroxyurea (HU) is the first approved pharmacological treatment of sickle cell anemia (SCA). The objectives of this study were to develop population pharmacokinetic(PK)-pharmacodynamic(PD) models for HU in order to characterize the exposure-efficacy relationships and their variability, compare two dosing regimens by simulations and develop some recommendations for monitoring the treatment.MethodsThe models were built using population modelling software NONMEM VII based on data from two clinical studies of SCA adult patients receiving 500-2000 mg of HU once daily. Fetal hemoglobin percentage (HbF%) and mean corpuscular volume (MCV) were used as biomarkers for response. A sequential modelling approach was applied. Models were evaluated using simulation-based techniques. Comparisons of two dosing regimens were performed by simulating 10000 patients in each arm during 12 months.ResultsThe PK profiles were described by a bicompartmental model. The median (and interindividual coefficient of variation (CV)) of clearance was 11.6 L/h (30%), the central volume was 45.3 L (35%). PK steady-state was reached in about 35 days. For a given dosing regimen, HU exposure varied approximately fivefold among patients. The dynamics of HbF% and MCV were described by turnover models with inhibition of elimination of response. In the studied range of drug exposures, the effect of HU on HbF% was at its maximum (median Imax was 0.57, CV was 27%); the effect on MCV was close to its maximum, with median value of 0.14 and CV of 49%. Simulations showed that 95% of the steady-state levels of HbF% and MCV need 26 months and 3 months to be reached, respectively. The CV of the steady-state value of HbF% was about 7 times larger than that of MCV. Simulations with two different dosing regimens showed that continuous dosing led to a stronger HbF% increase in some patients.ConclusionsThe high variability of response to HU was related in part to pharmacokinetics and to pharmacodynamics. The steady-state value of MCV at month 3 is not predictive of the HbF% value at month 26. Hence, HbF% level may be a better biomarker for monitoring HU treatment. Continuous dosing might be more advantageous in terms of HbF% for patients who have a strong response to HU.Trial RegistrationThe clinical studies whose data are analysed and reported in this work were not required to be registered in France at their time. Both studies were approved by local ethics committees (of Mondor Hospital and of Kremlin-Bicetre Hospital) and written informed consent was obtained from each patient.