Hydroxyurea Research Articles

Burden of vaso-occlusive crisis, its management and impact on quality of life of Indian sickle cell disease patients.

Sickle cell disease (SCD) with vaso-occlusive pain crisis (VOC) significantly impacts patient well-being and often results in extensive healthcare resource utilization. This study assessed the VOC burden, its management and its impact on patients' quality of life (QoL). A cross-sectional observational study was conducted between November 2021 and June 2022, including 1000 SCD patients from high-prevalence states in India. Data on demographics, clinical characteristics, VOC severity, management and QoL were collected. The study revealed that 33.5% of patients reported at least one VOC episode during the study period. In the year prior to their enrolment, 836 (83.60%) patients reported at least one VOC episode, with an equal proportion of 407/487 (83.6%) adults and 429/513 (83.6%) paediatric patients, reducing their QoL across all domains compared to patients without VOC. Of these, 469/1000 patients (46.9%) experienced ≥3 VOC episodes. Additionally, 764/1000 (76.40%) patients managed their VOCs at healthcare facilities, with 501/1000 (50.1%) requiring inpatient admissions. Further, 71.80% of patients received Hydroxyurea (HU) therapy. The study depicts the severity of the Arab-Indian haplotype in Indian SCD patients visiting healthcare settings based on high VOC burden. This highlights the urgent need for better management strategies and resource allocation for these patients.

Impact of Vitamin C and Hydroxyurea on the Reproductive System Health in Male Rats

Hydroxyurea (HU) is a medication used to treat various diseases and is also being studied for its effects on spermatogenesis. Vitamin C (VC), an antioxidant, has been shown to protect sperm cells from oxidative stress, potentially improving fertility and sperm quality. In a study involving twenty-four adult male albino rats divided into four groups, Group 1 served as the control, Group 2 received 5 mg of vitamin C, Group 3 received 100 mg of hydroxyurea per body weight, and Group 4 received a combination of vitamin C and hydroxyurea to assess essential functions of the reproductive system, including hormone levels, antioxidant markers, oxidative stress indicators, histopathology, and identification of DNA damage. The study found that hydroxyurea significantly reduced testicular weight, SOD, CAT, and GSH while increasing FSH and MDA levels and causing abnormalities in sperm morphology. Hydroxyurea also caused apparent alterations in the histological structure of the testes and comet parameters. Rats treated with vitamin C showed a significant increase in absolute and relative epididymis weight compared to the control group. Moreover, vitamin C intervention reversed the adverse effects observed in rats fed hydroxyurea, indicating that low doses of vitamin C can protect against testicular damage.

Prescribing Hydroxyurea in Sickle Cell Disease Patients: The Pattern and Association with Co-Prescribed Medications Used to Manage the Disease Complications.

Background and Objectives: Hydroxyurea (HU) is an effective medication used to reduce the frequency of painful crises associated with sickle cell disease (SCD). However, data describing its prevalence among SCD patients in the Eastern Region of Saudi Arabia are scarce. This is a multi-center, retrospective, cross-sectional study that aims to investigate the pattern of prescribing HU in SCD patients and to determine the association between prescribing HU and other co-prescribed medications used to manage SCD complications. Methods: Data were collected from patients who visited the hematology clinics of Al-Qatif Central Hospital (QCH) and King Fahad Hospital in Hofuf (KFHH) between June 2021 to May 2023. The data included demographics, prescribed medications, and recent laboratory test results, all of which were collected from patients' medical records. Descriptive statistics were utilized to assess the difference between HU users vs. non-users. A binary logistic regression model was used to determine the association between prescribing HU and co-prescribed medications used to manage SCD complications. The results are presented as the odds ratio (OR) and 95% confidence interval (95% CI). Results: This study included 2816 SCD patients with a 56% prevalence of HU prescription. HU was prescribed for young age groups more often compared to old age group patients. Young males were more likely to be prescribed with HU compared to females, and it becomes dominant in females after the age of 36. HU users were more likely to have paracetamol (69% vs. 53%, OR = 1.9, 95% CI 1.6-2.2), NSAIDs (50% vs. 35%, OR = 1.7, 95% CI 1.5-2), and opioids (41% vs. 37%, OR = 1.3, 95% CI 1.1-1.6) co-prescribed, and less often to have laxatives (8% vs. 5%, OR = 0.66, 95% CI 0.48-0.9) and anticoagulants (22% vs. 15%, OR = 0.56, 95% CI 0.46-0.68) co-prescribed compared to non-users. Conclusions: The pattern of prescribing HU, supported by the association findings, raises concerns about patients' compliance and adherence to HU therapy. Early health education, specifically to young female SCD patients, is warranted to increase the success rate of HU therapy.

Hydroxyurea Pharmacokinetic Evaluation in Patients with Sickle Cell Disease

Background: Hydroxyurea (HU), also known as hydroxycarbamide, is an oral ribonucleotide reductase inhibitor. In 1999, the United States Food and Drug Administration (FDA) approved HU for the treatment of sickle cell disease (SCD). Since then, it has become the cornerstone in the management of SCD patients, helping to reduce vaso-occlusive crises, acute chest syndrome, the need for blood transfusions, hospitalizations and mortality. There is considerable variability among individuals in HU pharmacokinetic (Pk) parameters that can influence treatment efficacy and toxicity. The objective of this work is part of a clinical study aimed at investigating HU Pk and determining the optimal sampling time to estimate the Area Under the Curve (AUC) in SCD patients. Methods: HU plasma concentration in 80 patients at various time points (2, 4, 6, 24 h) following a 48-h drug washout was quantified using High-Pressure Liquid Chromatography (HPLC) coupled with an ultraviolet (UV) detection method previously described in the literature and adapted to new conditions with partial modifications. Results: The mean HU administered dose was 19.5 ± 5.1 mg/kg (range: 7.7–37.5 mg/kg). The median AUC quantified in plasma patients was 101.3 mg/L/h (Interquartile Range (IQR): 72.5–355.9) and it was not influenced by the weight-based dose. However, there was a strong positive correlation between AUC and Body Mass Index (BMI) as well as dose per Body Surface Area (BSA). Along with a three-point approach for AUC determination present in the literature, we show results obtained from a four-point sampling strategy, which is more useful and effective for better optimizing dose escalation to the maximum tolerated dose (MTD). Moreover, we observed that most patients achieved the maximum HU plasma concentration two hours after drug administration, regardless of age differences. Conclusions: HU treatment, which represents a milestone in the treatment of SCD due to its ability to reduce disease complications and improve patients’ quality of life, requires careful monitoring to optimize the individual dose for saving potential side effects and/or adverse events.

Revised mechanism of hydroxyurea-induced cell cycle arrest and an improved alternative

Replication stress describes endogenous and exogenous challenges to DNA replication in the S-phase. Stress during this critical process causes helicase-polymerase decoupling at replication forks, triggering the S-phase checkpoint, which orchestrates global replication fork stalling and delayed entry into G2. The replication stressor most often used to induce the checkpoint response in yeast is hydroxyurea (HU), a clinically used chemotherapeutic. The primary mechanism of S-phase checkpoint activation by HU has thus far been considered to be a reduction of deoxynucleotide triphosphate synthesis by inhibition of ribonucleotide reductase (RNR), leading to helicase-polymerase decoupling and subsequent activation of the checkpoint, facilitated by the replisome-associated mediator Mrc1. In contrast, we observe that HU causes cell cycle arrest in budding yeast independent of both the Mrc1-mediated replication checkpoint response and the Psk1-Mrc1 oxidative signaling pathway. We demonstrate a direct relationship between HU incubation and reactive oxygen species (ROS) production in yeast and human cells and show that antioxidants restore growth of yeast in HU. We further observe that ROS strongly inhibits the in vitro polymerase activity of replicative polymerases (Pols), Pol α, Pol δ, and Pol ε, causing polymerase complex dissociation and subsequent loss of DNA substrate binding, likely through oxidation of their integral iron-sulfur (Fe-S) clusters. Finally, we present "RNR-deg," a genetically engineered alternative to HU in yeast with greatly increased specificity of RNR inhibition, allowing researchers to achieve fast, nontoxic, and more readily reversible checkpoint activation compared to HU, avoiding harmful ROS generation and associated downstream cellular effects that may confound interpretation of results.

Understanding the adsorption performance of hetero-nanocages (C12-B6N6, C12-Al6N6, and B6N6-Al6N6) towards hydroxyurea anticancer drug: a comprehensive study using DFT.

Cancer is a paramount health challenge to global health, which forms tumors that can invade nearby tissues and spread to neighboring cells. Recently, nanotechnology has been used to control the growth of cancer, in which anticancer drugs are delivered to cancerous cells via nanoparticles without damaging healthy tissues. In this study, DFT investigations were carried out to examine the adsorption behavior of C24, B12N12, and Al12N12 nanocages as well as their heterostructures C12-B6N6, C12-Al6N6, and B6N6-Al6N6 towards the hydroxyurea (HU) anticancer drug. In this regard, adsorption energy, interaction distance between the drug and nanocages, charge transfer, energy gap, dipole moment, quantum molecular descriptors, work function, and COSMO surface analysis were analyzed to understand their adsorption performance. Findings demonstrate that the adsorption energies of two hetero-nanocages on their hexagonal (SH) and tetragonal (ST) sites are favorable for the drug delivery process. The computed adsorption energy of B6N6-Al6N6 of the ST/AlN site is 183.59 kJ mol-1, which is higher than that of the C12-Al6N6 nanocage, including minimum adsorption distances. Negative adsorption energy with low adsorption distances implies an attractive interaction between the drug and nanocages. During the interaction, a significant amount of charge is transferred between the drug and nanocages. Furthermore, for both complexes, larger dipole moments were observed in water media compared to gas media. From DOS spectra, prominent peaks were found in the Fermi level after adsorption of HU on the nanocages, implying the reduction of the energy gap. Noticeable overlaps between the PDOS spectra of the nanocages and HU's close contact atom demonstrate the formation of chemical bonds between two specific atoms. Therefore, it can be concluded that among the nanocages, C12-Al6N6 and B6N6-Al6N6 may be suitable carriers for HU drug.

Lifespan Extension by Retrotransposons under Conditions of Mild Stress Requires Genes Involved in tRNA Modifications and Nucleotide Metabolism

Retrotransposons are mobile DNA elements that are more active with increasing age and exacerbate aging phenotypes in multiple species. We previously reported an unexpected extension of chronological lifespan in the yeast, Saccharomyces paradoxus, due to the presence of Ty1 retrotransposons when cells were aged under conditions of mild stress. In this study, we tested a subset of genes identified by RNA-seq to be differentially expressed in S. paradoxus strains with a high-copy number of Ty1 retrotransposons compared with a strain with no retrotransposons and additional candidate genes for their contribution to lifespan extension when cells were exposed to a moderate dose of hydroxyurea (HU). Deletion of ADE8, NCS2, or TRM9 prevented lifespan extension, while deletion of CDD1, HAC1, or IRE1 partially prevented lifespan extension. Genes overexpressed in high-copy Ty1 strains did not typically have Ty1 insertions in their promoter regions. We found that silencing genomic copies of Ty1 prevented lifespan extension, while expression of Ty1 from a high-copy plasmid extended lifespan in medium with HU or synthetic medium. These results indicate that cells adapt to expression of retrotransposons by changing gene expression in a manner that can better prepare them to remain healthy under mild stress.

Prognostic value of response to first-line hydroxyurea according to IPSET stratification in essential thrombocythemia.

Hydroxyurea (HU) constitutes the first-line treatment in most patients with essential thrombocythemia (ET), but criteria for changing therapy are not clearly established. The prognostic value of complete hematological response (CHR) and resistance/intolerance to HU was assessed in 1080 patients from the Spanish Registry of ET, classified according to revised IPSET-Thrombosis stratification (Very low- n = 61, Low- n = 83, Intermediate- n = 261, and High-risk n = 675). With a median therapy duration of 5 years, CHR was registered in 720 (67%) patients (1-year probability 51%) and resistance/intolerance in 219 (20%) patients (5-years probability 13%). After correction by other risk factors, High-risk patients achieving CHR showed a reduced risk of arterial thrombosis (HR: 0.35, 95%CI: 0.2-0.6, p = 0.001) and a trend towards lower risk of venous thrombosis (HR: 0.45, 95%CI: 0.2-1.02, p = 0.06) whereas no association was observed for intermediate- or low-risk patients. In comparison with non-responders, intermediate- and high-risk patients achieving CHR had longer survival and lower myelofibrosis incidence. Development of resistance/intolerance to HU, mainly cytopenia, was associated with higher probability of myelofibrosis but no effect on survival or thrombotic risk was demonstrated. In conclusion, CHR with HU is associated with better outcomes and might be an early indicator for selecting candidates to second-line clinical trials.

Strengths and limitations of the worm development and activity test (wDAT) as a chemical screening tool for developmental hazards

The worm Development and Activity Test (wDAT) measures C. elegans developmental milestone acquisition timing and stage-specific spontaneous locomotor activity (SLA). Previously, the wDAT identified developmental delays and SLA level changes in C. elegans with mammalian developmental toxicants arsenic, lead, and mercury. 5-fluorouracil (5FU), cyclophosphamide (CP), hydroxyurea (HU), and ribavirin (RV) are teratogens that also induce growth retardation in developing mammals. In at least some studies on each of these chemicals, fetal weight reductions were seen at mammalian exposures below those that had teratogenic effects, suggesting that screening for developmental delay in a small alternative whole-animal model could act as a general toxicity endpoint to identify chemicals for further testing for more specific adverse developmental outcomes. Consistent with mammalian developmental effects, 5FU, HU, and RV were associated with developmental delays with the wDAT. Exposures associated with developmental delay induced hypoactivity with 5FU and HU, but slight hyperactivity with RV. CP is a prodrug that requires bioactivation by cytochrome P450s for both therapeutic and toxic effects. CP tests as a false negative in several in vitro assays, and it was also a false negative with the wDAT. These results suggest that the wDAT has the potential to identify some developmental toxicants, and that a positive wDAT result with an unknown may warrant further testing in mammals. Further assessment with larger panels of positive and negative controls will help qualify the applicability and utility of this C. elegans wDAT assay within toxicity test batteries or weight of evidence approaches for developmental toxicity assessment.

The Effect of Resveratrol on Gamma Globin Gene Expression in Patients with Beta Thalassemia: The Role of Adaptation to Cellular Stress

HbF induction is an appropriate strategy to ameliorate the severity of β-thalassemia symptoms. Hydroxyurea (HU) is the most common chemical agent introduced as an HbF inducer but responsiveness to HU is variable and the introduction of HbF inducers alternative to HU with low cytotoxicity has been a crucial challenge. Resveratrol is an HbF inducer agent that may have favorable effects on the differentiation of hematopoietic erythroid progenitors (HEPs). The present study aimed to investigate the effect of resveratrol on γ-globin, stress response, and anti-apoptotic gene expression among hydroxyurea (HU)-responders and HU-nonresponders (HU-NR). Four cases of HU-R and four cases of HU-NR were studied. HEPs of the patients were cultured, and the expression of γ-globin, Foxo3, and Bclxl was assessed. Moreover, the differentiation and apoptotic rate of the cells were investigated using flow cytometry analysis. In three cases, the γ-globin gene expression increased after resveratrol treatment. All of the HU-NR patients were also non-responders to resveratrol (Res-NR). The expression of Foxo3 and Bclxl genes was higher in responders to resveratrol (Res-R) compared to non-responders (Res-NR). The rate of apoptosis in Res-R patients was also lower than in Res-NR. Responders to resveratrol also had a higher rate of HEP maturation. The cells of both HU–NR and Res-NR patients could not adapt to stress conditions and proceed to the erythroid differentiation. In conclusion, resveratrol increased the γ-globin expression in HEPs of β-thalassemia patients. The response was observed only in R-HU patients with similar cellular pathways.

Single-cell proteo-transcriptomic profiling reveals altered characteristics of stem and progenitor cells in patients receiving cytoreductive hydroxyurea in early-phase chronic myeloid leukemia.

Hydroxyurea (HU) is frequently used in the early phase of chronic myeloid leukemia (CML) to achieve cytoreduction prior to tyrosine kinase inhibitor (TKI) therapy. However, its impact on CML stem and progenitor cells (SPC) remains largely unknown. This study utilized targeted proteo-transcriptomic expression data on 596 genes and 51 surface proteins in 60,000 CD14-CD34+ cells from chronic phase CML patients to determine effects of shortterm HU treatment (4-19 days) on CML SPC. Peripheral blood and bone marrow samples were obtained from 17 CML patients eligible for short-term HU treatment (three patients before and after HU; seven patients before HU; and seven patients after HU) and subjected to single-cell CITE-seq and/or flow cytometry analysis. The analysis revealed enhanced frequencies of hemoglobin-expressing (HBA1, HBA2, HBB) erythroid progenitor cells in blood and bone marrow following HU treatment. In addition, there was an accumulation of cell subsets with S/G2/M phase-related gene and protein expression, likely representing cells arrested in, or progressing slowly through, the cell cycle. The increased frequency of cells in S/G2/M phase after HU was observed already among the most immature leukemic stem cells (LSC), and patients with a high fraction of LSC in the S/G2/M phase showed poor responsiveness to TKI treatment. We conclude that short-term HU treatment entails differentiation of erythroid progenitor cells and alters the characteristics of LSC in CML. The results imply that studies of LSC and progenitor populations in CML should take effects of initial HU therapy into account.

Hydroxyurea mobile directly observed therapy versus standard monitoring in patients with sickle cell anemia: a phase 2 randomized trial

BackgroundSickle cell anemia (SCA) prevalence remains high in sub-Saharan Africa. Long-term treatment with hydroxyurea (HU) increases survival, however, poor adherence to treatment could limit effectiveness. Whilst HU treatment adherence is currently high, this might decrease over time.MethodsWe conducted a single-center, randomized, open-label, parallel group phase 2 controlled clinical trial to determine whether mobile Directly Observed Therapy (m-DOT) increases HU treatment adherence (NCT02844673). Eligible participants were adults with homozygous SCA. People on a chronic blood transfusion program, with hemoglobin (Hb) A levels greater than 20% of the total Hb, total Hb less than 4 g/dL, pregnant or HIV positive were excluded. After a 3-month pre-treatment period participants were randomized to either m-DOT or standard monitoring arm. All participants received smart mobile phones and were treated with HU (15 mg/kg) daily for three months. In the m-DOT arm, drug intake was video recorded on cell phone by the participant and the video sent to the study team. The primary objective was to evaluate the effect of m-DOT on adherence to HU treatment by medication possession ratio (MPR).ResultsOf the 86 participants randomized, 76 completed the trial (26.13 ± 6.97 years, 63.5 % female). Adherence was high (MPR > 95 %) in both groups, 29 (80.6 %) in m-DOT versus 37 (94.9 %) in the standard monitoring arm (P = 0.079). No HU treatment was withheld from participants due to safety concerns.Conclusionsm-DOT did not increase adherence to HU treatment. We recommend that further testing in larger trials with a longer follow up period be undertaken.

Genome editing in K562 cells suggests a functional role for the XmnI Gg polymorphism: a widely used genetic marker in β-thalassemia and sickle cell disease patients.

The XmnI Gg -158 C/T polymorphism has been widely associated with fetal hemoglobin (HbF) levels, the severity of disease, and the response to the drug hydroxyurea (HU) in both β-thalassemia (β-thal) and sickle cell disease (SCD) patients. However, the functional significance of this single nucleotide polymorphism (SNP) remains unclear. To gain insight, green fluorescence protein (GFP) cassettes harboring the XmnI C or T alleles in their left homology arms (i.e. Gg promoters) were knocked into the Gg gene(s) of K562 cells via CRISPR/Cas9. Subsequently, the GFP fluorescence levels were compared in the ensuing cell populations and isolated clones. In both instances, median fluorescence intensities (MFI) of the knockin cells having the inserted XmnI T allele were higher than those having the XmnI C allele. Our results suggest that the XmnI T allele can increase Gg expression in K562 cells. The possible functional significance of the XmnI Gg -158 C/T polymorphism provides a rationale for the aforementioned associations. Furthermore, the XmnI polymorphism as a functional SNP substantiates its importance as a prognostic marker.

Enhancing the sensing performance of Al-modified graphene+ based sensor for anticancer medicinal molecules: A DFT study

It is recently reported that a new pure carbon-based structure graphene+ (G+) exhibits more excellent properties such as buckling structure similar to penta-graphene and Dirac cones like graphene. In this work, a comprehensive exploration and comparison of the adsorption behaviors and sensing performances of optimal Al-doped G+ (Al_G+) and pristine G+ are explored by combing density functional theory with non-equilibrium Green’s function for anticancer drugs molecules, namely Cisplatin (CP), Hydroxyurea (HU), 5-fluorouracil (5-FU) and 6-Mercaptopurine (6-MP). Firstly, the stable and optimal structure of Al_G+ is obtained by sequentially substituting three distinct carbon atoms with Al atom. Moreover, it is found that the introduction of Al atom leads to the disappearance of the Dirac cones, resulting in a transition from semi-metallic to metallic. Subsequently, CP and HU exhibit physical adsorption, 5-FU and 6-MP are chemically adsorbed on the surface of G+ by high adsorption energy. However, the adsorption energy of Al_G+ for both CP and HU all increased by about 1.5 eV compared with G+. 5-FU and 6-MP are chemically adsorbed on Al_G+ by appropriate adsorption energies. Finally, the G+/Al_G+-based sensor is constructed to investigate the sensitivity of medicinal molecules according to chemisorption. It is seen that the sensitivity of the G+ to 5-FU and 6-MP is all less than 22 %. Although the Al_G+ has the sensitivity below 22 % for CP, HU and 5-FU, which has up to 62 % for 6-MP, more than 40 % higher than other medicinal molecules. Further, the high sensitivity and selectivity of Al_G+ towards 6-MP are elucidated through scattering states and transmission spectra of sensors. Upon the results, it suggests that Al_G+ has broad application prospects in multiple fields such as drug delivery and medicinal molecular detection especially for 6-MP.

Impact of hydroxyurea on follicle density in patients with sickle cell disease

AbstractThe impact of hydroxyurea (HU) on the ovarian reserve of female patients with sickle cell disease (SCD) remains poorly elucidated. Only direct histological analysis of ovarian follicle density can effectively evaluate HU’s effect on ovarian reserve. By analyzing digitized slides of ovarian tissue from girls and young women with SCD who underwent ovarian tissue cryopreservation (OTC) before hematological stem cell transplantation, we meticulously counted follicles and categorized them based on their growth stage. We then calculated the densities of different follicle types and assessed their correlation with patient characteristics, clinical manifestations, and treatments extracted from medical records. Seventy-six patients with SCD participated in the study, with a median age at OTC of 10.2 years (interquartile range [IQR], 7.5-14.6), and 50 (65.8%) were prepubertal. Of these, 35 patients (46.1%) had received HU, with a median daily dosage of 23.0 mg/kg (IQR, 20.0-25.0) and median exposure time of 44 months (IQR, 24.0-54.0). Primordial follicle density was comparable between the HU and non-HU groups (5.8 follicles per mm2 [IQR, 1.0-13.3] vs 4.2 follicles per mm2 [IQR, 1.1-14.4], respectively; P = .95). However, in the HU group, after adjusting for age, the density of growing follicles was marginally lower than that in the non-HU group (P = .09). Notably, other parameters such as vaso-occlusive crisis did not affect follicular density. In conclusion, exposure to HU did not demonstrate a reduction in ovarian reserve in girls or women with SCD. Therefore, fertility preservation measures before initiating HU treatment do not seem necessary.

Towards genomic medicine: a tailored next-generation sequencing panel for hydroxyurea pharmacogenomics in Tanzania

BackgroundPharmacogenomics of hydroxyurea is an important aspect in the management of sickle cell disease (SCD), especially in the era of genomic medicine. Genetic variations in loci associated with HbF induction and drug metabolism are prime targets for hydroxyurea (HU) pharmacogenomics, as these can significantly impact the therapeutic efficacy and safety of HU in SCD patients.MethodsThis study involved designing of a custom panel targeting BCL11A, ARG2, HBB, HBG1, WAC, HBG2, HAO2, MYB, SAR1A, KLF10, CYP2C9, CYP2E1 and NOS1 as potential HU pharmacogenomics targets. These genes were selected based on their known roles in HbF induction and HU metabolism. The panel was designed using the Illumina Design Studio (Illumina, San Diego, CA, USA) and achieved a total coverage of 96% of all genomic targets over a span of 51.6 kilobases (kb). This custom panel was then sequenced using the Illumina MiSeq platform to ensure high coverage and accuracy.ResultsWe are reporting a successfully designed Illumina (MiSeq) HU pharmacogenomics custom panel encompassing 51.6 kilobases. The designed panel achieved greater than 1000x amplicon coverage which is sufficient for genomic analysis.ConclusionsThis study provides a valuable tool for research in HU pharmacogenomics, especially in Africa where SCD is highly prevalent, and personalized medicine approaches are crucial for improving patient outcomes. The custom-designed Illumina (MiSeq) panel, with its extensive coverage and high sequencing depth, provides a robust platform for studying genetic variations associated with HU response. This panel can contribute to the development of tailored therapeutic strategies, ultimately enhancing the management of SCD through more effective and safer use of hydroxyurea.

Utilization and Perceptions of Hydroxyurea Therapy Among Adult Patients With Sickle Cell Disease in Al Ahsa, Saudi Arabia: A Cross-Sectional Study.

Sickle cell disease (SCD) is a prevalent genetic disorder characterized by abnormal hemoglobin formation, resulting in severe complications. Hydroxyurea (HU) therapy has demonstrated efficacy in reducing SCD-related complications; however, its utilization patterns and patient perceptions remain underexplored, particularly in the Al Ahsa region of Saudi Arabia. This cross-sectional study aimed to assess the prevalence of HU usage among adult patients with SCD in Al Ahsa; identify the barriers to starting, maintaining, and discontinuing HU therapy; and evaluate the patient-reported outcomes associated with its use. Data were collected through face-to-face surveys and medical record reviews of adult SCD patients attending outpatient clinics in the Hereditary Blood Diseases Center of Al Ahsa, Saudi Arabia, between December 2023 and March 2024. Descriptive statistics and inferential analyses were performed using SPSS version 26. A total of 345 adult SCD patients were included, with a mean age of 34.12 ± 11.1 years. Most participants were male (58.6%) and unmarried (55.4%). HU utilization was reported by 57.1% of the participants, with the highest adherence observed among older age groups (p = 0.001). Significant improvements in pain severity, hospitalization rates, and quality of life were reported among HU users (p < 0.001). Common barriers to HU use included concerns about side effects, lack of medical justification, and absence of medical advice. This study provides valuable insights into theutilization and perceptions of HU therapy among adults with SCDin Al Ahsa, Saudi Arabia. Addressing identified barriers and promoting patient education are crucial for optimizing therapy adherence and improving clinical outcomes in this population.

Early Detection of Renal Complication in Children With Sickle Cell Disease: A Single Center Prospective Study.

This observational cross-sectional study aimed to identify predictors of renal complications in pediatric patients with sickle cell disease (SCD) at King Salman Armed Forces Hospital, Tabuk, Saudi Arabia, over six months from February 2023 to July 2023. The study evaluated microalbuminuria as an early indicator of renal injury and explored its correlations with clinical and laboratory parameters and abdominal ultrasound (US) findings. Included were pediatric patients aged 1 to 14 years with confirmed SCD, excluding those with acute infections or pre-existing renal diseases. Data from 100 patients' electronic medical records were analyzed using IBM SPSS Statistics for Windows, Version 26 (Released 2019; IBM Corp., Armonk, New York, United States), with a significance set at p ≤ 0.05. The mean age was 7.6 ± 3.3 years, with 51 males and 49 females; 11 were diagnosed with Hb-S-beta thalassemia. Hydroxyurea (HU) compliance was high, with only four non-compliant patients, though all took folic acid. Among 42 tested for albuminuria, all had negative results (<30 mg/g creatinine). A significant association was found between SCD diagnosis and kidney, ureter, and bladder (KUB) US results (p=0.008), with abnormal KUB findings more prevalent in the Hb-S-beta thalassemia group. Patients with abnormal KUB results had significantly lower mean weight (p=0.024). Additionally, Hb-S-beta thalassemia patients had lower mean weight than hemoglobin SS (HGSS) patients (p=0.04). Though not statistically significant, Hb-S-beta thalassemia patients had higher mean systolic blood pressure (p=0.053). Significant associations were identified between SCD diagnosis type and renal US results, with lower body weight emerging as a potential predictor of renal complications. High HU compliance and its impact on renal outcomes warrant further investigation. Routine monitoring of microalbuminuria and KUB US may aid early detection of renal complications in pediatric SCD patients. Further studies with larger sample sizes are recommended to validate these findings and develop comprehensive renal protective strategies.

Bone Disease among Children with Sickle Cell Disease: A Scoping Review of Incidence and Interventions.

Children with sickle cell disease (SCD) are more likely to have deficient serum levels of vitamin D for bone metabolism. However, appropriate interventions are essential to prevent its progression and alleviate symptoms. The aim of this study is to determine interventions for managing bone disease in children with SCD. This study uses a scoping review. A literature review was conducted using PubMed, CINAHL, ScienceDirect, Scopus, and Google Scholar search engines. The study was eligible for inclusion if it included articles published from 2013 to 2023, full-text, and original study design. Study quality was assessed using the Joanna Briggs Institute (JBI) appraisal tool. This review identified six studies and 114 children with SCD, including 57 boys (50%) and 57 girls (50%). The majority of SCD types experienced were HbSS (86.84%), HbS-B0 Thal (7.01%), HbSC (5.27%), and the HbSS Arab-Indian haplotype (0.88%). Bone disease problems that often arise in children with SCD include Avascular Necrosis (AVN) (78.08%), Osteonecrosis of the Femoral Head (ONFH) (18.42%), and other bone problems (3.50%). Meanwhile, four types of intervention findings were used in managing bone disease among children with SCD: 1). Surgical procedures 53 (41.09%) included total hip arthroplasty (THA), Osteotomy, and Multiple epiphyseal drilling with Autologous Bone Marrow Implantation (AMBI); 2). Invasive procedures 67 (51.93%) included intravenous bisphosphonates, hydroxyurea (HU), and core decompression (CD) with bone marrow aspirate concentrate injection: 3). Oral pharmacological or Vitamin D3 (cholecalciferol) 4 (3.10%); 4). Non-pharmacology or physical therapy 5 (3.88%). Our findings highlight that surgical, invasive, pharmacological, and physical therapy interventions positively impact increasing bone mineral density (BMD) and functional improvement of bone disease among children with SCD. The interventions provided excellent functional outcomes with minimal complications and no life-threatening side effects.

KBM-mediated interactions with KU80 promote cellular resistance to DNA replication stress in CHO cells

The KU heterodimer (KU70/80) is rapidly recruited to DNA double-strand breaks (DSBs) to regulate their processing and repair. Previous work has revealed that the amino-terminal von Willebrand-like (vWA-like) domain in KU80 harbours a conserved hydrophobic pocket that interacts with a short peptide motif known as the Ku-binding motif (KBM). The KBM is present in a variety of DNA repair proteins such as APLF, CYREN, and Werner protein (WRN). Here, to investigate the importance of KBM-mediated protein-protein interactions for KU80 function, we employed KU80-deficient Chinese Hamster Ovary (Xrs-6) cells transfected with RFP-tagged wild-type human KU80 or KU80 harbouring a mutant vWA-like domain (KU80L68R). Surprisingly, while mutant RFP-KU80L68R largely or entirely restored NHEJ efficiency and radiation resistance in KU80-deficient Xrs-6 cells, it failed to restore cellular resistance to DNA replication stress induced by camptothecin (CPT) or hydroxyurea (HU). Moreover, KU80-deficient Xrs-6 cells expressing RFP-KU80L68R accumulated pan-nuclear γH2AX in an S/G2-phase-dependent manner following treatment with CPT or HU, suggesting that the binding of KU80 to one or more KBM-containing proteins is required for the processing and/or repair of DNA ends that arise during DNA replication stress. Consistent with this idea, depletion of WRN helicase/exonuclease recapitulated the CPT-induced γH2AX phenotype, and did so epistatically with mutation of the KU80 vWA-like domain. These data identify a role for the KBM-binding by KU80 in the response and resistance of CHO cells to arrested and/or collapsed DNA replication forks, and implicate the KBM-mediated interaction of KU80 with WRN as a critical effector of this role.