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1.
Science ; 385(6704): 91-99, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38963839

RESUMEN

Sickle cell disease (SCD) is a prevalent, life-threatening condition attributable to a heritable mutation in ß-hemoglobin. Therapeutic induction of fetal hemoglobin (HbF) can ameliorate disease complications and has been intently pursued. However, safe and effective small-molecule inducers of HbF remain elusive. We report the discovery of dWIZ-1 and dWIZ-2, molecular glue degraders of the WIZ transcription factor that robustly induce HbF in erythroblasts. Phenotypic screening of a cereblon (CRBN)-biased chemical library revealed WIZ as a previously unknown repressor of HbF. WIZ degradation is mediated by recruitment of WIZ(ZF7) to CRBN by dWIZ-1, as resolved by crystallography of the ternary complex. Pharmacological degradation of WIZ was well tolerated and induced HbF in humanized mice and cynomolgus monkeys. These findings establish WIZ degradation as a globally accessible therapeutic strategy for SCD.


Asunto(s)
Anemia de Células Falciformes , Antidrepanocíticos , Hemoglobina Fetal , Factores de Transcripción de Tipo Kruppel , Proteínas del Tejido Nervioso , Animales , Humanos , Ratones , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Anemia de Células Falciformes/tratamiento farmacológico , Anemia de Células Falciformes/metabolismo , Antidrepanocíticos/química , Antidrepanocíticos/farmacología , Antidrepanocíticos/uso terapéutico , Cristalografía por Rayos X , Descubrimiento de Drogas , Hemoglobina Fetal/genética , Hemoglobina Fetal/metabolismo , Factores de Transcripción de Tipo Kruppel/metabolismo , Macaca fascicularis , Proteínas del Tejido Nervioso/metabolismo , Proteolisis/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/farmacología , Bibliotecas de Moléculas Pequeñas/uso terapéutico , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética
3.
PLoS One ; 19(6): e0304644, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38917111

RESUMEN

Sickle cell disease (SCD) is an inherited blood disorder that affects approximately 100,000 Americans, primarily from underrepresented racial minority populations, and results in costly, multi-organ complications. Hydroxyurea, the primary disease-modifying therapy for SCD, is effective at reducing most complications; however, adherence to hydroxyurea remains suboptimal and is the primary barrier to clinical effectiveness. Video directly observed therapy (VDOT) has shown promise as an adherence-promoting intervention for hydroxyurea, yet previous VDOT trials were limited by high attrition from gaps in technology access, use of unvalidated adherence measures, and healthcare system limitations of delivering VDOT to patients. As such, we fostered a small business partnership to compare VDOT for hydroxyurea to attention control to address previous shortcomings, promote equitable trial participation, and maximize scalability. VDOT will be administered by Scene Health (formerly emocha Health) and adherence monitoring will be performed using a novel electronic adherence monitor developed to meet the unique needs of the target population. Adolescent and young adult patients as well as caregivers of younger patients (<11 years of age) will be recruited. In addition to visit incentives, all participants will be offered a smartphone with a data plan to ensure all participants have equal opportunity to complete study activities. The primary objectives of this pilot, multi-center, randomized controlled trial (RCT) are to assess retention and sustained engagement and to explore needs and preferences for longer-term adherence monitoring and interventions. This RCT is registered with the National Institutes of Health (NCT06264700). Findings will inform a future efficacy RCT applying VDOT to hydroxyurea to address adherence gaps and improve outcomes within this vulnerable population.


Asunto(s)
Anemia de Células Falciformes , Hidroxiurea , Humanos , Anemia de Células Falciformes/tratamiento farmacológico , Hidroxiurea/uso terapéutico , Hidroxiurea/administración & dosificación , Adolescente , Niño , Cumplimiento de la Medicación , Adulto Joven , Antidrepanocíticos/uso terapéutico , Masculino , Femenino , Adulto
4.
PLoS One ; 19(6): e0304241, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38848387

RESUMEN

BACKGROUND: Evidence supports the benefits of hydroxyurea (HU) in adults with sickle cell disease (SCD), but reservations remain due to long-term concerns of fertility. Retrospective analysis of clinical records of SCD patients (haemoglobin SS genotype) have identified gender-related differences in disease progression. This could inform risk stratification during SCD at diagnosis with the possibility to guide therapeutic decisions. METHODS: This systemic review and meta-analysis evaluated fertility parameters in both children (aged ≥ 6 years) and adults with SCD receiving HU therapy. Studies were sourced from PubMed and EMBASE from inception to July 2023. A total of 160 potentially relevant articles were identified. RESULTS: Four studies were included that evaluated the effects of HU on sperm parameters in males. A further 4 studies assessed anti-mullerian hormone (AMH) levels and ovarian reserves in females. Differences from baseline values were used to identify compromised fertility. Amongst males, HU treatment negatively impacted the concentration of spermatozoa (MD = -15.48 million/mL; 95% CI: [-20.69, -10.26]; p< 0.001), which continued following treatment cessation (MD = -20.09 million/mL; 95% CI: [-38.78, -1.40]; P = 0.04). HU treatment also led to lower total sperm counts (MD = -105.87 million; 95% CI: [-140.61, -71.13]; P< 0.001) which persisted after treatment (MD = -53.05 million; 95% CI: [-104.96, -1.14]; P = 0.05). Sperm volume, initial forward motility and morphology were unaffected by HU treatment. In females, HU treatment decreased the mean AMH levels 1.83 (95% CI [1.42, 2.56]. A total of 18.2.% patients treated with HU showed reduced ovarian reserves. INTERPRETATION & CONCLUSIONS: This systemic review and meta-analysis suggest that the use of HU for SCD impacts seminal fluid parameters in males and can diminish AMH levels and ovarian reserves in females.


Asunto(s)
Anemia de Células Falciformes , Fertilidad , Hidroxiurea , Adulto , Niño , Femenino , Humanos , Masculino , Anemia de Células Falciformes/tratamiento farmacológico , Hormona Antimülleriana/sangre , Antidrepanocíticos/efectos adversos , Fertilidad/efectos de los fármacos , Hidroxiurea/efectos adversos , Reserva Ovárica/efectos de los fármacos , Recuento de Espermatozoides , Espermatozoides/efectos de los fármacos
5.
PLoS One ; 19(6): e0296196, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38935785

RESUMEN

Sickle cell disease (SCD) decreases the oxygen-carrying capacity of red blood cells. Children with SCD have reduced/restricted cerebral blood flow, resulting in neurocognitive deficits. Hydroxyurea is the standard treatment for SCD; however, whether hydroxyurea influences such effects is unclear. A key area of SCD-associated neurocognitive impairment is working memory, which is implicated in other cognitive and academic skills. The neural correlates of working memory can be tested using n-back tasks. We analyzed functional magnetic resonance imaging (fMRI) data of patients with SCD (20 hydroxyurea-treated patients and 11 controls, aged 7-18 years) while they performed n-back tasks. Blood-oxygenation level-dependent (BOLD) signals were assessed during working memory processing at 2 time points: before hydroxyurea treatment and ~1 year after treatment was initiated. Neurocognitive measures were also assessed at both time points. Our results suggested that working memory was stable in the treated group. We observed a treatment-by-time interaction in the right cuneus and angular gyrus for the 2- >0-back contrast. Searchlight-pattern classification of the 2 time points of the 2-back tasks identified greater changes in the pattern and magnitude of BOLD signals, especially in the posterior regions of the brain, in the control group than in the treated group. In the control group at 1-year follow-up, 2-back BOLD signals increased across time points in several clusters (e.g., right inferior temporal lobe, right angular gyrus). We hypothesize that these changes resulted from increased cognitive effort during working memory processing in the absence of hydroxyurea. In the treated group, 0- to 2-back BOLD signals in the right angular gyrus and left cuneus increased continuously with increasing working memory load, potentially related to a broader dynamic range in response to task difficulty and cognitive effort. These findings suggest that hydroxyurea treatment helps maintain working memory function in SCD.


Asunto(s)
Anemia de Células Falciformes , Hidroxiurea , Imagen por Resonancia Magnética , Memoria a Corto Plazo , Humanos , Hidroxiurea/uso terapéutico , Hidroxiurea/farmacología , Anemia de Células Falciformes/tratamiento farmacológico , Anemia de Células Falciformes/fisiopatología , Memoria a Corto Plazo/efectos de los fármacos , Niño , Adolescente , Masculino , Femenino , Antidrepanocíticos/uso terapéutico , Antidrepanocíticos/farmacología , Encéfalo/diagnóstico por imagen , Encéfalo/efectos de los fármacos , Encéfalo/fisiopatología , Estudios de Casos y Controles
6.
Lancet Haematol ; 11(6): e425-e435, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38701812

RESUMEN

BACKGROUND: Realizing Effectiveness Across Continents with Hydroxyurea (REACH) is an open-label non-randomised trial of hydroxyurea (hydroxycarbamide) in children with sickle cell anaemia in sub-Saharan Africa. The short-term results of REACH on safety, feasibility, and effectiveness of hydroxyurea were published previously. In this paper we report results from extended hydroxyurea treatment in the REACH cohort up to 8 years. METHODS: In this open-label, non-randomised, phase 1/2 trial, participants were recruited from four clinical sites in Kilifi, Kenya; Mbale, Uganda; Luanda, Angola; and Kinshasa, Democratic Republic of Congo. Eligible children were 1-10 years old with documented haemoglobin SS or haemoglobin Sß zero thalassaemia, weighing at least 10 kg. Participants received fixed-dose hydroxyurea of 17.5 (±2.5) mg/kg per day for 6 months (fixed-dose phase), followed by 6 months of dose escalation (2·5-5·0 mg/kg increments every 8 weeks) as tolerated, up to 20-35 mg/kg per day (maximum tolerated dose; MTD), defined as mild myelosuppression. After the MTD was reached, hydroxyurea dosing was optimised for each participant on the basis of changes in bodyweight and laboratory values over time (MTD with optimisation phase). After completion of the first 12 months, children with an acceptable toxicity profile and favourable responses were given the opportunity to continue hydroxyurea until the age of 18 years. The safety and feasibility results after 3 years has been reported previously. Here, haematological responses, clinical events, and toxicity rates were compared across the dosing phases (fixed-dose hydroxyurea vs MTD with optimisation phase) as protocol-specified outcomes. REACH is registered on ClinicalTrials.gov (NCT01966731) and is ongoing. FINDINGS: We enrolled 635 children between July 4, 2014, and Nov 11, 2016. 606 children were given hydroxyurea and 522 (86%; 266 [51%] boys and 256 [49%] girls) received treatment for a median of 93 months (IQR 84-97) with 4340 patient-years of treatment. The current (Oct 5, 2023) mean dose is 28·2 (SD 5·2) mg/kg per day with an increased mean haemoglobin concentration (7·3 [SD 1·1] g/dL at baseline to 8·5 [1·5] g/dL) and mean fetal haemoglobin level (10·9% [SD 6·8] to 23·3% [9·5]) and decreased absolute neutrophil count (6·8 [3·0] × 109 cells per L to 3·6 [2·2] × 109 cells per L). Incidence rate ratios (IRR) comparing MTD with fixed-dose hydroxyurea indicate decreased vaso-occlusive episodes (0·60; 95% CI 0·52-0·70; p<0·0001), acute chest syndrome events (0·21; 0·13-0·33; p<0·0001), recurrent stroke events (0·27; 0·07-1·06; p=0·061), malaria infections (0·58; 0·46-0·72; p<0·0001), non-malarial infections (0·52; 0·46-0·58; p<0·0001), serious adverse events (0·42; 0·27-0·67; p<0·0001), and death (0·70; 0·25-1·97; p=0·50). Dose-limiting toxicity rates were similar between the fixed-dose (24·1 per 100 patient-years) and MTD phases (23·2 per 100 patient-years; 0·97; 0·70-1·35; p=0·86). Grade 3 and 4 adverse events were infrequent (18·5 per 100 patient-years) and included malaria infection, non-malarial infections, vaso-occlusive pain, and acute chest syndrome. Serious adverse events were uncommon (3·6 per 100 patient-years) and included malaria infections, parvovirus-associated anaemia, sepsis, and stroke, with no treatment-related deaths. INTERPRETATION: Hydroxyurea dose escalation to MTD with dose optimisation significantly improved clinical responses and treatment outcomes, without increasing toxicities in children with sickle cell anaemia in sub-Saharan Africa. FUNDING: US National Heart, Lung, and Blood Institute and Cincinnati Children's Research Foundation.


Asunto(s)
Anemia de Células Falciformes , Antidrepanocíticos , Hidroxiurea , Humanos , Hidroxiurea/uso terapéutico , Hidroxiurea/administración & dosificación , Hidroxiurea/efectos adversos , Anemia de Células Falciformes/tratamiento farmacológico , Anemia de Células Falciformes/complicaciones , Anemia de Células Falciformes/sangre , Preescolar , Niño , Masculino , Femenino , África del Sur del Sahara , Estudios de Seguimiento , Lactante , Antidrepanocíticos/uso terapéutico , Antidrepanocíticos/efectos adversos , Antidrepanocíticos/administración & dosificación , Resultado del Tratamiento , Relación Dosis-Respuesta a Droga
8.
J Pediatr Hematol Oncol ; 46(5): e277-e283, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38718300

RESUMEN

Therapeutic options for sickle cell disease (SCD) have increased recently as well as the development of updated national guidelines. It is not known how these options are being offered or to what degree guidelines are incorporated into clinical practice. This study aimed to describe practice patterns for pediatric hematologists regarding the use of disease-modifying and potentially curative therapies for SCD. A 9-section, cross-sectional electronic survey was disseminated during a 3-month period via SurveyMonkey, to members of the American Society of Pediatric Hematology/Oncology Hemoglobinopathy Special Interest Group (ASPHO HSIG). A total of 88 physician members of the ASPHO HSIG were surveyed. Ninety percent of respondents (72/80) start hydroxyurea routinely in patients with HbSS and HbSß 0 thalassemia, regardless of disease severity. Laboratory monitoring was recommended every 3 months for stable dosing in 63.8% (51/80). New therapies were recommended for patients on hydroxyurea who were still experiencing SCD complications: L-glutamine 68.5% (37/54) or crizanlizumab 93.1% (54/58). Voxelotor was recommended for patients on hydroxyurea with low hemoglobin in 65.1% (43/66) of cases. Matched sibling transplant was considered for any disease severity by 55.1% (38/69). Gene therapy trials are offered on-site by 29% (20/69). Our study demonstrated the enhanced utilization of hydroxyurea while revealing the unexplored potential of other disease-modifying therapies in SCD. These findings underscore the importance of continued knowledge acquisition about the long-term efficacy of new medical therapies and addressing barriers to the use of proven therapies and guide the development of future studies of optimal SCD management.


Asunto(s)
Anemia de Células Falciformes , Hidroxiurea , Pautas de la Práctica en Medicina , Humanos , Anemia de Células Falciformes/terapia , Anemia de Células Falciformes/tratamiento farmacológico , Hidroxiurea/uso terapéutico , Estudios Transversales , Pautas de la Práctica en Medicina/estadística & datos numéricos , Masculino , Femenino , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales Humanizados/administración & dosificación , Antidrepanocíticos/uso terapéutico , Niño , Encuestas y Cuestionarios , Benzaldehídos , Pirazinas , Pirazoles
9.
BMC Health Serv Res ; 24(1): 666, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38802815

RESUMEN

BACKGROUND: In 2016, Uganda added Hydroxyurea (HU) to the list of essential drugs to treat sickle cell disease SCD. However, Hydroxyurea utilization has been low for several countries in sub-Saharan Africa. This study examined patient-related barriers to hydroxyurea use among adolescent and adult patients with sickle cell disease in Mulago and Kiruddu hospitals, in Uganda. METHODS: To understand the patient-related barriers to hydroxyurea use among adolescent and adult patients with sickle cell disease, we conducted a parallel convergent mixed methods study at outpatient departments of two national referral hospitals in Uganda from October 2022 to January 2023. The cross-sectional mixed-methods study employed both quantitative and qualitative methods. We collected survey data from a systematic sample of 259 participants and conducted individual interviews with a purposive sample of 40 participants (20 adolescents or their caregivers and 20 adult patients with SCD) and interviewed them individually on their knowledge, perceptions, barriers, and facilitators of HU utilization. Descriptive data were analyzed using Stata 16, whereas qualitative data were analyzed thematically using an inductive approach supported by NVivo 12 software. We triangulated data to determine the concordance of qualitative and quantitative data. RESULTS: The study enrolled 40 participants for qualitative interviews and 259 patients for quantitative, with an average age of 16, over half being female, 46% having secondary education, and 96% unmarried. The prevalence of HU use was 78%. The study identified three themes as follows: Patient barriers at the individual including Inadequate knowledge about HU, Persistent pain, Poor adherence to HU, Poor communication with health care workers, and Psychosocial and emotional challenges. At the facility level, long queues and poor quality of care, drug-related side effects that affect HU, and drug stock-outs were reported. Myths, rumors, and misconceptions about HU, and gender-related barriers were reported to affect HU utilization at a community level. Facilitators for the use of HU and recommendations for improvement. Facilitators included perceived benefits, long duration on HU, information sharing by healthcare workers, availability of complementary drugs, confirmation of diagnosis, and availability of medication at public health facilities or private pharmacies. Patients suggested continuous adherence support, encouragement from healthcare workers, sensitization about benefits and risks, a peer-to-peer approach, and financial support for adolescents and women to start businesses to resolve financial problems. CONCLUSION: Implementing the use of HU has been challenging in Uganda and needs improvement. Facilitators to hydroxyurea use have been highlighted, though Patient-identified barriers at individual, facility, and community levels that need to be resolved. The experiences and insights shared by our participants provide invaluable guidance for increasing the uptake of HU. Further studies are needed to establish validated instruments to assess patients' pain communication and adherence to the HU regimen.


Asunto(s)
Anemia de Células Falciformes , Antidrepanocíticos , Hidroxiurea , Investigación Cualitativa , Humanos , Hidroxiurea/uso terapéutico , Uganda , Anemia de Células Falciformes/tratamiento farmacológico , Anemia de Células Falciformes/psicología , Femenino , Masculino , Adulto , Adolescente , Estudios Transversales , Antidrepanocíticos/uso terapéutico , Adulto Joven , Conocimientos, Actitudes y Práctica en Salud , Persona de Mediana Edad
11.
J Ethnopharmacol ; 331: 118280, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38714239

RESUMEN

ETHNO-PHARMACOLOGICAL RELEVANCE: Globally, the prevalence of sickle cell disease is on the rise, with developing countries experiencing particularly alarming mortality rate compared to developed nations. The World Health Organization (WHO) and United Nations (UN) have acknowledged sickle cell disease as a significant global public health concern. Unfortunately, a cure for this condition is yet to be discovered, and existing allopathic treatments, while offering relief, come with serious side effects. In recent times, there has been a growing interest in exploring the potential of medicinal plants for treating sickle cell disease due to their content of secondary metabolites that may impact the disease's mechanisms. Cajanus cajan, a crucial grain legume in rain-fed agriculture in semi-arid tropics, has been traditionally used in folk medicine to manage various illnesses and is suggested to possess anti-sickling properties. AIM OF THE STUDY: The present study investigated two varieties of C. cajan for their effectiveness in treating sickle cell beta thalassemia, a variant of sickle cell disease. MATERIALS AND METHODS: The study was divided into four groups consisting of the untreated group (group 1), group treated with standard drug (group 2), group treated with white C. cajan (group 3) and group treated with brown C. cajan (group 4). The effects of the two variety of C. cajan were measured by polymerization test, reversibility test, osmotic fragility test, deoxygenation and beta globin synthesis test. RESULT: The results revealed that both varieties of C. cajan demonstrated a reduction in polymerization rates, reversed sickled red blood cells, increased the oxygen affinity of Hb-S/ß, elevated the Fe2+/Fe3+ ratio, and maintained the membrane stability of red blood cells. Notably, the white variety exhibited superior anti-sickling properties compared to the brown variety. CONCLUSION: This suggests that this significant leguminous crop could be utilized for the treatment and management of sickling disorders, particularly in low-income countries where conventional treatments may be financially inaccessible to patients.


Asunto(s)
Antidrepanocíticos , Cajanus , Extractos Vegetales , Talasemia beta , Cajanus/química , Humanos , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Antidrepanocíticos/uso terapéutico , Antidrepanocíticos/farmacología , Anemia de Células Falciformes/tratamiento farmacológico , Eritrocitos/efectos de los fármacos , Eritrocitos/metabolismo , Fitoterapia
12.
Pediatr Blood Cancer ; 71(7): e31017, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38706206

RESUMEN

BACKGROUND: National sickle cell disease (SCD) guidelines recommend oral hydroxyurea (HU) starting at 9 months of age, and annual transcranial Doppler (TCD) screenings to identify stroke risk in children aged 2-16 years. We examined prevalence and proportion of TCD screenings in North Carolina Medicaid enrollees to identify associations with sociodemographic factors and HU adherence over 3 years. STUDY DESIGN: We conducted a longitudinal study with children ages 2-16 years with SCD enrolled in NC Medicaid from years 2016-2019. Prevalence of TCD screening claims was calculated for 3 years, and proportion was calculated for 12, 24, and 36 months of Medicaid enrollment. Enrollee HU adherence was categorized using HU proportion of days covered. Multivariable Poisson regression assessed for TCD screening rates by HU adherence, controlling for age, sex, and rurality. RESULTS: The prevalence of annual TCD screening was between 39.5% and 40.1%. Of those with 12-month enrollment, 77.8% had no TCD claims, compared to 22.2% who had one or higher TCD claims. Inversely, in children with 36 months of enrollment, 36.7% had no TCD claims compared to 63.3% who had one or higher TCD claims. The proportion of children with two or higher TCD claims increased with longer enrollment (10.5% at 12 months, 33.7% at 24 months, and 52.6% at 36 months). Children with good HU adherence were 2.48 (p < .0001) times more likely to have TCD claims than children with poor HU adherence. CONCLUSION: While overall TCD screening prevalence was low, children with better HU adherence and longer Medicaid enrollment had more TCD screenings. Multilevel interventions are needed to engage healthcare providers and families to improve both evidence-based care and annual TCD screenings in children with SCD.


Asunto(s)
Anemia de Células Falciformes , Antidrepanocíticos , Hidroxiurea , Ultrasonografía Doppler Transcraneal , Humanos , Anemia de Células Falciformes/tratamiento farmacológico , Anemia de Células Falciformes/epidemiología , Anemia de Células Falciformes/diagnóstico por imagen , Niño , Hidroxiurea/uso terapéutico , Femenino , Masculino , Adolescente , Preescolar , Estudios Longitudinales , Antidrepanocíticos/uso terapéutico , Medicaid/estadística & datos numéricos , Cumplimiento de la Medicación/estadística & datos numéricos , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/prevención & control , Estados Unidos/epidemiología , Estudios de Seguimiento , North Carolina/epidemiología , Pronóstico
13.
Blood Cells Mol Dis ; 107: 102853, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38574498

RESUMEN

Sickle cell disease (SCD) is an hemoglobinopathy resulting in the production of an abnormal Hb (HbS) which can polymerize in deoxygenated conditions, leading to the sickling of red blood cells (RBC). These alterations can decrease the oxygen-carrying capacity leading to impaired function and energetics of skeletal muscle. Any strategy which could reverse the corresponding defects could be of interest. In SCD, endurance training is known to improve multiples muscle properties which restores patient's exercise capacity but present reduced effects in anemic patients. Hydroxyurea (HU) can increase fetal hemoglobin production which can reduce anemia in patients. The present study was conducted to determine whether HU can improve the effects of endurance training to improve muscle function and energetics. Twenty SCD Townes mice have been trained for 8 weeks with (n = 11) or without (n = 9) HU. SCD mice muscle function and energetics were analyzed during a standardized rest-exercise-recovery protocol, using Phosphorus-31 Magnetic resonance spectroscopy (31P-MRS) and transcutaneous stimulation. The combination of training and HU specifically decreased fatigue index and PCr consumption while muscle oxidative capacity was improved. These results illustrate the potential synergistic effects of endurance training and HU on muscle function and energetics in sickle cell disease.


Asunto(s)
Anemia de Células Falciformes , Metabolismo Energético , Hidroxiurea , Músculo Esquelético , Condicionamiento Físico Animal , Animales , Anemia de Células Falciformes/tratamiento farmacológico , Hidroxiurea/farmacología , Hidroxiurea/uso terapéutico , Ratones , Músculo Esquelético/metabolismo , Músculo Esquelético/efectos de los fármacos , Metabolismo Energético/efectos de los fármacos , Entrenamiento Aeróbico , Modelos Animales de Enfermedad , Antidrepanocíticos/farmacología , Antidrepanocíticos/uso terapéutico
14.
Pediatr Blood Cancer ; 71(6): e30945, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38462769

RESUMEN

Consistent with studies showing a high prevalence of the Duffy null phenotype among healthy Black Americans, this retrospective study found that Duffy null was present in >75% of a young and contemporary cohort of children with sickle cell disease (SCD) in the United States. Despite the potential for this phenotype to impact absolute neutrophil counts, hydroxyurea (HU) dosing, and outcomes, it was not associated with being prescribed a lower HU dose or having increased acute SCD visits early in the HU treatment course. Future studies are needed to confirm these findings in older children with SCD.


Asunto(s)
Anemia de Células Falciformes , Antidrepanocíticos , Sistema del Grupo Sanguíneo Duffy , Hidroxiurea , Humanos , Hidroxiurea/uso terapéutico , Hidroxiurea/administración & dosificación , Anemia de Células Falciformes/tratamiento farmacológico , Anemia de Células Falciformes/epidemiología , Masculino , Femenino , Estudios Retrospectivos , Preescolar , Estados Unidos/epidemiología , Niño , Sistema del Grupo Sanguíneo Duffy/genética , Prevalencia , Antidrepanocíticos/uso terapéutico , Lactante , Receptores de Superficie Celular/genética , Adolescente
15.
Am J Hematol ; 99(4): 625-632, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38332651

RESUMEN

Children with sickle cell anemia (SCA) in Africa frequently require transfusions for SCA complications. Despite limited blood supplies, strategies to reduce their transfusion needs have not been widely evaluated or implemented. We analyzed transfusion utilization in children with SCA before and during hydroxyurea treatment. REACH (Realizing Effectiveness Across Continents with Hydroxyurea, NCT01966731) is a longitudinal Phase I/II trial of hydroxyurea in children with SCA from Angola, Democratic Republic of Congo, Kenya, and Uganda. After enrollment, children had a two-month pre-treatment screening period followed by 6 months of fixed-dose hydroxyurea (15-20 mg/kg/day), 18 months of dose escalation, and then stable dosing at maximum tolerated dose (MTD). Characteristics associated with transfusions were analyzed with univariate and multivariable models. Transfusion incidence rate ratios (IRR) across treatment periods were calculated. Among 635 enrolled children with 4124 person-years of observation, 258 participants (40.4%) received 545 transfusions. The transfusion rate per 100 person-years was 43.2 before hydroxyurea, 21.7 on fixed-dose, 14.5 during dose escalation, and 10.8 on MTD. During MTD, transfusion incidence was reduced by 75% compared to pre-treatment (IRR 0.25, 95% confidence interval [CI] 0.18-0.35, p < .0001), and by 50% compared to fixed dose (IRR 0.50, 95% CI 0.39-0.63, p < .0001). Hydroxyurea at MTD decreases transfusion utilization in African children with SCA. If widely implemented, universal testing and hydroxyurea treatment at MTD could potentially prevent 21% of all pediatric transfusions administered in sub-Saharan Africa. Increasing hydroxyurea access for SCA should decrease the transfusion burden and increase the overall blood supply.


Asunto(s)
Anemia de Células Falciformes , Hidroxiurea , Niño , Humanos , Hidroxiurea/uso terapéutico , Antidrepanocíticos/uso terapéutico , Anemia de Células Falciformes/complicaciones , Anemia de Células Falciformes/tratamiento farmacológico , Uganda , Kenia
16.
J Natl Med Assoc ; 116(3): 247-251, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38310045

RESUMEN

BACKGROUND: Effective management of complications in sickle cell disease (SCD), such as stroke prevention, often necessitates the use of blood transfusions. However, individuals who adhere to the religious tenets of Jehovah's Witnesses strictly abstain from accepting blood transfusions, thereby presenting a formidable challenge in clinical decision-making. CASE REPORT: This is a case of a 3 year old child Jehovah's Witness who was found to have significantly elevated transcranial Doppler (TCD) velocity values between 193 and 203 cm/s, following routine screening. This was an otherwise clinically stable child, whose mother was diligently ensuring he had adequate medical care. Ideally, a prophylactic exchange blood transfusion program would have been commenced immediately but was not done due to due to the lack of consent from the caregiver. Patient was initially on hydroxyurea at 15 mg/kg and self medicating on omega 3 supplements and astymin syrup. Further elevation of TCD velocity upto 242 cm/s after a repeat testing, necessitated graduated increase of the dosage of hydroxyurea to 35 mg/kg to optimize its therapeutic effect, and discontinuation of omega 3 fatty acids and replacement of astymin with folic acid, vitamin C and B complex. Following these adjustments, the TCD dropped to below 190 cm/s reducing the risk of stroke in the child. CONCLUSION: This case report demonstrates the successful implementation of a bloodless management strategy for stroke prevention in a Jehovah's Witness child with SCD. This study contributes to the existing literature by providing valuable insights and practical guidance for healthcare providers facing similar ethical and medical dilemmas.


Asunto(s)
Anemia de Células Falciformes , Testigos de Jehová , Ultrasonografía Doppler Transcraneal , Humanos , Masculino , Preescolar , Hidroxiurea/uso terapéutico , Velocidad del Flujo Sanguíneo , Antidrepanocíticos/uso terapéutico
18.
Pediatr Blood Cancer ; 71(4): e30878, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38321562

RESUMEN

Despite disease-modifying effects of hydroxyurea on sickle cell disease (SCD), poor adherence among affected youth commonly impedes treatment impact. Following our prior feasibility trial, the "Hydroxyurea Adherence for Personal Best in Sickle Cell Treatment (HABIT)" multi-site randomized controlled efficacy trial aimed to increase hydroxyurea adherence for youth with SCD ages 10-18 years. Impaired adherence was identified primarily through flagging hydroxyurea-induced fetal hemoglobin (HbF) levels compared to prior highest treatment-related HbF. Eligible youth were enrolled as dyads with their primary caregivers for the 1-year trial. This novel semi-structured supportive, multidimensional dyad intervention led by community health workers (CHW), was augmented by daily tailored text message reminders, compared to standard care during a 6-month intervention phase, followed by a 6-month sustainability phase. Primary outcomes from the intervention phase were improved Month 6 HbF levels compared to enrollment and proportion of days covered (PDC) for hydroxyurea versus pre-trial year. The secondary outcome was sustainability of changes up to Month 12. The 2020-2021 peak coronavirus disease 2019 (COVID-19) pandemic disrupted enrollment and clinic-based procedures; CHW in-person visits shifted to virtual scheduled interactions. We enrolled 50 dyads, missing target enrollment. Compared to enrollment levels, both HbF level and PDC significantly - but not sustainably - improved within the intervention group (p = .03 and .01, respectively) with parallel increased mean corpuscular volume (MCV) (p = .05), but not within controls. No significant between-group differences were found at Months 6 or 12. These findings suggest that our community-based, multimodal support for youth-caregiver dyads had temporarily improved hydroxyurea usage. Durability of impact should be tested in a trial with longer duration of CHW-led and mobile health support.


Asunto(s)
Anemia de Células Falciformes , Hidroxiurea , Adolescente , Humanos , Anemia de Células Falciformes/tratamiento farmacológico , Antidrepanocíticos/uso terapéutico , Agentes Comunitarios de Salud , Hemoglobina Fetal/análisis , Hábitos , Hidroxiurea/uso terapéutico , Cumplimiento de la Medicación , Niño , Ensayos Clínicos Controlados Aleatorios como Asunto
19.
Syst Rev ; 13(1): 60, 2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-38331925

RESUMEN

BACKGROUND: Hydroxyurea is an affordable drug that reduces vaso-occlusive crises and transfusion requirements in sickle cell disease. However, its effectiveness in preventing chronic organ damage is still unclear. This systematic review and meta-analysis aimed to evaluate the role of hydroxyurea in preventing organ morbidity. METHOD: We included original articles published in English from 1st January 1990 to 31st January 2023, reporting hydroxyurea therapy and organ damage from PubMed, Google Scholar, Scopus, and CrossRef databases. A total of 45 studies with 4681 sickle cell disease patients were evaluated for organ damage. RESULTS: Our analysis showed that hydroxyurea intervention significantly lowered transcranial Doppler and tricuspid regurgitant velocity, with a standardized mean difference of - 1.03 (- 1.49; - 0.58); I 2 = 96% and - 1.37 (CI - 2.31, - 0.42); I 2 = 94%, respectively. Moreover, the pooled estimate for albuminuria showed a beneficial effect post-hydroxyurea therapy by reducing the risk of albuminuria by 58% (risk ratio of 0.42 (0.28; 0.63); I 2 = 28%). CONCLUSION: Our study found that a hydroxyurea dose above 20 mg/kg/day with a mean rise in HbF by 18.46% post-hydroxyurea therapy had a beneficial role in reducing transcranial doppler velocity, tricuspid regurgitant velocity, albuminuria, and splenic abnormality. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42023401187.


Asunto(s)
Anemia de Células Falciformes , Hidroxiurea , Humanos , Hidroxiurea/uso terapéutico , Antidrepanocíticos/uso terapéutico , Albuminuria/tratamiento farmacológico , Anemia de Células Falciformes/complicaciones , Anemia de Células Falciformes/tratamiento farmacológico , Transfusión Sanguínea
20.
Blood ; 143(14): 1425-1428, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38169476

RESUMEN

ABSTRACT: After starting hydroxyurea treatment, Ugandan children with sickle cell anemia had 60% fewer severe or invasive infections, including malaria, bacteremia, respiratory tract infections, and gastroenteritis, than before starting hydroxyurea treatment (incidence rate ratio, 0.40 [95% confidence interval, 0.29-0.54]; P < .001).


Asunto(s)
Anemia de Células Falciformes , Malaria , Niño , Humanos , Hidroxiurea/uso terapéutico , Antidrepanocíticos/uso terapéutico , Uganda/epidemiología , Anemia de Células Falciformes/complicaciones , Anemia de Células Falciformes/tratamiento farmacológico , Anemia de Células Falciformes/epidemiología , Malaria/complicaciones , Malaria/tratamiento farmacológico , Malaria/epidemiología
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