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The Cochrane Database of Systematic... Sep 2022Sickle cell disease (SCD) is one of the most common inherited diseases worldwide. It is associated with lifelong morbidity and a reduced life expectancy. Hydroxyurea... (Review)
Review
BACKGROUND
Sickle cell disease (SCD) is one of the most common inherited diseases worldwide. It is associated with lifelong morbidity and a reduced life expectancy. Hydroxyurea (hydroxycarbamide), an oral chemotherapeutic drug, ameliorates some of the clinical problems of SCD, in particular that of pain, by raising foetal haemoglobin (HbF). This is an update of a previously published Cochrane Review.
OBJECTIVES
The aims of this review are to determine through a review of randomised or quasi-randomised studies whether the use of hydroxyurea in people with SCD alters the pattern of acute events, including pain; prevents, delays or reverses organ dysfunction; alters mortality and quality of life; or is associated with adverse effects. In addition, we hoped to assess whether the response to hydroxyurea in SCD varies with the type of SCD, age of the individual, duration and dose of treatment, and healthcare setting.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Haemoglobinopathies Register, comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also searched online trial registries. The date of the most recent search was 17 February 2022.
SELECTION CRITERIA
Randomised and quasi-randomised controlled trials (RCTs and quasi-RCTs), of one month or longer, comparing hydroxyurea with placebo or standard therapy in people with SCD.
DATA COLLECTION AND ANALYSIS
Authors independently assessed studies for inclusion, carried out data extraction, assessed the risk of bias and assessed the quality of the evidence using GRADE.
MAIN RESULTS
We included nine RCTs recruiting 1104 adults and children with SCD (haemoglobin SS (HbSS), haemoglobin SC (HbSC) or haemoglobin Sβºthalassaemia (HbSβºthal) genotypes). Studies lasted from six to 30 months. We judged the quality of the evidence for the first two comparisons below as moderate to low as the studies contributing to these comparisons were mostly large and well-designed (and at low risk of bias); however, the evidence was limited and imprecise for some outcomes such as quality of life, deaths during the studies and adverse events, and the results are applicable only to individuals with HbSS and HbSβºthal genotypes. We judged the quality of the evidence for the third and fourth comparisons to be very low due to the limited number of participants, the lack of statistical power (both studies were terminated early with approximately only 20% of their target sample size recruited) and the lack of applicability to all age groups and genotypes. Hydroxyurea versus placebo Five studies (784 adults and children with HbSS or HbSβºthal) compared hydroxyurea to placebo; four recruited individuals with only severe disease and one recruited individuals with all disease severities. Hydroxyurea probably improves pain alteration (using measures such as pain crisis frequency, duration, intensity, hospital admissions and opoid use) and life-threatening illness, but we found no difference in death rates (10 deaths occurred during the studies, but the rates did not differ by treatment group) (all moderate-quality evidence). Hydroxyurea may improve measures of HbF (low-quality evidence) and probably decreases neutrophil counts (moderate-quality evidence). There were no consistent differences in terms of quality of life and adverse events (including serious or life-threatening events) (low-quality evidence). There were fewer occurrences of acute chest syndrome and blood transfusions in the hydroxyurea groups. Hydroxyurea and phlebotomy versus transfusion and chelation Two studies (254 children with HbSS or HbSβºthal also with risk of primary or secondary stroke) contributed to this comparison. There were no consistent differences in terms of pain alteration, death or adverse events (low-quality evidence) or life-threatening illness (moderate-quality evidence). Hydroxyurea with phlebotomy probably increased HbF and decreased neutrophil counts (moderate-quality evidence), but there were more occurrences of acute chest syndrome and infections. Quality of life was not reported. In the primary prevention study, no strokes occurred in either treatment group but in the secondary prevention study, seven strokes occurred in the hydroxyurea and phlebotomy group (none in the transfusion and chelation group) and the study was terminated early. Hydroxyurea versus observation One study (22 children with HbSS or HbSβºthal also at risk of stoke) compared hydroxyurea to observation. Pain alteration and quality of life were not reported. There were no differences in life-threatening illness, death (no deaths reported in either group) or adverse events (very low-quality evidence). We are uncertain if hydroxyurea improves HbF or decreases neutrophil counts (very low-quality evidence). Treatment regimens with and without hydroxyurea One study (44 adults and children with HbSC) compared treatment regimens with and without hydroxyurea. Pain alteration, life-threatening illness and quality of life were not reported. There were no differences in death rates (no deaths reported in either group), adverse events or neutrophil levels (very low-quality evidence). We are uncertain if hydroxyurea improves HbF (very low-quality evidence).
AUTHORS' CONCLUSIONS
There is evidence to suggest that hydroxyurea may be effective in decreasing the frequency of pain episodes and other acute complications in adults and children with sickle cell anaemia of HbSS or HbSβºthal genotypes and in preventing life-threatening neurological events in those with sickle cell anaemia at risk of primary stroke by maintaining transcranial Doppler velocities. However, there is still insufficient evidence on the long-term benefits of hydroxyurea, particularly with regard to preventing chronic complications of SCD, or recommending a standard dose or dose escalation to maximum tolerated dose. There is also insufficient evidence about the long-term risks of hydroxyurea, including its effects on fertility and reproduction. Evidence is also limited on the effects of hydroxyurea on individuals with the HbSC genotype. Future studies should be designed to address such uncertainties.
Topics: Acute Chest Syndrome; Adult; Anemia, Sickle Cell; Antisickling Agents; Child; Hemoglobin, Sickle; Humans; Hydroxyurea; Pain; Stroke
PubMed: 36047926
DOI: 10.1002/14651858.CD002202.pub3 -
The Cochrane Database of Systematic... Sep 2018This is an update of the original Cochrane review first published in Issue 1, 2003, and previously updated in 2009, 2012 and 2014. Chronic pain, defined as pain that... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
This is an update of the original Cochrane review first published in Issue 1, 2003, and previously updated in 2009, 2012 and 2014. Chronic pain, defined as pain that recurs or persists for more than three months, is common in childhood. Chronic pain can affect nearly every aspect of daily life and is associated with disability, anxiety, and depressive symptoms.
OBJECTIVES
The aim of this review was to update the published evidence on the efficacy of psychological treatments for chronic and recurrent pain in children and adolescents.The primary objective of this updated review was to determine any effect of psychological therapy on the clinical outcomes of pain intensity and disability for chronic and recurrent pain in children and adolescents compared with active treatment, waiting-list, or treatment-as-usual care.The secondary objective was to examine the impact of psychological therapies on children's depressive symptoms and anxiety symptoms, and determine adverse events.
SEARCH METHODS
Searches were undertaken of CENTRAL, MEDLINE, MEDLINE in Process, Embase, and PsycINFO databases. We searched for further RCTs in the references of all identified studies, meta-analyses, and reviews, and trial registry databases. The most recent search was conducted in May 2018.
SELECTION CRITERIA
RCTs with at least 10 participants in each arm post-treatment comparing psychological therapies with active treatment, treatment-as-usual, or waiting-list control for children or adolescents with recurrent or chronic pain were eligible for inclusion. We excluded trials conducted remotely via the Internet.
DATA COLLECTION AND ANALYSIS
We analysed included studies and we assessed quality of outcomes. We combined all treatments into one class named 'psychological treatments'. We separated the trials by the number of participants that were included in each arm; trials with > 20 participants per arm versus trials with < 20 participants per arm. We split pain conditions into headache and mixed chronic pain conditions. We assessed the impact of both conditions on four outcomes: pain, disability, depression, and anxiety. We extracted data at two time points; post-treatment (immediately or the earliest data available following end of treatment) and at follow-up (between three and 12 months post-treatment).
MAIN RESULTS
We identified 10 new studies (an additional 869 participants) in the updated search. The review thus included a total of 47 studies, with 2884 children and adolescents completing treatment (mean age 12.65 years, SD 2.21 years). Twenty-three studies addressed treatments for headache (including migraine); 10 for abdominal pain; two studies treated participants with either a primary diagnosis of abdominal pain or irritable bowel syndrome, two studies treated adolescents with fibromyalgia, two studies included adolescents with temporomandibular disorders, three were for the treatment of pain associated with sickle cell disease, and two studies treated adolescents with inflammatory bowel disease. Finally, three studies included adolescents with mixed pain conditions. Overall, we judged the included studies to be at unclear or high risk of bias.Children with headache painWe found that psychological therapies reduced pain frequency post-treatment for children and adolescents with headaches (risk ratio (RR) 2.35, 95% confidence interval (CI) 1.67 to 3.30, P < 0.01, number needed to treat for an additional beneficial outcome (NNTB) = 2.86), but these effects were not maintained at follow-up. We did not find a beneficial effect of psychological therapies on reducing disability in young people post-treatment (SMD -0.26, 95% CI -0.56 to 0.03), but we did find a beneficial effect in a small number of studies at follow-up (SMD -0.34, 95% CI -0.54 to -0.15). We found no beneficial effect of psychological interventions on depression or anxiety symptoms.Children with mixed pain conditionsWe found that psychological therapies reduced pain intensity post-treatment for children and adolescents with mixed pain conditions (SMD -0.43, 95% CI -0.67 to -0.19, P < 0.01), but these effects were not maintained at follow-up. We did find beneficial effects of psychological therapies on reducing disability for young people with mixed pain conditions post-treatment (SMD -0.34, 95% CI -0.54 to -0.15) and at follow-up (SMD -0.27, 95% CI -0.49 to -0.06). We found no beneficial effect of psychological interventions on depression symptoms. In contrast, we found a beneficial effect on anxiety at post-treatment in children with mixed pain conditions (SMD -0.16, 95% CI -0.29 to -0.03), but this was not maintained at follow-up.Across all pain conditions, we found that adverse events were reported in seven trials, of which two studies reported adverse events that were study-related.Quality of evidenceWe found the quality of evidence for all outcomes to be low or very low, mostly downgraded for unexplained heterogeneity, limitations in study design, imprecise and sparse data, or suspicion of publication bias. This means our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect, or we have very little confidence in the effect estimate; or the true effect is likely to be substantially different from the estimate of effect.
AUTHORS' CONCLUSIONS
Psychological treatments delivered predominantly face-to-face might be effective for reducing pain outcomes for children and adolescents with headache or other chronic pain conditions post-treatment. However, there were no effects at follow-up. Psychological therapies were also beneficial for reducing disability in children with mixed chronic pain conditions at post-treatment and follow-up, and for children with headache at follow-up. We found no beneficial effect of therapies for improving depression or anxiety. The conclusions of this update replicate and add to those of a previous version of the review which found that psychological therapies were effective in reducing pain frequency/intensity for children with headache and mixed chronic pain conditions post-treatment.
Topics: Abdominal Pain; Adolescent; Anxiety; Child; Chronic Pain; Cognitive Behavioral Therapy; Depression; Fibromyalgia; Headache; Hemoglobin SC Disease; Humans; Pain Management; Psychotherapy; Randomized Controlled Trials as Topic; Recurrence; Temporomandibular Joint Disorders
PubMed: 30270423
DOI: 10.1002/14651858.CD003968.pub5 -
JAMA Network Open Oct 2023Sickle cell disease (SCD) is a monogenic disorder, yet clinical outcomes are influenced by additional genetic factors. Despite decades of research, the genetics of SCD... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Sickle cell disease (SCD) is a monogenic disorder, yet clinical outcomes are influenced by additional genetic factors. Despite decades of research, the genetics of SCD remain poorly understood.
OBJECTIVE
To assess all reported genetic modifiers of SCD, evaluate the design of associated studies, and provide guidelines for future analyses according to modern genetic study recommendations.
DATA SOURCES
PubMed, Web of Science, and Scopus were searched through May 16, 2023, identifying 5290 publications.
STUDY SELECTION
At least 2 reviewers identified 571 original, peer-reviewed English-language publications reporting genetic modifiers of human SCD phenotypes, wherein the outcome was not treatment response, and the comparison was not between SCD subtypes or including healthy controls.
DATA EXTRACTION AND SYNTHESIS
Data relevant to all genetic modifiers of SCD were extracted, evaluated, and presented following STREGA and PRISMA guidelines. Weighted z score meta-analyses and pathway analyses were conducted.
MAIN OUTCOMES AND MEASURES
Outcomes were aggregated into 25 categories, grouped as acute complications, chronic conditions, hematologic parameters or biomarkers, and general or mixed measures of SCD severity.
RESULTS
The 571 included studies reported on 29 670 unique individuals (50% ≤ 18 years of age) from 43 countries. Of the 17 757 extracted results (4890 significant) in 1552 genes, 3675 results met the study criteria for meta-analysis: reported phenotype and genotype, association size and direction, variability measure, sample size, and statistical test. Only 173 results for 62 associations could be cross-study combined. The remaining associations could not be aggregated because they were only reported once or methods (eg, study design, reporting practice) and genotype or phenotype definitions were insufficiently harmonized. Gene variants regulating fetal hemoglobin and α-thalassemia (important markers for SCD severity) were frequently identified: 19 single-nucleotide variants in BCL11A, HBS1L-MYB, and HBG2 were significantly associated with fetal hemoglobin (absolute value of Z = 4.00 to 20.66; P = 8.63 × 10-95 to 6.19 × 10-5), and α-thalassemia deletions were significantly associated with increased hemoglobin level and reduced risk of albuminuria, abnormal transcranial Doppler velocity, and stroke (absolute value of Z = 3.43 to 5.16; P = 2.42 × 10-7 to 6.00 × 10-4). However, other associations remain unconfirmed. Pathway analyses of significant genes highlighted the importance of cellular adhesion, inflammation, oxidative and toxic stress, and blood vessel regulation in SCD (23 of the top 25 Gene Ontology pathways involve these processes) and suggested future research areas.
CONCLUSIONS AND RELEVANCE
The findings of this comprehensive systematic review and meta-analysis of all published genetic modifiers of SCD indicated that implementation of standardized phenotypes, statistical methods, and reporting practices should accelerate discovery and validation of genetic modifiers and development of clinically actionable genetic profiles.
Topics: Humans; Fetal Hemoglobin; alpha-Thalassemia; Anemia, Sickle Cell; Genotype; Genetic Variation
PubMed: 37851445
DOI: 10.1001/jamanetworkopen.2023.37484 -
Archives of Plastic Surgery May 2023Hemoglobinopathies such as sickle cell disease (SCD) are traditionally considered a relative contraindication to free tissue transfer, due to concerns that erythrocyte...
Hemoglobinopathies such as sickle cell disease (SCD) are traditionally considered a relative contraindication to free tissue transfer, due to concerns that erythrocyte sickling will increase the risk of microvascular thrombosis and flap failure. This article describes a case report with the successful use of free tissue transfer in a patient with SCD and provides a systematic literature review on free tissue transfer in SCD. A retrospective chart review was performed of a patient with SCD who underwent free tissue transfer at the authors' institution. A systematic literature review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed using the keywords "free tissue transfer," "free flap," or "microsurgery" and "sickle cell" on PubMed, Ovid/Medline, and Scopus. A 29-year-old male with delayed presentation of an electrical burn to the face and scalp underwent wound closure with a free anterolateral thigh flap. Key management principles included red blood cell transfusion to keep hemoglobin S under 30% and hemoglobin greater than 10 g/dL, maintenance of hydration, normothermia, adequate analgesia, and postoperative anticoagulation. Systematic literature review identified 7 articles describing 13 cases of free tissue transfer in 10 patients with SCD, with combined complete free flap success in 10 of the 13 flaps. Free tissue transfer can be successfully performed in patients with SCD. However, evidence on the optimal management of this unique patient population in the perioperative period after free tissue transfer is limited to case reports in the literature.
PubMed: 37256042
DOI: 10.1055/s-0043-1763260 -
Clinica Chimica Acta; International... Nov 2020Hemolysis is one of the main pathophysiological characteristics of sickle cell disease (SCD) and might cause or could be the result of oxidative stress. Antioxidants are... (Review)
Review
Hemolysis is one of the main pathophysiological characteristics of sickle cell disease (SCD) and might cause or could be the result of oxidative stress. Antioxidants are studied in SCD due to their potential to ensure redox balance and minimize deleterious effects on erythrocyte membranes. The objective of this systematic review was to evaluate the efficacy of antioxidant nutrient supplementation on reducing hemolysis in SCD patients through randomized clinical trials. We conducted our study according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses and the Cochrane Handbook for Systematic Reviews of Interventions investigating whether antioxidants could improve the hemolytic status of SCD patients. This study included 587 articles published until April 2020. We reduced this pool to 12 articles by excluding duplicates, reviews, comments, and studies with non-human subjects. Omega-3 fatty acids, vitamin A, and zinc were the antioxidants that reportedly improved the indirect hemolysis parameters such as hemoglobin, hematocrit, mean corpuscular volume, or red blood cells. High-dose vitamin C and E supplementation worsened hemolysis, causing increased reticulocytes, lactate dehydrogenase, indirect bilirubin, and haptoglobin. More intervention studies especially high-quality controlled randomized clinical trials are needed to investigate the effects of antioxidant nutrients in reducing hemolysis in SCD.
Topics: Anemia, Sickle Cell; Antioxidants; Erythrocytes; Hemolysis; Humans; Nutrients
PubMed: 32673671
DOI: 10.1016/j.cca.2020.07.020 -
Haemoglobinopathies and the clinical epidemiology of malaria: a systematic review and meta-analysis.The Lancet. Infectious Diseases Jun 2012Haemoglobinopathies can reduce the risk of malaria syndromes. We aimed to quantify the relation between different haemoglobin mutations and malaria protection to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Haemoglobinopathies can reduce the risk of malaria syndromes. We aimed to quantify the relation between different haemoglobin mutations and malaria protection to strengthen the foundation for translational studies of malaria pathogenesis and immunity.
METHODS
We systematically searched the Medline and Embase databases for studies that estimated the risk of malaria in patients with and without haemoglobinopathies up to Sept 9, 2011, and identified additional studies from reference lists. We included studies that enrolled mainly children or pregnant women and had the following outcomes: Plasmodium falciparum severe malaria, uncomplicated malaria, asymptomatic parasitaemia, or pregnancy-associated malaria, and Plasmodium vivax malaria. Two reviewers identified studies independently, assessed quality of the studies, and extracted data. We produced odds ratios (ORs; 95% CIs) for case-control studies and incidence rate ratios (IRRs; 95% CIs) for prospective studies. We did the meta-analysis with a random-effects model when equivalent outcomes were reported in more than one study.
FINDINGS
Of 62 identified studies, 44 reported data for haemoglobin AS, 19 for haemoglobin AC and CC, and 18 for α-thalassaemia. Meta-analysis of case-control studies showed a decreased risk of severe P. falciparum malaria in individuals with haemoglobin AS (OR 0·09, 95% CI 0·06-0·12), haemoglobin CC (0·27, 0·11-0·63), haemoglobin AC (0·83, 0·67-0·96), homozygous α-thalassaemia (0·63, 0·48-0·83), and heterozygous α-thalassaemia (0·83, 0·74-0·92). In meta-analysis of prospective trials only haemoglobin AS was consistently associated with protection from uncomplicated malaria (IRR 0·69, 95% CI 0·61-0·79); no haemoglobinopathies led to consistent protection from asymptomatic parasitaemia. Few clinical studies have investigated β-thalassaemia, haemoglobin E, P. vivax malaria, or pregnancy-associated malaria.
INTERPRETATION
Haemoglobin AS, CC, and AC genotypes and homozygous and heterozygous α-thalassaemia provide significant protection from severe malaria syndromes, but these haemoglobinopathies differ substantially in the degree of protection provided and confer mild or no protection against uncomplicated malaria and asymptomatic parasitaemia. Through attenuation of severity of malaria, haemoglobinopathies could serve as a model for investigation of the mechanisms of malaria pathogenesis and immunity.
FUNDING
US National Institute of Allergy and Infectious Diseases.
Topics: Hemoglobin, Sickle; Hemoglobinopathies; Humans; Malaria; Malaria, Falciparum; Risk Factors; alpha-Thalassemia
PubMed: 22445352
DOI: 10.1016/S1473-3099(12)70055-5 -
The Cochrane Database of Systematic... Nov 2020Sickle cell disease encompasses a group of genetic disorders characterized by the presence of at least one hemoglobin S (Hb S) allele, and a second...
BACKGROUND
Sickle cell disease encompasses a group of genetic disorders characterized by the presence of at least one hemoglobin S (Hb S) allele, and a second abnormal allele that could allow abnormal haemoglobin polymerisation leading to a symptomatic disorder. Autosomal recessive disorders (such as sickle cell disease) are good candidates for gene therapy because a normal phenotype can be restored in diseased cells with only a single normal copy of the mutant gene. This is an update of a previously published Cochrane Review.
OBJECTIVES
The objectives of this review are: - to determine whether gene therapy can improve survival and prevent symptoms and complications associated with sickle cell disease; - to examine the risks of gene therapy against the potential long-term gain for people with sickle cell disease.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register, which comprises of references identified from comprehensive electronic database searches and searching relevant journals and abstract books of conference proceedings. We also searched online trial registries, Date of the most recent search of the Group's Haemoglobinopathies Trials Register: 21 September 2020.
SELECTION CRITERIA
All randomised or quasi-randomised clinical trials (including any relevant phase 1, 2 or 3 trials) of gene therapy for all individuals with sickle cell disease, regardless of age or setting.
DATA COLLECTION AND ANALYSIS
No trials of gene therapy for sickle cell disease were found.
MAIN RESULTS
No trials of gene therapy for sickle cell disease were reported.
AUTHORS' CONCLUSIONS
No randomised or quasi-randomised clinical trials of gene therapy for sickle cell disease were reported. Thus, no objective conclusions or recommendations in practice can be made on gene therapy for sickle cell disease. This systematic review has identified the need for well-designed, randomised controlled trials to assess the benefits and risks of gene therapy for sickle cell disease.
Topics: Anemia, Sickle Cell; Genetic Therapy; Humans
PubMed: 33251574
DOI: 10.1002/14651858.CD007652.pub7 -
Journal of Translational Medicine Jun 2021Sickle cell disease (SCD) is commonly encountered in Africa and Middle Eastern countries. The causative mutation in the gene encoding the hemoglobin subunit β (HBB)... (Review)
Review
BACKGROUND
Sickle cell disease (SCD) is commonly encountered in Africa and Middle Eastern countries. The causative mutation in the gene encoding the hemoglobin subunit β (HBB) leads to various genotypic variants of the disease. This results in varied phenotypes, with a spectrum of complications, from benign to fatal. Hemoglobin SS (HBSS) genotype is associated with most of these complications; hence, it is a severe form of SCD. On the other hand, rare genotypes such as hemoglobin SE (HBSE) are considered benign. There is limited literature about the clinical manifestations and characteristics of patients with HBSE. We pooled all available data describing the phenotypic manifestations of HBSE heterozygote worldwide to perform a systematic review.
METHODS
We performed a systematic review according to PRISMA guidelines using PubMed, SCOPUS, and Google Scholar databases. Two independent reviewers (FA and IK) evaluated studies for eligibility and extracted data. We synthesized data on demographics, manifestations, and management of HBSE disease. PROSPERO Registration Number: CRD42021229877.
RESULTS
We found 68 HBSE patients reported in the literature. 24 cases were extracted from case reports whereas 44 cases from case series and retrospective studies. Turkey reported the highest number of patients (n = 22). 32 (47%) of the patients were males. The mean age was 20.9 ± 18.26 years. The mean HBS and HBE percentages were 61.1% ± 7.25% and 32.3% ± 5.06%, respectively, whereas the mean hemoglobin was 11.64 ± 1.73 g/dl. Reported manifestations of HBSE disease included acute vaso-occlusive pain crisis (n = 22, 32.3%), splenomegaly (n = 11, 16.1%), hemolytic anemia (n = 10, 14.7%), infections (n = 8. 11.7%), bone infarction (n = 4, 5.8%), gallstones (n = 3, 4.4%), venous thromboembolism (VTE) (n = 2, 2.9%) and stroke (n = 2, 2.9%), and hematuria (n = 2, 2.9%). Death due to HBSE complications was reported in three patients.
CONCLUSION
HBSE is a rare genotypic variant of SCD. It has been considered a benign form; however, there are multiple reports of severe complications. Severe complications observed in HBSE disease include vaso-occlusive crisis, acute chest syndrome, stroke, bone marrow embolism, and death.
Topics: Adolescent; Adult; Africa; Anemia, Sickle Cell; Child; Child, Preschool; Hemoglobin, Sickle; Humans; Male; Pain; Retrospective Studies; Young Adult
PubMed: 34134694
DOI: 10.1186/s12967-021-02931-1 -
The Cochrane Database of Systematic... May 2016Sickle cell disease is a genetic disorder involving a defect in the red blood cells due to its sickled hemoglobin. The main therapeutic interventions include preventive... (Review)
Review
BACKGROUND
Sickle cell disease is a genetic disorder involving a defect in the red blood cells due to its sickled hemoglobin. The main therapeutic interventions include preventive and supportive measures. Hematopoietic stem cell transplantations are carried out with the aim of replacing the defective cells and their progenitors (hematopoietic (i.e. blood forming) stem cells) in order to correct the disorder. This is an update of a previously published review.
OBJECTIVES
To determine whether stem cell transplantation can improve survival and prevent symptoms and complications associated with sickle cell disease. To examine the risks of stem cell transplantation against the potential long-term gain for people with sickle cell disease.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Group's Haemoglobinopathies Trials Register complied from electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (updated each new issue of The Cochrane Library) and quarterly searches of MEDLINE.Unpublished work was identified by searching the abstract books of major conference proceedings and we conducted a search of the website: www.ClinicalTrials.gov.Date of the most recent search of the Group's Haemoglobinopathies Trials Register: 06 October 2015.
SELECTION CRITERIA
Randomized controlled and quasi-randomized studies that compared any method of stem cell transplantation with either each other or with any of the preventive or supportive interventions (e.g. periodic blood transfusion, use of hydroxyurea, antibiotics, pain relievers, supplemental oxygen) in people with sickle cell disease irrespective of the type of sickle cell disease, gender and setting.
DATA COLLECTION AND ANALYSIS
No relevant trials were identified.
MAIN RESULTS
Ten trials were identified by the initial search and none for the update. None of these trials were suitable for inclusion in this review.
AUTHORS' CONCLUSIONS
Reports on the use of hematopoietic stem cell transplantation improving survival and preventing symptoms and complications associated with sickle cell disease are currently limited to observational and other less robust studies. No randomized controlled trial assessing the benefit or risk of hematopoietic stem cell transplantations was found. Thus, this systematic review identifies the need for a multicentre randomized controlled trial assessing the benefits and possible risks of hematopoietic stem cell transplantations comparing sickle status and severity of disease in people with sickle cell disease.
Topics: Anemia, Sickle Cell; Child; Hematopoietic Stem Cell Transplantation; Humans
PubMed: 27194464
DOI: 10.1002/14651858.CD007001.pub4 -
Frontiers in Pharmacology 2021Hydroxyurea has long been used for the treatment of sickle cell anemia (SCA), and its clinical effectiveness is related to the induction of fetal hemoglobin (HbF), a... (Review)
Review
Hydroxyurea has long been used for the treatment of sickle cell anemia (SCA), and its clinical effectiveness is related to the induction of fetal hemoglobin (HbF), a major modifier of SCA phenotypes. However, there is substantial variability in response to hydroxyurea among patients with SCA. While some patients show an increase in HbF levels and an ameliorated clinical condition under low doses of hydroxyurea, other patients present a poor effect or even develop toxicity. However, the effects of genetic polymorphisms on increasing HbF levels in response to hydroxyurea in patients with SCA (Hb SS) have been less explored. Therefore, we performed a systematic review to assess whether single-nucleotide polymorphisms (SNPs) affect HbF levels in patients with SCA treated with hydroxyurea. Moreover, we performed pathway analysis using the set of genes with SNPs found to be associated with changes in HbF levels in response to hydroxyurea among the included studies. The systematic literature search was conducted on Medline/PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, and Web of Science. Seven cohort studies were included following our inclusion and exclusion criteria. From the 728 genetic polymorphisms examined in the included studies, 50 different SNPs of 17 genes were found to be associated with HbF changes in patients with SCA treated with hydroxyurea, which are known to affect baseline HbF but are not restricted to them. Enrichment analysis of this gene set revealed reactome pathways with the lowest adjusted -values and highest combined scores related to VEGF ligand-receptor interactions (R-HSA-194313; R-HSA-195399) and the urea cycle (R-HSA-70635). Pharmacogenetic studies of response to hydroxyurea therapy in patients with SCA are still scarce and markedly heterogeneous regarding candidate genes and SNPs examined for association with HbF changes and outcomes, suggesting that further studies are needed. The reviewed findings highlighted that similar to baseline HbF, changes in HbF levels upon hydroxyurea therapy are likely to be regulated by multiple loci. There is evidence that SNPs in intron 2 of affect HbF changes in response to hydroxyurea therapy, a potential application that might improve the clinical management of SCA. (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=208790).
PubMed: 35126118
DOI: 10.3389/fphar.2021.779497