Abstract

BACKGROUND Non-transfusion-dependent β-thalassaemia (NTDβT) is a subset of inherited haemoglobin disorders characterised by reduced production of the β-globin chain of haemoglobin leading to anaemia of varying severity. Although blood transfusion is not a necessity for survival, it may be required to prevent complications of chronic anaemia, such as impaired growth and hypercoagulability. People with NTDβT also experience iron overload due to increased iron absorption from food sources which becomes more pronounced in those requiring blood transfusion. People with a higher foetal haemoglobin (HbF) level have been found to require fewer blood transfusions, thus leading to the emergence of treatments that could increase its level. HbF inducers stimulate HbF production without altering any gene structures. Evidence for the possible benefits and harms of these inducers is important for making an informed decision on their use. OBJECTIVES To compare the effectiveness and safety of the following for reducing blood transfusion for people with NTDβT: 1. HbF inducers versus usual care or placebo; 2. single HbF inducer with another HbF inducer, and single dose with another dose; and 3. combination of HbF inducers versus usual care or placebo, or single HbF inducer. SEARCH METHODS We used standard, extensive Cochrane search methods. The latest search date was 21 August 2022. SELECTION CRITERIA We included randomised controlled trials (RCTs) or quasi-RCTs comparing single HbF inducer with placebo or usual care, with another single HbF inducer or with a combination of HbF inducers; or comparing different doses of the same HbF inducer. DATA COLLECTION AND ANALYSIS We used standard Cochrane methods. Our primary outcomes were blood transfusion and haemoglobin levels. Our secondary outcomes were HbF levels, the long-term sequelae of NTDβT, quality of life and adverse events. MAIN RESULTS We included seven RCTs involving 291 people with NTDβT, aged two to 49 years, from five countries. We reported 10 comparisons using eight different HbF inducers (four pharmacological and four natural): three RCTs compared a single HbF inducer to placebo and seven to another HbF inducer. The duration of the intervention lasted from 56 days to six months. Most studies did not adequately report the randomisation procedures or whether and how blinding was achieved. HbF inducer against placebo or usual care Three HbF inducers, HQK-1001, Radix Astragali or a 3-in-1 combined natural preparation (CNP), were compared with a placebo. None of the comparisons reported the frequency of blood transfusion. We are uncertain whether Radix Astragali and CNP increase haemoglobin at three months (mean difference (MD) 1.33 g/dL, 95% confidence interval (CI) 0.54 to 2.11; 1 study, 2 interventions, 35 participants; very low-certainty evidence). We are uncertain whether Radix Astragali and CNP have any effect on HbF (MD 12%, 95% CI -0.74% to 24.75%; 1 study, 2 interventions, 35 participants; very low-certainty evidence). Only medians on haemoglobin and HbF levels were reported for HQK-1001. Adverse effects reported for HQK-1001 were nausea, vomiting, dizziness and suprapubic pain. There were no prespecified adverse effects for Radix Astragali and CNP. HbF inducer versus another HbF inducer Four studies compared a single inducer with another over three to six months. Comparisons included hydroxyurea versus resveratrol, hydroxyurea versus thalidomide, hydroxyurea versus decitabine and Radix Astragali versus CNP. No study reported our prespecified outcomes on blood transfusion. Haemoglobin and HbF were reported for the comparison Radix Astragali versus CNP, but we are uncertain whether there were any differences (1 study, 24 participants; low-certainty evidence). Different doses of the same HbF inducer Two studies compared two different types of HbF inducers at different doses over two to six months. Comparisons included hydroxyurea 20 mg/kg/day versus 10 mg/kg/day and HQK-1001 10 mg/kg/day, 20 mg/kg/day, 30 mg/kg/day and 40 mg/kg/day. Blood transfusion, as prespecified, was not reported. In one study (61 participants) we are uncertain whether the lower levels of both haemoglobin and HbF at 24 weeks were due to the higher dose of hydroxyurea (haemoglobin: MD -2.39 g/dL, 95% CI -2.80 to -1.98; very low-certainty evidence; HbF: MD -10.20%, 95% CI -16.28% to -4.12%; very low-certainty evidence). The study of the four different doses of HQK-1001 did not report results for either haemoglobin or HbF. We are not certain if major adverse effects may be more common with higher hydroxyurea doses (neutropenia: risk ratio (RR) 9.93, 95% CI 1.34 to 73.97; thrombocytopenia: RR 3.68, 95% CI 1.12 to 12.07; very low-certainty evidence). Taking HQK-1001 20 mg/kg/day may result in the fewest adverse effects. A combination of HbF inducers versus a single HbF inducer Two studies compared three combinations of two inducers with a single inducer over six months: hydroxyurea plus resveratrol versus resveratrol or hydroxyurea alone, and hydroxyurea plus l-carnitine versus hydroxyurea alone. Blood transfusion was not reported. Hydroxyurea plus resveratrol may reduce haemoglobin compared with either resveratrol or hydroxyurea alone (MD -0.74 g/dL, 95% CI -1.45 to -0.03; 1 study, 54 participants; low-certainty evidence). We are not certain whether the gastrointestinal disturbances, headache and malaise more commonly reported with hydroxyurea plus resveratrol than resveratrol alone were due to the interventions. We are uncertain whether hydroxyurea plus l-carnitine compared with hydroxyurea alone may increase mean haemoglobin, and reduce pulmonary hypertension (1 study, 60 participants; very low-certainty evidence). Adverse events were reported but not in the intervention group. None of the comparisons reported the outcome of HbF. AUTHORS' CONCLUSIONS We are uncertain whether any of the eight HbF inducers in this review have a beneficial effect on people with NTDβT. For each of these HbF inducers, we found only one or at the most two small studies. There is no information on whether any of these HbF inducers have an effect on our primary outcome, blood transfusion. For the second primary outcome, haemoglobin, there may be small differences between intervention groups, but these may not be clinically meaningful and are of low- to very low-certainty evidence. Data on adverse effects and optimal doses are limited. Five studies are awaiting classification, but none are ongoing.

Abstract

Hemophilia A, the most common hereditary disorder, is caused by clotting factor deficiency. Challenges encountered in the current treatment of hemophilia A [factor VIII (FVIII) replacement therapy] due to inhibitor development have caused ineffective treatment as well as morbidity and mortality among patients. However, there are no studies comparing the two types of FVIII treatments in terms of inhibitor development rate. Therefore, we conducted this systematic review to devise a better treatment option with a lower risk of inhibitor development. The systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and by searching several databases. Data extraction on study characteristics and outcomes was conducted. Reviewers also conducted a risk of bias assessment on all studies. All eligible studies for quantitative analysis were then processed using RevMan 5.4.1 and the data was extrapolated into cumulative outcomes and expressed in forest and funnel plots. Nine studies were included in the meta-analysis, involving a total of 2,531 hemophilia A patients who were followed up from birth until death. A higher incidence of inhibitor development was found to be associated with recombinant FVIII (rFVIII) [odds ratio (OR)=1.57, 95% confidence interval (CI): 0.95-2.59; hazard ratio (HR)=1.89, 95% CI: 1.15-3.12]. The same trend was also found for high-responding inhibitors (OR=1.38, 95% CI: 0.70-2.70; HR=1.42, 95% CI: 0.84-2.39). rFVIII is associated with a higher risk of overall and high-responding inhibitor development compared to plasma-derived FVIII (pdFVIII).

Abstract

Thrombocytopenia is a common and unsolved problem in myelodysplastic syndrome (MDS) patients; we aimed to summarize the evidence of TPO-RA treatment for heath-related quality of life (HRQoL) and platelet transfusion burden of MDS patients. We searched Pubmed, Web of Science, EMBASE, and CENTRAL for randomized clinical trials (RCTs) comparing TPO-RA to placebo in MDS published until July 31, 2021. A random-effect model was used. Eight RCTs with 908 patients were identified. Only three RCTs involving eltrombopag reported HRQoL, and all three studies treated HRQoL as a secondary outcome. In these three RCTs, the HRQoL instruments used in each study were different. However, this outcome cannot be meta-analyzed because some studies did not provide complete data. Subsequent clinical trials should pay more attention to this. Compared to placebo, TPO-RA did not affect platelet transfusion incidence 0.83 (95% CI 0.60-1.15). There was no evidence for subgroup differences in the analyses of different types of TPO-RA, different additional agent, and different types of MDS risk groups. However, platelet transfusion units (RR = 0.68, 95% CI 0.53 to 0.84) were significantly decreased. The RR of patients who did not require platelet transfusion for 56 or more consecutive days was not different between groups (RR = 0.98, 95% CI 0.41 to 2.34). TPO-RA may decrease platelet transfusion units in MDS patients with thrombocytopenia. But the significance of this finding should be interpreted with caution, because too few studies were meta-analyzed.

Abstract

Introduction Immune thrombotic thrombocytopenic purpura (iTTP) is an acquired, fatal microangiopathy if untreated. Randomized controlled trials (RCT's) demonstrated faster time-to-response with adding caplacizumab to standard of care (SOC). However, concerns about RCT selection bias and the high cost of caplacizumab warrant examination of all evidence, including real-world observational studies. Methods In this systematic review and meta-analysis, we searched the literature for comparative studies evaluating SOC with or without caplacizumab for the treatment of iTTP. We assessed risk-of-bias using the Cochrane RoB-2 tool (RCT's) and Newcastle-Ottawa Scale (observational studies). The primary efficacy outcome was all-cause mortality, and the primary safety outcome was treatment-emergent bleeding. Secondary outcomes included exacerbation and relapse, refractory iTTP, and time-to-response. Results We included two high-quality RCT's and three observational studies at high-risk-of-bias comprising 632 participants. Compared with SOC, caplacizumab was associated with a non-significant reduction in the RR (0.21 [CI 0.05-1.74]) of death in RCT's and observational studies (RR 0.62 [CI 0.07, 4.41]). Compared with SOC, caplacizumab was associated with an increased risk of bleeding in RCT's (RR 1.37 [CI 1.06, 1.77]). In observational studies, the risk of bleeding was not significantly increased (RR 7.10 [CI 0.90, 56.14]). Addition of caplacizumab was also associated with a significant reduction in refractory iTTP and exacerbation, increased risk of relapse, and shortened response time. Conclusion Frontline addition of caplacizumab does not significantly reduce all-cause mortality compared with SOC alone, although it reduces refractory disease risk, shortens time-to-response, and improves exacerbation rates, at the expense of increased relapse and bleeding risk.

Abstract

One possible side effect of thrombopoietin receptor agonists in immune thrombocytopenia is thrombosis. Our aim is to systematically review whether patients with ITP that were treated with a TPO-RA have an increased risk for thrombosis as compared to ITP patients without TPO-RA. Patients in the intervention group were required to receive TPO-RA therapy. The primary outcome was the incidence of thromboembolic events. Eleven studies were included in the pooled analysis. More thromboembolic events were noted in the TPO-RA group than in the control group: 25 compared to 4. Ten out of 11 studies showed a relative risk greater than 1. However, none of these individual risk ratios was statistically significant. The meta-analysis showed a RR of 1.82 [95% CI 0.78-4.24]. Our findings indicate there is a non-significant higher chance of thrombosis in ITP patients with TPO-RA treatments versus ITP patients without TPO-RA treatment.

Abstract

BACKGROUND Von Willebrand Disease (VWD) is a common inherited bleeding disorder. Patients with VWD suffering from severe bleeding may benefit from the use of secondary long-term prophylaxis. AIM: Systematically summarize the evidence on the clinical outcomes of secondary long-term prophylaxis in patients with VWD and severe recurrent bleedings. METHODS We searched Medline and EMBASE through October 2019 for relevant randomized clinical trials (RCTs) and comparative observational studies (OS) assessing the effects of secondary long-term prophylaxis in patients with VWD. We used Cochrane Risk of Bias (RoB) tool and the RoB for Non-Randomized Studies of interventions (ROBINS-I) tool to assess the quality of the included studies. We conducted random-effects meta-analyses and assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. RESULTS We included 12 studies. Evidence from one placebo controlled RCT suggested that VWD prophylaxis as compared to no prophylaxis reduced the rate of bleeding episodes (Rate ratio [RR], .24; 95% confidence interval [CI], .17-.35; low certainty evidence), and of epistaxis (RR, .38; 95%CI, .21-.67; moderate certainty evidence), and may increase serious adverse events RR 2.73 (95%CI .12-59.57; low certainty). Evidence from four before-and-after studies in which researchers reported comparative data suggested that VWD prophylaxis reduced the rate of bleeding (RR .34; 95%CI, .25-.46; very low certainty evidence). CONCLUSION VWD prophylaxis treatment seems to reduce the risk of spontaneous bleeding, epistaxis, and hospitalizations. More RCTs should be conducted to increase the certainty in these benefits.

Abstract

The CRISPR/Cas9 technique is easily programmable, fast, more powerful, and efficient at generating a mutation compared to previous gene therapy methods. β-thalassemia is the most common autosomal recessive disorder worldwide. Appropriate genomic changes in the β gene can be modified to alleviate the symptoms of the disease using the CRISPR/Cas9 system. PubMed/Medline, Scopus, Web of Science, and SID databases were searched in Persian and English from February 2000 to September 2022. Finally, 39 articles had inclusion criteria which were reviewed by two separate individuals. Among the reviewed articles, articles were divided into three categories. In the first group, studies attemped to increase the expression of γ-globin and production of hemoglobin F. The strategy of second group of studies were the reduction of the α-globin chain to prevent hemolysis of RBCs by accumulation of excessive α-globins. The third group corrected the mutations causing β-thalassemia. Studies have shown that the genome of β-thalassemia patients can be modified using the CRISPR/Cas9 technique, and this approach might be promising for the treatment of β-thalassemia.

Abstract

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.

Abstract

OBJECTIVE To evaluate the efficacy and safety of romiplostim (thrombopoietin-receptor agonist) in the treatment of pediatric immune thrombocytopenia (ITP). METHODS Searches were conducted in MEDLINE, EMBASE, LILACS, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov (from January 2011 to August 2021). Randomized controlled trials (RCTs), double-blind, comparing romiplostim with a placebo in pediatric persistent or chronic ITP were included. The primary outcome was the overall response rate (platelets ≥ 50 × 10(9)/L) in the absence of rescue therapy for at least two consecutive weeks. The secondary endpoints were the minimization of clinically significant bleeding and the necessity for rescue treatments and the maximization of safety (incidence of overall adverse events) and durable response (maintaining platelet counts for at least twelve weeks). RESULTS Two double-blind randomized placebo-controlled trials (84 participants) were included in this systematic review. Our data showed that, compared to the placebo group, the proportion of patients achieving durable platelet response was significantly higher in the romiplostim group (p = 0.003, RR = 6.34, 95%CI = 1.89 - 21.23), as was the overall response in the romiplostim group (p = 0.002, RR = 3.62, 95%CI = 1.63 - 8.03). Significant bleeding incidents (p = 0.49), overall adverse events (p = 0.71) and the need for rescue treatment (p = 0.13) were not statistically different between the romiplostim and placebo groups. CONCLUSIONS Romiplostim might improve both durable and overall platelet response in children and adolescents with ITP, compared to a placebo. More clinical trials are needed to evaluate the efficacy and safety of romiplostim and to compare it with other second-line treatments that are being used in pediatric ITP.

Abstract

BACKGROUND Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease affecting 1 in 5000 individuals. Epistaxis is seen in more than 90% of patients with HHT. Severe recurrent epistaxis can significantly decrease quality of life and may be resistant to standard treatment measures. Dysregulation of angiogenesis has been shown to cause the proliferation of abnormal blood vessels. As such, antiangiogenic treatments have been investigated including beta-blockers. OBJECTIVE A systematic review of the efficacy of beta-blockers in topical treatment of epistaxis in patients with HHT based on epistaxis duration, frequency, and severity. METHODS A systematic search was performed using the PubMed, Embase via Ovid, and Cochrane databases. The Preferred Items for Systematic Reviews and Meta-Analyses guidelines were followed. Studies that measured the efficacy of beta-blocker treatment of epistaxis in patients with HHT were included for qualitative analysis. RESULTS Five studies (3 randomized controlled trials and 2 case series) with a total of 132 patients were included. Administration (systemically or topically via a spray or gel) of timolol and propranolol showed mixed evidence of improvement in epistaxis frequency, severity, and duration when compared with control groups. The evidence for propranolol appears more promising than timolol. CONCLUSION There are significant limitations in the included studies, and further investigation with larger longitudinal or randomized prospective trials is recommended. The available evidence suggests that beta-blocker treatment may have a positive effect on HHT-related epistaxis.