Enzyme replacement therapy for late-onset Pompe disease.

BACKGROUND: Pompe disease is caused by a deficiency of the enzyme acid alpha-glucosidase (GAA). People with infantile-onset disease have either a complete or a near-complete enzyme deficiency; people with late-onset Pompe disease (LOPD) retain some residual enzyme activity. GAA deficiency is treated with an intravenous infusion of recombinant human acid alglucosidase alfa, an enzyme replacement therapy (ERT). Alglucosidase alfa and avalglucosidase alfa are approved treatments, but cipaglucosidase alfa with miglustat is not yet approved. OBJECTIVES: To assess the effects of enzyme replacement therapies in people with late-onset Pompe disease. SEARCH METHODS: We searched the Cochrane Inborn Errors of Metabolism Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched MEDLINE OvidSP, clinical trial registries, and the reference lists of relevant articles and reviews. Date of last search: 21 April 2022. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of ERT in people with LOPD of any age. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial eligibility, extracted data, assessed the risk of bias and the certainty of the evidence (using GRADE). We resolved disagreements through discussion and by consulting a third author. MAIN RESULTS: We included six trials (358 randomised participants) lasting from 12 to 78 weeks. A single trial reported on each comparison listed below. None of the included trials assessed two of our secondary outcomes: need for respiratory support and use of a walking aid or wheelchair. Certainty of evidence was most commonly downgraded for selective reporting bias. Alglucosidase alfa versus placebo (90 participants) After 78 weeks, alglucosidase alfa probably improves the six-minute walk test (6MWT) distance compared to placebo (mean difference (MD) 30.95 metres, 95% confidence interval (CI) 7.98 to 53.92; moderate-certainty evidence) and probably improves respiratory function, measured as the change in per cent (%) predicted forced vital capacity (FVC) (MD 3.55, 95% CI 1.46 to 5.64; moderate-certainty evidence). There may be little or no difference between the groups in occurrence of infusion reactions (risk ratio (RR) 1.21, 95% CI 0.57 to 2.61; low-certainty evidence), quality of life physical component score (MD -1.36 points, 95% CI -5.59 to 2.87; low-certainty evidence), or adverse events (RR 0.94, 95% CI 0.64 to 1.39; low-certainty evidence). Alglucosidase alfa plus clenbuterol versus alglucosidase alfa plus placebo (13 participants) The evidence is very uncertain about the effect of alglucosidase alfa plus clenbuterol compared to alglucosidase alfa plus placebo on: change in 6MWT distance after 52 weeks (MD 34.55 metres, 95% CI-10.11 to 79.21; very low-certainty evidence) and change in % predicted FVC (MD -13.51%, 95% CI -32.44 to 5.41; very low-certainty evidence). This study did not measure infusion reactions, quality of life, and adverse events. Alglucosidase alfa plus albuterol versus alglucosidase alfa plus placebo (13 participants) The evidence is very uncertain about the effect of alglucosidase alfa plus albuterol compared to alglucosidase alfa plus placebo on: change in 6MWT distance after 52 weeks (MD 30.00 metres, 95% CI 0.55 to 59.45; very low-certainty evidence), change in % predicted FVC (MD -4.30%, 95% CI -14.87 to 6.27; very low-certainty evidence), and risk of adverse events (RR 0.67, 95% CI 0.38 to 1.18; very low-certainty evidence). This study did not measure infusion reactions and quality of life. VAL-1221 versus alglucosidase alfa (12 participants) Insufficient information was available about this trial to generate effect estimates measured at one year or later. Compared to alglucosidase alfa, VAL-1221 may increase or reduce infusion-associated reactions at three months, but the evidence is very uncertain (RR 2.80, 95% CI 0.18 to 42.80). This study did not measure quality of life and adverse events. Cipaglucosidase alfa plus miglustat versus alglucosidase alfa plus placebo (125 participants) Compared to alglucosidase alfa plus placebo, cipaglucosidase alfa plus miglustat may make little or no difference to: 6MWT distance at 52 weeks (MD 13.60 metres, 95% CI -2.26 to 29.46); infusion reactions (RR 0.94, 95% CI 0.49 to 1.80); quality of life scores for physical function (MD 1.70, 95% CI -2.13 to 5.53) and fatigue (MD -0.30, 95% CI -2.76 to 2.16); and adverse effects potentially related to treatment (RR 0.83, 95% CI 0.49 to 1.40) (all low-certainty evidence). Cipaglucosidase alfa plus miglustat probably improves % predicted FVC compared to alglucosidase alfa plus placebo (MD 3.10%, 95% CI 1.04 to 5.16; moderate-certainty evidence); however, it may make little or no change in % predicted sniff nasal inspiratory pressure (MD -0.06%, 95% CI -8.91 to 7.71; low-certainty evidence). Avalglucosidase alfa versus alglucosidase alfa (100 participants) After 49 weeks, avalglucosidase alfa probably improves 6MWT compared to alglucosidase alfa (MD 30.02 metres, 95% CI 1.84 to 58.20; moderate-certainty evidence). Avalglucosidase alfa probably makes little or no difference to % predicted FVC compared to alglucosidase alfa (MD 2.43%, 95% CI -0.08 to 4.94; moderate-certainty evidence). Avalglucosidase alfa may make little or no difference to infusion reactions (RR 0.78, 95% CI 0.42 to 1.45), quality of life (MD 0.77, 95% CI -2.09 to 3.63), or treatment-related adverse events (RR 0.92, 95% CI 0.61 to 1.40), all low-certainty evidence. AUTHORS' CONCLUSIONS: One trial compared the effect of ERT to placebo in LOPD, showing that alglucosidase alfa probably improves 6MWT and respiratory function (both moderate-certainty evidence). Avalglucosidase alfa probably improves 6MWT compared with alglucosidase alfa (moderate-certainty evidence). Cipaglucosidase plus miglustat probably improves FVC compared to alglucosidase alfa plus placebo (moderate-certainty evidence). Other trials studied the adjunct effect of clenbuterol and albuterol along with alglucosidase alfa, with little to no evidence of benefit. No significant rise in adverse events was noted with all ERTs. The impact of ERT on some outcomes remains unclear, and longer RCTs are needed to generate relevant information due to the progressive nature of LOPD. Alternative resources, such as post-marketing registries, could capture some of this information.

Recombinant growth hormone therapy for X-linked hypophosphatemia in children.

BACKGROUND: Conventional treatment of X-linked hypophosphatemia with oral phosphate and calcitriol can heal rickets, but it does not always raise serum phosphate concentrations significantly, nor does it always normalize linear growth. Some clinical trials suggest that combining recombinant human growth hormone therapy with conventional treatment improves growth velocity, phosphate retention, and bone mineral density, but some clinical trials suggest that it appears to aggravate the pre-existent disproportionate stature of such children. This is an updated version of a previously published review. OBJECTIVES: To determine whether recombinant human growth hormone therapy for children with X-linked hypophosphatemia is associated with changes in longitudinal growth, mineral metabolism, endocrine function, renal function, bone mineral density, body proportions, and also with any adverse effects. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. In addition, we searched the Cochrane Central Register of Controlled Trials, Ovid MEDLINE and the reference lists of identified trials and other reviews. We also undertook some additional handsearching of relevant journals and conference proceedings. Date of the most recent search: 12 January 2021 SELECTION CRITERIA: All randomized controlled studies or quasi-randomized controlled studies comparing growth hormone (alone or combined with conventional treatment) with either placebo or conventional treatment alone in children with X-linked hypophosphatemia. DATA COLLECTION AND ANALYSIS: Two authors independently assessed studies for risk of bias and extracted data from eligible studies. GRADE criteria were used to assess the certainty of the evidence for each outcome. MAIN RESULTS: We included two studies (20 participants) in the review. In one cross-over study, results showed that recombinant human growth hormone therapy may improve the height standard deviation (SDS) score (z score), but we are unsure whether the intervention was the reason behind a transient increase in serum phosphate and tubular maximum for phosphate reabsorption. In the second, parallel study, treatment may also have improved the height SDS from baseline in the rhGH group compared to the control group, although no significant difference was seen between groups after three years, MD 0.50 SDS (95 % CI -0.54 to 1.54) (low-certainty evidence). The treatment was possibly well-tolerated during both studies with only transient adverse effects seen in three participants (low-certainty evidence). We are uncertain whether growth hormone improves serum phosphate levels or change in TmP/GFR (very low-certainty evidence). The treatment may make little or no difference to alkaline phosphatase levels (low-certainty evidence). AUTHORS' CONCLUSIONS: We do not have enough high-certainty evidence to recommend the use of recombinant human growth hormone therapy in children with X-linked hypophosphatemia.

Rituximab for eradicating inhibitors in people with acquired haemophilia A.

BACKGROUND: Acquired haemophilia A is a rare bleeding disorder caused by the development of specific autoantibodies against coagulation factor VIII. Standard treatment, usually steroids alone, or in combination with cyclophosphamide, aims to stop acute bleeds by using haemostatic agents to promote clotting. Rituximab may be an alternative approach to the treatment of acquired haemophilia by eradicating FVIII autoantibodies. This is an update of a previously published Cochrane Review. OBJECTIVES: To assess the efficacy and adverse effects of rituximab for treating people with acquired haemophilia A. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's trials registers, comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and conference proceedings (January 2021). We also undertook searches of CENTRAL, MEDLINE and online trial registries (January 2021). SELECTION CRITERIA: Randomised and quasi-randomised controlled trials of rituximab for people with acquired haemophilia A, with no restrictions on gender, age or ethnicity. DATA COLLECTION AND ANALYSIS: No trials matching the selection criteria were eligible for inclusion. MAIN RESULTS: No trials matching the selection criteria were eligible for inclusion. AUTHORS' CONCLUSIONS: We found no randomised clinical trials of rituximab for acquired haemophilia A. Thus, we are not able to draw any conclusions or make any recommendations on rituximab for eradicating inhibitors in people with acquired haemophilia A based on the highest quality evidence. Given that undertaking randomised controlled trials in this field is a complex task, we suggest that, while planning such trials, clinicians treating the disease continue to base their choices on alternative, lower-quality sources of evidence. In a future update of this review, we plan to appraise and incorporate eligible randomised controlled trials, as well as other high-quality, non-randomised studies.

Tyrosine supplementation for phenylketonuria.

BACKGROUND: Phenylketonuria is an inherited disease for which the main treatment is the dietary restriction of the amino acid phenylalanine. The diet has to be initiated in the neonatal period to prevent or reduce mental handicap. However, the diet is very restrictive and unpalatable and can be difficult to follow. A deficiency of the amino acid tyrosine has been suggested as a cause of some of the neuropsychological problems exhibited in phenylketonuria. Therefore, this review aims to assess the efficacy of tyrosine supplementation for phenylketonuria. This is an update of previously published versions of this review. OBJECTIVES: To assess the effects of tyrosine supplementation alongside or instead of a phenylalanine-restricted diet for people with phenylketonuria, who commenced on diet at diagnosis and either continued on the diet or relaxed the diet later in life. To assess the evidence that tyrosine supplementation alongside, or instead of a phenylalanine-restricted diet improves intelligence, neuropsychological performance, growth and nutritional status, mortality rate and quality of life. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Register which is comprised of references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. Additional studies were identified from handsearches of the Journal of Inherited Metabolic Disease (from inception in 1978 to 1998). The manufacturers of prescribable dietary products used in the treatment of phenylketonuria were also contacted for further references. Date of the most recent search of the Group's Inborn Errors of Metabolism Trials Register: 07 December 2020. SELECTION CRITERIA: All randomised or quasi-randomised trials investigating the use of tyrosine supplementation versus placebo in people with phenylketonuria in addition to, or instead of, a phenylalanine-restricted diet. People treated for maternal phenylketonuria were excluded. DATA COLLECTION AND ANALYSIS: Two authors independently assessed the trial eligibility, methodological quality and extracted the data. MAIN RESULTS: Six trials were found, of which three trials reporting the results of a total of 56 participants, were suitable for inclusion in the review. The blood tyrosine concentrations were significantly higher in the participants receiving tyrosine supplements than those in the placebo group, mean difference 23.46 (95% confidence interval 12.87 to 34.05). No significant differences were found between any of the other outcomes measured. The trials were assessed as having a low to moderate risk of bias across several domains. AUTHORS' CONCLUSIONS: From the available evidence no recommendations can be made about whether tyrosine supplementation should be introduced into routine clinical practice. Further randomised controlled studies are required to provide more evidence. However, given this is not an active area of research, we have no plans to update this review in the future.

Dietary interventions for phenylketonuria.

BACKGROUND: Phenylketonuria is an inherited disease treated with dietary restriction of the amino acid phenylalanine. The diet is initiated in the neonatal period to prevent learning disability; however, it is restrictive and can be difficult to follow. Whether the diet can be relaxed or discontinued during adolescence or should be continued for life remains a controversial issue, which we aim to address in this review. This is an updated version of a previously published review. OBJECTIVES: To assess the effects of a low-phenylalanine diet commenced early in life for people with phenylketonuria. To assess the possible effects of relaxation or termination of the diet on intelligence, neuropsychological outcomes and mortality, growth, nutritional status, eating behaviour and quality of life. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. Most recent search of the Inborn Errors of Metabolism Trials Register: 30 April 2020. SELECTION CRITERIA: All randomised or quasi-randomised controlled trials comparing a low-phenylalanine diet to relaxation or termination of dietary restrictions in people with phenylketonuria. DATA COLLECTION AND ANALYSIS: Two authors independently assessed study eligibility and methodological quality, and subsequently extracted the data. MAIN RESULTS: We included four studies in this review (251 participants), and found few significant differences between treatment and comparison groups for the outcomes of interest. Blood phenylalanine levels were significantly lower in participants with phenylketonuria following a low-phenylalanine diet compared to those on a less restricted diet, mean difference (MD) at three months -698.67 (95% confidence interval (CI) -869.44 to -527.89). Intelligence quotient was significantly higher in participants who continued the diet than in those who stopped the diet, MD after 12 months 5.00 (95% CI 0.40 to 9.60). However, these results came from a single study. AUTHORS' CONCLUSIONS: The results of non-randomised studies have concluded that a low-phenylalanine diet is effective in reducing blood phenylalanine levels and improving intelligence quotient and neuropsychological outcomes. We were unable to find any randomised controlled studies that have assessed the effect of a low-phenylalanine diet versus no diet from diagnosis. In view of evidence from non-randomised studies, such a study would be unethical and it is recommended that low-phenylalanine diet should be commenced at the time of diagnosis. There is uncertainty about the precise level of phenylalanine restriction and when, if ever, the diet should be relaxed. This should be addressed by randomised controlled studies; however, no new studies are expected in this area so we do not plan to update this review.

Combination antimicrobial susceptibility testing for acute exacerbations in chronic infection of Pseudomonas aeruginosa in cystic fibrosis.

BACKGROUND: Antibiotic therapy for acute pulmonary exacerbations in people with cystic fibrosis is usually chosen based on the results of antimicrobial susceptibility testing of individual drugs. Combination antimicrobial susceptibility testing assesses the efficacy of drug combinations including two or three antibiotics in vitro and can often demonstrate antimicrobial efficacy against bacterial isolates even when individual antibiotics have little or no effect. Therefore, choosing antibiotics based on combination antimicrobial susceptibility testing could potentially improve response to treatment in people with cystic fibrosis with acute exacerbations. This is an updated version of a previously published review. OBJECTIVES: To compare antibiotic therapy based on conventional antimicrobial susceptibility testing to antibiotic therapy based on combination antimicrobial susceptibility testing in the treatment of acute pulmonary exacerbations in people with cystic fibrosis and chronic infection with Pseudomonas aeruginosa. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Cystic Fibrosis Trials Register which comprises of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Date of latest search: 19 March 2020. We also searched ongoing trials registries. Date of latest search: 07 April 2020. SELECTION CRITERIA: Randomised and quasi-randomised controlled studies of antibiotic therapy based on conventional antimicrobial susceptibility testing compared to antibiotic therapy based on combination antimicrobial susceptibility testing in the treatment of acute pulmonary exacerbations in cystic fibrosis due to chronic infection with Pseudomonas aeruginosa. DATA COLLECTION AND ANALYSIS: Both authors independently selected studies, assessed their quality and extracted data from eligible studies. Additionally, the authors contacted the study investigators to obtain further information. MAIN RESULTS: The search identified one multicentre study eligible for inclusion in the review. This study prospectively assessed whether the use of multiple combination bactericidal antibiotic testing improved clinical outcomes in participants with acute pulmonary exacerbations of cystic fibrosis who were infected with multiresistant bacteria. A total of 132 participants were randomised in the study. The study investigators provided data specific to the 82 participants who were only infected with Pseudomonas aeruginosa for their primary outcome of time until next pulmonary exacerbation. For participants specifically infected with only Pseudomonas aeruginosa, the hazard ratio of a subsequent exacerbation was 0.82, favouring the control group (95% confidence interval 0.44 to 1.51) (P = 0.52). No further data for any of this review's outcomes specific to participants infected with Pseudomonas aeruginosa were available. The risk of bias for the included study was deemed to be low. The quality of the evidence was moderate for the only outcome providing data solely for individuals with infection due to Pseudomonas aeruginosa. For other outcomes, we were unable to judge the quality of the evidence as no data were available for the relevant subset of participants. AUTHORS' CONCLUSIONS: The current evidence, limited to one study, shows that there is insufficient evidence to determine effect of choosing antibiotics based on combination antimicrobial susceptibility testing compared to choosing antibiotics based on conventional antimicrobial susceptibility testing in the treatment of acute pulmonary exacerbations in people with cystic fibrosis with chronic Pseudomonas aeruginosa infection. A large international and multicentre study is needed to further investigate this issue. The only study included in the review was published in 2005, and we have not identified any further relevant studies up to March 2017. We therefore do not plan to update this review until new studies are published.

Enteral tube feeding for cystic fibrosis.

BACKGROUND: Enteral tube feeding is routinely used in many cystic fibrosis centres when oral dietary and supplement intake has failed to achieve an adequate nutritional status. The use of this method of feeding is assessed on an individual basis taking into consideration the patients age and clinical status. This is a final update of a previously published review. OBJECTIVES: To examine the evidence that in people with cystic fibrosis, supplemental enteral tube feeding improves nutritional status, respiratory function, and quality of life without significant adverse effects. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also contacted the companies that market enteral feeds and reviewed their databases.Date of the most recent search of the Group's Cystic Fibrosis Trials Register: 10 July 2019.Date of the most recent hand search of PubMed: 26 October 2018. SELECTION CRITERIA: All randomised controlled trials comparing supplemental enteral tube feeding for one month or longer with no specific intervention in people with cystic fibrosis. DATA COLLECTION AND ANALYSIS: The searches identified 44 trials; however, none were eligible for inclusion in this review. MAIN RESULTS: There are no trials included in this review. AUTHORS' CONCLUSIONS: Supplemental enteral tube feeding is widely used throughout the world to improve nutritional status in people with cystic fibrosis. The methods mostly used, nasogastric or gastrostomy feeding, are expensive and may have a negative effect on self-esteem and body image. Reported use of enteral tube feeding suggests that it results in nutritional and respiratory improvement; but, efficacy has not been fully assessed by randomised controlled trials. It is acknowledged, however, that performing a randomised controlled trial would be difficult due to the ethics of withholding an intervention in a group of people whose nutritional status necessitates it.

Enzyme replacement therapy with laronidase (Aldurazyme®) for treating mucopolysaccharidosis type I.

BACKGROUND: Mucopolysaccharidosis type I can be classified as three clinical sub-types; Hurler syndrome, Hurler-Scheie syndrome and Scheie syndrome, with the scale of severity being such that Hurler syndrome is the most severe and Scheie syndrome the least severe. It is a rare, autosomal recessive disorder caused by a deficiency of alpha-L-iduronidase. Deficiency of this enzyme results in the accumulation of glycosaminoglycans within the tissues. The clinical manifestations are facial dysmorphism, hepatosplenomegaly, upper airway obstruction, skeletal deformity and cardiomyopathy. If Hurler syndrome is left untreated, death ensues by adolescence. There are more attenuated variants termed Hurler-Scheie or Scheie syndrome, with those affected potentially not presenting until adulthood. Enzyme replacement therapy has been used for a number of years in the treatment of Hurler syndrome, although the current gold standard would be a haemopoietic stem cell transplant in those diagnosed by 2.5 years of age. This is an updated version of the original Cochrane Review published in 2013 and previously updated in 2015. OBJECTIVES: To evaluate the effectiveness and safety of treating mucopolysaccharidosis type I with laronidase enzyme replacement therapy as compared to placebo. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Trials Register, MEDLINE via OVID and Embase.Date of most recent search: 30 January 2019. SELECTION CRITERIA: Randomised and quasi-randomised controlled studies of laronidase enzyme replacement therapy compared to placebo. DATA COLLECTION AND ANALYSIS: Two authors independently screened the identified studies. The authors then appraised and extracted data. The quality of the evidence was assessed using GRADE. MAIN RESULTS: One study (45 participants) met the inclusion criteria. This double-blind, placebo-controlled, randomised, multinational study looked at laronidase at a dose of 0.58 mg/kg/week versus placebo in people with mucopolysaccharidosis type I. All primary outcomes listed in this review were studied in this study. The laronidase group achieved statistically significant improvements in per cent predicted forced vital capacity compared to placebo, MD 5.60 (95% confidence intervals 1.24 to 9.96) (low-quality evidence) and in the six-minute-walk test (mean improvement of 38.1 metres in the laronidase group; P = 0.039, when using a prospectively planned analysis of covariance) (low-quality evidence). The levels of urinary glycoaminoglycans were also significantly reduced (low-quality evidence). In addition, there were improvements in hepatomegaly, sleep apnoea and hypopnoea. Laronidase antibodies were detected in nearly all participants in the treatment group with no apparent clinical effect and titres were reducing by the end of the study (very low-quality evidence). Infusion-related adverse reactions occurred in both groups but all were mild and none necessitated medical intervention or infusion cessation (low-quality evidence). As assessed by questionnaires,changes in a 'Disability Index' after treatment were small and did not differ between groups (low-quality evidence). There were no deaths in either group (low-quality evidence). AUTHORS' CONCLUSIONS: The current evidence demonstrates that laronidase is effective when compared to placebo in the treatment of mucopolysaccharidosis type I. The included study was comprehensive, with few participants and of low quality. The study included all of the key outcome measures we wished to look at. It demonstrated that laronidase is efficacious in relation to reducing biochemical parameters (reduced urine glycosaminoglycan excretion) and improved functional capacity as assessed by forced vital capacity and the six-minute-walk test. In addition glycosaminoglycan storage was reduced as ascertained by a reduction in liver volume. Laronidase appeared to be safe and, while antibodies were generated, these titres were reducing by the end of the study. More studies are required to determine long-term effectiveness and safety and to assess the impact upon quality of life. Enzyme replacement therapy with laronidase can be used pre- and peri-haemopoietic stem cell transplant, which is now the gold standard treatment in those individuals diagnosed under 2.5 years of age. We do not anticipate any further trials to be undertaken and therefore do not plan to update this review.

Splenectomy versus conservative management for acute sequestration crises in people with sickle cell disease.

BACKGROUND: Acute splenic sequestration crises are a complication of sickle cell disease, with high mortality rates and frequent recurrence in survivors of first attacks. Splenectomy and blood transfusion, with their consequences, are the mainstay of long-term management used in different parts of the world. This is a 2017 update of a Cochrane Review first published in 2002, and previously updated, most recently in 2015. OBJECTIVES: To assess whether splenectomy (total or partial), to prevent acute splenic sequestration crises in people with sickle cell disease, improved survival and decreased morbidity in people with sickle cell disease, as compared with regular blood transfusions. 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 handsearching relevant journals and abstract books of conference proceedings. We also searched clinical trial registries. Additional trials were sought from the reference lists of the trials and reviews identified by the search strategy.Date of the most recent search: 14 August 2017. SELECTION CRITERIA: All randomized or quasi-randomized controlled trials comparing splenectomy (total or partial) to prevent recurrence of acute splenic sequestration crises with no treatment or blood transfusions in people with sickle cell disease. DATA COLLECTION AND ANALYSIS: No trials of splenectomy for acute splenic sequestration were found. MAIN RESULTS: No trials of splenectomy for acute splenic sequestration were found. AUTHORS' CONCLUSIONS: Splenectomy, if full, will prevent further sequestration and if partial, may reduce the recurrence of acute splenic sequestration crises. However, there is a lack of evidence from trials showing that splenectomy improves survival and decreases morbidity in people with sickle cell disease. There is a need for a well-designed, adequately-powered, randomized controlled trial to assess the benefits and risks of splenectomy compared to transfusion programmes, as a means of improving survival and decreasing mortality from acute splenic sequestration in people with sickle cell disease.There are no trials included in the review and we have not identified any relevant trials up to August 2017. We will continue to run searches to identify any potentially relevant trials; however, we do not plan to update other sections of the review until new trials are published.

Oral anti-pseudomonal antibiotics for cystic fibrosis.

BACKGROUND: Pseudomonas aeruginosa is the most common bacterial pathogen causing lung infections in people with cystic fibrosis and appropriate antibiotic therapy is vital. Antibiotics for pulmonary exacerbations are usually given intravenously, and for long-term treatment, via a nebuliser. Oral anti-pseudomonal antibiotics with the same efficacy and safety as intravenous or nebulised antibiotics would benefit people with cystic fibrosis due to ease of treatment and avoidance of hospitalisation. This is an update of a previous review. OBJECTIVES: To determine the benefit or harm of oral anti-pseudomonal antibiotic therapy for people with cystic fibrosis, colonised with Pseudomonas aeruginosa, in the:1. treatment of a pulmonary exacerbation; and2. long-term treatment of chronic infection. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.We contacted pharmaceutical companies and checked reference lists of identified trials.Date of last search: 08 July 2016. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials comparing any dose of oral anti-pseudomonal antibiotics, to other combinations of inhaled, oral or intravenous antibiotics, or to placebo or usual treatment for pulmonary exacerbations and long-term treatment. DATA COLLECTION AND ANALYSIS: Two authors independently selected the trials, extracted data and assessed quality. We contacted trial authors to obtain missing information. MAIN RESULTS: We included three trials examining pulmonary exacerbations (171 participants) and two trials examining long-term therapy (85 participants). We regarded the most important outcomes as quality of life and lung function. The analysis did not identify any statistically significant difference between oral anti-pseudomonal antibiotics and other treatments for these outcome measures for either pulmonary exacerbations or long-term treatment. One of the included trials reported significantly better lung function when treating a pulmonary exacerbation with ciprofloxacin when compared with intravenous treatment; however, our analysis did not confirm this finding. We found no evidence of difference between oral anti-pseudomonal antibiotics and other treatments regarding adverse events or development of antibiotic resistance, but trials were not adequately powered to detect this. None of the studies had a low risk of bias from blinding which may have an impact particularly on subjective outcomes such as quality of life. The risk of bias for other criteria could not be clearly stated across the studies. AUTHORS' CONCLUSIONS: We found no conclusive evidence that an oral anti-pseudomonal antibiotic regimen is more or less effective than an alternative treatment for either pulmonary exacerbations or long-term treatment of chronic infection with P. aeruginosa. Until results of adequately-powered future trials are available, treatment needs to be selected on a pragmatic basis, based upon any available non-randomised evidence, the clinical circumstances of the individual, the known effectiveness of drugs against local strains and upon individual preference.

Enzyme replacement therapy with laronidase (Aldurazyme(®)) for treating mucopolysaccharidosis type I.

BACKGROUND: Mucopolysaccharidosis type I can be classified as three clinical sub-types; Hurler syndrome, Hurler-Scheie syndrome and Scheie syndrome, with the scale of severity being such that Hurler syndrome is the most severe and Scheie syndrome the least severe. It is a rare, autosomal recessive disorder caused by a deficiency of alpha-L-iduronidase. Deficiency of this enzyme results in the accumulation of glycosaminoglycans within the tissues. The clinical manifestations are facial dysmorphism, hepatosplenomegaly, upper airway obstruction, skeletal deformity and cardiomyopathy. If Hurler syndrome is left untreated, death ensues by adolescence. There are more attenuated variants termed Hurler-Scheie or Scheie syndrome, with those affected potentially not presenting until adulthood. Enzyme replacement therapy has been used for a number of years in the treatment of Hurler syndrome, although the current gold standard would be a haemopoietic stem cell transplant in those diagnosed by 2.5 years of age. This is an updated version of the original Cochrane review published in 2013. OBJECTIVES: To evaluate the effectiveness and safety of treating mucopolysaccharidosis type I with laronidase enzyme replacement therapy as compared to placebo. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Trials Register, MEDLINE via OVID and Embase.Date of most recent search: 05 October 2015. SELECTION CRITERIA: Randomised and quasi-randomised controlled studies of laronidase enzyme replacement therapy compared to placebo. DATA COLLECTION AND ANALYSIS: Two authors independently screened the identified studies. The authors then appraised and extracted data. MAIN RESULTS: One study of 45 patients met the inclusion criteria. This double-blind, placebo-controlled, randomised, multinational study looked at laronidase at a dose of 0.58 mg/kg/week versus placebo in patients with mucopolysaccharidosis type I. All primary outcomes listed in this review were studied in this study. The laronidase group achieved statistically significant improvements in per cent predicted forced vital capacity compared to placebo, MD 5.60 (95% confidence intervals 1.24 to 9.96) and in the six-minute-walk test (mean improvement of 38.1 metres in the laronidase group; P = 0.039, when using a prospectively planned analysis of covariance). The levels of urinary glycoaminoglycans were also significantly reduced. In addition, there were improvements in hepatomegaly, sleep apnoea and hypopnoea. Laronidase antibodies were detected in nearly all patients in the treatment group with no apparent clinical effect and titres were reducing by the end of the study. Infusion-related adverse reactions occurred in both groups but all were mild and none necessitated medical intervention or infusion cessation. AUTHORS' CONCLUSIONS: The current evidence demonstrates that laronidase is effective when compared to placebo in the treatment of mucopolysaccharidosis type I. The included study was comprehensive and of good quality, although there were few participants. The study included all of the key outcome measures we wished to look at. It demonstrated that laronidase is efficacious in relation to reducing biochemical parameters (reduced urine glycosaminoglycan excretion) and improved functional capacity as assessed by forced vital capacity and the six-minute-walk test. In addition glycosaminoglycan storage was reduced as ascertained by a reduction in liver volume. Laronidase appeared to be safe and, while antibodies were generated, these titres were reducing by the end of the study. More studies are required to determine long-term effectiveness and safety and to assess the impact upon quality of life. Enzyme replacement therapy with laronidase can be used pre- and peri-haemopoietic stem cell transplant, which is now the gold standard treatment in those patients diagnosed under 2.5 years of age.

Newborn screening for homocystinuria.

BACKGROUND: Homocystinuria is a rare inherited disorder due to a deficiency in cystathionine beta synthase. Individuals with this condition appear normal at birth but develop serious complications in childhood. Diagnosis and treatment started sufficiently early in life can effectively prevent or reduce the severity of these complications. This is an update of a previously published review. OBJECTIVES: To determine if newborn population screening for the diagnosis of homocystinuria due to cystathionine beta synthase deficiency leads to clinical benefit compared to later clinical diagnosis. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Trials Register.Date of the most recent search of the Inborn Errors of Metabolism Register: 08 June 2015. SELECTION CRITERIA: Randomised controlled trials and controlled clinical trials assessing the use of any neonatal screening test to diagnose infants with homocystinuria before the condition becomes clinically evident. Eligible studies compare a screened population versus a non-screened population. DATA COLLECTION AND ANALYSIS: No studies were identified for inclusion in the review. MAIN RESULTS: No studies were identified for inclusion in the review. AUTHORS' CONCLUSIONS: We were unable to identify eligible studies for inclusion in this review and hence it is not possible to draw any conclusions based on controlled studies; however, we are aware of uncontrolled case-series which support the efficacy of newborn screening for homocystinuria and its early treatment. Any future randomised controlled trial would need to be both multicentre and long term in order to provide robust evidence for or against screening and to allow a cost effectiveness analysis to be undertaken.

Splenectomy versus conservative management for acute sequestration crises in people with sickle cell disease.

BACKGROUND: Acute splenic sequestration crises are a complication of sickle cell disease, with high mortality rates and frequent recurrence in survivors of first attacks. Splenectomy and blood transfusion, with their consequences, are the mainstay of long-term management used in different parts of the world. This is a 2015 update of a Cochrane review first published in 2002, and previously updated in 2013. OBJECTIVES: To assess whether splenectomy (total or partial), to prevent acute splenic sequestration crises in people with sickle cell disease, improved survival and decreased morbidity in people with sickle cell disease, as compared with regular blood transfusions. 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 handsearching relevant journals and abstract books of conference proceedings.Additional trials were sought from the reference lists of the trials and reviews identified by the search strategy.Date of the most recent search: 10 June 2015. SELECTION CRITERIA: All randomized or quasi-randomized controlled trials comparing splenectomy (total or partial) to prevent recurrence of acute splenic sequestration crises with no treatment or blood transfusions in people with sickle cell disease. DATA COLLECTION AND ANALYSIS: No trials of splenectomy for acute splenic sequestration were found. MAIN RESULTS: No trials of splenectomy for acute splenic sequestration were found. AUTHORS' CONCLUSIONS: Splenectomy, if full, will prevent further sequestration and if partial, may reduce the recurrence of acute splenic sequestration crises. However, there is a lack of evidence from trials showing that splenectomy improves survival and decreases morbidity in people with sickle cell disease. There is a need for a well-designed, adequately-powered, randomized controlled trial to assess the benefits and risks of splenectomy compared to transfusion programmes, as a means of improving survival and decreasing mortality from acute splenic sequestration in people with sickle cell disease.There are no trials included in the review and we have not identified any relevant trials up to June 2015. We will continue to run searches to identify any potentially relevant trals; however, we do not plan to update other sections of the review until new trials are published.

Early additional food and fluids for healthy breastfed full-term infants.

BACKGROUND: Widespread recommendations from health organisations encourage exclusive breastfeeding for six months. However, the addition of other fluids or foods before six months is common in many countries and communities. This practice suggests perceived benefits of early supplementation or lack of awareness of the possible risks. OBJECTIVES: To assess the benefits and harms of supplementation for full-term healthy breastfed infants and to examine the timing and type of supplementation. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (21 March 2014) and reference lists of all relevant retrieved papers. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials in infants under six months of age comparing exclusive breastfeeding versus breastfeeding with any additional food or fluids. DATA COLLECTION AND ANALYSIS: Two review authors independently selected the trials, extracted data and assessed risk of bias. MAIN RESULTS: We included eight trials (984 randomised infants/mothers). Six trials (n = 613 analysed) provided data on outcomes of interest to this review. The variation in outcome measures and time points made it difficult to pool results from trials. Data could only be combined in a meta-analysis for one secondary outcome (weight change). The trials that provided outcome data compared exclusively breastfed infants with breastfed infants who were allowed additional nutrients in the form of artificial milk, glucose, water or solid foods.In relation to the majority of the older trials, the description of study methods was inadequate to assess the risk of bias. The two more recent trials, were found to be at low risk of bias for selection and detection bias. The overall quality of the evidence for the main comparison was low.In one trial (170 infants) comparing exclusively breastfeeding infants with infants who were allowed additional glucose water, there was a significant difference favouring exclusive breastfeeding up to and including week 20 (risk ratio (RR) 1.45, 95% confidence interval (CI) 1.05 to 1.99), with more infants in the exclusive breastfed group still exclusively breastfeeding. Conversely in one small trial (39 infants) comparing exclusive breastfed infants with non-exclusive breastfed infants who were provided with artificial milk, fewer infants in the exclusive breastfed group were exclusively breastfeeding at one week (RR 0.58, 95% CI 0.37 to 0.92) and at three months (RR 0.44, 95% CI 0.26 to 0.76) and there was no significant difference in the proportion of infants continuing any breastfeeding at three months between groups (RR 0.76, 95% CI 0.56 to 1.03).For infant morbidity (six trials), one newborn trial (170 infants) found a statistically, but not clinically, significant difference in temperature at 72 hours (mean difference (MD) 0.10 degrees, 95% CI 0.01 to 0.19), and that serum glucose levels were higher in glucose supplemented infants in the first 24 hours, though not at 48 hours (MD -0.24 mmol/L, 95% CI -0.51 to 0.03). Weight loss was also higher (grams) in infants at six, 12, 24 and 48 hours of life in the exclusively breastfed infants compared to those who received additional glucose water (MD 7.00 g, 95% CI 0.76 to 13.24; MD 11.50 g, 95% CI 1.71 to 21.29; MD 13.40 g, 95% CI 0.43 to 26.37; MD 32.50 g, 95% CI 12.91 to 52.09), but no difference between groups was observed at 72 hours of life. In another trial (47 infants analysed), we found no significant difference in weight loss between the exclusively breastfeeding group and the group allowed either water or glucose water on either day three or day five (MD 1.03%, 95% CI -0.18 to 2.24) and (MD 0.20%, 95% CI -1.18 to 1.58).Three trials with four- to six-month-old infants provided no evidence to support any benefit from the addition of complementary foods at four months versus exclusive breastfeeding to six months nor any risks related either morbidity or weight change (or both).None of the trials reported on the remaining primary outcomes, infant mortality or physiological jaundice. AUTHORS' CONCLUSIONS: We were unable to fully assess the benefits or harms of supplementation or to determine the impact from timing and type of supplementation. We found no evidence of benefit to newborn infants and possible negative effects on the duration of breastfeeding from the brief use of additional water or glucose water, and the quality of the evidence from a small pilot study on formula supplementation was insufficient to suggest a change in practice away from exclusive breastfeeding. For infants at four to six months, we found no evidence of benefit from additional foods nor any risks related to morbidity or weight change. Future studies should examine the longer-term effects on infants and mothers, though randomising infants to receive supplements without medical need may be problematic.We found no evidence for disagreement with the recommendation of international health associations that exclusive breastfeeding should be recommended for healthy infants for the first six months.

Finding and filling the gaps in the evidence with high quality clinical trials - the experience of one Cochrane Review Group.

The Cochrane Cystic Fibrosis and Genetic Disorders Group publishes systematic reviews of randomized trials for many genetic disorders. Given the rarity of these disorders, there are often few relevant trials to be included. Therefore, it is common for the reviews to be 'empty' and unable to present evidence which aids decision-making in clinical practice. However, we do not regard this as negative; rather we see this as a challenge and an opportunity to influence the research agenda. We have several reviews which clearly illustrate the cycle of assessing the evidence base, identifying the lack of data, generating high quality research and incorporating the resulting data into the original systematic review.

Oral anti-pseudomonal antibiotics for cystic fibrosis.

BACKGROUND: Pseudomonas aeruginosa is the most common bacterial pathogen causing lung infections in people with CF and appropriate antibiotic therapy is vital. Antibiotics for pulmonary exacerbations are usually given intravenously, and for long-term treatment, via a nebuliser. Oral anti-pseudomonal antibiotics with the same efficacy and safety as intravenous or nebulised antibiotics would benefit people with CF due to ease of treatment and avoidance of hospitalisation. OBJECTIVES: To determine the benefit or harm of oral anti-pseudomonal antibiotic therapy for people with CF, colonised with Pseudomonas aeruginosa, in the:1. treatment of a pulmonary exacerbation; and 2. long-term treatment of chronic infection. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.We contacted pharmaceutical companies and checked reference lists of identified trials.Date of last search: 28 June 2013. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials comparing any dose of oral anti-pseudomonal antibiotics, to other combinations of inhaled, oral or intravenous antibiotics, or to placebo or usual treatment for pulmonary exacerbations and long-term treatment. DATA COLLECTION AND ANALYSIS: Two authors independently selected the trials, extracted data and assessed quality. We contacted trial authors to obtain missing information. MAIN RESULTS: We included three trials examining pulmonary exacerbations (171 participants) and two trials examining long-term therapy (85 participants). We regarded the most important outcomes as quality of life and lung function. The analysis did not identify any statistically significant difference between oral anti-pseudomonal antibiotics and other treatments for these outcome measures for either pulmonary exacerbations or long-term treatment. One of the included trials reported significantly better lung function when treating a pulmonary exacerbation with ciprofloxacin when compared with intravenous treatment; however, our analysis did not confirm this finding. We found no evidence of difference between oral anti-pseudomonal antibiotics and other treatments regarding adverse events or development of antibiotic resistance, but trials were not adequately powered to detect this. None of the studies had a low risk of bias from blinding which may have an impact particularly on subjective outcomes such as quality of life. The risk of bias for other criteria could not be clearly stated across the studies. AUTHORS' CONCLUSIONS: We found no conclusive evidence that an oral anti-pseudomonal antibiotic regimen is more or less effective than an alternative treatment for either pulmonary exacerbations or long-term treatment of chronic infection with P. aeruginosa. Until results of adequately-powered future trials are available, treatment needs to be selected on a pragmatic basis, based upon any available non-RCT evidence, the clinical circumstances of the individual, the known effectiveness of drugs against local strains and upon individual preference.

Newborn screening for homocystinuria.

BACKGROUND: Homocystinuria is a rare inherited disorder due to a deficiency in cystathionine beta synthase. Individuals with this condition appear normal at birth but develop serious complications in childhood. Diagnosis and treatment started sufficiently early in life can effectively prevent or reduce the severity of these complications. OBJECTIVES: To determine if newborn population screening for the diagnosis of homocystinuria due to cystathionine beta synthase deficiency leads to clinical benefit compared to later clinical diagnosis. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Trials Register.Date of the most recent search of the Inborn Errors of Metabolism Register: 15 May 2013. SELECTION CRITERIA: Randomised controlled trials and controlled clinical trials assessing the use of any neonatal screening test to diagnose infants with homocystinuria before the condition becomes clinically evident. Eligible studies compare a screened population versus a non-screened population. DATA COLLECTION AND ANALYSIS: No studies were identified for inclusion in the review. MAIN RESULTS: No studies were identified for inclusion in the review. AUTHORS' CONCLUSIONS: We were unable to identify eligible studies for inclusion in this review and hence it is not possible to draw any conclusions based on controlled studies; however, we are aware of uncontrolled case-series which support the efficacy of newborn screening for homocystinuria and its early treatment. Any future randomised controlled trial would need to be both multicentre and long term in order to provide robust evidence for or against screening and to allow a cost effectiveness analysis to be undertaken.