Improved outcomes using unmanipulated haploidentical hematopoietic stem cells combined with third-party umbilical cord blood transplantation for non-malignant diseases in children: The experience of a single center.

BACKGROUND: Unmanipulated haploid HSCT for SAA has resulted in improved outcomes over recent years. However, studies related to unmanipulated haploid HSCs combined with tp-UCB transplantation for other types of NMD are rare. Accordingly, we present the outcomes of 109 pediatric patients with life-threatening NMD undergoing unmanipulated haploid HSCs combined with tp-UCB transplantation. PROCEDURE: We retrospectively investigated 109 pediatric patients with life-threatening NMD treated with unmanipulated haploid HSCs combined with tp-UCB transplantation in a single center. RESULTS: The median days of neutrophil and platelet engraftment were +13 and +22 days, respectively. None of the cases experienced PGF. The incidence rates for grade I-II, III-IV aGVHD and cGVHD were 44.9%, 24.8%, and 9.3%, respectively. The incidence rates of CMV and EBV viremia were 46.7% and 39.4%, respectively. The median follow-up duration was 997 days. In total, 106 patients survived, including 104 cases with FFS and 2 cases with SGF. Three patients died. The 5-year TRM, OS, and FFS were 2.8%, 97.2%, and 96.2%, respectively. CONCLUSION: The results of unmanipulated haploid HSCs combined with tp-UCB in pediatric patients with life-threatening NMD were promising. However, further research is now needed to determine specific factors that might influence the engraftment of HSCs.

An inducible intestinal epithelial cell-specific NHE3 knockout mouse model mimicking congenital sodium diarrhea.

The sodium-hydrogen exchanger isoform 3 (NHE3, SLC9A3) is abundantly expressed in the gastrointestinal tract and is proposed to play essential roles in Na+ and fluid absorption as well as acid-base homeostasis. Mutations in the SLC9A3 gene can cause congenital sodium diarrhea (CSD). However, understanding the precise role of intestinal NHE3 has been severely hampered due to the lack of a suitable animal model. To navigate this problem and better understand the role of intestinal NHE3, we generated a tamoxifen-inducible intestinal epithelial cell-specific NHE3 knockout mouse model (NHE3IEC-KO). Before tamoxifen administration, the phenotype and blood parameters of NHE3IEC-KO were unremarkable compared with control mice. After tamoxifen administration, NHE3IEC-KO mice have undetectable levels of NHE3 in the intestine. NHE3IEC-KO mice develop watery, alkaline diarrhea in combination with a swollen small intestine, cecum and colon. The persistent diarrhea results in higher fluid intake. After 3 weeks, NHE3IEC-KO mice show a ∼25% mortality rate. The contribution of intestinal NHE3 to acid-base and Na+ homeostasis under normal conditions becomes evident in NHE3IEC-KO mice that have metabolic acidosis, lower blood bicarbonate levels, hyponatremia and hyperkalemia associated with drastically elevated plasma aldosterone levels. These results demonstrate that intestinal NHE3 has a significant contribution to acid-base, Na+ and volume homeostasis, and lack of intestinal NHE3 has consequences on intestinal structural integrity. This mouse model mimics and explains the phenotype of individuals with CSD carrying SLC9A3 mutations.

Clinical report and biochemical analysis of a patient with fumarate hydratase deficiency.

Fumarate hydratase deficiency (FHD) is a rare metabolic disease caused by two defective copies of the FH gene, which encodes the Krebs cycle enzyme fumarase. FHD is associated with brain and developmental abnormalities, seizures, and high childhood mortality. We describe the symptoms and treatment of a patient with FHD. While infantile spasms are common in FHD, the patient presented with epileptic spasms later in childhood. Also unexpectedly, the patient responded excellently to lacosamide for her non-convulsive status epilepticus and epileptic spasms after three first-line medication trials failed. We biochemically analyzed the patient's two fumarase variants (E432Kfs*17 and D65G). While E432Kfs*17 was extremely enzymatically defective, D65G exhibited only a mild defect, possibly playing a role in the patient's longer survival.

Short-term results of continuous venovenous haemodiafiltration versus peritoneal dialysis in 40 neonates with inborn errors of metabolism.

Several recent studies have reported that toxic metabolites accumulated in the body as a product of inborn errors of metabolism (IEM) are eliminated more rapidly with continuous venovenous hemodiafiltration (CVVHDF) than with peritoneal dialysis (PD). However, there is still uncertainty about the impacts of dialysis modalities on the short-term outcome. Here, it was aimed to investigate the effects of dialysis modalities on the short-term outcome. This retrospective study included 40 newborn infants who underwent PD (29 patients) or CVVHDF (11 patients) due to inborn errors of metabolism at a tertiary centre, between June 2013 and March 2018. The outcomes and the potential effects of the dialysis modality were evaluated. Of 40 patients, 21 were urea cycle defect, 14 were organic academia, and 5 were maple syrup urine disease. The median 50% reduction time of toxic metabolites were shorter in patients treated with CVVHDF (p < 0.05). Catheter blockage was the most common complication observed in PD group (24.1%), whereas in CVVHDF group hypotension and filter blockage were more common. There was no significant difference in mortality between dialysis groups (38% vs. 45.4%, p > 0.05). In patients with hyperammonaemia, duration of plasma ammonia > 200 µg/dL was the most important factor influencing mortality (OR 1.05, CI 1.01-1.09, p = 0.007).Conclusion: This study showed that CVVHDF is more efficient than PD to rapidly eliminate toxic metabolites caused by IEM in newborn infants, but not in improving survival. What is Known: •Toxic metabolites are eliminated more rapidly with CVVHDF than with PD. •Higher complication rates were reported with rigid peritoneal catheters in PD and catheter blockage in CVVHDF. What is New: •Prolonged duration of plasma ammonia levels above a safe limit (200 µg/dL) was associated with increased mortality. •Lower catheter-related complication rates may have been associated with the use of Tenckhoff catheters in PD and the use of right internal jugular vein in CVVHDF.

Infant mortality in Brazil attributable to inborn errors of metabolism associated with sudden death: a time-series study (2002-2014).

BACKGROUND: The literature suggests that 0.9 to 6% of infants who die unexpectedly may have had a metabolic disorder. At least 43 different inborn errors of metabolism (IEMs) have been associated with sudden death (SUDI). To date, the frequency of IEM-associated SUDI has not been studied in Brazil. The present study sought to characterize infant mortality related to IEMs known to cause SUDI disaggregated by each of the regions of Brazil. METHODS: This was a descriptive, cross-sectional, population-based study of data obtained from the Brazilian Ministry of Health Mortality Information System (SIM). Death records were obtained for all infants (age < 1 year) who died in Brazil in 2002-2014 in whom the underlying cause of death was listed as ICD-10 codes E70 (Disorders of aromatic amino-acid metabolism), E71 (Disorders of branched-chain amino-acid metabolism and fatty-acid metabolism), E72 (Other disorders of amino-acid metabolism), or E74 (Other disorders of carbohydrate metabolism), which are known to be associated with SUDI. RESULTS: From 2002 to 2014, 199 deaths of infants aged < 1 year were recorded in the SIM with an underlying cause corresponding to one of the IEMs of interest. The prevalence of IEM-related deaths was 0.67 per 10,000 live births (0.58-0.77). Of these 199 deaths, 18 (9.0%) occurred in the North of Brazil, 43 (21.6%) in the Northeast, 80 (40.2%) in the Southeast, 46 (23.1%) in the South, and 12 (6.0%) in the Center-West region. Across all regions of the country, ICD10-E74 was predominant. CONCLUSIONS: This 13-year time-series study provides the first analysis of the number of infant deaths in Brazil attributable to IEMs known to be associated with sudden death.

A retrospective study of small molecule disorder types of metabolism in paediatric patients in intensive care.

BACKGROUND: Although inborn errors of metabolism (IEM) are rare individually, collectively IEM cause substantial morbidity and mortality and the diagnosis is challenging. AIMS: To analyse epidemiological and clinical data, final diagnosis and clinical outcomes of patients with a suspected diagnosis of IEM (small molecule disorders type) admitted to a paediatric intensive care unit (PICU). METHODS: We collected and analysed medical records data of all patients admitted to the PICU at Alexandria University Children's Hospital, from January 2010 to December 2014, with a suspected or confirmed diagnosis of small molecule disorders, including clinical presentations, laboratory results and clinical outcomes. RESULTS: A total of 34 patients had a suspected or confirmed diagnosis of small molecule disorders at PICU admission. Diagnosis was confirmed in 22.7% of suspected cases at admission and in 25% of suspected cases during PICU stay. Consanguineous marriage was found in 50% of cases with confirmed small molecule disorders. CONCLUSIONS: A high index of suspicion is important for diagnosing and categorizing small molecule disorders in screening of high-risk individuals in low- and middle-income countries.

Follow-up of fatty acid ß-oxidation disorders in expanded newborn screening era.

Fatty acid ß-oxidation (FAO) disorders have a wide variety of symptoms, not usually evident between episodes of acute decompensations. Cardiac involvement is frequent, and severe ventricular arrhythmias are suspected of causing sudden death. Expanded newborn screening (ENS) for these disorders, hopefully, contribute to prevent potentially acute life-threatening events. In order to characterize acute decompensations observed in FAO-deficient cases identified by ENS, a retrospective analysis was performed, covering a period of 9 years. Demographic data, number/type of acute decompensations, treatment, and follow-up were considered. Eighty-three clinical charts, including 66 medium-chain acyl-CoA dehydrogenase deficiency (MCADD), 5 carnitine-uptake deficiency (CUD), 3 carnitine palmitoyltransferase I and II (CPT I/II) deficiency, 5 very long-chain acyl-CoA dehydrogenase deficiency (VLCADD), and 4 multiple acyl-CoA dehydrogenase deficiency (MADD) cases were reviewed. Nineteen patients had acute decompensations (1 CPT I, 1 CPT II, 3 MADD, 14 MCADD). Six patients developed symptoms previously to ENS diagnosis. Severe clinical manifestations included multiple organ failure, liver failure, heart failure, and sudden death. Long-chain FAO disorders had the highest number of decompensations per patient.Conclusion: Despite earlier diagnosis by ENS, sudden deaths were not avoided and acute decompensations with severe clinical manifestations still occur as well. What is Known: • Severe ventricular arrhythmias are suspected to cause unexpected death in FAO disorders. • Neonatal screening intends to reduce the incidence of severe metabolic crisis and death. What is New: • Acute severe decompensations occurred in FAO disorders diagnosed through neonatal screening. • Sudden deaths were not avoided by starting treatment precociously.

Auxiliary Partial Orthotopic Liver Transplantation for Selected Noncirrhotic Metabolic Liver Disease.

Auxiliary partial orthotopic liver transplantation (APOLT) in selected noncirrhotic metabolic liver diseases (NCMLDs) is a viable alternative to orthotopic liver transplantation (OLT) as it supplements the function of the native liver with the missing functional protein. APOLT for NCMLD is not universally accepted due to concerns of increased technical complications and longterm graft atrophy. Review of a prospectively collected database of all pediatric patients (age ≤16 years) who underwent liver transplantation for NCMLD from August 2009 up to June 2017 was performed. Patients were divided into 2 groups: group 1 underwent APOLT and group 2 underwent OLT. In total, 18 OLTs and 12 APOLTs were performed for NCMLDs during the study period. There was no significant difference in the age and weight of the recipients in both groups. All APOLT patients needed intraoperative portal flow modulation. Intraoperative peak and end of surgery lactate were significantly higher in the OLT group, and cold ischemia time was longer in the APOLT group. There were no differences in postoperative liver function tests apart from higher peak international normalized ratio in the OLT group. The incidence of postoperative complications, duration of hospital stay, and 1- and 5-year survivals were similar in both groups. In conclusion, we present the largest series of APOLT for NCMLD. APOLT is a safe and effective alternative to OLT and may even be better than OLT due to lesser physiological stress and the smoother postoperative period for selected patients with NCMLD.

Global birth prevalence and mortality from inborn errors of metabolism: a systematic analysis of the evidence.

BACKGROUND: Inborn errors of metabolism (IEM) are a group of over 500 heterogeneous disorders resulting from a defect in functioning of an intermediate metabolic pathway. Individually rare, their cumulative incidence is thought to be high, but it has not yet been estimated globally. Although outcomes can often be good if recognised early, IEM carry a high fatality rate if not diagnosed. As a result, IEM may contribute significantly to the burden of non-communicable childhood morbidity. METHODS: We conducted a systematic literature review of birth prevalence and case fatality of IEM globally, with search dates set from 1980 to 2017. Using random-effects meta-analysis, we estimated birth prevalence of separate classes of IEM and all-cause IEM, split by geographical region. We also estimated levels of parental consanguinity in IEM cases and global case fatality rates and resultant child deaths from all-cause IEM. FINDINGS: 49 studies met our selection criteria. We estimate the global birth prevalence of all-cause IEM to be 50.9 per 100 000 live births (95% confidence intervals (CI) = 43.4-58.4). Regional pooled birth prevalence rates showed the highest rates of IEM to be in the Eastern Mediterranean region (75.7 per 100 000 live births, 95% CI = 50.0-101.4), correlating with a higher observed rate of parental consanguinity in studies from this area. We estimate case fatality rates to be 33% or higher in low- and middle-income countries (LMICs), resulting in a minimum of 23 529 deaths from IEM per year globally (95% CI = 20 382-27 427), accounting for 0.4% of all child deaths worldwide. CONCLUSIONS: IEM represent a significant cause of global child morbidity and mortality, comprising a notable proportion of child deaths currently not delineated in global modelling efforts. Our data highlight the need for policy focus on enhanced laboratory capacity for screening and diagnosis, community interventions to tackle parental consanguinity, and increased awareness and knowledge regarding management of IEM, particularly in LMICs.

Renal replacement therapy in the neonatal intensive care unit.

BACKGROUND: Renal replacement therapy (RRT) is becoming increasingly necessary for supporting critically ill neonates. Few studies have reported the use of RRT in the neonatal intensive care unit (NICU). Therefore, we performed a retrospective study to describe the use of RRT in our NICU and its associated efficacy, complications, and outcomes. METHODS: We identified patients requiring RRT between January 2009 and January 2017. Demographic data, mode of RRT, and associated factors were recorded. Efficacy was calculated as the percentage reduction in the blood urea nitrogen (BUN) or toxic metabolite level after 24 h of RRT. Complications including hypotension, electrolyte disturbance, and technical and catheter-related complications were documented. Measures of clinical outcome included in-hospital survival, presence of neurological sequelae, and chronic kidney disease. The chi-square test and Mann-Whitney U test were used for categorical and continuous variables, respectively. RESULTS: We included 17 neonates in our study. The median gestational age at birth was 37 weeks (32-39 weeks), and the median birth weight was 2.7 kg (1.5-3.6 kg). Twelve neonates, including three with inborn errors of metabolism (IEM), received continuous RRT (CRRT), and five neonates underwent peritoneal dialysis (PD). The percentage reduction in ammonia in neonates with IEM who received CRRT was 87.2% at 24 h. The percentage reductions in BUN in the non-IEM neonates in the CRRT and PD groups were 33.7% and 23.7% at 24 h, respectively. The main complication was electrolyte disturbance including hypokalemia, hypocalcemia, and hypophosphatemia. All neonates with IEM survived, whereas the mortality rates for the non-IEM neonates in the CRRT and PD groups were 78% and 80%, respectively. CONCLUSION: Our study findings reveal RRT to be feasible, even in preterm neonates with low birth weight. CRRT had a higher efficacy level, particularly in neonates with IEM, and the complications encountered were transient and correctable.

Allogeneic hematopoietic stem cell transplantation in congenital disorders: A single-center experience.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the treatment of choice for a variety of congenital disorders. We report the experience of children affected by congenital diseases other than bone marrow failure syndromes who received allo-HSCT over a period of 25 years at G. Gaslini Paediatric Research Institute. HSCTs were performed in 57 children with congenital diseases (25 with congenital immunodeficiencies, 10 with severe combined immunodeficiencies, and 22 with metabolic diseases). Overall survival rate at 3 years in the whole group of patients was 76.9%, with a trend in favor of better outcome in children with metabolic diseases and in those who received cord blood cells (85.9%) vs bone marrow cells (72.4%).

Trends in hematopoietic stem cell transplant activity in Lebanon.

Hematopoietic stem cell transplantation (HSCT) has been accessible to the population residing in Lebanon and surrounding countries since 1997. HSCT programs were developed in two major hospitals in Beirut: American University of Beirut Medical Center (AUBMC) and Makassed General Hospital. Mount Lebanon Hospital initiated an autologous HSCT activity later. Between 2012 and 2016, the HSCT activity in Lebanon reached a total of 897 transplants, among which 303 (33.8%) were allogeneic HSCT and 594 (66.2%) were autologous HSCT. Overall, autologous HSCT activity has remained stable over the past 5years, whereas allogeneic HSCT activity has seen a steep increase between 2012 and 2013 followed by a modest increase later. Haploidentical transplantation has mushroomed and represented almost half of allogeneic HSCT activity in 2016. AUBMC and Makassed General Hospital are members of the European Blood and Marrow Transplantation (EBMT) and East Mediterranean Blood and Marrow Transplantation groups, and AUBMC has been accredited by JACIE (Joint Accreditation Committee - ISCT & EBMT) since 2016. The past 5years have seen an increase in HSCT-related research and publications, mainly from AUBMC. These research activities were predominantly focused on personalized conditioning for allogeneic HSCT and post-transplant maintenance therapy.

Allele-Level HLA Matching Impacts Key Outcomes Following Umbilical Cord Blood Transplantation for Inherited Metabolic Disorders.

Allogeneic hematopoietic stem cell transplantation has demonstrated efficacy for numerous inherited metabolic disorders (IMDs). Umbilical cord blood transplant (UCBT) is increasingly used as a graft source in IMDs, but little is known of the impact of cord blood unit (CBU)/recipient HLA allelic disparity on key outcomes following UCBT for IMD. We reviewed outcomes of 106 consecutive first, single UCBTs for IMD at the University of Minnesota with regard to CBU/recipient HLA allelic matching (HLA-A, -B, -C, and -DRB1). The median age at UCBT was 1 year, and 87 patients (82%) received myeloablative conditioning. Primary diagnoses were Hurler syndrome (41%), cerebral adrenoleukodystrophy (35%), metachromatic leukodystrophy/globoid cell leukodystrophy (9%), and other (16%). The 5-year overall survival (OS) for the entire cohort was 70% (95% confidence interval, 59% to 79%). Rates of severe acute and chronic graft-versus-host disease were low (6% for each). CBU/recipient HLA conventional matching was based on antigen-level matching at HLA-A and -B, and on allele-level matching at HLA-DRB1. Of 46 conventional matched UCBTs, 20 (43%) were mismatched at 1 or more alleles. Of 49 conventional 5/6 UCBTs, 30 (61%) were mismatched at ≥2 alleles and 19 (39%) were mismatched at ≥3 alleles. Within the 6/6 conventional match stratum, comparisons of key outcomes between allele-matched and allele-mismatched UCBT were as follows: 5-year OS, 88% versus 42% (P < .01); 1-year engrafted survival (ES) with ≥90% donor chimerism, 73% versus 60% (P = .33); graft failure, 8% versus 30% (P = .05); and transplantation-related mortality (TRM), 8% versus 30% (P = .04). For patients undergoing conventional 5/6 HLA-matched UCBT, better allelic matching was associated with similar outcomes: 5-year OS, 77% versus 74% (P = .72); 1-year ES, 73% versus 47% (P = .06); graft failure, 17% versus 42% (P = .05); and TRM, 10% versus 16% (P = .54). On multivariable analyses, fewer allele-level mismatches within each conventional match stratum continued to predict more favorable outcomes following UCBT. These data provide evidence that allele-level HLA matching considerations within a conventional HLA match stratum may better predict outcomes of interest after UCBT for IMD. Larger studies are warranted to confirm these findings and explore other allele-level HLA match dynamics.

Haematopoietic stem cell transplantation in inborn errors of metabolism.

PURPOSE OF REVIEW: This review summarizes the main results of haematopoietic stem cell transplantation (HSCT) in selected inborn errors of metabolism (IEMs). RECENT FINDINGS: Early diagnosis and immediate referral to an IEM specialist is of paramount importance to improve clinical outcome: patients who are transplanted early or in their presymptomatic phase generally achieve better correction of their somatic symptoms and neurocognitive development. Long-term outcome in children with Hurler syndrome is influenced by age at HSCT, baseline clinical status and post-HSCT enzyme levels. Myeloablative Busulfan-based conditioning regimens with therapeutic drug monitoring are recommended to achieve full donor engraftment and more robust enzyme delivery after HSCT. Gene therapy can lead to production of supranormal enzyme levels, and preliminary clinical results are also promising in IEMs historically not responsive to allogeneic HSCT. SUMMARY: Allogeneic HSCT has largely contributed to the improved survival and quality of life of many children affected by IEMs. Neonatal screening could enable earlier HSCT, and this might significantly reduce residual disease burden and improve clinical outcome. Novel strategies, such as gene therapy, have shown encouraging clinical results in selected IEMs and might become more widely available in the future, with potentially better enzyme delivery and reduced transplant-related toxicity.

Fluid overload and outcomes in neonates receiving continuous renal replacement therapy.

BACKGROUND: Continuous renal replacement therapy (CRRT) has emerged as the modality of choice for the management of high-risk neonates with acute kidney injury (AKI), inborn errors of metabolism and multi-organ dysfunction. The aim of this study was to evaluate fluid overload (FO) and investigate the factors associated with outcomes in neonates undergoing CRRT. METHODS: We retrospectively reviewed the medical records of 34 neonates with AKI who were admitted to the neonatal intensive care unit (NICU) of Samsung Medical Center, Seoul, Republic of Korea between January 2007 and December 2014 where they underwent at least 24 h of CRRT. RESULTS: The survival rates of patients with an FO of ≥30 % at the time of CRRT initiation were lower than those of patients with an FO of <30 % at the same time-point. Univariate Cox regression analysis revealed that a higher percentage FO at CRRT initiation and decreased urine output at the end of CRRT were associated with mortality, and multivariate Cox regression analysis indicated that mortality was associated with decreased urine output at the end of CRRT. Univariate linear regression analysis revealed that the length of hospital stay was associated with higher levels of serum creatinine at CRRT initiation, longer stay in the NICU prior to initiation of CRRT, longer duration of CRRT and lower body weight at the time of NICU admission. CONCLUSIONS: Neonates with a higher percentage FO and higher levels of serum creatinine at CRRT initiation showed poor outcomes. Early initiation of CRRT before the development of severe FO or azotemia might improve the outcomes of neonates requiring CRRT.

Respiratory manifestations in patients with inherited metabolic diseases.

Growing evidence indicates that inherited metabolic diseases are increasingly being recognised. Life expectancy for many patients is progressively improving because new therapeutic strategies are available. Because most inherited metabolic diseases are systemic disorders, virtually all organs may be involved. Respiratory disease complicates the management of several inherited metabolic diseases, either at presentation or as late-onset features. This review will describe the most exemplary respiratory manifestations of inherited metabolic diseases in childhood and adulthood. Since airways disease worsens the morbidity of many inherited metabolic disorders, leading to increased hospitalisations, mortality and overall healthcare costs, respiratory manifestations of inherited metabolic diseases need to be carefully recognised and treated. All patients with inherited metabolic disease and suspected airway disease should undergo a detailed diagnostic work-up. Current treatments for several inherited metabolic diseases (including enzyme replacement therapy, substrate reduction, bone marrow transplantation, or even more innovative strategies such as pharmacological chaperone or gene therapies) may provide significant benefits for associated respiratory disease. The integration of several specialists dedicated to airway disease management in a multidisciplinary team is essential to provide the most appropriate care to children and adults with inherited metabolic disease.

Acute liver failure in under two year-olds--are there markers of metabolic disease on admission?

INTRODUCTION: The early establishment of an etiology for acute liver failure (ALF) in infants is essential for the start of adequate treatment in the shortest timeframe possible. AIM: To identify markers of inherited metabolic disease on admission in children under two years of age with ALF. MATERIAL AND METHODS: A retrospective review of the medical records of all children (< 2 years old) with ALF admitted to the pediatric hepatology or intensive care units of a tertiary center over a twenty-three year period (January 1989 to December 2011) was done. Patients were divided into two groups: with (group A) or without (group B) a metabolic etiology. Clinical and laboratory parameters on admission were compared. RESULTS: Twenty-three children met inclusion criteria. Twelve had ALF of metabolic origin (group A). The median age in this group was 2.25 (Q1-Q3: 0.63-4.65) months and in group B 8.0 (Q1-Q3: 1.5-15) months. History of failure to thrive and/or vomiting was more frequent in group A (p = 0.022). Age, gender, encephalopathy and left ventricular hypertrophy were similar in both groups (p = 0.147, p = 1.000, p = 0.637, p = 1.000, respectively). Laboratory tests on admission (plasma lactate, ammonia, cholesterol, phosphate, INR, glucose, bilirubin, ALT, base excess and the presence of reducing substances in urine) showed no statistically significant differences between groups. CONCLUSION: This study showed that although infants with inborn errors of metabolism showed a trend towards lower age at presentation, the only marker of inherited metabolic disease found on admission was history of vomiting and/or failure to thrive.

Risk stratification at diagnosis for children with hypertrophic cardiomyopathy: an analysis of data from the Pediatric Cardiomyopathy Registry.

BACKGROUND: Treatment of children with hypertrophic cardiomyopathy might be improved if the risk of death or heart transplantation could be predicted by risk factors present at the time of diagnosis. METHODS: We analysed data from the Pediatric Cardiomyopathy Registry, which collected longitudinal data for 1085 children with hypertrophic cardiomyopathy from 1990 to 2009. Our goal was to understand how patient factors measured at diagnosis predicted the subsequent risk of the primary outcome of death or heart transplantation. The Kaplan-Meier method was used to calculate time-to-event rates from time of diagnosis to the earlier of heart transplantation or death for children in each subgroup. Cox proportional-hazards regression was used to identify univariable and multivariable predictors of death or heart transplantation within each causal subgroup. FINDINGS: The poorest outcomes were recorded for the 69 children with pure hypertrophic cardiomyopathy with inborn errors of metabolism, for whom the estimated rate of death or heart transplantation was 57% (95% CI 44-69) at 2 years. Children with mixed functional phenotypes also did poorly, with rates of death or heart transplantation of 45% (95% CI 32-58) at 2 years for the 69 children with mixed hypertrophic and dilated cardiomyopathy and 38% (95% CI 25-51) at 2 years for the 58 children with mixed hypertrophic and restrictive cardiomyopathy. For children diagnosed with hypertrophic cardiomyopathy at younger than 1 year, the rate of death or transplantation was 21% (95% CI 16-27) at 2 years. For children diagnosed with hypertrophic cardiomyopathy and a malformation syndrome, the rate of death or transplantation was 23% (95% CI 12-34) at 2 years. Excellent outcomes were reported for the 407 children who were diagnosed with idiopathic hypertrophic cardiomyopathy at age 1 year or older, with a rate of death or heart transplantation of 3% (95% CI 1-5) at 2 years. The risk factors for poor outcomes varied according to hypertrophic cardiomyopathy subgroup, but they generally included young age, low weight, presence of congestive heart failure, lower left ventricular fractional shortening, or higher left ventricular end-diastolic posterior wall thickness or end-diastolic ventricular septal thickness at the time of cardiomyopathy diagnosis. For all hypertrophic cardiomyopathy subgroups, the risk of death or heart transplantation was significantly increased when two or more risk factors were present and also as the number of risk factors increased. INTERPRETATION: In children with hypertrophic cardiomyopathy, the risk of death or heart transplantation was greatest for those who presented as infants or with inborn errors of metabolism or with mixed hypertrophic and dilated or restrictive cardiomyopathy. Risk stratification by subgroup of cardiomyopathy, by characteristics such as low weight, congestive heart failure, or abnormal echocardiographic findings, and by the presence of multiple risk factors allows for more informed clinical decision making and prognosis at the time of diagnosis. FUNDING: US National Institutes of Health and Children's Cardiomyopathy Foundation.