Metabolic Decompensation Research Articles

Neurodegenerative biomarkers and inflammation in patients with propionic and methylmalonic acidemias: effect of L-carnitine treatment.

Propionic and methylmalonic acidemias (PAcidemia and MMAcidemia, respectively) are genetic disorders characterized by acute metabolic decompensation and neurological complications. L-carnitine (LC) is effective in reducing toxic metabolites that are related to the pathophysiology of these diseases. Therefore we investigated biomarkers of inflammation (cytokines and C-reactive protein (CRP)), neurodegeneration (BDNF, NCAM-1 and cathepsin-D) and biomolecules oxidation (sulfhydryl content and thiobarbituric acid-reactive species (TBARS)), as well as carnitine concentrations in untreated patients with PAcidemia and MMAcidemia, in patients under treatment with LC and a protein-restricted diet for until 2 years and in patients under the same treatment for more than 2 years. It was verified an increase of CRP, IL-6, IL-8, TNF-α, IL-10, NCAM-1 and cathepsin-D in untreated patients compared to controls. On the other hand, reduced levels of TNF-α, CRP, IL-10, NCAM-1 and cathepsin-D were found in plasma from treated patients, as well as increased concentrations of LC. Furthermore, oxidative biomarkers were increased in untreated patients and were normalized with the prolonged treatment with LC. In conclusion, this work shows, for the first time, that inflammatory and neurodegenerative peripheral biomarkers are increased in patients with PAcidemia and MMAcidemia and that treatment with LC is effective to protect against these alterations.

Metabolic management of a successful pregnancy and postpartum complications in fructose-1,6-bisphosphatase deficiency.

Fructose-1,6-bisphosphatase (FBPase) deficiency is a rare, inborn error of metabolism, that causes hypoglycemia and lactic acidosis in response to inadequate glucose intake and/or high intakes of fructose, sucrose, or sorbitol. Pregnancy in women with FBPase deficiency puts them at high risk for metabolic decompensation due to increased glucose demands from the growing fetus. Here we report a 31-year-old primipara who was treated starting at 14 weeks gestation with a diet high in complex carbohydrates and low in fructose, sucrose, and sorbitol and close monitoring of glucose levels throughout her pregnancy. She delivered a healthy 2860 g baby at 37 weeks via vaginal delivery with no complications or hypoglycemia. At 5 months postpartum and 5 months of life, the patient and baby are doing well, although the patient experienced an episode of hypoglycemia and lactic acidosis at 4 months postpartum due to the increased metabolic demands of breastfeeding. This report adds to the limited case reports that discuss outcomes and proposed interventions during pregnancy in individuals with FBPase deficiency.

Triheptanoin in patients with long-chain fatty acid oxidation disorders: clinical experience in Italy

BackgroundLong-chain fatty acid oxidation disorders (LC-FAOD) are rare and potentially life-threatening diseases that cause deficient energy production and accumulation of toxic metabolites. Despite dietary management, adherence to maximum fasting guidelines, restricted long-chain triglyceride intake and supplementation with medium-chain triglyceride (MCT) oil (current standard of care), most patients experience recurrent decompensation episodes that can require hospitalisation. Herein, we analysed the effectiveness and safety of triheptanoin (a highly purified, synthetic medium odd-chain triglyceride) treatment in a cohort of Italian patients with LC-FAOD.MethodsThis retrospective, nationwide study included nine patients with LC-FAOD who switched from standard therapy with MCT oil to triheptanoin oral liquid. Data were collected between 2018 and 2022. Clinical outcome measures were the number and duration of intercurrent catabolic episodes and number and duration of metabolic decompensation episodes requiring hospitalisation. Creatine kinase (CK) levels and treatment-related adverse effects were also reported.ResultsPatients were provided a mean ± standard deviation (SD) triheptanoin dose of 1.5 ± 0.9 g/kg/day in four divided administrations, which accounted for 23.9 ± 8.9% of patients’ total daily caloric intake. Triheptanoin treatment was started between 2.7 and 16 years of age and was continued for 2.2 ± 0.9 years. The number of intercurrent catabolic episodes during triheptanoin treatment was significantly lower than during MCT therapy (4.3 ± 5.3 vs 22.0 ± 22.2; p = 0.034), as were the number of metabolic decompensations requiring hospitalisation (mean ± SD: 2.0 ± 2.5 vs 18.3 ± 17.7; p = 0.014), and annualised hospitalisation rates and duration. Mean CK levels (outside metabolic decompensation episodes) were lower with triheptanoin treatment versus MCT oil for seven patients. No intensive care unit admissions were required during triheptanoin treatment. Epigastric pain and diarrhoea were recorded as adverse effects during both MCT and triheptanoin treatment.ConclusionsThe significant improvement in clinical outcome measures after the administration of triheptanoin highlights that this treatment approach can be more effective than MCT supplementation in patients with LC-FAOD. Triheptanoin was well tolerated and decreased the number of intercurrent catabolic episodes, metabolic decompensation episodes requiring hospitalisation, and the annualised rate and duration of hospitalisations.

12355 An Adolescent Female With Congenital Lipodystrophy Presenting With Repeated Acute Metabolic Decompensations Rescued By A Novel Leptin Receptor Agonist

Abstract Disclosure: D.M. Chambers: None. Y. Chan: None. M.K. Crocker: None. Patient SH is a now 17-year-old female treated for generalized congenital lipodystrophy with a course complicated by severe hypertriglyceridemia, type 2 diabetes mellitus, hypertension, hepatosteatosis, and intermittent menstrual irregularity. She had been managed successfully with metreleptin for 2 years, but in 2022-2023, she developed repeated episodes of pancreatitis (4 times over a 14-month period) secondary to severe hypertriglyceridemia (serum triglycerides >8000 mg/dL). During her admissions, she had markedly increased insulin requirements (up to 12 units/kg/day) with refractory hyperglycemia despite maximal treatment with metreleptin, empagliflozin, and oral semaglutide. In the clinical context of her acute metabolic worsening, she was suspected of having a neutralizing antibody against metreleptin. Serum leptin was undetectable 1 hour after observed metreleptin doses; direct measurement of neutralizing antibodies is pending. She was transitioned from metreleptin to mibavademab, an investigational leptin receptor agonist, on an expanded use IND. She subsequently experienced significant improvements in her fasting triglyceride levels (<300 mg/dL) with no subsequent episodes of pancreatitis since starting therapy in August 2023. She has also had improvements in other aspects of her metabolic health including decreased insulin requirements with decreasing hemoglobin A1c, decreased need for adjunctive lipid and hypertension therapy, and improving menstrual regularity. Her clinical course demonstrates: 1) clinical indicators of a rare but serious loss of efficacy of metreleptin therapy; 2) adjunctive options for management of generalized lipodystrophy; and, 3) an individual experience with a novel leptin agonist therapy in the treatment of generalized lipodystrophy. Presentation: 6/3/2024

Evidence That Long-Term Treatment Prevents Tissue Oxidative Damage in Patients With Inherited Disorders of the Propionate Pathway.

Propionic and methylmalonic acidemias (PAcidemia and MMAcidemia, respectively) are genetic disorders clinically characterized by metabolic decompensation associated with life-threatening encephalopathic episodes in the neonatal period. Adequate and rapid therapeutic management is essential for patients' survival and prognosis. In this study, a restricted protein diet associated with L-carnitine (LC) supplementation was shown to decrease mortality and morbidity in patients affected by these disorders probably by decreasing the accumulation of the major metabolites and therefore their toxicity. Since oxidative stress was proposed as a contributing mechanism of tissue damage in PAcidemia and MMAcidemia and LC has potent antioxidant properties, our objective in this work was to investigate the effects of a long-term therapy consisting of reduced protein intake associated with LC supplementation on oxidative damage markers in patients affected by these diseases. We measured urinary isoprostanes, di-tyrosine, and oxidized guanine species, which reflect oxidative damage to lipids, proteins, and DNA/RNA, respectively, as well as the concentrations of NO products (nitrate plus nitrite) in patients untreated or submitted to short-term or a long-term treatment. Results revealed significant increases of isoprostanes, di-tyrosine, and oxidized guanine species, as well as a moderate nonsignificant increase of NO levels in the untreated patients, relatively to controls. Furthermore, these altered markers were attenuated after short-term treatment and normalized after prolonged treatment. In conclusion, data from this work show for the first time that long-standing treatment of patients with disorders of the propionate pathway can protect against oxidative damage. However, it remains to be elucidated whether oxidative stress identified in this study directly correlates with the clinical conditions of the affected patients.

Standardized emergency protocols to improve the management of patients with suspected or confirmed inherited metabolic disorders (IMDs): An initiative of the French IMDs Healthcare Network for Rare Diseases

ObjectivesPatients with inherited metabolic disorders (IMDs) may require emergency hospital care to prevent life-threatening situations such as metabolic decompensation. To date, over one thousand different rare IMDs have been identified, which means that healthcare professionals (HCPs) initiating emergency treatment may not be familiar with these conditions. The objective of this initiative was to provide HCPs with practical guidance for the acute management of children and adults with IMDs who need emergency care, regardless of the underlying reason. MethodsWe outline how a multidisciplinary working group from the French IMDs Healthcare Network for Rare Diseases, known as G2M, has created concise and standardized protocols _each consisting of a single double-sided A4 sheet _ focused on a specific disease, a group of diseases, or a particular symptom. Prior to validation, these protocols were reviewed by all French reference and competence centres for IMDs, as well as by medical experts from other specialities when necessary, physicians from emergency and intensive care units, and representatives from patient associations. Results and conclusionIn total, 51 emergency protocols containing essential information have been developed and provided to affected patients. All the emergency protocols are freely available in both French and English at https://www.filiere-g2m.fr/urgences. These standardized protocols aim to enhance the emergency care of patients without delay, while also assisting HCPs by increasing their confidence and efficiency, minimizing the risk of dosage errors when administering specialized treatments, saving time, and reducing the number of phone calls to metabolic medicine specialists on night duty. The protocols are scheduled for annual review to facilitate further improvements based on feedback from HCPs and patients, as well as to accommodate any changes in management practices as they evolve.

Presepsin Levels in Infection-Free Subjects with Diabetes Mellitus: An Exploratory Study.

Systemic inflammation has been recognized as the cause and consequence of metabolic dysregulation in diabetes mellitus (DM). Presepsin has recently emerged as a promising biomarker for the detection of bacterial infections and sepsis. There is evidence that gut dysbiosis results in the increased circulating concentrations of Gram-negative bacteria lipopolysaccharide, the linkage of presepsin, which in turn promotes insulin resistance and correlates with the risk of diabetic complications. Thus, we hypothesized that presepsin could reflect the magnitude of systemic inflammation and metabolic decompensation in patients with DM even in the absence of infection. In this cross-sectional pilot study, we included 75 infection-free individuals with well-controlled (n = 19) and uncontrolled (n = 23) type 2 diabetes (T2D), well-controlled (n = 10) and uncontrolled (n = 10) type 1 diabetes (T1D), and normoglycemic controls (n = 13). Presepsin levels were compared between the groups and potential associations with demographic, clinical, and laboratory parameters were explored. We observed that the duration of DM was associated with presepsin values (p = 0.008). When the participants were classified into the type of DM groups, the presepsin levels were found to be lower in the patients with T2D compared to those with T1D (p = 0.008). However, significance in that case was driven by the difference between the well-controlled groups. After adjusting for the effects of DM duration, presepsin was significantly lower in the well-controlled T2D group compared to the well-controlled T1D group [1.34 (2.02) vs. 2.22 (4.20) ng/mL, p = 0.01]. Furthermore, we adjusted our findings for various confounders, including age, body mass index, and waist circumference, and found that the difference in the presepsin values between the adequately controlled groups remained significant (p = 0.048). In conclusion, our findings suggest that presepsin could potentially serve as a surrogate marker of inflammation and metabolic control in people with DM.

Parental and child's psychosocial and financial burden living with an inherited metabolic disease identified by newborn screening.

Newborn screening (NBS) is one of the most effective measures of secondary prevention. While the benefit of NBS on the clinical long-term outcomes of children with inherited metabolic diseases (IMD) has been demonstrated, the potential burden of families living with an early diagnosed and treated child with an IMD has not been thoroughly investigated. The aim of this longitudinal questionnaire-based study on 369 families living with a child with an IMD was to investigate the psychosocial and financial burden following a true-positive NBS. The reported psychosocial burden differed between children and their parents, and was associated with the child's age, diagnosis, and treatment. At younger ages, parent-reported burden was higher for the parents than for the individual child, while it increased for children and decreased for parents as the child grew older. Furthermore, psychosocial burden increased if the child required a strict dietary treatment and was at risk of metabolic decompensation. Regardless of diagnosis and treatment, the developmental delay of their child independently increased the parental psychosocial burden. Financial burden was reported by 24% of all families, and was higher in low-income families and in families whose children required dietary treatment. In conclusion, a substantial psychosocial and financial burden was revealed for children and their families after true-positive NBS. Since this burden is likely to have a negative impact on the long-term individual health benefits of NBS, this study underlines the importance of regularly assessing the psychosocial and financial needs of these families.

Severity-adjusted evaluation of initial dialysis on short-term health outcomes in urea cycle disorders

ObjectiveIn individuals with urea cycle disorders (UCDs) and neonatal disease onset, extracorporeal detoxification by continuous kidney replacement therapy is considered the therapeutic method of choice in addition to metabolic emergency treatment to resolve hyperammonemic decompensation. However, the indications for the initiation of dialysis are heterogeneously implemented transnationally, thereby hampering our understanding of (optimal) short-term health outcomes. MethodsWe performed a retrospective comparative analysis evaluating the therapeutic effects of initial dialysis on survival as well as neurocognitive outcome parameters in individuals with UCDs in comparison to a severity-adjusted non-dialyzed control cohort. Overall, 108 individuals with a severe phenotype of male ornithine transcarbamylase deficiency (mOTC-D), citrullinemia type 1 (CTLN1) and argininosuccinic aciduria (ASA) were investigated by stratification based on a recently established and validated genotype-specific disease prediction model. ResultsMortality is associated with the height of initial peak plasma ammonium concentration, but appears to be independent from treatment with initial dialysis in mOTC-D. However, improved survival after initial dialysis was observed in CTLN1, while there was a trend towards improved survival in ASA. In survivors, annual frequency of (subsequent) metabolic decompensations did not differ between the dialyzed and non-dialyzed cohorts. Moreover, treatment with initial dialysis was not associated with improved neurocognitive outcomes. InterpretationThe present severity-adjusted comparative analysis reveals that general practice of initial dialysis is neither associated with improved survival in individuals with mOTC-D nor does it differ with regard to the neurocognitive outcome for the investigated UCD subtypes. However, initial dialysis might potentially prove beneficial for survival in CTLN1 and ASA.Clinical trial registration: The UCDC database is recorded at the US National Library of Medicine (https://clinicaltrials.gov).

Acute Metabolic Decompensation of Isovaleric Acidemia Presenting as Persistent Metabolic Acidosis in a Middle-Aged Man: A Case Report

Acute Metabolic Decompensation of Isovaleric Acidemia Presenting as Persistent Metabolic Acidosis in a Middle-Aged Man: A Case Report

Nutritional Management of Patients with Fatty Acid Oxidation Disorders.

Treatment of fatty acid oxidation disorders is based on dietary, pharmacological and metabolic decompensation measures. It is essential to provide the patient with sufficient glucose to prevent lipolysis and to avoid the use of fatty acids as fuel as far as possible. Dietary management consists of preventing periods of fasting and restricting fat intake by increasing carbohydrate intake, while maintaining an adequate and uninterrupted caloric intake. In long-chain deficits, long-chain triglyceride restriction should be 10% of total energy, with linoleic acid and linolenic acid intake of 3-4% and 0.5-1% (5/1-10/1 ratio), with medium-chain triglyceride supplementation at 10-25% of total energy (total MCT+LCT ratio = 20-35%). Trihepatnoin is a new therapeutic option with a good safety and efficacy profile. Patients at risk of rhabdomyolysis should ingest MCT or carbohydrates or a combination of both 20 min before exercise. In medium- and short-chain deficits, dietary modifications are not advised (except during exacerbations), with MCT contraindicated and slow sugars recommended 20 min before any significant physical exertion. Parents should be alerted to the need to increase the amount and frequency of carbohydrate intake in stressful situations. The main measure in emergency hospital treatment is the administration of IV glucose. The use of carnitine remains controversial and new therapeutic options are under investigation.

Long-Term Outcomes of Living Donor Liver Transplantation for Methylmalonic Acidemia.

Despite early diagnosis and medical interventions, patients with methylmalonic acidemia (MMA) suffer from multi-organ damage and recurrent metabolic decompensations. We conducted the largest retrospective multi-center cohort study so far, involving five transplant centers (NCCHD, KUH, KUHP, ATAK, and EMC), and identified all MMA patients (n = 38) undergoing LDLT in the past two decades. Our primary outcome was patient survival, and secondary outcomes included death-censored graft survival and posttransplant complications. The overall 10-year patient survival and death-censored graft survival rates were 92% and 97%, respectively. Patients who underwent LDLT within 2 years of MMA onset showed significantly higher 10-year patient survival compared to those with an interval more than 2 years (100% vs. 81%, p = 0.038), although the death-censored graft survival were not statistically different (100% vs. 93%, p = 0.22). Over the long-term follow-up, 14 patients (37%) experienced intellectual disability, while two patients developed neurological complications, three patients experienced renal dysfunction, and one patient had biliary anastomotic stricture. The MMA level significantly decreased from 2218.5 mmol/L preoperative to 307.5 mmol/L postoperative (p = 0.038). LDLT achieves favorable long-term patient and graft survival outcomes for MMA patients. While not resulting in complete cure, our findings support the consideration of early LDLT within 2 years of disease onset. This approach holds the potential to mitigate recurrent metabolic decompensations, and preserve the long-term renal function.

Ethical aspects in the prevention of insulin-dependent diabetes mellitus

Insulin-dependent diabetes mellitus (IDDM) seems to be on the rise today, especially in northern European populations. IDDM is a disease that leads to numerous complications (e.g., metabolic decompensation, macroangiopathy, microangiopathy, retinopathy, nephropathy etc.) and requires the individual to be on daily insulin administration, for life.

Sodium-Dependent Glucose Transporter Type 2 Inhibitors as a Breakthrough in Neutropenia and Neutrophil Dysfunction Management in Patients with Glycogen Storage Disease Type Ib

Glycogen storage disease type Ib (GSD Ib) is a rare and extremely severe disease included in the group of hereditary carbohydrate metabolism disorders. The condition is caused by pathogenic variants in the SLC37A4 gene leading to glucose metabolic disorder in the liver and kidneys, and as a result to severe organomegaly, hypoglycemia, and metabolic decompensation. Moreover, neutropenia and neutrophil dysfunction are noted in patients with GSD Ib. The use of granulocyte colony stimulating factor only increases the number of dysfunctional neutrophils without affecting their functional activity, what determines the inefficacy of such treatment. In recent years, the mechanism of neutropenia in GSD Ib has been clarified, so new therapeutic agents for its relief have been created. This article presents the overview of data on the successful results of renal sodium-glucose cotransporter type 2 inhibitors (gliflozins) usage in patients with GSD Ib.

LEUCINOSIS IN THE PRACTICE OF A NEONATOLOGIST (clinical case)

Background. Leucinosis ("maple syrup urine disease ") is a hereditary disease with an autosomal recessive type of inheritance, the basis of which is a violation of the metabolism of organic amino acids. The disease is characterized by the development of a life-threatening condition, accompanied by developmental delay, suppression of neuro-reflex excitability, a specific smell of urine (the smell of "maple syrup"), ketoacidosis, hypoglycemia. There are five clinical phenotypes of leucinosis: classic, intermediate, intermittent, E3-deficient, and thiamine-sensitive. Aim: To expand the knowledge of pediatricians and neonatologists regarding the clinical and paraclinical features of the course of leucinosis. Materials and methods. The article presents a clinical case of clinical-paraclinical and molecular-genetic features of the course of leucinosis with manifestation in the neonatal period. Description of a clinical case. Boy I., from the third pregnancy, which occurred against the background of anemia of the 1st century and chronic pyelonephritis. The first pregnancy ended with the birth of a boy who died at the age of 2 months due to the manifestations of neonatal dehydration and convulsive syndrome (14 years ago); second pregnancy - miscarriage at 6 weeks of pregnancy. From the 5th day of life, the child's restlessness, refusal to eat, weak sucking and weight loss were noted. During the 7-8th day of life, the child had an expiratory moan. On the 9th day, tonic convulsions appeared. During the stay at the NICU, a positive result of neonatal screening for leucine was obtained twice. According to the results of the conducted molecular genetic research, a mutation of the BCKDHA gene, namely the variant c.632C>T (p.Thr 211 Met) was found in a homozygous state, which confirmed the diagnosis of type Ia leucinosis. Conclusion. The presented clinical case demonstrates that leucinosis is a disease that manifests non-specific and multisystem lesions, is difficult to diagnose and, in the case of untimely started specific treatment, rapidly progresses in the neonatal age and can lead to the development of metabolic decompensation and end in death.

8-OR: Longitudinal Patterns of Heterogeneity in Metabolic Decompensation among Diabetes Prevention Program Outcomes Study (DPPOS) Participants over 20 Years

8-OR: Longitudinal Patterns of Heterogeneity in Metabolic Decompensation among Diabetes Prevention Program Outcomes Study (DPPOS) Participants over 20 Years

Interim analyses of a first-in-human phase 1/2 mRNA trial for propionic acidaemia

Propionic acidaemia is a rare disorder caused by defects in the propionyl-coenzyme A carboxylase α or β (PCCA or PCCB) subunits that leads to an accumulation of toxic metabolites and to recurrent, life-threatening metabolic decompensation events. Here we report interim analyses of a first-in-human, phase 1/2, open-label, dose-optimization study and an extension study evaluating the safety and efficacy of mRNA-3927, a dual mRNA therapy encoding PCCA and PCCB. As of 31 May 2023, 16 participants were enrolled across 5 dose cohorts. Twelve of the 16 participants completed the dose-optimization study and enrolled in the extension study. A total of 346 intravenous doses of mRNA-3927 were administered over a total of 15.69 person-years of treatment. No dose-limiting toxicities occurred. Treatment-emergent adverse events were reported in 15 out of the 16 (93.8%) participants. Preliminary analysis suggests an increase in the exposure to mRNA-3927 with dose escalation, and a 70% reduction in the risk of metabolic decompensation events among 8 participants who reported them in the 12-month pretreatment period.

Expanded Newborn Screening for Inborn Errors of Metabolism in Hong Kong: Results and Outcome of a 7 Year Journey.

Newborn screening (NBS) is an important public health program that aims to identify pre-symptomatic healthy babies that will develop significant disease if left undiagnosed and untreated. The number of conditions being screened globally is expanding rapidly in parallel with advances in technology, diagnosis, and treatment availability for these conditions. In Hong Kong, NBS for inborn errors of metabolism (NBSIEM) began as a pilot program in October 2015 and was implemented to all birthing hospitals within the public healthcare system in phases, with completion in October 2020. The number of conditions screened for increased from 21 to 24 in April 2016 and then to 26 in October 2019. The overall recruitment rate of the NBS program was 99.5%. In the period between October 2015 and December 2022, 125,688 newborns were screened and 295 were referred back for abnormal results. The recall rate was reduced from 0.26% to 0.12% after the implementation of second-tier testing. An inherited metabolic disorder (IMD) was eventually confirmed in 47 infants, making the prevalence of IMD in Hong Kong 1 in 2674. At the time of the NBS result, 78.7% of the newborns with IMD were asymptomatic. There were two deaths reported: one newborn with methylmalonic acidemia cobalamin B type (MMACblB) died after the initial crisis and another case of carnitine palmitoyltransferase II deficiency (CPTII) died at 18 months of age after metabolic decompensation. The most common IMD noted were disorders of fatty acid oxidation metabolism (40%, 19 cases), closely followed by disorders of amino acid metabolism (38%, 18 cases), with carnitine uptake defect (19.1%, 9 cases) and citrullinemia type II (17%, 8 cases) being the two most common IMD picked up by the NBSIEM in Hong Kong. Out of the all the IMDs identified, 19.1% belonged to diverse ethnic groups. False negative cases were reported for citrullinemia type II and congenital adrenal hyperplasia during this period.

Acute fatal ventricular arrhythmia induced by severe hyperkalemia in a toddler with decompensated methylmalonic acidemia

BackgroundMethylmalonic acidemia is a very rare genetic metabolic disease. Patients with isolated methylmalonic acidemia typically present with acute alterations of consciousness, failure to thrive, anorexia, vomiting, respiratory distress, and muscular hypotonia. Despite the evidence-based management, affected individuals experience significant morbidity and mortality. Hyperkalemia is one of the unusual complications of methylmalonic acidemia.Case presentationIn this paper, we describe a 4-year-old Persian boy with methylmalonic acidemia who developed life-threatening arrhythmia following severe hyperkalemia and metabolic acidosis. Emergent management of the condition was successfully carried out, and the rhythm changed to normal sinus rhythm by effectively reducing the serum potassium level. We discuss the possible etiology of this lethal condition and describe its management on the basis of the available evidence.ConclusionDuring metabolic decompensation in methylmalonic acidemia, frequent blood gas and electrolyte testing to prescribe and adjust therapy and annual echocardiogram and electrocardiogram screening are essential.

Assessing the quality and value of metabolic chart data for capturing core outcomes for pediatric medium-chain acyl-CoA dehydrogenase (MCAD) deficiency

BackgroundGenerating rigorous evidence to inform care for rare diseases requires reliable, sustainable, and longitudinal measurement of priority outcomes. Having developed a core outcome set for pediatric medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, we aimed to assess the feasibility of prospective measurement of these core outcomes during routine metabolic clinic visits.MethodsWe used existing cohort data abstracted from charts of 124 children diagnosed with MCAD deficiency who participated in a Canadian study which collected data from birth to a maximum of 11 years of age to investigate the frequency of clinic visits and quality of metabolic chart data for selected outcomes. We recorded all opportunities to collect outcomes from the medical chart as a function of visit rate to the metabolic clinic, by treatment centre and by child age. We applied a data quality framework to evaluate data based on completeness, conformance, and plausibility for four core MCAD outcomes: emergency department use, fasting time, metabolic decompensation, and death.ResultsThe frequency of metabolic clinic visits decreased with increasing age, from a rate of 2.8 visits per child per year (95% confidence interval, 2.3–3.3) among infants 2 to 6 months, to 1.0 visit per child per year (95% confidence interval, 0.9–1.2) among those ≥ 5 years of age. Rates of emergency department visits followed anticipated trends by child age. Supplemental findings suggested that some emergency visits occur outside of the metabolic care treatment centre but are not captured. Recommended fasting times were updated relatively infrequently in patients’ metabolic charts. Episodes of metabolic decompensation were identifiable but required an operational definition based on acute manifestations most commonly recorded in the metabolic chart. Deaths occurred rarely in these patients and quality of mortality data was not evaluated.ConclusionsOpportunities to record core outcomes at the metabolic clinic occur at least annually for children with MCAD deficiency. Methods to comprehensively capture emergency care received at outside institutions are needed. To reduce substantial heterogeneous recording of core outcome across treatment centres, improved documentation standards are required for recording of recommended fasting times and a consensus definition for metabolic decompensations needs to be developed and implemented.