Expression and function of the urea cycle in widely-used hepatic cellular models.

The group of rare metabolic defects termed urea cycle disorders (UCDs) occur within the ammonia elimination pathway and lead to significant neurocognitive sequelae for patients surviving decompensation episodes. Besides orthotopic liver transplantation, curative options are lacking for UCDs, with dietary management being the gold clinical standard. Novel therapeutic approaches are essential for UCDs; however, such effort presupposes preclinical testing in cellular models that effectively capture disease manifestation. Several cellular and animal models exist and aim to recapitulate the broad phenotypic spectrum of UCDs; however, the majority of those lack extensive molecular and biochemical characterization. The development of cellular models is emerging since animal models are extremely time and cost consuming, and subject to ethical considerations, including the 3R principle that endorses animal welfare over unchecked preclinical testing. The aim of this study was to compare the extent of expression and functionality of the urea cycle in two commercial hepatoma-derived cell lines, induced pluripotent stem cell hepatocytes (iPSC-Heps), primary human hepatocytes (PHHs) and human liver cell preparations. Using immunoblotting, immunocytochemistry, and stable isotope tracing of the urea cycle metabolites, we identified that the hepatoma-derived, 2-week differentiated HepaRG cells are urea cycle proficient and behave as cellular alternatives to PHHs. Furthermore, HepaRG cells were superior to iPSC-Heps, which are known to exhibit batch-to-batch variabilities in terms of hepatic maturity and enzyme expression. Finally, HepG2 cells lack the urea cycle enzymes ornithine transcarbamylase and arginase 1, the transporter ORNT1, which limits their suitability as model for the study of UCDs.

Outcomes of pediatric obesity-related lifestyle disease screenings in Kumamoto.

BACKGROUND: Obesity is an important issue causing both health hazards and socioeconomic loss to those affected. Kumamoto City regularly performs obesity-related lifestyle disease screenings for fourth grade children with obesity, including physical examinations, blood tests, and special examination referrals. We retrospectively analyzed the outcomes of the screenings conducted from 2011 to 2020. METHODS: The percentage of overweight was calculated using data from the Lifestyle Disease Screening Board of Kumamoto City from 2011 to 2020. The percentage of overweight, abdominal circumference, blood pressure, and laboratory test outcomes of the Secondary Lifestyle Disease Test were evaluated. RESULTS: The proportion of children with obesity in grades 1-4 in Kumamoto was higher than the national average, while that in grades 5-6 was lower than the national average. Among the fourth graders screened, 6521 were eligible for the Secondary Lifestyle Disease Tests, of which 3291 children underwent the test. In the testing, 22.3% of the boys and 29.1% of the girls were nonobese. Moreover, 25.9% of the boys and 19.2% of the girls, including nonobese children, required further examination and intervention. Notably, 62.1% of the boys and 46.2% of the girls who were nonobese and required special examination had a waist circumference of ≥75 cm or waist-to-height ratios of ≥0.5. CONCLUSIONS: Obesity-related lifestyle disease screenings contributed to preventing obesity progression. Abdominal circumference measurements may be useful in determining nonobese children at a risk of lifestyle diseases.

Changes in Internal Cerebral Vein Pulsation and Intraventricular Hemorrhage in Extremely Preterm Infants.

OBJECTIVES: This study aimed to investigate the relationship between internal cerebral vein (ICV) pulsation and intraventricular hemorrhage (IVH) and to identify the cut-off values that predict IVH. We hypothesized that the severity of ICV flow pulsations was related to IVH severity. STUDY DESIGN: In this prospective observational study, ICV flow was measured in 61 extremely preterm infants using ultrasonography at every 12 hours until 96 hours after birth and on days 7, 14, and 28. The ICV pulsation index (ICVPI = minimum/maximum ICV speed) was calculated and compared among the groups determined by Papile's IVH classification. The ICVPI cut-off values for IVH were determined by receiver operating characteristic curve analysis. RESULTS: Compared with those in the no IVH (NIVH) group (n = 51), the ICVPI median values in the severe IVH (SIVH; grades 3 and 4) group (n = 5) were lower at 25 to 96 hours and on day 7, whereas those in the mild IVH (MIVH; grades 1 and 2) group (n = 5) were lower at 37 to 60 hours. All SIVH events were initially detected within 60 hours after birth. The ICVPI cut-off values for SIVH were 0.92 at 13 to 24 hours, 0.42 at 25 to 36 hours, 0.58 at 37 to 48 hours, and 0.55 at 49 to 60 hours. Infants whose ICVPI values were below the cut-off value ≥3 times between 13 and 60 hours had a significantly higher SIVH incidence than those whose ICVPI values were below the cut-off value ≤2 times (57.1 vs. 1.9%, p < 0.001). CONCLUSION: Our results indicate that SIVH had sustained pronounced internal cerebral vein pulsations and that the ICVPI values may help predict SIVH. Further research on strategies to decrease venous pressure for IVH prevention is needed. KEY POINTS: · IVH preterm infants had sustained ICV pulsations.. · ICV flow in SIVH pulsated stronger.. · ICVPI fluctuation implies postnatal adaptation.. · We newly defined ICVPI to predict SIVH..

Variants associated with urea cycle disorders in Japanese patients: Nationwide study and literature review.

Urea cycle disorders (UCDs) are inherited metabolic diseases that lead to hyperammonemia with variable clinical manifestations. Using data from a nationwide study, we investigated the onset time, gene variants, clinical manifestations, and treatment of patients with UCDs in Japan. Of the 229 patients with UCDs diagnosed and/or treated between January 2000 and March 2018, identified gene variants and clinical information were available for 102 patients, including 62 patients with ornithine transcarbamylase (OTC) deficiency, 18 patients with carbamoyl phosphate synthetase 1 (CPS1) deficiency, 16 patients with argininosuccinate synthetase (ASS) deficiency, and 6 patients with argininosuccinate lyase (ASL) deficiency. A total of 13, 10, 4, and 5 variants in the OTC, CPS1, ASS, and ASL genes were respectively identified as novel variants, which were neither registered in ClinVar databases nor previously reported. The onset time and severity in patients with UCD could be predicted based on the identified gene variants in each patient from this nationwide study and previous studies. This genetic information may help in predicting the long-term outcome and determining specific treatment strategies such as liver transplantation in patients with UCDs.

Role of liver transplantation in urea cycle disorders: Report from a nationwide study in Japan.

Urea cycle disorders (UCDs) are inherited metabolic diseases causing hyperammonemia by defects in urea cycle enzymes or transporters. Liver transplantation (LT) currently is the only curative treatment option until novel therapies become available. We performed a nationwide questionnaire-based study between January 2000 and March 2018 to investigate the effect of LT in patients with UCDs in Japan. A total of 231 patients with UCDs were enrolled in this study. Of them, a total of 78 patients with UCDs (30 male and 16 female ornithine transcarbamylase deficiency (OTCD), 21 carbamoyl phosphate synthetase 1 deficiency (CPSD), 10 argininosuccinate synthetase deficiency (ASSD) and 1 arginase 1 deficiency (ARGD)) had undergone LT. Concerning the maximum blood ammonia levels at the onset time in the transplanted male OTCD (N = 28), female OTCD (N = 15), CPSD (N = 21) and ASSD (N = 10), those were median 634 (IQR: 277-1172), 268 (211-352), 806 (535-1382), and 628 (425-957) µmol/L, respectively. The maximum blood ammonia levels in female OTCD were thus significantly lower than in the other UCDs (all P < .01). LT was effective for long-term survival, prevented recurrent hyperammonemia attack, and lowered baseline blood ammonia levels in patients with UCDs. LT had limited effect for ameliorating neurodevelopmental outcome in patients with severe disease because hyperammonemia at the onset time already had a significant impact on the brain. Patients with ASSD may be more likely to survive without cognitive impairment by receiving early LT despite severe neonatal hyperammonemia ≥ 360 µmol/L. In patients with neonatal onset OTCD or CPSD, there may be additional factors with adverse effects on the brain that are not improved by LT.

Long-term outcome of urea cycle disorders: Report from a nationwide study in Japan.

Urea cycle disorders (UCDs) are inherited metabolic disorders with impaired nitrogen detoxification caused by defects in urea cycle enzymes. They often manifest with hyperammonemic attacks resulting in significant morbidity or death. We performed a nationwide questionnaire-based study between January 2000 and March 2018 to document all UCDs in Japan, including diagnoses, treatments, and outcomes. A total of 229 patients with UCDs were enrolled in this study: 73 males and 53 females with ornithine transcarbamylase deficiency (OTCD), 33 patients with carbamoylphosphate synthetase 1 deficiency, 48 with argininosuccinate synthetase deficiency, 14 with argininosuccinate lyase deficiency, and 8 with arginase deficiency. Survival rates at 20 years of age of male and female patients with late-onset OTCD were 100% and 97.7%, respectively. Blood ammonia levels and time of onset had a significant impact on the neurodevelopmental outcome (P < .001 and P = .028, respectively). Hemodialysis and liver transplantation did not prevent poor neurodevelopmental outcomes. While treatment including medication, hemodialysis, and liver transplantation may aid in decreasing blood ammonia and/or preventing severe hyperammonemia, a blood ammonia level ≥ 360 µmol/L was found to be a significant indicator for a poor neurodevelopmental outcome. In conclusion, although current therapy for UCDs has advanced and helped saving lives, patients with blood ammonia levels ≥ 360 µmol/L at onset often have impaired neurodevelopmental outcomes. Novel neuroprotective measures should therefore be developed to achieve better neurodevelopmental outcomes in these patients.

Effect of L-Carnitine on Amino Acid Metabolism in Elderly Patients Undergoing Regular Hemodialysis.

INTRODUCTION: Among patients regularly undergoing hemodialysis, hypocarnitinaemia often develops as a consequence of inadequate dietary intake, reduced synthesis in the body, and considerable losses during hemodialysis. OBJECTIVES: To evaluate the effects of L-carnitine supplementation on patients with end-stage kidney disease (ESKD) who underwent hemodialysis. METHODS: Thirty-one patients with ESKD, comprising 18 men and 13 women, with a median age of 72 (range 58-89) years, who underwent regular hemodialysis received treatment with L-carnitine for 1 year. The total and free carnitine, acylcarnitine, and amino acids (AA) levels before and after L-carnitine treatment were analyzed, and the blood biochemistry results and clinical profiles of the subjects were compared before and after treatment. RESULTS: The median (interquartile range [IQR]) serum total and free carnitine and acylcarnitine levels significantly increased from 34.5 (28.2-44.3), 20.9 (15.8-27.6), and 14.1 (11.2-17.6) µmol/L, respectively to 407.4 (371.6-493.5), 270.2 (228.3-316.0), and 155.0 (136.1-168.5) µmol/L, respectively, after treatment (all p < 0.001). The median (IQR) blood valine, tyrosine, phenylalanine, and citrulline levels increased from 0.94 (0.80-1.09), 0.45 (0.39-0.55), 0.61 (0.56-0.79), and 1.04 (0.79-1.26) mg/dL, respectively to 1.24 (1.13-1.54), 0.76 (0.62-0.85), 0.90 (0.70-1.04), and 1.22 (0.92-1.39) mg/dL, respectively, following L-carnitine treatment (p < 0.001, p < 0.001, p = 0.002, and p = 0.030, respectively); however, the median (IQR) blood arginine level decreased from 0.20 (0.13-0.24) to 0.09 (0.06-0.14) mg/dL after treatment (p < 0.001). The median (IQR) percentage fractional shortening (41.5 vs. 41.9%; p = 0.012) and left ventricular ejection fraction (65.2 vs. 67.3%; p = 0.036) increased significantly following treatment. CONCLUSIONS: L-Carnitine increased the blood acylcarnitine levels, enhanced fatty acid metabolism, and affected AAs metabolism; this may be beneficial for energy production within the cardiac and skeletal muscles.

Reversal of blood flow in deep cerebral vein in preterm intraventricular hemorrhage: two case reports.

BACKGROUND: Intraventricular hemorrhage during the early stage is a major complication in very low birth weight infants. Elevation of venous pressure is one of the contributing factors. The internal cerebral vein receives most of the venous flow from the subependymal germinal matrix, the most common site of origin of intraventricular hemorrhage. Recently, it has been reported that pulsatile or partially interrupted internal cerebral vein waveforms might also be risk factors for intraventricular hemorrhage in extremely low birth weight infants. Here, we report two cases of partially reversed internal cerebral vein flow with intraventricular hemorrhage. There are no published reports documenting this unique flow pattern. CASE PRESENTATION: Between 2013 and 2020, we had in our neonatal intensive care unit two cases of very low birth weight infants (27 and 25 weeks of gestational age) who showed a partially reversed internal cerebral vein waveform pattern, which was recognized as a new blood flow pattern. Their internal cerebral vein flow patterns were continuously flat early after birth. They showed an intraventricular hemorrhage on the unilateral side with partially interrupted internal cerebral vein flow at 31 and 41 hours after birth (27- and 25-week-old neonates, respectively). Consecutively, their internal cerebral vein flow changed to a partially reversed pattern with intraventricular hemorrhage on the contralateral side at 43 and 87 hours after birth (27- and 25-week-old neonates, respectively). Their flow patterns improved by day 7. These partially reversed patterns were equivalent to triphasic venous flow, and the reverse flow corresponded to A- and V-waves. CONCLUSION: In the two cases, the internal cerebral vein flow patterns were normal and flat before intraventricular hemorrhage and changed to a severe flow pattern (partially interrupted or reversed flow) at the same time as the detection of intraventricular hemorrhage. After the development of intraventricular hemorrhage, they improved. These cases indicate that a partially reversed or interrupted internal cerebral vein flow pattern may be derived from central venous pressure elevation and related to intraventricular hemorrhage in very low birth weight infants, however, it is difficult to determine when this flow pattern occurs in relation to intraventricular hemorrhage.

Urea cycle disorders-update.

The urea cycle is a metabolic pathway for the disposal of excess nitrogen, which arises primarily as ammonia. Nitrogen is essential for growth and life-maintenance, but excessive ammonia leads to life-threatening conditions. The urea cycle disorders (UCDs) comprise diseases presenting with hyperammonemia that arise in either the neonatal period (about 50% of cases) or later. Congenital defects of the enzymes or transporters of the urea cycle cause the disease. This cycle utilizes five enzymes, two of which, carbamoylphosphate synthetase 1 and ornithine transcarbamylase are present in the mitochondrial matrix, whereas the others (argininosuccinate synthetase, argininosuccinate lyase and arginase 1) are present in the cytoplasm. In addition, N-acetylglutamate synthase and at least two transporter proteins are essential to urea cycle function. Severity and age of onset depend on residual enzyme or transporter function and are related to the respective gene mutations. The strategy for therapy is to prevent the irreversible toxicity of high-ammonia exposure to the brain. The pathogenesis and natural course are poorly understood because of the rarity of the disease, so an international registry system and novel clinical trials are much needed. We review here the current concepts of the pathogenesis, diagnostics, including genetics and treatment of UCDs.

Newborn screening for Pompe disease in Japan: report and literature review of mutations in the GAA gene in Japanese and Asian patients.

A newborn screening program for Pompe disease using dried blood spots (DBSs) was initiated in Japan. Here, we summarized this screening program and described the results of the GAA gene analysis. From April 2013 to November 2016, 103,204 newborns were screened; 71 had low acid alpha-glucosidase (AαGlu) activity. GAA sequencing showed that 32 (45.1%) and 37 (52.1%) of these newborns were homozygous and heterozygous for pseudodeficiency alleles c.[1726G>A; 2965G>A], respectively. Moreover, 24 of 32 newborns with homozygous c.[1726G>A; 2965G>A] alleles had no mutations, and the other eight had one mutation each. Thirty-five of 37 newborns with heterozygous c.[1726G>A; 2965G>A] alleles had one mutation, and the other two had two mutations each. Only one newborn who had two mutations did not harbor c.[1726G>A; 2965G>A] alleles. Thus, it was difficult to distinguish newborns with c.[1726G>A; 2965G>A] alleles from newborns with pre-symptomatic Pompe disease using AαGlu assays in DBSs or fibroblasts; GAA gene sequencing was necessary. Seventy-one newborns had 50 variants, including 21 mutations or predictably pathogenic variants, and 29 polymorphisms or predictably non-pathogenic variants. Four of 21 mutations or predictably pathogenic variants and four of 29 polymorphisms or predictably non-pathogenic variants were novel. No infantile-onset Pompe disease was detected, and three newborns were diagnosed with potential late-onset Pompe disease. In the literature, 156 variants have been reported for 296 patients from 277 families in 41 articles from Japan, Korea, Taiwan, and China. Our results provide insights into GAA gene mutation profiles and the relationship between GAA and Pompe disease in Asian populations.

Associations among amino acid, lipid, and glucose metabolic profiles in childhood obesity.

BACKGROUND: Plasma-free amino acid profiles have been reported to correlate with obesity and glucose metabolism, and have been studied as potentially useful biomarkers of lifestyle-related diseases affecting metabolism in adulthood. However, knowledge of these relationships is lacking in children, despite the growing public health problem posed by childhood obesity. The aim of this study was to assess whether plasma-free amino acid profiles can serve as useful biomarkers of lifestyle-related diseases in children with obesity. METHODS: This retrospective study used the medical records of 26 patients (15 male, 11 female) aged 9 or 10 years presenting with moderate to severe obesity and hyperlipidemia between April 2015 and March 2017. A degree of obesity of 30% or more was defined as moderate or severe. Amino acid levels were compared between obese children with and without impaired glucose tolerance using a t-test or Mann-Whitney U test. In addition, the influence of factors such as intima media thickness, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, amino acids, and homeostasis model assessment-insulin resistance (HOMA-IR) were analyzed pairwise using Pearson's correlation or Spearman's rank correlation. RESULTS: HOMA-IR was positively correlated with valine, leucine (Leu), isoleucine, phenylalanine, tryptophan, methionine, threonine, lysine, alanine, tyrosine, glutamate (Glu), proline, arginine, ornithine, total free amino acids (all P < 0.01), and aspartate (P = 0.010). Moreover, blood uric acid levels were positively correlated with Leu (P = 0.005) and Glu (P = 0.019), and negatively correlated with serine, glycine, and asparagine (P = 0.007, P = 0.003, and P = 0.013, respectively). CONCLUSIONS: Amino acid profile reflects impaired glucose tolerance and hyperuricemia at an early stage of obesity. It is therefore a useful marker to inform early intervention in children with obesity, as in adults.

High-risk screening for Gaucher disease in patients with neurological symptoms.

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder caused by the deficiency of glucocerebrosidase enzyme activity. Clinical phenotypes of GD are categorized into three groups: (i) non-neuronopathic GD (type 1), (ii) acute neuronopathic GD (type 2) and (iii) subacute neuronopathic GD (type 3). The high-risk screening of neuronopathic GD has been performed using an enzymatic assay on the dried blood spot (DBS) samples. We enrolled a total of 102 individuals (47 females, 55 males; 0-57 years old; median age 10.5 years) with various neurological symptoms. We detected two patients with very low enzyme activity and they were diagnosed with the disease by using glucocerebrosidase gene analysis. Patient 1 was found to be compound heterozygous for the p.R159W/p.R170C locus and patient 2 was found to harbor two mutations at the IVS7+1G>T (c.999+1G>T) and p.L483P sites. This simple screening protocol using DBS samples is useful for early diagnosis of GD in high-risk and underdiagnosed patients suffering from various neurological symptoms.

Recovery of severe acute liver failure without transplantation in patients with Wilson disease.

Wilson disease (WD) is a disorder of copper metabolism that leads to liver cirrhosis. WD patients with a NWIS > 11 should receive LT; however, we encountered 2 WD patients with an NWIS > 11 who recovered from ALF without LT. The present report aimed to analyze cases of WD patients with a high NWIS who recovered from severe ALF and to discuss the clinical manifestations of the patients and the effects of treatments, including zinc (Zn) therapy, chelator therapy, PE, CHDF, and LT. We retrospectively evaluated the medical records of five patients (male, 2; female, 3) diagnosed with WD along with severe ALF. In cases 1, 2, and 3, complete recovery from ALF was noted without LT. In case 4, initial recovery from ALF was noted without LT; however, ALF worsened owing to bleeding from the esophageal varix. Thus, the patient eventually needed LT. In case 5, recovery from ALF was noted with LT. All cases, except case 2, showed ALF with maximum PELD/MELD scores ≥26 and NWISs ≥ 11, and had indications for LT. In cases of severe ALF with grade I or II encephalopathy, we recommend evaluations of the effects of Zn and chelator treatments while preparing for LT, as the condition may not improve without LT, and pediatricians or physicians can ask transplant surgeons to perform LT urgently if required.

A Significant Difference in the Blood Carnitine Values Obtained by the Enzymatic Cycling and Tandem Mass Spectrometry Methods.

BACKGROUND: There are no reports in the literature of blood samples obtained from the same individual being subjected to analysis at the same time using the enzymatic cycling (EC) method along with electrospray tandem mass spectrometry (ESI/MS/MS) before and after carnitine treatment. METHODS: Blood samples from 29 patients (median age: 73 years old, age range: 41 - 89 years) receiving regular hemodialysis for chronic renal failure before and after carnitine treatment for 3 months were measured by the EC method, and using a dried blood spot (DBS) and ESI/MS/MS. RESULTS: Before the carnitine treatment, the rate of increase or decrease in the free and acyl-carnitine levels of the DBS using the ESI/MS/MS method to those measured by the EC methods was a median of -28.6% (-36.0 to -14.1%) and -20.8% (-30.0 to 1.5%), respectively. After carnitine treatment, the rate of increase or decrease in the free and acyl-carnitine levels of the DBS with the ESI/MS/MS method compared to the EC method was a median of 52.0% (28.4 to 66.7%) and -31.9% (-47.2 to -21.1%), respectively. CONCLUSIONS: There were significant differences in the blood carnitine values using the ESI/MS/MS and EC methods. Caution should be exercised when evaluating DBS values measured by the ESI/MS/MS method.

Early liver transplantation in neonatal-onset and moderate urea cycle disorders may lead to normal neurodevelopment.

Urea cycle disorders (UCDs) are inherited metabolic diseases that lead to hyperammonemia. Neurodevelopmental outcomes of patients with UCDs depend on the maximum ammonia concentration (MAC) in the blood during onset. MAC ≥360 µM is a marker of poor neurodevelopmental outcomes. We investigated the neurodevelopmental outcomes and MAC at onset for 177 patients with UCDs in Japan (median age, 8 years and 2 months; range, 10 days-72 years), including 57 patients with male ornithine transcarbamylase (OTCD), 59 patients with female OTCD, 23 patients with carbamoyl-phosphate synthetase 1 deficiency (CPSD), 28 patients with arginosuccinate synthetase deficiency, 9 patients with arginosuccinate lyase deficiency (ALD), and 1 patient with arginase 1 deficiency. Neurodevelopmental outcomes of patients with CPSD and ALD were poor because most had neonatal onset with blood MAC ≥300 µM at onset. Although OTCD, particularly female late-onset OTCD, has good neurodevelopmental outcomes among those with UCDs, it is not necessarily a mild disease with good long-term outcomes. Patients with severe UCDs and MAC ≥300 µM at onset should undergo liver transplantation (LT). Moreover, this study suggested that if the onset of UCD began during the neonatal period, then even UCD patients with MAC <300 µM at onset should undergo LT to protect the brain.

Early-onset neonatal hyperkalemia associated with maternal hypermagnesemia: a case report.

BACKGROUND: Neonatal nonoliguric hyperkalemia (NOHK) is a metabolic abnormality that occurs in extremely premature neonates at approximately 24 h after birth and is mainly due to the immature functioning of the sodium (Na+)/potassium (K+) pump. Magnesium sulfate is frequently used in obstetrical practice to prevent preterm labor and to treat preeclampsia; this medication can also cause hypermagnesemia and hyperkalemia by a mechanism that is different from that of NOHK. Herein, we report the first case of very early-onset neonatal hyperkalemia induced by maternal hypermagnesemia. CASE PRESENTATION: A neonate born at 32 weeks of gestation developed hyperkalemia (K+ 6.4 mmol/L) 2 h after birth. The neonate's blood potassium concentration reached 7.0 mmol/L 4 h after birth, despite good urine output. The neonate and his mother had severe hypermagnesemia caused by intravenous infusion of magnesium sulfate given for tocolysis due to pre-term labor. CONCLUSION: The early-onset hyperkalemia may have been caused by the accumulation of potassium ions transported through the placenta, the shift of potassium ions from the intracellular to the extracellular space in the infant due to the malfunctioning of the Na+/K+ pump and the inhibition of renal distal tube potassium ion secretion, there is a possibility that these mechanisms were induced by maternal and fetal hypermagnesemia after maternal magnesium sulfate administration. Because neonatal hyperkalemia poses a significant risk for the development of life-threatening cardiac arrhythmia, this case highlights the necessity of maternal blood magnesium monitoring during magnesium sulfate administration and neonatal blood potassium monitoring when there is severe maternal hypermagnesemia at delivery.

Plasma exchange and chelator therapy rescues acute liver failure in Wilson disease without liver transplantation.

AIM: Wilson disease (WD) in patients with a New Wilson Index (NWI) score ≥ 11 is fatal, and these patients are good candidates for liver transplantation (LT). However, plasma exchange and chelator therapy are indispensable and effective even for WD with a score ≥ 11. Moreover, continuous hemodiafiltration (CHDF) with these treatments is essential for acute liver failure (ALF) in WD with hepatic encephalopathy because CHDF can exclude toxic metabolites that may cause damage to the brain. Here, we describe four rescued patients presenting with ALF in WD and discuss the available treatment options. METHODS: We have experienced 11 male and 8 female patients presenting with WD at the Department of Pediatrics, Kumamoto University Hospital between 1999 and 2014. A male and 4 female patients were diagnosed as WD with ALF using a combination of clinical findings and biochemical tests. RESULTS: The NWI score was ≥ 11 in cases 1 to 3. Cases 1 and 2 with hepatic encephalopathy received plasma exchange, CHDF, coagulation factor replacement treatment (CFRT) and LT. Cases 3 and 4 without encephalopathy obtained stable status without LT by plasma exchange, blood infusion, and CFRT. CONCLUSIONS: It is better to undergo LT for WD patients with a NWI score ≥ 11, however, there is a possibility of remission by plasma exchange and medical therapy even without LT. WD patients with a NWI score ≥ 11can be rescued by conservative therapy when the ALF of WD does not present with ALF and hepatic encephalopathy. Therefore, ALF with hepatic encephalopathy itself is an indication for LT in WD.

Liver transplantation may prevent neurodevelopmental deterioration in high-risk patients with urea cycle disorders.

UCDs are among the most common inherited metabolic diseases in Japan. We investigated the clinical manifestations, treatment, and prognoses of 177 patients with UCDs who were evaluated and treated from January 1999 to March 2009 in Japan, using a questionnaire survey. Among these 177 patients, 42 (seven with carbamoyl phosphate synthetase 1 deficiency, 27 with ornithine transcarbamylase deficiency, seven with argininosuccinate synthetase deficiency, and one with arginase 1 deficiency) underwent living-donor LT. Although this study was retrospective and included limited neurodevelopmental information before and after LT, we evaluated whether LT could improve neurodevelopmental outcomes in patients with UCDs. The neurodevelopmental outcomes of patients with a MAC of <300 µmol/L at the time of onset were not significantly different between the LT and non-LT groups (P=.222). LT may have prevented further neurodevelopmental complications in children with MAC ≥300 µmol/L (P=.008) compared with non-transplant management. Therefore, Liver transplant should be considered in patients with UCD with a MAC of ≥300 µmol/L at the time of disease onset.

Citrulline for urea cycle disorders in Japan.

BACKGROUND: The amino acid l-citrulline is used as a therapeutic agent for urea cycle disorders (UCD) including ornithine transcarbamylase deficiency (OTCD), carbamoyl phosphate synthetase I deficiency (CPSD), and N-acetylglutamate synthase deficiency. There are few reports, however, on the use of l-citrulline in Japan and little consensus regarding the effects of l-citrulline. METHODS: We conducted a questionnaire survey of patients undergoing l-citrulline treatment for a UCD to evaluate the current status of this therapy. The survey included patient background, details of l-citrulline treatment, clinical examination data, treatment, frequency of vomiting, and liver transplantation. RESULTS: We retrospectively investigated 43 questionnaire respondents (OTCD, n = 33; CPSD, n = 10). The weight of male OTCD patients improved by +0.79 SD, and the ammonia level decreased by a mean of 44.3 µmol/L in all patients. The protein intake of all patients and of male OTCD patients increased by 0.14 g/kg/day and 0.17 g/kg/day, respectively. CONCLUSIONS: l-Citrulline effectively reduced ammonia level, increased protein intake, and improved weight gain in UCD patients. l-Citrulline should be considered a standard therapy in OTCD and CPSD patients.