Growth differentiation factor 15 as a novel diagnostic and therapeutic marker for autoimmune hepatitis.

Growth differentiation factor 15 (GDF15) has been reported to be associated with fibrosis and cancer in liver disease. Diagnosis of autoimmune hepatitis (AIH) is often difficult because of the lack of specific markers. We investigated whether GDF15 is useful for diagnosing AIH and determined its therapeutic effects. We enrolled 171 Japanese patients as follows: AIH (n = 45), hepatitis B (HB) (n = 17), hepatitis C (HC) (n = 15), primary biliary cholangitis (PBC) (n = 20), and 74 healthy controls. Serum GDF15 levels were measured, and immunohistological analyses of GDF15 were performed using liver tissue of AIH patients. (1) GDF15 levels (pg/ml) were higher in AIH (1994.3 ± 1258.0) and HC (1568.0 ± 822.3) than in HB (953.2 ± 871.4), PBC (643.9 ± 247.0), and controls (475.3 ± 145.3) (p < 0.0001), as well as in cirrhosis patients (n = 31) than in non-cirrhosis patients (n = 66) (1926.6 ± 1026.0 vs. 1249.1 ± 1124.1, p < 0.0001). In non-cirrhosis patients, GDF15 levels were higher in AIH (1914.0 ± 1327.2) than in HC (955.7 ± 502.7), HB (519.3 ± 197.5), and PBC (643.9 ± 247.0) (p < 0.0001). (2) GDF15 was positively correlated with M2BPGi (r = 0.7728), total bilirubin (r = 0.6231), and PT-INR (r = 0.6332). (3) GDF15 levels could be used to distinguish AIH from other liver diseases in non-cirrhosis patients, with an area under the curve of 0.9373 (sensitivity 93.6%, specificity 79.3%, cut-off value 931.3). (4) GDF15 in AIH decreased after treatment. (5) Immunohistological analyses in AIH liver tissues revealed that GDF15 was strongly expressed in inflammatory cells, hepatic cytoplasm, and sinusoidal endothelial cells, but decreased after treatment. GDF15 is a novel diagnostic marker for AIH and is also expected to be a therapeutic marker for AIH.Clinical Trials Registration: The study protocol was approved by the institutional review board of Kurume University (Approval No.: 19049).

Community Consensus Guidelines to Support FAIR Data Standards in Clinical Research Studies in Primary Mitochondrial Disease.

Primary mitochondrial diseases (PMD) are genetic disorders with extensive clinical and molecular heterogeneity where therapeutic development efforts have faced multiple challenges. Clinical trial design, outcome measure selection, lack of reliable biomarkers, and deficiencies in long-term natural history data sets remain substantial challenges in the increasingly active PMD therapeutic development space. Developing "FAIR" (findable, accessible, interoperable, reusable) data standards to make data sharable and building a more transparent community data sharing paradigm to access clinical research metadata are the first steps to address these challenges. This collaborative community effort describes the current landscape of PMD clinical research data resources available for sharing, obstacles, and opportunities, including ways to incentivize and encourage data sharing among diverse stakeholders. This work highlights the importance of, and challenges to, developing a unified system that enables clinical research structured data sharing and supports harmonized data deposition standards across clinical consortia and research groups. The goal of these efforts is to improve the efficiency and effectiveness of drug development and improve understanding of the natural history of PMD. This initiative aims to maximize the benefit for PMD patients, research, industry, and other stakeholders while acknowledging challenges related to differing needs and international policies on data privacy, security, management, and oversight.

Mitochondrial DNA depletion syndrome with a mutation in SLC25A4 developing epileptic encephalopathy: A case report.

INTRODUCTION: Autosomal dominant mitochondrial DNA depletion syndrome (MTDPS-12A) is characterized by severe hypotonia from birth due to a mutation in the adenine nucleotide translocator 1 (ANT1). CASE REPORT: A 4-year-old female patient diagnosed with neonatal-onset mitochondrial disease, who had good cognitive function while receiving antiepileptic treatment, presented with sudden-onset status epilepticus with facial and limb myoclonus persisting for more than 30 min. Subsequently, she developed epileptic encephalopathy. Brain MRI showed progressive ventricular enlargement and marked white matter atrophy. She was unable to perform verbal communication or make eye contact and fingertip movements. She lacked any signs of cardiomyopathy. Sanger sequencing demonstrated a heterozygous de novo mutation of c.239G>A (p.Arg80His) in SLC25A4. Her right quadriceps muscle tissue showed lowered complexes I, III, and IV activities and mitochondria DNA depletion (mitochondria/nuclear DNA: 14.6 ± 2.2%) through the quantitative polymerase chain reaction. She was definitively diagnosed with MTDPS-12A. CONCLUSION: Status epilepticus causes encephalopathy in patients with MTDPS-12A. Reducing the energy requirement on the cardiac muscle and brain may be a treatment strategy for patients with MTDPS-12A. Therefore, seizure management and preventive treatment of status epilepticus are considered to be important for maintaining neurodevelopmental outcomes.

BCS1L mutations produce Fanconi syndrome with developmental disability.

Fanconi syndrome is a functional disorder of the proximal tubule, characterized by pan-aminoaciduria, glucosuria, hypophosphatemia, and metabolic acidosis. With the advancements in gene analysis technologies, several causative genes are identified for Fanconi syndrome. Several mitochondrial diseases cause Fanconi syndrome and various systemic symptoms; however, it is rare that the main clinical symptoms in such disorders are Fanconi syndrome without systematic active diseases like encephalomyopathy or cardiomyopathy. In this study, we analyzed two families exhibiting Fanconi syndrome, developmental disability and mildly elevated liver enzyme levels. Whole-exome sequencing (WES) detected compound heterozygous known and novel BCS1L mutations, which affect the assembly of mitochondrial respiratory chain complex III, in both cases. The pathogenicity of these mutations has been established in several mitochondria-related functional analyses in this study. Mitochondrial diseases with isolated renal symptoms are uncommon; however, this study indicates that mitochondrial respiratory chain complex III deficiency due to BCS1L mutations cause Fanconi syndrome with developmental disability as the primary indications.

Temporal changes and control variables of growth differentiation factor 15 levels during the first week of life in hospitalised newborn infants.

Serum growth differentiation factor 15 (GDF15) is a useful biomarker of mitochondrial diseases; its utility in newborns remains unknown. To investigate the temporal change in GDF15 within the first week of life, and to identify its potential control variables, blood samples were obtained from 18 newborns. The GDF15 levels declined to approximately 35% of the cord blood levels within the first week of life and were negatively correlated with postnatal age and Z-score of birth weight but were positively correlated with N-terminal pro-brain natriuretic peptide and lactate levels. GDF15 levels may reflect the progress of postnatal transition to aerobic metabolism.

A new diagnostic indication device of a biomarker growth differentiation factor 15 for mitochondrial diseases: From laboratory to automated inspection.

Mitochondrial diseases (MDs) are occasionally difficult to diagnose. Growth differentiation factor 15 (GDF15) has been reported as a biomarker useful for not only diagnosing MDs, but also evaluating disease severity and therapeutic efficacy. To enable the measurement of serum GDF15 concentrations at medical institutions, we developed a new latex-enhanced turbidimetric immunoassay (LTIA) as an automated diagnostic indication test for MDs. We also examined the equivalency of specificity and sensitivity in measuring serum GDF15 concentrations between a commercially available enzyme-linked immunosorbent assay (ELISA) kit and a novel LTIA device in patients with MDs, disease controls, and healthy controls. A clinical performance study used a newly developed LTIA device and an existing ELISA kit to measure the concentrations of GDF15 in 35 MD patients, 111 disease controls, and 86 healthy controls. The median (first quartile-third quartile) of serum GDF15 concentrations measured with the LTIA device was significantly higher (P < .001) in MD patients (1389.0 U/mL [869.5-1776.0 U/mL]) than in healthy controls (380.5 U/mL [330.2-471.8 U/mL]); the interquartile ranges did not overlap between MD patients and healthy controls. The areas under the curve in disease and healthy controls were 0.812 (95% confidence interval [CI]: 0.734-0.886) and 0.951 (95% CI: 0.910-0.992), respectively. The automated, high-throughput technology-based LTIA device has definite advantages over the ELISA kit in shorter processing time and lower estimated cost per sample measurement. The LTIA device of GDF15 may be a sufficiently reliable, frontline, diagnostic indicator of individuals with suspected MDs in the general population.

Growth differentiation factor 15 as a useful biomarker of heart failure in young patients with unrepaired congenital heart disease of left to right shunt.

BACKGROUND: Growth differentiation factor 15 (GDF 15) is a member of the transforming growth factor-beta superfamily and is considered to be a useful biomarker for severity of heart failure (HF) in repaired congenital heart disease (CHD). The aim of this study was to determine the clinical implication of GDF 15 in children with unrepaired CHD. METHODS: Subjects included 69 patients (≤14 years old) who had unrepaired CHD with left to right shunt and underwent cardiac catheterization. Demographic and hemodynamic data, including oxygen demand-supply relationship, were collected from medical records. Severity of HF was evaluated using modified Ross score. Serum GDF 15 levels were determined using enzyme-linked immunosorbent assay and correlated with patients' demographics, hemodynamic data, and blood chemistry data. RESULTS: Subjects had median age of 71 (range 1-173) months and simple acyanotic CHDs with mean pulmonary to systemic flow ratio of 2.0 (1.0-5.6), median N-terminal pro type Brain natriuretic peptide (NT-pro-BNP) of 162.8 (17.1-8789) pg/mL, and median GDF 15 of 242.1 (13.6-1116.7) pg/mL. GDF 15 significantly positively correlated with the modified Ross score, mean pulmonary artery pressure, oxygen extraction rate (OER), and Ln NT-pro-BNP, but negatively correlated with age, oxygen delivery and its components, and estimated glomerular filtration rate (eGFR). Multiple linear regression analysis revealed significant correlation of GDF 15 levels with the modified Ross score, OER, and eGFR. CONCLUSIONS: GDF 15 mainly reflects oxygen demand-supply relationship and can be used as a diagnostic marker of HF in unrepaired CHD with left to right shunt for a wide range of age and diagnoses.

Arginine therapy in mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes.

PURPOSE OF REVIEW: We would like to inform clinicians that the systematic administration of oral and intravenous L-arginine is therapeutically beneficial and clinically useful for patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), when they maintain plasma arginine concentration at least 168 µmol/l. RECENT FINDINGS: MELAS is associated with endothelial dysfunction by decreased plasma L-arginine, nitric oxide (NO), and cyclic guanosine monophosphate. Endothelial dysfunction is also evident using flow-mediated vasodilation measurement by high-resolution Doppler echocardiography in the forearm artery in patients with MELAS. L-arginine is known to be an important precursor of NO to normalize the endothelial function in MELAS. In our clinical trial followed by 7 years follow-up study, the systematic administration of L-arginine to patients with MELAS significantly improved the survival curve of patients compared with natural history. Maintaining plasma arginine concentration at least 168 µmol/l may prevent the ictuses through the putative pathophysiologic mechanism and optimal normalization of endothelial dysfunction. SUMMARY: Neither death nor bedriddenness occurred during the 2-year clinical trials, and the latter did not develop during the 7-year follow-up despite the progressively neurodegenerative and eventually life-threatening nature of MELAS. Therapeutic regimen of L-arginine on MELAS may be beneficial and clinically useful for patient care with MELAS.

GDF-15, a mitochondrial disease biomarker, is associated with the severity of multiple sclerosis.

GDF-15, a member of the transforming growth factor beta superfamily, regulates inflammatory and apoptotic pathways in various diseases, such as heart failure, kidney dysfunction, and cancer. We aimed to clarify potentially confounding variables affecting GDF-15 and demonstrate its utility as a mitochondrial biomarker using serum samples from 15 patients with mitochondrial diseases (MD), 15 patients with limbic encephalitis (LE), 10 patients with multiple sclerosis/neuromyelitis optica spectrum disorders (MS/NMOSD), and 19 patients with amyotrophic lateral sclerosis (ALS). GDF-15 and FGF-21 were significantly elevated in MD. GDF-15 and FGF-21 showed a good correlation in MD but not in LE, MS, and ALS. GDF-15 was potentially influenced by age in LE, MS/NMOSD, and ALS but not in MD. FGF-21 was not correlated with age in MS/NMOSD, ALS, LE, and MD. GDF-15 was not correlated with clinical features in LE or BMI or body weight in ALS. GDF-15 positively correlated with the Expanded Disability Status Scale (EDSS) in MS/NMOSD, while EDSS showed no correlation with age. In conclusion, the results revealed that GDF-15 may be influenced by EDSS in MS/NMOPSD and by age in LE, MS/NMOSD, and ALS but not in MD. Mitochondrial damage in MS/NMOSD is a potentially confounding variable affecting GDF-15.

Successful treatment of infantile-onset ACAD9-related cardiomyopathy with a combination of sodium pyruvate, beta-blocker, and coenzyme Q10.

Mitochondrial acyl-CoA dehydrogenase 9 (ACAD9) deficiency is one of the common causes of respiratory chain complex I deficiency, which is characterized by cardiomyopathy, lactic acidemia, and muscle weakness. Infantile cardiomyopathy is the most common phenotype and is usually lethal by the age of 5 years. Riboflavin treatment is known to be effective in ~65% of the patients; however, the remaining are unresponsive to riboflavin and are in need of additional treatment measures. In this report, we describe a patient with ACAD9 deficiency who developed progressive cardiomyopathy at 8 months of age. As the patient's left ventricular ejection fraction (LVEF) kept decreasing to 45.4% at 1 year 8 months, sodium pyruvate treatment was introduced together with a beta-blocker and coenzyme Q10. This resulted in a steady improvement, with full and sustained normalization of cardiac function without riboflavin. The therapy, therefore, might be a useful addition for the treatment of ACAD9 deficiency.

A case of combined 21-hydroxylase deficiency and CHARGE syndrome featuring micropenis and cryptorchidism.

BACKGROUND: 21-hydroxylase deficiency (21-OHD) is caused due to CYP21A2 gene variant. In males, the excess androgens produce varying degrees of penile enlargement and small testes. CHARGE syndrome (CS) has a broad spectrum of symptoms. In males, genital features such as micropenis and cryptorchidism are found in 48% of CS. There are no reports of patients with combined 21-OHD and CS; therefore, it is unknown whether the external genitalia shows penile enlargement or micropenis with/without cryptorchidism. CASE: A boy, born at 37 weeks and 5 days of gestational age with no consanguineous marriage, was admitted to our hospital due to congenital cleft lip, cleft palate, micropenis, cryptorchidism, and a ventricular septal defect. He had severe hyponatremia and hyperkalemia on day 10. He was diagnosed to have 21-OHD and CS. His external genitalia demonstrated both cryptorchidism and micropenis, but not penile enlargement. METHODS: DNA was extracted from peripheral leukocytes using standard procedures. Sanger sequence was performed in CYP21A2. Exome sequence was performed, and then, Sanger sequence was performed around variant in CHD7. RESULTS: Genetic screening for CYP21A2 gene was performed and compound heterozygous variants of c.293-13A/C>G (IVS2-13A/C>G) and c.518T>A (p.I172N) were detected in chromosome 6p21.3. His mother had been heterozygous variant of c.293-13A/C>G, and his father had been heterozygous variant of c.518T>A. Simultaneously, a de novo splicing acceptor alteration in c.7165-4 A>G, in chromodomain helicase DNA binding protein-7 (CHD7), located in chromosome 8q12 was detected, and the patient was diagnosed with 21-OHD and CS. CONCLUSION: Although these two disorders exhibit different modes of inheritance and their co-morbidity is extremely rare, we encountered one male patient who suffered from both 21-OHD and CS.

Biomarkers and clinical rating scales for sodium pyruvate therapy in patients with mitochondrial disease.

Biomarkers and two clinical rating scales-the Japanese mitochondrial disease-rating scale (JMDRS) and Newcastle mitochondrial disease adult scale (NMDAS)-are clinically used when treating patients with mitochondrial disease. We explored the biomarker(s) and clinical rating scale(s) that are appropriate in preparing the protocol for a future clinical trial of sodium pyruvate (SP) therapy. A 48-week, prospective, single-centre, exploratory, clinical study enrolled 11 Japanese adult patients with genetically, biochemically, and clinically confirmed mitochondrial disease; they had intractable lactic acidosis and received SP (0.5 g/kg t.i.d. PO). Plasma concentrations of lactate and pyruvate, lateral ventricular levels of lactate, and serum concentrations of growth differentiation factor 15 (GDF15) and fibroblast growth factor 21 were measured at baseline and at weeks 12 and 48 of SP therapy. At week 48, plasma lactate (P = .004), the lactate/pyruvate ratio (P = .012), serum GDF15 (P = .020), and lateral ventricular lactate (P = .038) decreased significantly from the baseline values; the JMDRS and NMDAS scores did not decrease significantly, although the NMDAS overall score showed a strong tendency (P = .059). Two patients with end-stage MELAS at baseline died during SP therapy. The present study showed significant decreases in plasma and lateral ventricular lactate, the L/P ratio, and serum GDF15. Therefore, the protocol for a future clinical study of SP therapy in this patient population needs to include plasma and lateral ventricular lactate, the L/P ratio, and serum GDF15 as diagnostic indicators, and exclude patients with end-stage mitochondrial disease.

Temple syndrome diagnosed in an adult patient with clinical autism spectrum disorder.

Temple syndrome (TS14) leads to growth failure, precocious puberty, and diabetes mellitus. However, the long-term prognosis, including the development of social behavior in TS14 patients, remains unclarified. We report the clinical course of a male patient with autism spectrum disorder that received a diagnosis of TS14 at 33 years of age.

Taurine supplementation for prevention of stroke-like episodes in MELAS: a multicentre, open-label, 52-week phase III trial.

OBJECTIVE: The aim of this study was to evaluate the efficacy and safety of high-dose taurine supplementation for prevention of stroke-like episodes of MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes), a rare genetic disorder caused by point mutations in the mitochondrial DNA that lead to a taurine modification defect at the first anticodon nucleotide of mitochondrial tRNALeu(UUR), resulting in failure to decode codons accurately. METHODS: After the nationwide survey of MELAS, we conducted a multicentre, open-label, phase III trial in which 10 patients with recurrent stroke-like episodes received high-dose taurine (9 g or 12 g per day) for 52 weeks. The primary endpoint was the complete prevention of stroke-like episodes during the evaluation period. The taurine modification rate of mitochondrial tRNALeu(UUR) was measured before and after the trial. RESULTS: The proportion of patients who reached the primary endpoint (100% responder rate) was 60% (95% CI 26.2% to 87.8%). The 50% responder rate, that is, the number of patients achieving a 50% or greater reduction in frequency of stroke-like episodes, was 80% (95% CI 44.4% to 97.5%). Taurine reduced the annual relapse rate of stroke-like episodes from 2.22 to 0.72 (P=0.001). Five patients showed a significant increase in the taurine modification of mitochondrial tRNALeu(UUR) from peripheral blood leukocytes (P<0.05). No severe adverse events were associated with taurine. CONCLUSIONS: The current study demonstrates that oral taurine supplementation can effectively reduce the recurrence of stroke-like episodes and increase taurine modification in mitochondrial tRNALeu(UUR) in MELAS. TRIAL REGISTRATION NUMBER: UMIN000011908.

Therapeutic regimen of L-arginine for MELAS: 9-year, prospective, multicenter, clinical research.

OBJECTIVE: To examine the efficacy and safety of the therapeutic regimen using oral and intravenous L-arginine for pediatric and adult patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). METHODS: In the presence and absence of an ictus of stroke-like episodes within 6 h prior to efficacy assessment, we correspondingly conducted the systematic administration of oral and intravenous L-arginine to 15 and 10 patients with MELAS in two, 2-year, prospective, multicenter clinical trials at 10 medical institutions in Japan. Subsequently, patients were followed up for 7 years. The primary endpoint in the clinical trial of oral L-arginine was the MELAS scale, while that for intravenous L-arginine was the improvement rates of headache and nausea/vomiting at 2 h after completion of the initial intravenous administration. The relationships between the ictuses of stroke-like episodes and plasma arginine concentrations were examined. RESULTS: Oral L-arginine extended the interictal phase (p = 0.0625) and decreased the incidence and severity of ictuses. Intravenous L-arginine improved the rates of four major symptoms-headache, nausea/vomiting, impaired consciousness, and visual disturbance. The maximal plasma arginine concentration was 167 µmol/L when an ictus developed. Neither death nor bedriddenness occurred during the 2-year clinical trials, and the latter did not develop during the 7-year follow-up despite the progressively neurodegenerative and eventually life-threatening nature of MELAS. No treatment-related adverse events occurred, and the formulations of L-arginine were well tolerated. CONCLUSIONS: The systematic administration of oral and intravenous L-arginine may be therapeutically beneficial and clinically useful for patients with MELAS.

Phenotypic expression of a novel desmin gene mutation: hypertrophic cardiomyopathy followed by systemic myopathy.

Hypertrophic cardiomyopathy is a heterogeneous disease caused by gene mutations. Most of the disease-causing mutations were found in the genes for sarcomeric proteins, but there are several cases carrying mutations in genes for extra-sarcomeric cytoskeletons. Desmin is a member of extra-sarcomeric cytoskeletons and plays an important role in muscle contraction. Mutations in the desmin gene cause various type of general myopathy and/or cardiomyopathy, known as desmin-related myopathies. We identified a novel desmin missense mutation, Thr219Pro, in the homozygous state in a patient, who first manifested with hypertrophic cardiomyopathy and later progressed to general myopathy. His parents were heterozygous for the mutation, but showed no clinical abnormality, suggesting the recessive inheritance of the mutation. We here report a severe phenotype of hypertrophic cardiomyopathy preceded the onset of general myopathy caused by a novel homozygous missense mutation in the 1B α-helix domain of desmin.

The first Japanese case of central precocious puberty with a novel MKRN3 mutation.

MKRN3, located on chromosome 15q11.2, encodes makorin ring-finger 3, which is an upstream suppressor of the hypothalamic-pituitary-gonadal axis. Mutation of this gene induces central precocious puberty (CPP). As MKRN3 is maternally imprinted, only the paternal allele is expressed. This is the first report of an 8-year-old Japanese girl with CPP caused by a novel frameshift mutation in MKRN3 (p.Glu229Argfs*3).

Mitochondrial diseases.

Mitochondrial diseases are a group of genetic disorders that are characterized by defects in oxidative phosphorylation and caused by mutations in genes in the nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) that encode structural mitochondrial proteins or proteins involved in mitochondrial function. Mitochondrial diseases are the most common group of inherited metabolic disorders and are among the most common forms of inherited neurological disorders. One of the challenges of mitochondrial diseases is the marked clinical variation seen in patients, which can delay diagnosis. However, advances in next-generation sequencing techniques have substantially improved diagnosis, particularly in children. Establishing a genetic diagnosis allows patients with mitochondrial diseases to have reproductive options, but this is more challenging for women with pathogenetic mtDNA mutations that are strictly maternally inherited. Recent advances in in vitro fertilization techniques, including mitochondrial donation, will offer a better reproductive choice for these women in the future. The treatment of patients with mitochondrial diseases remains a challenge, but guidelines are available to manage the complications of disease. Moreover, an increasing number of therapeutic options are being considered, and with the development of large cohorts of patients and biomarkers, several clinical trials are in progress.