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Patient registries for rare diseases enable systematic data collection and can also be used to facilitate postauthorization safety studies (PASS) for orphan drugs. This study evaluates the PASS for betaine anhydrous (Cystadane), conducted as public private partnership (PPP) between the European network and registry for homocystinurias and methylation defects and the marketing authorization holder (MAH). Data were prospectively collected, 2013–2016, in a noninterventional, international, multicenter, registry study. Putative adverse and severe adverse events were reported to the MAH's pharmacovigilance. In total, 130 individuals with vitamin B6 nonresponsive (N = 54) and partially responsive (N = 7) cystathionine beta-synthase (CBS) deficiency, as well as 5,10-methylenetetrahydrofolate reductase (MTHFR; N = 21) deficiency and cobalamin C (N = 48) disease were included. Median (range) duration of treatment with betaine anhydrous was 6.8 (0–9.8) years. The prescribed betaine dose exceeded the recommended maximum (6 g/day) in 49% of individuals older than 10 years because of continued dose adaptation to weight; however, with disease-specific differences (minimum: 31% in B6 nonresponsive CBS deficiency, maximum: 67% in MTHFR deficiency). Despite dose escalation no new or potential risk was identified. Combined disease-specific treatment decreased mean ± SD total plasma homocysteine concentrations from 203 ± 116 to 81 ± 51 μmol/L (p < 0.0001), except in MTHFR deficiency. Recommendations for betaine anhydrous dosage were revised for individuals ≥ 10 years. PPPs between MAH and international scientific consortia can be considered a reliable model for implementing a PASS, reutilizing well-established structures and avoiding data duplication and fragmentation.

Nutritional status is an important protection factor against viral infections. Both undernutrition and malnutrition cause deficits in micronutrients, trace elements and vitamins necessary for various physiological functions and the appropriate functioning of the immune system. These deficiencies and infectious diseases often coexist, with complex interactions. An assessment of the micro-nutrient nutritional status of Covid-19 patients has not been at the center of priorities and recommendations, due to both the medical emergency and the absence of direct evidence and rapid effects of supplementation. Few recommendations have come from learned societies due to the lack of significant evidence of the effects of supplementation in positive patients and a need for robust studies. Essential trace elements and vitamins are necessary for the differentiation, activation and execution of many functions of immune cells, but their specific role has yet to be defined. This review article discusses in the context of Covid-19 the importance of micronutrients (selenium, copper, zinc, vitamins C, D, A and those of group B) in the host to tend towards an optimization of the immune response to infections. A nutritional balance remains the key word for achieving micronutrient homeostasis. Attention had to be paid to micronutrients in primary prevention, in the general population, in order to reduce the risk of impaired nutritional status in case of major health situations.Le statut nutritionnel est important pour protéger des infections virales. La dénutrition comme la malnutrition induisent des déficits en micronutriments, éléments-trace et vitamines nécessaires aux fonctions physiologiques et au fonctionnement du système immunitaire. Ces carences et les maladies infectieuses coexistent souvent en complexes interactions. Une évaluation de l’état nutritionnel en micronutriments des patients Covid-19 n’a pas été au centre des priorités face à l’urgence médicale et à l’absence de preuves directes et rapides des effets de supplémentation. Peu de recommandations ont émané des sociétés savantes par manque de preuves significatives des effets de supplémentations, avec une nécessité d’études robustes. S’il est reconnu que les oligo-éléments essentiels et les vitamines sont nécessaires à la différenciation, l’activation et l’exécution de fonctions des cellules immunitaires, leur rôle spécifique reste encore à définir. Cette synthèse aborde dans la Covid-19 l’importance des micronutriments (sélénium, cuivre, zinc, vitamines C, D, A et groupe B) chez l’hôte pour tendre vers une optimisation de la réponse immunitaire aux infections. En prévention primaire, en population générale, un équilibre nutritionnel reste central pour atteindre l’homéostasie des micronutriments, pour diminuer le risque des situations de déséquilibre et de fragilisation face à des situations sanitaires d’ampleur.

Item does not contain fulltext 5,10-Methylenetetrahydrofolate reductase (MTHFR) deficiency usually presents as a severe neonatal disease. This study aimed to characterize natural history, biological and molecular data, and response to treatment of patients with late-onset MTHFR deficiency. The patients were identified through the European Network and Registry for Homocystinuria and Methylation Defects and the Adult group of the French Society for Inherited Metabolic Diseases; data were retrospectively colleted. To identify juvenile to adult-onset forms of the disease, we included patients with a diagnosis established after the age of 10 years. We included 14 patients (median age at diagnosis: 32 years; range: 11-54). At onset (median age: 20 years; range 9-38), they presented with walking difficulties (n = 8), cognitive decline (n = 3) and/or seizures (n = 3), sometimes associated with mild mental retardation (n = 6). During the disease course, symptoms were almost exclusively neurological with cognitive dysfunction (93%), gait disorders (86%), epilepsy (71%), psychiatric symptoms (57%), polyneuropathy (43%), and visual deficit (43%). Mean diagnostic delay was 14 years. Vascular events were observed in 28% and obesity in 36% of the patients. One patient remained asymptomatic at the age of 55 years. Upon treatment, median total homocysteine decreased (from 183 μmol/L, range 69-266, to 90 μmol/L, range 20-142) and symptoms improved (n = 9) or stabilized (n = 4). Missense pathogenic variants in the C-terminal regulatory domain of the protein were over-represented compared to early-onset cases. Residual MTHFR enzymatic activity in skin fibroblasts (n = 4) was rather high (17%-58%). This series of patients with late-onset MTHFR deficiency underlines the still unmet need of a prompt diagnosis of this treatable disease.

BACKGROUND: Urea cycle disorders (UCD) are rare diseases that usually affect neonates or young children. During decompensations, hyperammonemia is neurotoxic, leading to severe symptoms and even coma and death if not treated rapidly. AIMS: Description of a cohort of patients with adult onset of UCDs. METHODS: Multicentric, retrospective and descriptive study of French adult patients with a diagnosis after 16 years of age of UCDs due to a deficiency in one of the 6 enzymes (arginase, ASL, ASS, CPS1, NAGS, OTC) or the two transporters (ORNT1 or citrin). RESULTS: Seventy-one patients were included (68% female, 32% male). The diagnosis was made in the context of (i) a metabolic decompensation (42%), (ii) family history (55%), or (iii) chronic symptoms (3%). The median age at diagnosis was 33 years (range 16-86). Eighty-nine percent of patients were diagnosed with OTC deficiency, 7% CPS1 deficiency, 3% HHH syndrome and 1% argininosuccinic aciduria. For those diagnosed during decompensations (including 23 OTC cases, mostly female), 89% required an admission in intensive care units. Seven deaths were attributed to UCD - 6 decompensations and 1 epilepsy secondary to inaugural decompensation. CONCLUSION: This is the largest cohort of UCDs diagnosed in adulthood, which confirms the triad of neurological, gastrointestinal and psychiatric symptoms during hyperammonemic decompensations. We stress that females with OTC deficiency can be symptomatic. With 10% of deaths in this cohort, UCDs in adults remain a life-threatening condition. Physicians working in adult care must be aware of late-onset presentations given the implications for patients and their families. This article is protected by copyright. All rights reserved.

During glutamine sufficiency, both Notch‐positive and Notch‐negative T‐ALL cells promote glutamine catabolism, leading to mammalian target of rapamycin complex 1 (mTORC1) activation and cell growth and proliferation. However, during glutamine scarcity, only Notch‐negative T‐ALL cells can perform a metabolic adaptation by promoting glutamine synthesis. By contrast, Notch‐positive T‐ALL cells maintain glutamine catabolism during glutamine restriction, leading to glutamine addiction and mTORC1 dependency., The cellular receptor Notch1 is a central regulator of T‐cell development, and as a consequence, Notch1 pathway appears upregulated in > 65% of the cases of T‐cell acute lymphoblastic leukemia (T‐ALL). However, strategies targeting Notch1 signaling render only modest results in the clinic due to treatment resistance and severe side effects. While many investigations reported the different aspects of tumor cell growth and leukemia progression controlled by Notch1, less is known regarding the modifications of cellular metabolism induced by Notch1 upregulation in T‐ALL. Previously, glutaminolysis inhibition has been proposed to synergize with anti‐Notch therapies in T‐ALL models. In this work, we report that Notch1 upregulation in T‐ALL induced a change in the metabolism of the important amino acid glutamine, preventing glutamine synthesis through the downregulation of glutamine synthetase (GS). Downregulation of GS was responsible for glutamine addiction in Notch1‐driven T‐ALL both in vitro and in vivo. Our results also confirmed an increase in glutaminolysis mediated by Notch1. Increased glutaminolysis resulted in the activation of the mammalian target of rapamycin complex 1 (mTORC1) pathway, a central controller of cell growth. However, glutaminolysis did not play any role in Notch1‐induced glutamine addiction. Finally, the combined treatment targeting mTORC1 and limiting glutamine availability had a synergistic effect to induce apoptosis and to prevent Notch1‐driven leukemia progression. Our results placed glutamine limitation and mTORC1 inhibition as a potential therapy against Notch1‐driven leukemia.

International audience; Metabolic reprogramming is a common hallmark of cancer, but a large variability in tumor bioenergetics exists between patients. Using high-resolution respirometry on fresh biopsies of human lung adenocarcinoma, we identified 2 subgroups reflected in the histologically normal, paired, cancer-adjacent tissue: high (OX+) mitochondrial respiration and low (OX-) mitochondrial respiration. The OX+ tumors poorly incorporated [F-18]fluorodeoxy-glucose and showed increased expression of the mitochondrial trifunctional fatty acid oxidation enzyme (MTP; HADHA) compared with the paired adjacent tissue. Genetic inhibition of MTP altered OX+ tumor growth in vivo. Trimetazidine, an approved drug inhibitor of MTP used in cardiology, also reduced tumor growth and induced disruption of the physical interaction between the MTP and respiratory chain complex I, leading to a cellular redox and energy crisis. MTP expression in tumors was assessed using histology scoring methods and varied in negative correlation with [F-18]fluorodeoxy-glucose incorporation. These findings provide proof-of-concept data for preclinical, precision, bioenergetic medicine in oxidative lung carcinomas.

Background Continuous renal replacement therapy (CRRT) is associated with micronutrients loss. Current recommendations are to administer 1–1.5 g/kg/day of proteins during CRRT. We aim to evaluate the net effect of CRRT on amino acids (AA), vitamins A and C (Vit A, Vit C) levels. Methods This is a prospective observational study embedded within a randomised controlled trial comparing two CRRT doses in patients with septic shock. CRRT was provided in continuous veno-venous haemofiltration mode at a dose of either 35 ml/kg/h or 70 ml/kg/h. All patients received parenteral nutrition with standard trace elements and vitamins (protein intake 1 g/kg/d). We measured serum levels of glutamine, valine and alanine as well as Vit A and Vit C upon randomisation, study day four and eight. In addition, we measured a larger panel of AA in a subset of 11 patients. Results We included 30 patients (17 allocated to 70 ml/kg/h and 13 to 35 ml/kg/h CRRT). Before CRRT initiation, mean plasma levels of glutamine and valine, Vit A and Vit C were low. CRRT was not associated with any significant change in AA levels except for a decrease in cystein. It was associated with an increase in Vit A and a decrease in Vit C levels. CRRT dose had no impact on those nutrients blood levels. Conclusions Irrespective of dose, CRRT was associated with a decrease in cysteine and Vit C and an increase in Vit A with no significant change in other AA. Further studies should focus on lean mass wasting during CRRT.

International audience; Background: Despite ACADS (aryl-CoA dehydrogenase, short-chain) gene susceptibility variants (c.511C \textgreater T and c.625G \textgreater A) are considered to be non-pathogenic, encoded proteins are known to exhibit altered kinetics. Whether or not, they might affect overall fatty acid beta-oxidation still remains, however, unclear. Methods: De novo biosynthesis of acylcarnitines by whole blood samples incubated with deuterated palmitate (16-H-2(3),15-H-2(2)-palmitate) is suitable as a fluxomic exploration to distinguish between normal and disrupted beta-oxidation, abnormal profiles and ratios of acylcarnitines with different chain-lengths being indicative of the site for enzymatic blockade. Determinations in 301 control subjects of ratios between deuterated butyrylcarnitine and sum of deuterated C2 to C14 acylcarnitines served here as reference values to state specifically functional SCAD impairment in patients addressed for clinical and/or biological suspicion of a beta-oxidation disorder. Results: Functional SCAD impairment was found in 39 patients. The 27 patients accepting subsequent gene studies were all positive for ACADS mutations. Twenty-six of 27 patients were positive for c.625G \textgreater A variant. Twenty-three of 27 patients harbored susceptibility variants as sole ACADS alterations (18 homozygous and 3 heterozygous for c.625G \textgreater A, 2 compound heterozygous for c.625G \textgreater A/c.511C \textgreater T). Conclusion: Our present fluxomic assessment of SCAD suggests a link between ACADS susceptibility variants and abnormal beta-oxidation consistent with known altered kinetics of these variants.

Background: The encephalomyopathic mtDNA depletion syndrome with methylmalonic aciduria is associated with deficiency of succinate-CoA ligase, caused by mutations in SUCLA2 or SUCLG1. We report here 25 new patients with succinate-CoA ligase deficiency, and review the clinical and molecular findings in these and 46 previously reported patients. Patients and results: Of the 71 patients, 50 had SUCLA2 mutations and 21 had SUCLG1 mutations. In the newly-reported 20 SUCLA2 patients we found 16 different mutations, of which nine were novel: two large gene deletions, a 1 bp duplication, two 1 bp deletions, a 3 bp insertion, a nonsense mutation and two missense mutations. In the newly-reported SUCLG1 patients, five missense mutations were identified, of which two were novel. The median onset of symptoms was two months for patients with SUCLA2 mutations and at birth for SUCLG1 patients. Median survival was 20 years for SUCLA2 and 20 months for SUCLG1. Notable clinical differences between the two groups were hepatopathy, found in 38 % of SUCLG1 cases but not in SUCLA2 cases, and hypertrophic cardiomyopathy which was not reported in SUCLA2 patients, but documented in 14 % of cases with SUCLG1 mutations. Long survival, to age 20 years or older, was reported in 12 % of SUCLA2 and in 10 % of SUCLG1 patients. The most frequent abnormality on neuroimaging was basal ganglia involvement, found in 69 % of SUCLA2 and 80 % of SUCLG1 patients. Analysis of respiratory chain enzyme activities in muscle generally showed a combined deficiency of complexes I and IV, but normal histological and biochemical findings in muscle did not preclude a diagnosis of succinate-CoA ligase deficiency. In five patients, the urinary excretion of methylmalonic acid was only marginally elevated, whereas elevated plasma methylmalonic acid was consistently found. Conclusions: To our knowledge, this is the largest study of patients with SUCLA2 and SUCLG1 deficiency. The most important findings were a significantly longer survival in patients with SUCLA2 mutations compared to SUCLG1 mutations and a trend towards longer survival in patients with missense mutations compared to loss-of-function mutations. Hypertrophic cardiomyopathy and liver involvement was exclusively found in patients with SUCLG1 mutations, whereas epilepsy was much more frequent in patients with SUCLA2 mutations compared to patients with SUCLG1 mutations. The mutation analysis revealed a number of novel mutations, including a homozygous deletion of the entire SUCLA2 gene, and we found evidence of two founder mutations in the Scandinavian population, in addition to the known SUCLA2 founder mutation in the Faroe Islands.

Fossard, Gaelle Blond, Emilie Balsat, Marie Morisset, Stephane Giraudier, Stephane Escoffre-Barbe, Martine Labussiere-Wallet, Helene Heiblig, Mael Bert, Arthur Etienne, Madeleine Drai, Jocelyne Sobh, Mohamad Redonnet-Vernhet, Isabelle Lega, Jean-Christophe Mahon, Francois-Xavier Etienne, Gabriel Nicolini, Franck Emmanuel; International audience

Many risk factors of aseptic osteonecrosis (AO) are well-known, even if 40% of events are idiopathic. Intravascular thrombosis is one of the physiopathological mechanisms of AO. The aim of this study is to determine the influence of coagulopathies on AO set-up. We performed a prospective case–control study, with 39 cases and 39 controls matched on age and sex. Cases are defined according to radiological criteria, and controls as non-affected by renal or hepatic insuffiency, and without inflammatory syndrome. Well-known AO risk factors were studied. Assessment of thrombosis was based on anti-phospholipid, anti s2 Glycoprotein I, antiprothrombin, anti-cardiolipin, antithrombin, protein S and C, factor V Leiden, prothrombin gene and MTHFR mutations. 71% of cases presented a classical AO risk factor, vs. 38% of the controls. A significant association was also found between smoking and risk of AO. No significant difference in coagulopathy frequency was shown between cases and controls (56.4% vs. 48.7% respectively, p > 0.05). Only abusive consumption of alcohol and tobacco is associated with risk of AO. Our study did not demonstrate any implication of coagulopathies in AO susceptibility. Further studies are needed to investigate more precisely these features.

Resume Objectifs Bien que de nombreux facteurs de risque aient ete decrits au cours de l’osteonecrose aseptique (ON), le bilan etiologique n’identifie aucun de ces facteurs dans environ 40 % des cas qui sont alors consideres comme idiopathique. Depuis quelques annees, differentes coagulopathies ont ete incriminees dans le risque de thrombose intravasculaire. Ces coagulopathies pourraient-elles intervenir dans la physiopathologie de certaines ON et expliquer une part des formes dites idiopathiques ? Methodes Nous avons realise une etude prospective comportant 39 cas et 39 temoins. Les cas sont des sujets affectes d’une ON d’apres des criteres radiologiques. Les temoins sont apparies sur l’âge et le sexe, indemnes d’insuffisance renale, hepatique et syndrome inflammatoire. Les facteurs de risque classique d’ON ont ete recherches pour chacun des patients. Le bilan de thrombose comprenait : antiphospholipides, anti-2GPI, antiprothrombine, anticoagulant circulant lupique, lipoproteine (a), proteines S et C, antithrombine, resistance a la proteine C activee, mutation du gene de la prothrombine et de la 5,10 Methylenetetrahydrofolate reductase (MTHFR). Resultats Soixante et onze pour cent des cas presentaient un facteur de risque classique d’ON contre 38 % des temoins. Le tabagisme, non identifie comme un facteur de risque traditionnel d’ON, est egalement plus frequemment retrouve chez les cas que chez les temoins. Un pourcentage de 56,4 % des cas presentaient au moins une coagulopathie contre 48,7% des temoins (difference non significative). Conclusion Les facteurs classiques d’ON qui sont statistiquement significatives sont l’exogenose et le tabagisme. Notre etude ne plaide pas pour une influence des coagulopathies dans la constitution d’une ON. Des etudes de plus grande envergure sont necessaires pour confirmer ces conclusions.

The Papillon–Lefèvre syndrome (PLS) is an autosomal recessive disorder. The gene responsible for the disease, cathepsin C (CTSC), is localized in 11q14.1–q14.21. We performed mutational and functional analyses of CTSC in two patients affected by this condition. Three previously unreported CTSC mutations were identified. The first patient had a compound heterozygous status with a p.G386R missense mutation and an intragenic deletion spanning exons 3–7. Second patient carried a homozygous splice site mutation, p.A253SfsX30. CTSC activity was undetectable in both patients, thus demonstrating the pathological effect of these mutations. We describe early evidence of an original intragenic deletion reported in PLS. Since this mutational mechanism could not be detected by direct sequencing, intragenic deletion has to be specifically investigated using gene dosage analysis techniques such as quantitative multiplex fluorescent polymerase chain reaction. We consider that this technique should be performed in patients with apparently homozygous CTSC mutations when one parent does not carry the expected mutation or is not available for analysis.

Keypoints Fabry disease is a rare and underrecognized disease associated with an altered X-linked gene controlling hydrolase alpha-galactosidase A activity. This mutation impairs the glycosphingolipid metabolism. A multisystemic disease with a highly variable clinical presentation , its principal symptom is acroparesthesia. Manifestations of Fabry disease occur mostly in hemizygous males but also in heterozygous females. Before enzyme replacement therapy was available, life expectancy was about 50 years in men and 70 years in women. Early diagnosis is essential to prevent irreversible organ damage. Diagnosis is based on an assay of alpha-galactosidase A activity in male patients and on genetic analysis in female patients. Prognosis is related principally to three complications: involvement of the central nervous system, kidneys, and heart. Management of Fabry patients should in all cases combine symptomatic therapy and regular clinical, laboratory and morphological follow-up by specialists in genetic metabolic diseases. Enzyme replacement therapy should be considered in all adult male patients and should probably begin early. In adult heterozygous female patients and in children, this treatment should be considered only for patients with severe pain, organ damage, or central nervous system, kidney, or heart involvement. After a proband is identified, a genealogical tree should be used to identify other affected members of the family.

Introduction Les syndromes de deficit en creatine regroupent trois maladies hereditaires affectant le metabolisme de la creatine : le deficit en guanidinoacetate methyltransferase (GAMT), le deficit en arginine : glycine amidinotransferase (AGAT) et le deficit en transporteur membranaire de la creatine (CRTR). Ces pathologies se traduisent par un deficit cerebral en creatine ayant pour consequence une atteinte neurologique peu specifique avec retard mental. Le dosage du guanidinoacetate et de la creatine au niveau urinaire et plasmatique par LC-MS/MS permet de poser le diagnostic, et d’orienter vers l’un des trois deficits. A ce jour, l’analyse de ces molecules polaires et basiques s’avere delicate. En effet pour l’etude de ces molecules peu retenues sur colonne standard, la methode de reference requiert une etape de derivatisation par butanol/HCl 6 M rendant la technique longue et contraignante. Pour s’affranchir de cette etape, il a ete choisi d’utiliser la technique d’appariement d’ions. Le principe consiste en l’ajout, au niveau des deux phases mobiles, d’un ion de charge opposee a la molecules d’interet, de telle sorte qu’ils puissent ensemble former un complexe non charge. Le contre ion, ici l’acide perfluoropentanoique, possedant une chaine hydrophobe, va interagir via celle-ci avec la phase stationnaire organique permettant ainsi une plus forte retention du complexe. Materiels et methode Une gamme d’etalonnage a ete choisie pour couvrir les valeurs biologiques et pathologiques. Les points de gamme, les controles de qualite interne et les urines des patients sont diluees au 1/20 dans une solution aqueuse d’etalon interne. Apres agitation et centrifugation, ils sont analyses directement par LC-MS/MS (Alliance, Quattromicro Waters). L’utilisation de la technique d’appariement d’ions permet d’eliminer une etape de derivatisation par esterification lente et delicate. Pour valider la methode, il a ete choisi de suivre les recommandations du COFRAC (portee B) tout en les adaptant aux criteres specifiques des dosages realises par technique chromatographique. Resultas Les CV intra-jours representant la repetabilite et les CV inter-jours representant la reproductibilite sont tous inferieurs a 15 % meme pour la LOQ prouvant ainsi la fidelite de notre methode. La justesse, evaluee par les echantillons externes de qualite, s’est averee bonne avec des biais Conclusion Dans le dosage du guanidinoacetate et de la creatine par LC MS/MS, l’utilisation de l’appariement d’ions que nous avons developpe permet une simplification technique de la methode ainsi qu’un un gain de temps et apparait donc comme une optimisation de la methode actuelle.

Because mobilized peripheral blood (mPB) represents an attractive source of cells for gene therapy, we investigated lentiviral gene transfer in CD34(+) cells and the stem/progenitor-cell-enriched CD34(+)/38(-)/lin(-) cell subset isolated from mPB. In this study, we used an optimized third-generation self-inactivating lentiviral vector containing both the central polypurine tract and the woodchuck hepatitis posttranscriptional regulatory element sequences and encoding enhanced green fluorescent protein (EGFP) under the control of the elongation factor lalpha promoter. This lentivector was first used to compare multiplicity of infection (MOI)-dependent gene transfer efficiency in cord blood (CB) versus mPB CD34(+)-derived cells, colony-forming cells (CFCs), and long-term culture-initiating cells (LTC-ICs). Results showed a difference in the percentage of transduced cells particularly significant at low MOIs. A plateau was reached where 15% and 25% of CB and mPB cells, respectively, remained refractory to lentiviral trans-duction. Effects of a cytokine prestimulation period (18 hours) with interleukin-3, stem cell factor, Flt-3 ligand, and thrombopoietin were then analyzed in total cells, CFCs, and LTC-ICs derived from mPB CD34(+) cells. Transduction levels in those conditions demonstrated a two- and fourfold increase in CFCs and LTC-ICs, respectively, compared with unstimulated ( 85% of colonies derived from LTC-ICs expressing EGFP and gene transfer levels remaining stable for 10 weeks in liquid culture. We therefore demonstrate a highly efficient gene transfer in this therapeutically relevant target cell population.

Background Erythropoietic protoporphyria (EPP) is an inherited disease characterised by a ferrochelatase (FECH) deficiency, the latest enzyme of the heme biosynthetic pathway, leading to the accumulation of toxic protoporphyrin in the liver, bone marrow and spleen. We have previously shown that a successful gene therapy of a murine model of the disease was possible with lentiviral vectors even in the absence of preselection of corrected cells, but lethal irradiation of the recipient was necessary to obtain an efficient bone marrow engraftment. To overcome a preconditioning regimen, a selective growth advantage has to be conferred to the corrected cells. Methods We have developed a novel bicistronic lentiviral vector that contains the human alkylating drug resistance mutant O6-methylguanine DNA methyltransferase (MGMT G156A) and FECH cDNAs. We tested their capacity to protect hematopoietic cell lines efficiently from alkylating drug toxicity and correct enzymatic deficiency. Results EPP lymphoblastoid (LB) cell lines, K562 and cord-blood-derived CD34+ cells were transduced at a low multiplicity of infection (MOI) with the bicistronic constructs. Resistance to O6-benzylguanine (BG)/N,N′-bis(2-chloroethyl)-N-nitrosourea (BCNU) was clearly shown in transduced cells, leading to the survival and expansion of provirus-containing cells. Corrected EPP LB cells were selectively amplified, leading to complete restoration of enzymatic activity and the absence of protoporphyrin accumulation. Conclusions This study demonstrates that a lentiviral vector including therapeutic and G156A MGMT genes followed by BG/BCNU exposure can lead to a full metabolic correction of deficient cells. This vector might form the basis of new EPP mouse gene therapy protocols without a preconditioning regimen followed by in vivo selection of corrected hematopoietic stem cells. Copyright © 2003 John Wiley & Sons, Ltd.

The molecular defects in the LIPA gene encoding the lysosomal acid lipase (LAL) were investigated in two unrelated patients affected with cholesteryl ester storage disease (CESD), an autosomal recessive disorder associated with LAL-deficient activity. In cell lysates from both patients there was a severely reduced LAL activity. In a female patient, nucleotide sequencing of amplified LAL genomic DNA or reverse-transcribed mRNA demonstrated that she was a compound heterozygote for two previously reported mutations, a G --> A transition at position -1 of the exon 8 splice donor site, resulting in skipping of the complete exon 8, and a C923 --> T substitution leading to the replacement of His274 to Tyr. The second, male CESD patient was heterozygous for the splice junction mutation and a yet undescribed C --> T substitution at position 233, which introduces a premature in-frame termination codon. The functional consequences of these genetic alterations were evaluated for the first time by studying the catabolic turnover of radiolabeled cholesteryl oleate in intact cells. A lower in situ residual LAL activity was found in cells carrying the stop codon mutation than in cells having the His274 --> Tyr substitution. Since the severely reduced LAL activity was seen in cells from an adult patient with a mild CESD, we conclude that there is no simple direct correlation between the LAL molecular lesions and the biochemical and clinical phenotypes.

The molecular defects in the HEXB gene encoding the common beta-subunit of lysosomal beta-hexosaminidase A (beta-Hex A, alpha beta) and beta-Hex B (beta beta) were investigated in a Portuguese family affected with late onset Sandhoff disease (GM2-gangliosidosis variant 0). This family comprised two unaffected daughters and three affected sibs who developed at about age 17 cerebellar ataxia and mental deficiency. Their parents were consanguineous and clinically asymptomatic. There was no detectable beta-Hex B activity and a profound reduction in the activity of beta-Hex A in the leukocytes and transformed lymphoid cell lines from the affected sibs. The expected intermediate values were observed in the parents as well as in one daughter and her children. Western analysis revealed the presence of reduced, but detectable amounts of mature beta-chain protein in cell lysates from the probands and intermediate levels in the parents. Nucleotide sequencing of amplified, reverse-transcribed beta-chain mRNA demonstrated the presence of two single point mutations: an A619 to G transition in exon 5 (Ile207-->Val), and a G1514 to A transition in exon 13 (Arg505-->Gln). Both of these two mutations have been previously linked to the adult form of Sandhoff disease in compound heterozygote patients. All three affected sibs were found to be homoallelic for both mutations. Interestingly, while the mother was heterozygous for each mutation, the father was homozygote for the A619-->G substitution and heterozygote for the G1514-->A transition. Since the father is homozygote for the A619-->G mutation but expresses a biochemical phenotype consistent with a carrier of Sandhoff disease and is clinically asymptomatic, this substitution is likely a neutral mutation. We confirmed this hypothesis by finding this transition present in 4 of 30 alleles from normal individuals. We conclude that homozygosity for the G1514-->A mutation is exclusively responsible for the adult form of Sandhoff disease in this family, and that the A619-->G substitution is not a deleterious mutation but rather a common HEXB polymorphism.

Phenylketonuria (PKU) leads to severe neurological disorders in childhood, shunned by the diet. The long-term prognosis after diet diversification at adolescence is uncertain. We report a case of cortical blindness in a young patient regressive 1 month after the diet was resumed.Mr M., 25 years old, had PKU detected at birth. He maintained good serum levels of Phenylalanine (Phe) (120-300 μmol/L) during childhood and got a normal intellectual development. During adolescence he diversified his diet but maintained low meat and fish intake; Phe was ~1,200 μmol/L with no symptoms. In 2009, the patient stopped the low-Phe amino acid substitutes due to weariness. On June 27, 2011, he consulted for a decrease of visual acuity progressing for 6 months. Ophthalmologic examination found that visual acuity was 2/10 in two eyes associated to a central visual field defect. The visual evoked potentials were altered. MRI showed bilateral and symmetric occipital FLAIR hyperintensities. On admission in the Nutrional Unit on June 29, 2011, blood pressure was 120/70 mmHg, there was no other neurological abnormality. Phe was at 1,512 μmol/L, and not responsive to BH4. He was then treated with a very low-Phe diet with an amino acid substitute, and he obtained Phe between 120 and 300 μmol/L. Visual acuity was suddenly restored on August 1, 2011, with a dramatic attenuation of the MRI hyperintensities.Our observation shows that the withdrawal of the diet and substitutes exposes to serious neurological complications in adults that may reverse with a fast nutritional support.

We were very interested by the recent article by Almurdhi et al. (1) that reported a reduction of lower-limb strength in patients with type 2 diabetes mellitus (T2DM) and neuropathy. Unexpectedly, the authors did not detect any relation between the reduced muscle strength and the 25-hydroxyvitamin D levels. We wondered whether another modifiable factor, the treatment with statins, may play a role in lower-limb weakness and neuropathy in these patients. We are presently researching whether any modifiable superimposed factor may contribute to neuropathy in patients with T2DM. In …

Medium-chain acyl-CoA deshydrogenase deficiency (MCADD) is the most frequent disorder of mitochondrial fatty acid oxidation (MFAO). We report a 3 year-old girl with enterovirus viremia who was referred after 36 hours of fasting with hypoketotic hypoglycemic coma and myolysis. Evolution was complicated by acute renal failure, increased serum levels of transaminases and hypoparathyroidism. Diagnosis of MCADD was supported by typical plasma acylcarnitine and urinary organic acid profiles, and confirmed by homozygosity for the common missense A985G mutation. Whereas myolysis is frequent in MFAO defects, it is rarely reported as a major accompanying sign in MCADD. Hypoparathyroidism has been previously reported in some MFAO deficiencies but has never been mentioned in association with MCADD. We review the possible mechanisms of hypoparathyroidism in MFAO deficiencies. Parathyroid glands and pancreas dysfunction should be screened in MFAO defects as these organs could be implicated in the clinical spectrum of the frequent A985G MCADD disease-causing mutation.

Fabry disease is a rare and under-recognized disease associated with an altered X-linked gene controlling hydrolase alpha-galactosidase A activity. This mutation impairs the glycosphingolipid metabolism. A multisystemic disease with a highly variable clinical presentation, its principal symptom is acroparesthesia. Manifestations of Fabry disease occur mostly in hemizygous males but also in heterozygous females. Before enzyme replacement therapy was available, life expectancy was about 50 years in men and 70 years in women. Early diagnosis is essential to prevent irreversible organ damage. Diagnosis is based on an assay of alpha-galactosidase A activity in male patients and on genetic analysis in female patients. Prognosis is related principally to three complications: involvement of the central nervous system, kidneys, and heart. Management of Fabry patients should in all cases combine symptomatic therapy and regular clinical, laboratory and morphological follow-up by specialists in genetic metabolic diseases. Enzyme replacement therapy should be considered in all adult male patients and should probably begin early. In adult heterozygous female patients and in children, this treatment should be considered only for patients with severe pain, organ damage, or central nervous system, kidney, or heart involvement. After a proband is identified, a genealogical tree should be used to identify other affected members of the family.

Despite its high efficacy on CML, long-term exposure to nilotinib, a second generation tyrosine kinase inhibitor (TKI2), has been reported to increase the onset of arterial cardiovascular events (CVE) in chronic phase (CP) CML patients (pts), especially in pts with cardiovascular risk factors. However, some pts without any cardiovascular risk factors may experience arterial thrombotic events and the pathogenesis of this phenomenon remains obscure. Homocystein (HC) is a key sulphured amino-acid derived from methionin, independently associated with increased frequencies of thrombo-embolic events, early arteriosclerosis and increased cardiovascular mortality (Nygard NEJM 1997). In addition, in vitro, this amino-acid induces the proliferation of smooth muscle cells, endothelial cell dysfunction, increased collagen synthesis and exerts pro-inflammatory rearrangements within the arterial wall. In the present study, we wanted to determine if hyperhomocysteinemia might influence the onset of cardio-vascular events in a series of 114 CP CML pts on nilotinib. We have prospectively analysed in a multicentric study, on-nilotinib cohorts of CP CML pts between September 2011 and July 2014 with standard clinical assessments [height, weight, body mass index (BMI)], onset of any CV events, and basic routine blood metabolic laboratory assessments (fasting glucose, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, glycosylated haemoglobin, homocysteinemia (Biorad kit on HLPC on Summit Dionex system, Thermo Fischer scientific, France), vitamines B9 and B12. All the 114 pts were in CP-CML on nilotinib [43 as first-line, 71 as second-line or more, since a median of 51.5 (3-164) months], 49 were males, with a median age of 51.7 (18-81) at CML diagnosis and 58 (82-20) at nilotinib initiation. Twenty-eight (24.5%) pts presented some CV risk factors prior to nilotinib initiation, and 24 (21%) had an active tobacco abuse at assessment (4 patients unknown). Median weight was 69 (44-149) kg and median BMI was 24.5 (16.5-46) kg/m2 (8 patients >30). Overall, 21 (18.5) pts presented new or worsened pre-existing CVE on nilotinib after a median follow-up of 51.5 months since TKI2 initiation. These CVE occurred after a median of 47 (7.5-82.3) months with a regular increase along the years (Cumulative incidence (CI) 3% at 1 year, 4.12% at 2, 5.15% at 3, 9.30 at 5 and 20.62% at 8.3 years). In total, 3 pts died, 2 from brain stroke, 1 from sudden death in a pt with a history of myocardial infarction. In an univariate analysis we compared our cohort of nilotinib pts to a similar cohort of 17 pts on imatinib as control [median age 56 years since CML diagnosis (p=ns), median duration of imatinib 39 months (p=ns), median weight 70.5 kg (p=ns), BMI 25.9 kg/m2 (p=ns)]. None of these imatinib pts had shown any CVE during follow-up. HC was significantly lower in imatinib-treated pts (p=0.029), in female pts (p=0.018) and increased with age (p Figure 1 Cumulative incidence of CVE on nilotinib according to the level of HC. Figure 1. Cumulative incidence of CVE on nilotinib according to the level of HC. The CI of CVE was significantly higher in pts on nilotinib 800 mg daily (38% at latest follow-up) versus pts on ≤600 mg daily, (10%, p=0.005, Gray test). Finally multivariate analysis identified age [p In conclusion, nilotinib seems to favour CVE in the long-term in CP CML pts, especially in patients with CV risk factors, and these CVE are specifically linked to higher doses of nilotinib and high levels of homocysteinemia. This marker could represent a useful tool to detect pts at risk of arterial CVE on nilotinib. Whether hyperhomocysteinemia is one of the causes of CVE of a consequence of nilotinib treatment remains to be determined. Disclosures Michallet: Genzyme: Consultancy; Oseus: Consultancy; BMS: lectures, lectures Other; Novartis: lectures, lectures Other; MSD: lectures Other. Etienne:Novartis: Consultancy; BMS: lectures, lectures Other. Nicolini:Novartis: Consultancy, Honoraria; BMS: Consultancy, Honoraria.

Erythropoietic protoporphyria (EPP) is an inherited disease characterised by a ferrochelatase (FECH) deficiency, the latest enzyme of the heme biosynthetic pathway, leading to the accumulation of toxic protoporphyrin in the liver, bone marrow and spleen. We have previously shown that a successful gene therapy of a murine model of the disease was possible with lentiviral vectors even in the absence of preselection of corrected cells, but lethal irradiation of the recipient was necessary to obtain an efficient bone marrow engraftment. To overcome a preconditioning regimen, a selective growth advantage has to be conferred to the corrected cells.We have developed a novel bicistronic lentiviral vector that contains the human alkylating drug resistance mutant O(6)-methylguanine DNA methyltransferase (MGMT G156A) and FECH cDNAs. We tested their capacity to protect hematopoietic cell lines efficiently from alkylating drug toxicity and correct enzymatic deficiency.EPP lymphoblastoid (LB) cell lines, K562 and cord-blood-derived CD34(+) cells were transduced at a low multiplicity of infection (MOI) with the bicistronic constructs. Resistance to O(6)-benzylguanine (BG)/N,N'-bis(2-chloroethyl)-N-nitrosourea (BCNU) was clearly shown in transduced cells, leading to the survival and expansion of provirus-containing cells. Corrected EPP LB cells were selectively amplified, leading to complete restoration of enzymatic activity and the absence of protoporphyrin accumulation.This study demonstrates that a lentiviral vector including therapeutic and G156A MGMT genes followed by BG/BCNU exposure can lead to a full metabolic correction of deficient cells. This vector might form the basis of new EPP mouse gene therapy protocols without a preconditioning regimen followed by in vivo selection of corrected hematopoietic stem cells.

Because mobilized peripheral blood (mPB) represents an attractive source of cells for gene therapy, we investigated lentiviral gene transfer in CD34(+) cells and the stem/progenitor-cell-enriched CD34(+)/38(-)/lin(-) cell subset isolated from mPB. In this study, we used an optimized third-generation self-inactivating lentiviral vector containing both the central polypurine tract and the woodchuck hepatitis posttranscriptional regulatory element sequences and encoding enhanced green fluorescent protein (EGFP) under the control of the elongation factor lalpha promoter. This lentivector was first used to compare multiplicity of infection (MOI)-dependent gene transfer efficiency in cord blood (CB) versus mPB CD34(+)-derived cells, colony-forming cells (CFCs), and long-term culture-initiating cells (LTC-ICs). Results showed a difference in the percentage of transduced cells particularly significant at low MOIs. A plateau was reached where 15% and 25% of CB and mPB cells, respectively, remained refractory to lentiviral trans-duction. Effects of a cytokine prestimulation period (18 hours) with interleukin-3, stem cell factor, Flt-3 ligand, and thrombopoietin were then analyzed in total cells, CFCs, and LTC-ICs derived from mPB CD34(+) cells. Transduction levels in those conditions demonstrated a two- and fourfold increase in CFCs and LTC-ICs, respectively, compared with unstimulated (3 hours) control cells. Moreover, using the same transduction protocol, we were able to efficiently transduce CD34(+)/38(-)/lin(-) cells isolated from mPB, with up to85% of colonies derived from LTC-ICs expressing EGFP and gene transfer levels remaining stable for 10 weeks in liquid culture. We therefore demonstrate a highly efficient gene transfer in this therapeutically relevant target cell population.

Congenital erythropoietic porphyria (CEP) is an inherited disease due to a deficiency in the uroporphyrinogen III synthase, the fourth enzyme of the heme biosynthesis pathway. It is characterized by accumulation of uroporphyrin I in the bone marrow, peripheral blood and other organs. The prognosis of CEP is poor, with death often occurring early in adult life. For severe transfusion-dependent cases, when allogeneic cell transplantation cannot be performed, the autografting of genetically modified primitive/stem cells may be the only alternative. In vitro gene transfer experiments have documented the feasibility of gene therapy via hematopoietic cells to treat this disease. In the present study lentiviral transduction of porphyric cell lines and primary CD34(+) cells with the therapeutic human uroporphyrinogen III synthase (UROS) cDNA resulted in both enzymatic and metabolic correction, as demonstrated by the increase in UROS activity and the suppression of porphyrin accumulation in transduced cells. Very high gene transfer efficiency (up to 90%) was achieved in both cell lines and CD34(+) cells without any selection. Expression of the transgene remained stable over long-term liquid culture. Furthermore, gene expression was maintained during in vitro erythroid differentiation of CD34(+) cells. Therefore the use of lentiviral vectors is promising for the future treatment of CEP patients by gene therapy.

We describe two female monozygotic (MZ) twins heterozygous for Fabry disease, an X linked disorder resulting from the deficient activity of alpha-galactosidase A. While one of the twins was clinically affected, the other was asymptomatic. Enzymatic assay of alpha-galactosidase in blood leucocytes, skin fibroblasts, Epstein-Barr virus transformed lymphoid cell lines, and hair follicles of the twins and their parents confirmed the heterozygous status of the twins and indicated that Fabry disease had occurred as a result of a de novo mutation. The son of the unaffected twin sister was shown to be hemizygous. Molecular analysis of the alpha-galactosidase A gene permitted the identification of an as yet undescribed point mutation at position 10182 of exon 5 which causes an Asp to Asn substitution at codon 231. Single strand conformation polymorphism (SSCP) analysis again showed the heterozygous status of the twins and a normal pattern in their parents. The basis for the discordant expression of this d novo mutation in the twins was investigated by studying their X inactivation status. Analysis of the inactive X specific methylation at the androgen receptor gene showed unbalanced inactivation in the twins' fibroblasts and in opposite directions. While the maternally derived X chromosome was preferentially active in the asymptomatic twin, the paternal X chromosome was active in the other, affected twin and was found in her hemizygotic nephew. These data suggest that the paternal X chromosome carries the de novo alpha-galactosidase A mutation and that uneven X inactivation is the underlying mechanism for disease expression in this novel female MZ twin pair. This is the first documented case of female twins discordant for Fabry disease.