Combined germline and somatic human FADD mutations cause autoimmune lymphoproliferative syndrome.

BACKGROUND: The autoimmune lymphoproliferative syndrome (ALPS) is a noninfectious and nonmalignant lymphoproliferative disease frequently associated with autoimmune cytopenia resulting from defective FAS signaling. We previously described germline monoallelic FAS (TNFRSF6) haploinsufficient mutations associated with somatic events, such as loss of heterozygosity on the second allele of FAS, as a cause of ALPS-FAS. These somatic events were identified by sequencing FAS in DNA from double-negative (DN) T cells, the pathognomonic T-cell subset in ALPS, in which the somatic events accumulated. OBJECTIVE: We sought to identify whether a somatic event affecting the FAS-associated death domain (FADD) gene could be related to the disease onset in 4 unrelated patients with ALPS carrying a germline monoallelic mutation of the FADD protein inherited from a healthy parent. METHODS: We sequenced FADD and performed array-based comparative genomic hybridization using DNA from sorted CD4+ or DN T cells. RESULTS: We found homozygous FADD mutations in the DN T cells from all 4 patients, which resulted from uniparental disomy. FADD deficiency caused by germline heterozygous FADD mutations associated with a somatic loss of heterozygosity was a phenocopy of ALPS-FAS without the more complex symptoms reported in patients with germline biallelic FADD mutations. CONCLUSIONS: The association of germline and somatic events affecting the FADD gene is a new genetic cause of ALPS.

Simultaneous pharmacokinetic modeling of unbound and total darunavir with ritonavir in adolescents: a substudy of the SMILE trial.

Darunavir (DRV) is an HIV protease inhibitor commonly used as part of antiretroviral treatment regimens globally for children and adolescents. It requires a pharmacological booster, such as ritonavir (RTV) or cobicistat. To better understand the pharmacokinetics (PK) of DRV in this younger population and the importance of the RTV boosting effect, a population PK substudy was conducted within SMILE trial, where the maintenance of HIV suppression with once daily integrate inhibitor + darunavir/ritonavir in children and adolescents is evaluated. A joint population PK model that simultaneously used total DRV, unbound DRV, and total RTV concentrations was developed. Competitive and non-competitive models were examined to define RTV's influence on DRV pharmacokinetics. Linear and non-linear equations were tested to assess DRV protein binding. A total of 443 plasma samples from 152 adolescents were included in this analysis. Darunavir PK was best described by a one-compartment model first-order absorption and elimination. The influence of RTV on DRV pharmacokinetics was best characterized by ritonavir area under the curve on DRV clearance using a power function. The association of non-linear and linear equations was used to describe DRV protein binding to alpha-1 glycoprotein and albumin, respectively. In our population, simulations indicate that 86.8% of total and unbound DRV trough concentrations were above 0.55 mg/L [10 times protein binding-adjusted EC50 for wild-type (WT) HIV-1] and 0.0243 mg/L (10 times EC90 for WT HIV-1) targets, respectively. Predictions were also in agreement with observed outcomes from adults receiving 800/100 mg DRV/r once a day. Administration of 800/100 mg of DRV/r once daily provides satisfactory concentrations and exposures for adolescents aged 12 years and older.

Gut microbiome alterations at acute myeloid leukemia diagnosis are associated with muscle weakness and anorexia.

The gut microbiota makes critical contributions to host homeostasis, and its role in the treatment of acute myeloid leukaemia (AML) has attracted attention. We investigated whether the gut microbiome is affected by AML, and whether such changes are associated with cachectic hallmarks. Biological samples and clinical data were collected from 30 antibiotic-free AML patients at diagnosis and matched volunteers (1:1) in a multicenter cross-sectional prospective study. The composition and functional potential of the faecal microbiota were analyzed using shotgun metagenomics. Faecal, blood, and urine metabolomics analyses were performed. AML patients displayed muscle weakness, anorexia, signs of altered gut function, and glycaemic disorders. The composition of the faecal microbiota differed between patients with AML and control subjects, with an increase in oral bacteria. Alterations in bacterial functions and faecal metabolome support an altered redox status in the gut microbiota, which may contribute to the altered redox status observed in patients with AML. Eubacterium eligens, reduced 3-fold in AML patients, was strongly correlated with muscle strength and citrulline, a marker of enterocyte mass and function. Blautia and Parabacteroides, increased in patients with AML, were correlated with anorexia. Several bacterial taxa and metabolites (e.g. Blautia, Prevotella, phenylacetate, and hippurate) previously associated with glycaemic disorders were altered. Our work revealed important perturbations in the gut microbiome of AML patients at diagnosis, which are associated with muscle strength, altered redox status, and anorexia. These findings pave the way for future mechanistic work to explore the function and therapeutic potential of the bacteria identified in this study.

Vitamin C levels in a Central-African mother-infant cohort: Does hypovitaminosis C increase the risk of enteric infections?

In the MITICA (Mother-to-Infant TransmIssion of microbiota in Central-Africa) study, 48 mothers and their 50 infants were followed from delivery to 6 months between December 2017 and June 2019 in Bangui (Central-African Republic). Blood tests and stool analyses were performed in mothers at delivery, and their offspring at birth, 11 weeks and 25 weeks. Stool cultures were performed in specific growth media for Salmonella, Shigella, E. coli, Campylobacter, Enerobacter, Vibrio cholerae, Citrobacter and Klebsiella, as well as rotavirus, yeasts and parasitological exams. The median vitamin C levels in mothers at delivery were 15.3 µmol/L (inter-quartile-range [IQR] 6.2-27.8 µmol/L). In infants, the median vitamin C levels at birth were 35.2 µmol/L (IQR 16.5-63.9 µmol/L). At 11 and 25 weeks, the median vitamin C levels were 41.5 µmol/L (IQR 18.7-71.6 µmol/L) and 18.2 µmol/L (IQR 2.3-46.6 µmol/L), respectively. Hypovitaminosis C was defined as seric vitamin C levels <28 µmol/L and vitamin C deficiency was defined as vitamin C levels <11 µmol/L according to the WHO definition. In mothers, the prevalence of hypovitaminosis-C and vitamin C deficiency at delivery was 34/45 (75.6%) and 19/45 (42.2%), respectively. In infants, the prevalence of hypovitaminosis-C and vitamin C deficiency at 6 months was 18/33 (54.6%) and 11/33 (33.3%), respectively. Vitamin C levels in mothers and infants were correlated at birth (Spearman's rho = 0.5; P value = 0.002), and infants had significantly higher levels of vitamin C (median = 35.2 µmol/L; IQR 16.5-63.9 µmol/L), compared to mothers (median = 15.3 µmol/L; IQR 6.2-27.8 µmol/L; P value <0.001). The offspring of vitamin C-deficient mothers had significantly lower vitamin C levels at delivery (median = 18.7 µmol/L; IQR 13.3-30.7 µmol/L), compared to the offspring of non-deficient mothers (median = 62.2 µmol/L; IQR 34.6-89.2 µmol/L; P value <0.001). Infants with hypovitaminosis-C were at significantly higher risk of having a positive stool culture during the first 6 months of life (adjusted OR = 5.3, 95% CI 1.1; 26.1; P value = 0.038).

Hypervitaminosis A is associated with immunological non-response in HIV-1-infected adults: a case-control study.

For people living with HIV, determinants of immunological non-response (INR) to combined antiretroviral therapy (cART) have not been fully elucidated. In a case-control study, we evaluated the influence of the nutritional and antioxidant status in HIV-1 adults whose cART was initiated between January 2001 and December 2013. Cases had persistent CD4 counts < 350/µL vs. > 350/µL for controls, after at least 2 years of cART with persistent viral loads (VL) < 50 copies/mL. Twelve cases and twenty-eight control subjects with the same CD4 count at cART initiation were compared for their nutritional and antioxidant status after age adjustment at dosage assessment. Patients were predominantly male (70%), Caucasian (82%) and at AIDS stage (62%). The median age was 53, and the median CD4 count was 245/mm3 for cases and 630/mm3 for controls after a median time of 7 years on cART. Despite higher energy intakes in cases, anthropometric data was comparable between groups who had similar vitamins B9/B12/C/D/E, zinc, citrulline and glutamine levels. Nine cases (75%) and 8 controls (29%) had hypervitaminosis A (> 2.70 µmol/L) (p = 0.030). Cases had lower erythrocyte resistance when exposed to a controlled free radical attack (p = 0.014). Most cases had hypervitaminosis A and altered antioxidant capacities that could affect immunological response. Wide-scale studies are required, but in the meantime, screening of their vitamin A status must be encouraged in these patients.

Lean Body Mass and Endocrine Status But Not Age Are Determinants of Resting Energy Expenditure in Patients with Non-Small Cell Lung Cancer.

BACKGROUND: Cancer and aging are both frequently associated with malnutrition, a factor of poor prognosis. In adult cancer patients, this may be related in part to impaired energy metabolism, with higher than predicted resting energy expenditure (REE) in about 50% of patients. We hypothesized that frequently impaired energy metabolism in elderly patients could potentiate cancer-associated hypermetabolism, further promoting risk of malnutrition. OBJECTIVE: To study the hypermetabolic response to cancer in a predominantly aged population and the potential underlying determinants. METHODS: This was a cross-sectional exploratory study in patients with non-small-cell lung cancer. REE was measured by indirect calorimetry. Body composition was determined from a single CT scan imaging at L3 level. Endocrine, inflammatory, nutritional and metabolic status were evaluated. RESULTS: Twenty-seven patients, of median age 68 years (range 32-81) completed the study. In this population, mean measured REE was 7.5% higher than calculated REE. Sex and weight accounted for about 51% of REE variations, whereas age accounted only for 4%. However, these parameters did not explain the REE-to-lean body mass (LBM) ratio variations, suggesting that they influenced REE only through their effect on LBM. Among the other parameters evaluated, only the thyroid-stimulating hormone and interleukin-6 plasma levels appeared to have an influence on REE. The study of the consequences of this increase in REE-to-LBM ratio showed a growing inability of patients to meet their energy needs but showed no effect on nutritional markers such as transthyretin. CONCLUSIONS: The results of this pilot study suggest that in our population, age was not an important factor of REE. The elevated energy metabolism was associated with patients' failure to increase their energy intakes sufficiently, which can contribute to the development of cachexia. CLINICAL TRIAL: This trial is registered at clinicaltrials.gov under NCT0314.

Citrulline directly modulates muscle protein synthesis via the PI3K/MAPK/4E-BP1 pathway in a malnourished state: evidence from in vivo, ex vivo, and in vitro studies.

Citrulline (CIT) is an endogenous amino acid produced by the intestine. Recent literature has consistently shown CIT to be an activator of muscle protein synthesis (MPS). However, the underlying mechanism is still unknown. Our working hypothesis was that CIT might regulate muscle homeostasis directly through the mTORC1/PI3K/MAPK pathways. Because CIT undergoes both interorgan and intraorgan trafficking and metabolism, we combined three approaches: in vivo, ex vivo, and in vitro. Using a model of malnourished aged rats, CIT supplementation activated the phosphorylation of S6K1 and 4E-BP1 in muscle. Interestingly, the increase in S6K1 phosphorylation was positively correlated (P < 0.05) with plasma CIT concentration. In a model of isolated incubated skeletal muscle from malnourished rats, CIT enhanced MPS (from 30 to 80% CIT vs. Ctrl, P < 0.05), and the CIT effect was abolished in the presence of wortmannin, rapamycin, and PD-98059. In vitro, on myotubes in culture, CIT led to a 2.5-fold increase in S6K1 phosphorylation and a 1.5-fold increase in 4E-BP1 phosphorylation. Both rapamycin and PD-98059 inhibited the CIT effect on S6K1, whereas only LY-294002 inhibited the CIT effect on both S6K1 and 4E-BP1. These findings show that CIT is a signaling agent for muscle homeostasis, suggesting a new role of the intestine in muscle mass control.

Effects of Postexercise Protein Intake on Muscle Mass and Strength During Resistance Training: Is There an Optimal Ratio Between Fast and Slow Proteins?

While effects of the two classes of proteins found in milk (i.e., soluble proteins, including whey, and casein) on muscle protein synthesis have been well investigated after a single bout of resistance exercise (RE), the combined effects of these two proteins on the muscle responses to resistance training (RT) have not yet been investigated. Therefore, the aim of this study was to examine the effects of protein supplementation varying by the ratio between milk soluble proteins (fast-digested protein) and casein (slow-digested protein) on the muscle to a 9-week RT program. In a double-blind protocol, 31 resistance-trained men, were assigned to 3 groups receiving a drink containing 20g of protein comprising either 100% of fast protein (FP(100), n = 10), 50% of fast and 50% of slow proteins (FP(50), n = 11) or 20% of fast protein and 80% of casein (FP(20), n = 10) at the end of training bouts. Body composition (DXA), and maximal strength in dynamic and isometric were analyzed before and after RT. Moreover, blood plasma aminoacidemia kinetic after RE was measured. The results showed a higher leucine bioavailability after ingestion of FP(100) and FP(50) drinks, when compared with FP(20) (p< .05). However, the RT-induced changes in lean body mass (p < .01), dynamic (p < .01), and isometric muscle strength (p < .05) increased similarly in all experimental groups. To conclude, compared with the FP(20) group, the higher rise in plasma amino acids following the ingestion of FP(100) and FP(50) did not lead to higher muscle long-term adaptations.

Inhibiting glutamine uptake represents an attractive new strategy for treating acute myeloid leukemia.

Cancer cells require nutrients and energy to adapt to increased biosynthetic activity, and protein synthesis inhibition downstream of mammalian target of rapamycin complex 1 (mTORC1) has shown promise as a possible therapy for acute myeloid leukemia (AML). Glutamine contributes to leucine import into cells, which controls the amino acid/Rag/mTORC1 signaling pathway. We show in our current study that glutamine removal inhibits mTORC1 and induces apoptosis in AML cells. The knockdown of the SLC1A5 high-affinity transporter for glutamine induces apoptosis and inhibits tumor formation in a mouse AML xenotransplantation model. l-asparaginase (l-ase) is an anticancer agent also harboring glutaminase activity. We show that l-ases from both Escherichia coli and Erwinia chrysanthemi profoundly inhibit mTORC1 and protein synthesis and that this inhibition correlates with their glutaminase activity levels and produces a strong apoptotic response in primary AML cells. We further show that l-ases upregulate glutamine synthase (GS) expression in leukemic cells and that a GS knockdown enhances l-ase-induced apoptosis in some AML cells. Finally, we observe a strong autophagic process upon l-ase treatment. These results suggest that l-ase anticancer activity and glutamine uptake inhibition are promising new therapeutic strategies for AML.

Citrulline Supplementation Induces Changes in Body Composition and Limits Age-Related Metabolic Changes in Healthy Male Rats.

BACKGROUND: Aging is associated with profound metabolic disturbances, and citrulline may be of use to limit them. OBJECTIVE: The aim of this work was to evaluate the long-term effect of citrulline supplementation on metabolism in healthy aged rats. METHODS: Twenty-month-old male rats were randomly assigned to be fed (ad libitum) for 12 wk with either a citrulline-enriched diet (1 g ⋅ kg(-1) ⋅ d(-1)) or a standard diet [rendered isonitrogenous by addition of nonessential amino acids (NEAAs)]. Motor activity and muscle strength were measured, body composition was assessed, and muscle metabolism (protein structure, mitochondrial exploration, and transductional factors) and lipid metabolism (lipoprotein composition and sensitivity to oxidative stress) were explored. RESULTS: Compared with the NEAA-treated group, citrulline supplementation was associated with lower mortality (0% vs. 20%; P = 0.05), 9% higher lean body mass (P < 0.05), and 13% lower fat mass (P < 0.05). Compared with the NEAA-treated group, citrulline-treated rats had greater muscle mass (+14-48% depending on type of muscle; P < 0.05 for tibialis, gastrocnemius, and plantaris). Susceptibility to oxidation of lipoproteins, as measured by the maximal concentration of 7-ketocholesterol after copper-induced VLDL and LDL oxidation, was lower in citrulline-treated rats than in NEAA-treated rats (187 ± 8 µmol/L vs. 243 ± 7 µmol/L; P = 0.0005). CONCLUSIONS: Citrulline treatment in male aged rats favorably modulates body composition and protects against lipid oxidation and, thus, emerges as an interesting candidate to help prevent the aging process.

Disturbed intestinal nitrogen homeostasis in a mouse model of high-fat diet-induced obesity and glucose intolerance.

The oligopeptide transporter peptide cotransporter-1 Slc15a1 (PEPT1) plays a major role in the regulation of nitrogen supply, since it is responsible for 70% of the dietary nitrogen absorption. Previous studies demonstrated that PEPT1 expression and function in jejunum are reduced in diabetes and obesity, suggesting a nitrogen malabsorption from the diet. Surprisingly, we reported here a decrease in gut nitrogen excretion in high-fat diet (HFD)-fed mice and further investigated the mechanisms that could explain this apparent contradiction. Upon HFD, mice exhibited an increased concentration of free amino acids (AAs) in the portal vein (60%) along with a selective increase in the expression of two AA transporters (Slc6a20a, Slc36a1), pointing to a specific and adaptive absorption of some AAs. A delayed transit time (+40%) and an increased intestinal permeability (+80%) also contribute to the increase in nitrogen absorption. Besides, HFD mice exhibited a 2.2-fold decrease in fecal DNA resulting from a reduction in nitrogen catabolism from cell desquamation and/or in the intestinal microbiota. Indeed, major quantitative (2.5-fold reduction) and qualitative alterations of intestinal microbiota were observed in feces of HFD mice. Collectively, our results strongly suggest that both increased AA transporters, intestinal permeability and transit time, and changes in gut microbiota are involved in the increased circulating AA levels. Modifications in nitrogen homeostasis provide a new insight in HFD-induced obesity and glucose intolerance; however, whether these modifications are beneficial or detrimental for the HFD-associated metabolic complications remains an open issue.

Autoimmune lymphoproliferative syndrome caused by a homozygous null FAS ligand (FASLG) mutation.

BACKGROUND: Autoimmune lymphoproliferative syndrome (ALPS) is characterized by chronic nonmalignant lymphoproliferation, accumulation of double-negative T cells, hypergammaglobulinemia G and A, and autoimmune cytopenia. OBJECTIVES: Although mostly associated with FAS mutations, different genetic defects leading to impaired apoptosis have been described in patients with ALPS, including the FAS ligand gene (FASLG) in rare cases. Here we report on the first case of complete FAS ligand deficiency caused by a homozygous null mutant. METHODS: Double-negative T-cell counts and plasma IL-10 and FAS ligand concentrations were determined as ALPS markers. The FASLG gene was sequenced, and its expression was analyzed by means of Western blotting. FAS ligand function was assessed based on reactivation-induced cell death. RESULTS: We describe a patient born to consanguineous parents who presented with a severe form of ALPS caused by FASLG deficiency. Although the clinical presentation was compatible with a homozygous FAS mutation, FAS-induced apoptosis was normal, and plasma FAS ligand levels were not detectable. This patient carries a homozygous, germline, single-base-pair deletion in FASLG exon 1, leading to a premature stop codon (F87fs x95) and a complete defect in FASLG expression. The healthy parents were each heterozygous for the mutation, confirming its recessive trait. CONCLUSION: FAS ligand deficiency should be screened in patients presenting with ALPS features but lacking the usual markers, including plasma soluble FAS ligand and an in vitro apoptotic defect. An activation-induced cell death test could help in discrimination.

Study of the potential role of CASPASE-10 mutations in the development of autoimmune lymphoproliferative syndrome.

Autoimmune lymphoproliferative syndrome (ALPS) is a primary disorder of lymphocyte homeostasis, leading to chronic lymphoproliferation, autoimmune cytopenia, and increased risk of lymphoma. The genetic landscape of ALPS includes mutations in FAS, FASLG, and FADD, all associated with apoptosis deficiency, while the role of CASP10 defect in the disease remains debated. In this study, we aimed to assess the impact of CASP10 variants on ALPS pathogenesis. We benefit from thousands of genetic analysis datasets performed in our Institute's genetic platform to identify individuals carrying CASP10 variants previously suspected to be involved in ALPS outcome: p.C401LfsX15, p.V410I and p.Y446C, both at heterozygous and homozygous state. Clinical and laboratory features of the six included subjects were variable but not consistent with ALPS. Two individuals were healthy. Comprehensive analyses of CASP10 protein expression and FAS-mediated apoptosis were conducted and compared to healthy controls and ALPS patients with FAS mutations. Missense CASP10 variants (p.V410I and p.Y446C), which are common in the general population, did not disrupt CASP10 expression, nor FAS-mediated apoptosis. In contrast, homozygous p.C401LfsX15 CASP10 variant lead to a complete abolished CASP10 expression but had no impact on FAS-mediated apoptosis function. At heterozygous state, this p.C401LfsX15 variant lead to a reduced CASP10 protein levels but remained associated with a normal FAS-mediated apoptosis function. These findings demonstrate that CASPASE 10 is dispensable for FAS-mediated apoptosis. In consequences, CASP10 defect unlikely contribute to ALPS pathogenesis, since they did not result in an impairment of FAS-mediated apoptosis nor in clinical features of ALPS in human. Moreover, the absence of FAS expression up-regulation in subjects with CASP10 variants rule out any compensatory mechanisms possibly involved in the normal apoptosis function observed. In conclusion, this study challenges the notion that CASP10 variants contribute to the development of ALPS.

Best temperature for static liver graft storage is 1°C.

BACKGROUND: The best storage temperature in liver transplantation remains an unsolved question. METHODS: After storage for 24h in University of Wisconsin solution at +4°C, +1°C, or -0.5°C, rat livers were subjected, or not, to 15min of warm ischemia, rinsed with Ringer lactate, and subsequently reperfused with oxygenated Krebs-Henseleit buffer. RESULTS: In the presence of warm ischemia, for livers stored at +4°C, creatine kinase (CK) peaked at 21±5IUg(-1)h(-1), hepatic resistance at 34,700±1500dynscm(-5), bile flow reached 18±4µLg(-1)h(-1) after 10min, and oxygen consumption stabilized at about 25µmolg(-1)h(-1) after 20min. When livers were stored at +1°C, CK and hepatic resistance were lowered, bile production was 33±6µLg(-1)h(-1) (P<0.05 versus +4°C), and oxygen consumption was 105±10µmolg(-1)h(-1) (P<0.001). For livers stored at-0.5°C, results were not statistically different from those of the +1°C group except for bile flow, which was significantly lower. Without warm ischemia, the peak of CK (P=0.015) and the peak hepatic resistance (P<0.001) of the +4°C group were significantly increased compared with the +1°C or -0.5°C groups. However, no difference in bile flow or oxygen consumption was observed. The number of trypan blue-positive nonparenchymal cells (P=0.003) and the gain in liver weight during the reperfusion (P=0.015) were minimal after storage at +1°C. CONCLUSIONS: Static storage at +1°C improved liver function compared with +4°C or -0.5°C. Main beneficial effect was observed with parameters reflecting sinusoidal cells injury.

Evaluation of the taurine concentrations in dog plasma and aqueous humour: a pilot study.

In the 70s, the amino acid taurine was found essential for photoreceptor survival. Recently, we found that taurine depletion can also trigger retinal ganglion cell degeneration both in vitro and in vivo. Therefore, evaluation of taurine levels could be a crucial biomarker for different pathologies of retinal ganglion cells such as glaucoma. Because different breeds of dog can develop glaucoma, we performed taurine measurements on plasma and aqueous humour samples from pet dogs. Here, we exposed results from a pilot study on normal selected breed of pet dogs, without any ocular pathology. Samples were collected by veterinarians who belong to the Réseau Européen d'Ophtalmologie Vétérinaire et de Vision Animale. Following measurements by high-performance liquid chromatography (HPLC), the averaged taurine concentration was 162.3 µM in the plasma and 51.8 µM in the aqueous humour. No correlation was observed between these two taurine concentrations, which exhibited a ratio close to 3. Further studies will determine if these taurine concentrations are changed in glaucomatous dogs.

Four-week administration of an energy and protein dense oral nutritional supplement improves micronutrient concentrations but does not completely correct deficiencies in institutionalized malnourished older adults.

Introduction: Poor food intake is common among elderly living in nursing homes, leading to micronutrient deficiency (MD). There are no recommendations for the management of MD in malnourished older adults. Methods: We conducted a single arm, open-label, multicenter interventional study in institutionalized malnourished older adults to describe the effect of a 4-week daily energy and protein dense oral nutritional supplementation (ONS, 600 kcal, 30 g protein per unit) containing 50% of the recommended daily micronutrient intake on micronutrient status. Plasma concentrations of vitamins (A, B9, B12, C, E), magnesium (Mg), selenium (Se) and zinc (Zn), and erythrocyte vitamin B9 were measured at baseline and after 4 weeks. Results: Forty-six participants completed the study (age 87.4 ± 6.6). At baseline, the most frequent MD were Se (48%), Zn (35%), Mg (24%) and vitamin C (24%). Plasma concentrations of vitamins B9, B12, C and E, Mg, Se and Zn significantly increased and the proportion of subjects with at least one MD decreased (p = 0.006). However, after 4 weeks, 40% of subjects still had at least one MD. Discussion: ONS consumption improved micronutrient status but did not correct MD in all participants. Our data suggest that the prescription of vitamin, mineral and trace element supplementation should be considered in institutionalized malnourished older adults in addition to high energy and high protein ONS.

[Pernicious anemia with false normal vitamin B12 levels caused by intrinsic factor antibodies interference: a case report]. / Maladie de Biermer avec dosage de vitamine B12 faussement normal par interférence avec les anticorps anti-facteur intrinsèque : à propos d'un cas.

We present a case of a 48-year-old woman with a fortuitous discovery of macrocytic anemia and thrombocytopenia. Serum folate and vitamin B12 levels were normal. However, due to the presence of indirect signs of cobalamin deficiency, such as elevated homocysteine and methylmalonic acid, and signs of dyserythropoiesis on the bone marrow aspirate, pernicious anemia was suspected. Vitamin B12 dosage was repeated finding fluctuating but always normal results. Anti-intrinsic factor antibodies were present at a very high level, explaining the fluctuations and the interference found on the assay using competitive binding chemiluminescence (CBLA). Serum vitamin B12 dosage by electrochemiluminescence, a method described as not interfering with intrinsic factor antibodies, showed a collapsed vitamin B12 level. Measurement of vitamin B12 with CBLA after adsorption of immunoglobulins in the sample using protein G SepharoseTM, confirmed the interference of the cobalamin assay with autoantibodies. This case illustrates the difficulties regarding the analysis and standardization of the vitamin B12 assay for the diagnosis of pernicious anemia.

Gut microbiota alterations induced by intensive chemotherapy in acute myeloid leukaemia patients are associated with gut barrier dysfunction and body weight loss.

BACKGROUND & AIMS: Acute myeloid leukaemia (AML) chemotherapy has been reported to impact gut microbiota composition. In this study, we investigated using a multi -omics strategy the changes in the gut microbiome induced by AML intense therapy and their association with gut barrier function and cachectic hallmarks. METHODS: 10 AML patients, allocated to standard induction chemotherapy (SIC), were recruited. Samples and data were collected before any therapeutic intervention (T0), at the end of the SIC (T1) and at discharge (T4). Gut microbiota composition and function, markers of inflammation, metabolism, gut barrier function and cachexia, as well as faecal, blood and urine metabolomes were assessed. RESULTS: AML patients demonstrated decreased appetite, weight loss and muscle wasting during hospitalization, with an incidence of cachexia of 50%. AML intensive treatment transiently impaired the gut barrier function and led to a long-lasting change of gut microbiota composition characterized by an important loss of diversity. Lactobacillaceae and Campylobacter concisus were increased at T1 while Enterococcus faecium and Staphylococcus were increased at T4. Metabolomics analyses revealed a reduction in urinary hippurate and faecal bacterial amino acid metabolites (bAAm) (2-methylbutyrate, isovalerate, phenylacetate). Integration using DIABLO revealed a deep interconnection between all the datasets. Importantly, we identified bacteria which disappearance was associated with impaired gut barrier function (Odoribacter splanchnicus) and body weight loss (Gemmiger formicilis), suggesting these bacteria as actionable targets. CONCLUSION: AML intensive therapy transiently impairs the gut barrier function while inducing enduring alterations in the composition and metabolic activity of the gut microbiota that associate with body weight loss. TRIAL REGISTRATION: NCT03881826, https://clinicaltrials.gov/ct2/show/NCT03881826.

NBEAL2 deficiency in humans leads to low CTLA-4 expression in activated conventional T cells.

Loss of NBEAL2 function leads to grey platelet syndrome (GPS), a bleeding disorder characterized by macro-thrombocytopenia and α-granule-deficient platelets. A proportion of patients with GPS develop autoimmunity through an unknown mechanism, which might be related to the proteins NBEAL2 interacts with, specifically in immune cells. Here we show a comprehensive interactome of NBEAL2 in primary T cells, based on mass spectrometry identification of altogether 74 protein association partners. These include LRBA, a member of the same BEACH domain family as NBEAL2, recessive mutations of which cause autoimmunity and lymphocytic infiltration through defective CTLA-4 trafficking. Investigating the potential association between NBEAL2 and CTLA-4 signalling suggested by the mass spectrometry results, we confirm by co-immunoprecipitation that CTLA-4 and NBEAL2 interact with each other. Interestingly, NBEAL2 deficiency leads to low CTLA-4 expression in patient-derived effector T cells, while their regulatory T cells appear unaffected. Knocking-down NBEAL2 in healthy primary T cells recapitulates the low CTLA-4 expression observed in the T cells of GPS patients. Our results thus show that NBEAL2 is involved in the regulation of CTLA-4 expression in conventional T cells and provide a rationale for considering CTLA-4-immunoglobulin therapy in patients with GPS and autoimmune disease.

Effects of a diabetes-specific enteral nutrition on nutritional and immune status of diabetic, obese, and endotoxemic rats: interest of a graded arginine supply.

OBJECTIVE: Obese and type 2 diabetic patients present metabolic disturbance-related alterations in nonspecific immunity, to which the decrease in their plasma arginine contributes. Although diabetes-specific formulas have been developed, they have never been tested in the context of an acute infectious situation as can be seen in intensive care unit patients. Our aim was to investigate the effects of a diabetes-specific diet enriched or not with arginine in a model of infectious stress in a diabetes and obesity situation. As a large intake of arginine may be deleterious, this amino acid was given in graded fashion. DESIGN: Randomized, controlled experimental study. SETTING: University research laboratory. SUBJECTS: Zucker diabetic fatty rats. INTERVENTIONS: Gastrostomized Zucker diabetic fatty rats were submitted to intraperitoneal lipopolysaccharide administration and fed for 7 days with either a diabetes-specific enteral nutrition without (G group, n=7) or with graded arginine supply (1-5 g/kg/day) (GA group, n=7) or a standard enteral nutrition (HP group, n=10). MEASUREMENTS AND MAIN RESULTS: Survival rate was better in G and GA groups than in the HP group. On day 7, plasma insulin to glucose ratio tended to be lower in the same G and GA groups. Macrophage tumor necrosis factor-α (G: 5.0±1.1 ng/2×106 cells·hr⁻¹; GA: 3.7±0.8 ng/2×106 cells·hr⁻¹; and HP: 1.7±0.6 ng/2×106 cells·hr⁻¹; p<.05 G vs. HP) and nitric oxide (G: 4.5±1.1 ng/2×106 cells·hr⁻¹; GA: 5.1±1.0 ng/2×106 cells·hr⁻¹; and HP: 1.0±0.5 nmol/2×106 cells·hr⁻¹; p<.05 G and GA vs. HP) productions were higher in the G and GA groups compared to the HP group. Macrophages from the G and GA groups exhibited increased arginine consumption. CONCLUSIONS: In diabetic obese and endotoxemic rats, a diabetes-specific formula leads to a lower mortality, a decreased insulin resistance, and an improvement in peritoneal macrophage function. Arginine supplementation has no additional effect. These data support the use of such disease-specific diets in critically ill diabetic and obese patients.