Translocating Lactobacillus torments tumors via tryptophan catabolism.

Variability in the efficacy of immune checkpoint inhibitors in cancer patients is associated with the human gut microbiota. However, detailed mechanisms are unclear. In this issue of Cell, Bender et al. uncovered that a probiotic Lactobacillus strain translocates into murine tumors to enhance immunotherapy via the tryptophan metabolite indole-3-aldehyde (I3A).

Genetically modified ZIKA virus as a microRNA-sensitive oncolytic virus against central nervous system tumors.

Here we introduce a first-in-class microRNA-sensitive oncolytic Zika virus (ZIKV) for virotherapy application against central nervous system (CNS) tumors. The described methodology produced two synthetic modified ZIKV strains that are safe in normal cells, including neural stem cells, while preserving brain tropism and oncolytic effects in tumor cells. The microRNA-sensitive ZIKV introduces genetic modifications in two different virus sites: first, in the established 3'UTR region, and secondly, in the ZIKV protein coding sequence, demonstrating for the first time that the miRNA inhibition systems can be functional outside the UTR RNA sites. The total tumor remission in mice bearing human CNS tumors, including metastatic tumor growth, after intraventricular and systemic modified ZIKV administration, confirms the promise of this virotherapy as a novel agent against brain tumors-highly deadly diseases in urgent need of effective advanced therapies.

Newborn Skin Maturity Medical Device Validation for Gestational Age Prediction: Clinical Trial.

BACKGROUND: Early access to antenatal care and high-cost technologies for pregnancy dating challenge early neonatal risk assessment at birth in resource-constrained settings. To overcome the absence or inaccuracy of postnatal gestational age (GA), we developed a new medical device to assess GA based on the photobiological properties of newborns' skin and predictive models. OBJECTIVE: This study aims to validate a device that uses the photobiological model of skin maturity adjusted to the clinical data to detect GA and establish its accuracy in discriminating preterm newborns. METHODS: A multicenter, single-blinded, and single-arm intention-to-diagnosis clinical trial evaluated the accuracy of a novel device for the detection of GA and preterm newborns. The first-trimester ultrasound, a second comparator ultrasound, and data regarding the last menstrual period (LMP) from antenatal reports were used as references for GA at birth. The new test for validation was performed using a portable multiband reflectance photometer device that assessed the skin maturity of newborns and used machine learning models to predict GA, adjusted for birth weight and antenatal corticosteroid therapy exposure. RESULTS: The study group comprised 702 pregnant women who gave birth to 781 newborns, of which 366 (46.9%) were preterm newborns. As the primary outcome, the GA as predicted by the new test was in line with the reference GA that was calculated by using the intraclass correlation coefficient (0.969, 95% CI 0.964-0.973). The paired difference between predicted and reference GAs was -1.34 days, with Bland-Altman limits of -21.2 to 18.4 days. As a secondary outcome, the new test achieved 66.6% (95% CI 62.9%-70.1%) agreement with the reference GA within an error of 1 week. This agreement was similar to that of comparator-LMP-GAs (64.1%, 95% CI 60.7%-67.5%). The discrimination between preterm and term newborns via the device had a similar area under the receiver operating characteristic curve (0.970, 95% CI 0.959-0.981) compared with that for comparator-LMP-GAs (0.957, 95% CI 0.941-0.974). In newborns with absent or unreliable LMPs (n=451), the intent-to-discriminate analysis showed correct preterm versus term classifications with the new test, which achieved an accuracy of 89.6% (95% CI 86.4%-92.2%), while the accuracy for comparator-LMP-GA was 69.6% (95% CI 65.3%-73.7%). CONCLUSIONS: The assessment of newborn's skin maturity (adjusted by learning models) promises accurate pregnancy dating at birth, even without the antenatal ultrasound reference. Thus, the novel device could add value to the set of clinical parameters that direct the delivery of neonatal care in birth scenarios where GA is unknown or unreliable. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1136/bmjopen-2018-027442.

Safety, Tumor Reduction, and Clinical Impact of Zika Virus Injection in Dogs with Advanced-Stage Brain Tumors.

Malignant brain tumors are among the most aggressive cancers with poor prognosis and no effective treatment. Recently, we reported the oncolytic potential of Zika virus infecting and destroying the human central nervous system (CNS) tumors in vitro and in immunodeficient mice model. However, translating this approach to humans requires pre-clinical trials in another immunocompetent animal model. Here, we analyzed the safety of Brazilian Zika virus (ZIKVBR) intrathecal injections in three dogs bearing spontaneous CNS tumors aiming an anti-tumoral therapy. We further assessed some aspects of the innate immune and inflammatory response that triggers the anti-tumoral response observed during the ZIKVBR administration in vivo and in vitro. For the first time, we showed that there were no negative clinical side effects following ZIKVBR CNS injections in dogs, confirming the safety of the procedure. Furthermore, the intrathecal ZIKVBR injections reduced tumor size in immunocompetent dogs bearing spontaneous intracranial tumors, improved their neurological clinical symptoms significantly, and extended their survival by inducing the destruction specifically of tumor cells, sparing normal neurons, and activating an immune response. These results open new perspectives for upcoming virotherapy using ZIKV to destroy and induce an anti-tumoral immune response in CNS tumors for which there are currently no effective treatments.

Metabolic control of T cell immune response through glycans in inflammatory bowel disease.

Mucosal T lymphocytes from patients with ulcerative colitis (UC) were previously shown to display a deficiency in branched N-glycosylation associated with disease severity. However, whether this glycosylation pathway shapes the course of the T cell response constituting a targeted-specific mechanism in UC remains largely unknown. In this study, we demonstrated that metabolic supplementation of ex vivo mucosal T cells from patients with active UC with N-acetylglucosamine (GlcNAc) resulted in enhancement of branched N-glycosylation in the T cell receptor (TCR), leading to suppression of T cell growth, inhibition of the T helper 1 (Th1)/Th17 immune response, and controlled T cell activity. We further demonstrated that mouse models displaying a deficiency in the branched N-glycosylation pathway (MGAT5-/-, MGAT5+/-) exhibited increased susceptibility to severe forms of colitis and early-onset disease. Importantly, the treatment of these mice with GlcNAc reduced disease severity and suppressed disease progression due to a controlled T cell-mediated immune response at the intestinal mucosa. In conclusion, our human ex vivo and preclinical results demonstrate the targeted-specific immunomodulatory properties of this simple glycan, proposing a therapeutic approach for patients with UC.

Carnoy solution versus GEWF solution for lymph node revealing in colorectal cancer: a randomized controlled trial.

PURPOSE: This study aimed to compare the performance of two lymph node revealing solutions. METHODS: This randomized clinical trial (NTC02704988) investigated patients with colon or rectal cancer who underwent surgical resection with D2 lymphadenectomy. Specimens submitted for conventional pathological examination were randomly assigned for additional fixation with Carnoy or GEWF solution, and dissection was performed to examine the missed lymph nodes. The number of lymph nodes retrieved, additional identified metastatic lymph nodes, lymph node upstaging, and complementary indication of adjuvant therapy were investigated. RESULTS: The number of lymph nodes retrieved was significantly higher with the use of lymph node revealing solutions than with the conventional method in colon cancer (GEWF: 29.5 vs 27; p < 0.001; Carnoy: 27.7 vs 25.2; p < 0.001) and rectal cancer (GEWF: 25.8 vs 23.6; p < 0.001; Carnoy: 23.1 vs 20.8; p < 0.001). There were no differences between the solutions and conventional examination with respect to the median number of additional metastatic lymph nodes identified (0 in all arms), the number of patients with lymph node upstaging (colon cancer: 1 in the Carnoy arm, 0 in the GEWF arm; rectal cancer: 1 in the GEWF arm, 0 in the Carnoy arm), or the number of patients with complementary indication of adjuvant therapy (colon cancer: 1 in the Carnoy arm, 0 in the GEWF arm; rectal cancer: 0 in both arms). CONCLUSION: Despite the higher number of lymph nodes retrieved, neither solution resulted in significant changes in patient staging or treatment. Both solutions exhibited equal performance with respect to all outcomes. TRIAL REGISTRATION: NTC02704988.

Glycans as critical regulators of gut immunity in homeostasis and disease.

The diversity of glycans expression within a cell or an organism is enormous and the amount of relevant biological information that each glycan structure encodes is far from being clarified. The importance of glycans in health and life sciences is highlighted by their multiple functional implications in different cellular and molecular biology processes with impact in homeostasis and diseases, such as cancer and inflammatory conditions. Glycans actively participate in the regulatory circuits that govern both innate and adaptive immune response. Changes in the glycans repertoire occur during the transition from normal to inflamed conditions and the aberrant expression of glycans dictates either pro-inflammatory or anti-inflammatory responses. This review summarizes how glycans integrate the regulatory networks of immune response with a focus on gut immunity.

Local and systemic effects of a silver nitrate coated indwelling pleural catheter in an animal model of pleurodesis.

Purpose/Aim of the study: This study assessed the safety and potential toxicity of a silver nitrate coated indwelling pleural catheter (SNCIPC) designed to create pleurodesis in a large animal model. MATERIALS AND METHODS: Sixteen animals underwent insertion of either a SNCIPC or an uncoated silicone catheter. Half of the animals were sacrificed at day 7 and the others at day 30. Animal weight and assessment of well-being, pleural fluid and blood collection were performed at regular intervals. Pleurodesis was assessed at necropsy and histopathological examination of organs performed. RESULTS: No mortality or significant clinical findings were observed throughout the experiment. SNCIPC treated animals had increased pleural fluid drainage overall (p < 0.001) and specifically on days 1-4. No differences in hemoglobin, white blood cell count or neutrophil counts were detected between groups. No treatment related histological findings were observed in any of the evaluated tissues outside of the treated area. Serum silver levels in SNCIPC catheter treated animals peaked on Day 4 (0.185 µg/mL, 30 day group) then gradually decreased for the remainder of the study period. The highest tissue silver concentrations were noted in the SNCIPC groups in tissues close to the treatment site in addition to the liver (59.8ug/g +/- 8.6 and 73.3ug/g +/- 25). Pleurodesis scores were significantly higher in SNCIPC treated animals for both the 7 day (median 6.5 vs. 1.0, p = 0.029) and 30 day cohorts (median 7.0 vs. 1.5, p = 0.029). CONCLUSIONS: SNCIPC are well tolerated and not associated with any significant signs of toxicity. Silver levels were elevated in local tissues, serum and liver but without evidence of pathological impact. Effective pleurodesis was present by day 7 and more established by day 30. Clinical studies to investigate the safety and efficacy of this device in patients with malignant pleural effusions appear warranted.

Miniature Swine Breeds in Toxicology and Drug Safety Assessments: What to Expect during Clinical and Pathology Evaluations.

The use of miniature swine as a nonrodent species in safety assessment has continued to expand for over a decade, and they are becoming routinely used in toxicology and in pharmacology as well as a model for human diseases. Miniature swine models are regularly used for regulatory toxicity studies designed to assess safety of new therapeutic compounds given through different routes of exposure and are used as an alternative model to the canine or the nonhuman primate. Translational preclinical swine study data presented support the current finding that miniature swine are the animal model of choice for assessment of drug absorption, tolerance, and systemic toxicity following systemic exposures. Because research investigators need to be familiar with important anatomic and histopathologic features of the miniature swine in order to place toxicopathologic findings in their proper perspective, clinical and anatomic pathology data from a large number of Sinclair, Hanford, Yucatan, and Göttingen breeds from control groups from a wide variety of studies performed between 2004 and 2014 will be presented, compared, and partially illustrated.

[Teaching management disciplines in nursing education in Brazil: the experience of a group of teachers from the Federal University of Minas Gerais]. / L'enseignement des disciplines de gestion dans la formation des infirmiers au Brésil : l'expérience d'un groupe de professeurs de l'Université Fédérale de Minas Gerais.

Nursing education in Brazil is based on the following principles that guide profession : assistance, management, education and research. These activities can not be developed separately as the intersection between them is an important factor to provide nursing care to the population with safety and quality. Even recognizing the importance of this articulation, in this study it is highlighted the professional managerial training. The aim of this paper is to describe the management disciplines teaching in the training of nurses from a critical and reflective analysis of a group of teachers from the Federal University of Minas Gerais, Brazil. The Brazilian Health Reform Movement and the implementation of the National Curriculum Guidelines have resulted in significant advances in teaching Nursing Management, considering that currently content and practical activities take place at different moments of nursing training. It is concluded that, in this new context, teachers have sought more contemporary theoretical references, which focus on a more participative manage in order to train competent professionals who have a more humane and ethical practice.

Restoring the epigenome in Alzheimer's disease: advancing HDAC inhibitors as therapeutic agents.

Current treatment options for Alzheimer's disease (AD) focus on symptom relief rather than halting disease progression. In this context, targeting histone deacetylation emerges as a promising therapeutic alternative. Dysregulation of histone deacetylase (HDAC) activity is present in AD, contributing to cognitive decline. Pharmacological HDAC inhibition has shown benefits in preclinical models, namely reduced amyloid beta plaque formation, lower phosphorylation and aggregation of tau protein, greater microtubule stability, less neuroinflammation, and improved metabolic homeostasis and cell survival. Nonetheless, clinical trials evidenced limitations such as insufficient selectivity or blood-brain barrier penetration. Hence, future innovative strategies are required to enhance their efficacy/safety.

Bioconjugate based on cisplatin and bacterial exopolysaccharide with reduced side effects: A novel proposal for cancer treatment.

BACKGROUND: In the search for alternatives that attenuate the toxicity associated to oncologic treatment with cisplatin (CDDP) and considering the potential health-beneficial properties of exopolysaccharides (EPS) produced by lactic acid bacteria, it was aimed on this study to evaluate the cytotoxic, toxicologic and antitumoral efficacy of a bioconjugate based on CDDP and EPS, on the experimental tumor of sarcoma 180. METHODS: After the synthesis of the cis-[Pt(NH3)2(Cl)2] complex and of the conjugate containing Lactobacillus fermentum exopolysaccharide was tested both in vitro and in vivo for evaluating the acute toxicity. RESULTS: The antitumoral study was performed using mice transplanted with sarcoma 180. The bioconjugate showed low to medium cytotoxicity for the cell lines tested, as well moderated acute toxicity. After determining the LD50, the following experimental groups were established for the antitumor assay: Control (NaCl 0,9%), CDDP (1 mg/kg), EPS and bioconjugate composition (200 mg/kg). The bioconjugate promoted a 38% regression in tumor mass when compared to the control, and a regression of 41% when compared to CDDP. Liver histopathological analysis revealed discrete alterations in animals treated with (CDDP + EPS) when compared to control. The bioconjugate also minimized changes in the renal parenchyma resulting from the tumor. CONCLUSION: Our results indicate that when CDDP is associated with EPS, this composition was more biocompatible, showing itself as a potent chemotherapeutic agent and lower tissue toxicity.

Genetic Characterization and Population Structure of Drug-Resistant Mycobacterium tuberculosis Isolated from Brazilian Patients Using Whole-Genome Sequencing.

The present study aimed to determine the genetic diversity of isolates of Mycobacterium tuberculosis (Mtb) from presumed drug-resistant tuberculosis patients from several states of Brazil. The isolates had been submitted to conventional drug susceptibility testing for first- and second-line drugs. Multidrug-resistant (MDR-TB) (54.8%) was the most frequent phenotypic resistance profile, in addition to an important high frequency of pre-extensive resistance (p-XDR-TB) (9.2%). Using whole-genome sequencing (WGS), we characterized 298 Mtb isolates from Brazil. Besides the analysis of genotype distribution and possible correlations between molecular and clinical data, we determined the performance of an in-house WGS pipeline with other online pipelines for Mtb lineages and drug resistance profile definitions. Sub-lineage 4.3 (52%) was the most frequent genotype, and the genomic approach revealed a p-XDR-TB level of 22.5%. We detected twenty novel mutations in three resistance genes, and six of these were observed in eight phenotypically resistant isolates. A cluster analysis of 170 isolates showed that 43.5% of the TB patients belonged to 24 genomic clusters, suggesting considerable ongoing transmission of DR-TB, including two interstate transmissions. The in-house WGS pipeline showed the best overall performance in drug resistance prediction, presenting the best accuracy values for five of the nine drugs tested. Significant associations were observed between suffering from fatal disease and genotypic p-XDR-TB (p = 0.03) and either phenotypic (p = 0.006) or genotypic (p = 0.0007) ethambutol resistance. The use of WGS analysis improved our understanding of the population structure of MTBC in Brazil and the genetic and clinical data correlations and demonstrated its utility for surveillance efforts regarding the spread of DR-TB, hopefully helping to avoid the emergence of even more resistant strains and to reduce TB incidence and mortality rates.

Mycobacterium tuberculosis of the RDRio genotype is the predominant cause of tuberculosis and associated with multidrug resistance in Porto Alegre City, South Brazil.

Spoligotyping has shown Mycobacterium tuberculosis strains to be composed of different lineages, and some of them are not just geographically restricted but also affect specific ethnic populations and are associated with outbreaks and drug resistance. We recently described a particular subtype within the Latin American-Mediterranean (LAM) family, called RD(Rio), widespread in Brazil. Moreover, recent data also indicate that RD(Rio) is present in many countries on all continents and is associated with cavitary disease and multidrug resistance (MDR). To further explore the relationship between RD(Rio) and MDR, we conducted a study in a tuberculosis (TB) reference center responsible for the care of MDR patients in Rio Grande do Sul, the southernmost Brazilian state. From a collection of 237 clinical isolates, RD(Rio) alone was responsible for one-half of all MDR cases, including one large group composed of strains with identical IS6110-restriction fragment length polymorphism (RFLP) and having the LAM5 signature. We additionally had complete data records for 96 patients and could make comparisons between the presence and absence of RD(Rio). No difference in clinical, radiological or laboratory features was observed, but a significantly greater number of cases with MDR were described in patients infected with an RD(Rio) strain (P = 0.0015). Altogether, RD(Rio) was responsible for 38% of all TB cases. These data support and confirmed previous findings that RD(Rio) is the main agent responsible for TB in Brazil and is associated with drug resistance. Considering that RD(Rio) is a globally distributed genotype, such findings raise concern about the increase in MDR in certain human populations.

Nontuberculous mycobacteria in respiratory samples from patients with pulmonary tuberculosis in the state of Rondônia, Brazil.

The main cause of pulmonary tuberculosis (TB) is infection with Mycobacterium tuberculosis (MTB). We aimed to evaluate the contribution of nontuberculous mycobacteria (NTM) to pulmonary disease in patients from the state of Rondônia using respiratory samples and epidemiological data from TB cases. Mycobacterium isolates were identified using a combination of conventional tests, polymerase chain reaction-based restriction enzyme analysis of hsp65 gene and hsp65 gene sequencing. Among the 1,812 cases suspected of having pulmonary TB, 444 yielded bacterial cultures, including 369 cases positive for MTB and 75 cases positive for NTM. Within the latter group, 14 species were identified as Mycobacterium abscessus, Mycobacterium avium, Mycobacterium fortuitum, Mycobacterium intracellulare, Mycobacterium gilvum, Mycobacterium gordonae, Mycobacterium asiaticum, Mycobacterium tusciae, Mycobacterium porcinum, Mycobacterium novocastrense, Mycobacterium simiae, Mycobacterium szulgai, Mycobacterium phlei and Mycobacterium holsaticum and 13 isolates could not be identified at the species level. The majority of NTM cases were observed in Porto Velho and the relative frequency of NTM compared with MTB was highest in Ji-Paraná. In approximately half of the TB subjects with NTM, a second sample containing NTM was obtained, confirming this as the disease-causing agent. The most frequently observed NTM species were M. abscessus and M. avium and because the former species is resistant to many antibiotics and displays unsatisfactory cure rates, the implementation of rapid identification of mycobacterium species is of considerable importance.

Oral toxicity and pharmacokinetic studies of SHetA2, a new chemopreventive agent, in rats and dogs.

SHetA2 is a heteroarotinoid that has shown selective inhibition of cancer cell growth and an induction of apoptosis without activation of nuclear retinoic acid receptors. In the rat study, SHetA2 was administered in 1% aqueous methylcellulose/0.2% Tween 80 by oral gavage at 0, 100, 500, and 2,000 mg/kg/day for 28 days. The high-dose administration induced decreased activity in male rats, decreased body-weight gains and food consumption, and changes in organ weights. The major metabolite of SHetA2 in rat plasma was monohydroxy SHetA2, which was considerably higher than the parent compound after oral and intravenous administration. Pharmacokinetic analysis showed extremely low (<1%) systemic bioavailability of SHetA2 for all doses tested. The dose of 2,000 mg/kg/day was considered as the lowest observed adverse effect level. The no observed adverse effect level (NOAEL) was 500 mg/kg/day. In the dog study, no toxicity of SHetA2 in 30% aqueous Solutol(®) HS 15 was observed in any tested dose groups (0, 100, 400, and 1,500 mg/kg/day). The major metabolite of SHetA2 in dog plasma was also monohydroxy SHetA2, which was equal to or lower than the parent compound after oral administration. SHetA2 levels in dog plasma were notably higher, when compared to levels in rat plasma. However, exposure was not dose proportional, as exemplified by a lack of proportional increase in maximum concentration or area under the plasma concentration-time curve with increasing dose. The NOAEL was not established and was considered to be above 1,500 mg/kg/day.

Evolving concepts of host-pathobiont interactions in autoimmunity.

Autoimmune diseases are complex, multifactorial diseases with a polygenic trait and diverse environmental factors that contribute to triggering and exacerbating each disorder. The human microbiome is increasingly implicated in the multistep pathogenesis of autoimmune diseases. We summarize here the latest developments in the field of how the microbiota interacts with the host on a cellular and molecular level. We review how pathobionts evolve within the gut of autoimmune-prone hosts to translocate to secondary lymphoid tissues. On mucosal sites and in non-gut tissues, pathobionts trigger autoimmune pathways through various mechanisms, including cross-reactivity with autoantigens and secretion of metabolites that alter immune functions. A better understanding of these mechanisms will hasten the development of unconventional therapeutic approaches for autoimmune diseases.

Perinatal and post-weaning exposure to a high-fat diet causes histomorphometric, neuroplastic, and histopathological changes in the rat ileum.

Exposure to a diet with a high saturated fat content can influence the characteristics of the gastrointestinal tract, causing losses in the absorption of nutrients and favoring the appearance of diseases. The objective was to assess the effects of a high-fat diet (HFD) in the perinatal (pregnancy and lactation) and post-weaning period on the histomorphometry, neuroplasticity, and histopathology of the ileum. Wistar rats were divided into four subgroups: Control/Control (CC, n = 10) rats fed a control diet (C) throughout the trial period; Control/HFD (CH, n = 9) rats fed diet C (perinatal) and HFD after weaning; HFD/Control (HC, n = 10) rats fed HFD (perinatal) and diet C (post-weaning); HFD/HFD (HH, n = 9) rats fed HFD throughout the experimental period. There was atrophy of the Ileum wall with a reduction in the muscular tunic, submucosa, and mucosa thickness in the HH group of 37%, 28%, and 46%, respectively (p < 0.0001). The depth of the crypts decreased by 29% (p < 0.0001) and height increased by 5% (p < 0.0013). Villus height decreased by 41% and 18% in HH and HC groups (p < 0.0001) and width decreased by 11% in the HH (p < 0.0001). The height of the enterocytes decreased by 18% in the HH (p < 0.0001). There was a decrease in the area of the myenteric and submucosal plexus ganglia in the HH and HC groups (p < 0.0001). The number, occupation, and granules of Paneth cells increased in the HH and HC groups (p < 0.0001). Intraepithelial lymphocytes (IELs) increased in all groups exposed to the HFD. Goblet cells decreased in groups CH and HH (p < 0.0001). The evidence from this study suggests that the HFD had altered the histomorphometry, neuroplasticity, and histopathology of the ileum of the rats.

Effects of a high-fat diet on the bone structure of Wistar rats: a systematic review.

CONTEXT: Saturated fats found in diets known as high-fat, cafeteria, or Western diets appear to have a negative effect on bone structure; however, few studies have focused on investigating this association, and the data available in the literature remain controversial. OBJECTIVE: The aim of the current review was to investigate the effects of a high-fat dietary intake on the bone structure of Wistar rats. DATA SOURCES: A search for articles was carried out in the Pubmed/MEDLINE, Web of Science, Embase, and Scopus databases. DATA EXTRACTION: In total, 447 articles were found in the initial search; 5 articles were included in the systematic review, after application of the exclusion criteria. DATA ANALYSIS: The review was guided by the PICOS strategy and based on the PRISMA protocol for animal reviews. CONCLUSION: High-fat diets appear to affect bone structure of Wistar rats. Diet composition and exposure time are the factors determining the strength of the effect.

Metabolic Myopathies: Experience of a Reference Center of Inherited Metabolic Diseases.

INTRODUCTION: Metabolic myopathies (MM) are a heterogeneous group of genetic disorders affecting metabolic pathways involved in energy production during rest, exercise and physiologic stress (fever, fasting, …). Impairments in the pathways of glycolysis/ glycogenolysis, fatty acid transport/oxidation or in the mitochondrial respiratory chain present primarily with exercise intolerance, myalgias, weakness, cramps, or rhabdomyolysis. Depending on aetiology, the diagnosis can be made through neonatal screening, pre-symptomatic or in the set of clinical manifestations for which a high level of suspicion is important. METHODS: Retrospective descriptive study of the clinical, biochemical, and molecular features of patients with a confirmed diagnosis of MM followed by the multidisciplinary team of the Reference Center of Inherited Metabolic Diseases of Centro Hospitalar Universitário de Lisboa Central from 2009 to 2022. RESULTS: Twenty-three patients with MM were included: 9 (39%) glycogen storage diseases (7 McArdle and 2 Pompe), 7 (30%) fatty acid oxidation disorders (3 CPT2, 3 LCHAD and 1 MAD deficiencies), 6 (26%) mitochondrial disease with significant muscle involvement (2 Pearson, 1 Kearns Sayre, 1 VARS2, 1 SUCLA2 and 1 MT-TL1 deficiencies), and 1 myoadenylate deaminase deficiency. Ages varied from 15 months to 35 years. Eighteen (78%) patients were diagnosed by clinical symptoms, 3 by newborn screening (LCHAD) and 2 were asymptomatic (1 Pompe and 1 McArdle). Frequent symptoms were rhabdomyolysis triggered by illness or exercise 12 (52%), fatigue 11 (48%), exercise intolerance 10 (43%), and myalgia 9 (43%). Eight (35%) patients (LCHAD and mitochondrial) had multisystemic involvement. In 20 (87%) patients, the diagnosis was confirmed by biochemical and/or genetic analysis and 3 (McArdle) by muscle biopsy. CONCLUSION: MM are a heterogeneous set of disorders, but a careful history may guide the differential diagnosis among biochemical pathways and other etiologies. Nowadays, molecular testing has become a powerful tool for diagnosis confirmation, surpassing muscular biopsy in most cases. Accurate diagnosis is important to identify who may benefit from specific therapeutic options, such as enzyme replacement therapy, restricted diets, emergency regime and cofactors. All patients benefit from adequate lifestyle modifications, individualized exercise prescription, nutritional intervention, and genetic counselling.