Degeneración combinada subaguda / Subacute combined degeneration

Introducción: La degeneración combinada subaguda (DCS) es un trastorno caracterizado por la degeneración difusa de la sustancia blanca a nivel del SNC, que afecta específicamente los cordones posteriores y laterales de la médula espinal, con pérdida de la mielinización periférica y central. De manera frecuente, las manifestaciones clínicas son parestesias y debilidad generalizada causada por deficiencia de vitamina B12. Presentación del caso: Paciente masculino de 79 años, con cuadro clínico de 3 meses de evolución de limitación funcional para la marcha acompañado de desorientación. Al examen físico evidenció desorientación, cuadriparesia e hiporreflexia, con niveles séricos bajos de vitamina B12, RM cervical con focos hiperintensos en el segmento C3/C6 y endoscopia de vías digestivas altas con atrofia de la mucosa gástrica. Presentamos un caso clínico de DCS. Discusión: Este es un caso de DCS que se manifiesta por medio de una alteración neuropsiquiátrica, con una presentación inicial inespecífica que comprende deterioro de la marcha, movimientos anormales con afectación cognitiva y psiquiátrica dada por alucinaciones visuales y desorientación. Su sospecha es importante en pacientes con factores de riesgo por medio del conocimiento de la patología, para una adecuada sospecha diagnóstica y una instauración oportuna de reposición vitamínica, la cual presenta una excelente respuesta. Conclusión: La DCS es un trastorno en el que se evidencia anemia con deficiencia de vitamina B12, des-mielinización del tejido nervioso y en muchos casos signos sugestivos de atrofia gástrica, y para ello es crucial la detección temprana de esta enfermedad por medio de la determinación de niveles séricos de vitamina B12, asociado a síntomas neurológicos, para así lograr su adecuado diagnóstico y tratamiento.

Introduction: Subacute combined degeneration (DCS) is a disorder characterized by diffuse degeneration of white matter at the CNS level, specifically affecting the posterior and lateral cords of the spinal cord, also with loss of peripheral and central myelination, frequently the clinical manifestations are paresthesias and generalized weakness caused by vitamin B12 deficiency. Case presentation: A 79-year-old male patient with a 3-month history of functional limitation for walking accompanied by disorientation. On physical examination, he revealed disorientation, quadriparesis, and hyporeflexia, with low serum levels of vitamin B12, cervical MRI with hyperintense foci in segment C3/C6, and upper digestive tract endoscopy with atrophy of the gastric mucosa. We present a clinical case of DCS. Discussion: This is a case of DCS that manifests itself through neuropsychiatric alteration with a nonspecific initial presentation with gait impairment, abnormal movements with cognitive and psychiatric affectation given by visual hallucinations and disorientation. Its suspicion is important in patients with risk factors. risk through knowledge of the pathology for an adequate diagnostic suspicion and a timely establishment of vitamin replacement for which it presents an excellent response. Conclusion: DCS is a disorder where anemia with vitamin B12 deficiency, demyelination of the nervous tissue and in many cases signs suggestive of gastric atrophy are evident, for which early detection of this disease is crucial through the determination of serum levels of vitamin B12 associated with neurological symptoms, in order to achieve its proper diagnosis and treatment.

Methylmalonic acid induces inflammatory response and redox homeostasis disruption in C6 astroglial cells: potential glioprotective roles of melatonin and resveratrol.

Methylmalonic acidemia is a neurometabolic disorder biochemically characterized by the accumulation of methylmalonic acid (MMA) in different tissues, including the central nervous system (CNS). In this sense, it has been shown that high levels of this organic acid have a key role in the progressive neurological deterioration in patients. Astroglial cells actively participate in a wide range of CNS functions, such as antioxidant defenses and inflammatory response. Considering the role of these cells to maintain brain homeostasis, in the present study, we investigated the effects of MMA on glial parameters, focusing on redox homeostasis and inflammatory process, as well as putative mediators of these events in C6 astroglial cells. MMA decreased cell viability, glutathione levels, and antioxidant enzyme activities, increased inflammatory response, and changed the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), nuclear factor kappa B (NFκB), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), and adenosine receptors, suggesting that these transcriptional factors and proteins may underlie the glial responses induced by MMA. Moreover, we also demonstrated the protective roles of melatonin and resveratrol against MMA-induced inflammation and decrease in glutathione levels. In summary, our findings support the hypothesis that astroglial changes are associated with pathogenesis of methylmalonic acidemia. In addition, we showed that these cells might be potential targets for preventive/therapeutic strategies by using molecules, such as melatonin and resveratrol, which mediated glioprotection in this inborn error of metabolism.

Methylmalonic Acid Compromises Respiration and Reduces the Expression of Differentiation Markers of SH-SY5Y Human Neuroblastoma Cells.

Methylmalonic acidemia is a rare metabolic disorder caused by the deficient activity of l-methylmalonyl-CoA mutase or its cofactor 5-deoxyadenosylcobalamin and is characterized by accumulation of methylmalonic acid (MMA) and alternative metabolites. The brain is one of the most affected tissues and neurologic symptoms, characterized by seizures, mental retardation, psychomotor abnormalities, and coma, commonly appear in newborns. The molecular mechanisms of neuropathogenesis in methylmalonic acidemia are still poorly understood, specifically regarding the impairments in neuronal development, maturation, and differentiation. In this study, we investigated the effects of MMA in both undifferentiated and differentiated phenotypes of SH-SY5Y human neuroblastoma cells. We observed an increase in glucose consumption and reduction in respiratory parameters of both undifferentiated and differentiated cells after exposition to MMA, suggesting that differentiated cells are slightly more prone to perturbations in respiratory parameters by MMA than undifferentiated cells. Next, we performed qPCR of mature neuronal-specific gene markers and measured mitochondrial functioning to evaluate the role of MMA during differentiation. Our results showed that MMA impairs the respiratory parameters only at the late stage of differentiation and downregulates the transcriptional gene profile of mature neuronal markers neuron-specific enolase (ENO2) and synaptophysin (SYP). Altogether, our findings point out important changes observed during neuronal maturation and energetic stress vulnerability that can play a role in the neurological clinical symptoms at the newborn period and reveal important molecular mechanisms that could help the screening of targets to new approaches in the therapies of this disease.

Vitamin B12 supplementation orally and intramuscularly in people with obesity undergoing gastric bypass.

PURPOSE: Although bariatric surgery can facilitate weight loss and improve many diseases, it impairs the absorption of many vitamins and micronutrients. Vitamin B12 is important for these patients and should be controlled and supplemented postoperatively. The aim of this paper is to compare serum vitamin B12 levels in two forms of supplementation (oral vs. intramuscular) for 6 months after gastric bypass. METHODS: In a prospective controlled cohort study, people with obesity patients undergoing gastric bypass received vitamin B12 supplementation either orally or intramuscularly. The patients were followed for 6 months, receiving serial doses of vitamin B12 and methylmalonic acid assessment at 6 months. RESULTS: A total of 53 patients were divided into two homogeneous groups: an oral group (n=24) and an intramuscular group (n=29). Serum vitamin B12 was measured preoperatively and postoperatively at 1, 2, 3, and 6 months. Serum methylmalonic acid was measured at 6 months. At each point, the serum vitamin B12 level remained within reference values in both groups, although it was higher in the oral group (p<0.001). Methylmalonic acid also remained within reference values in both groups, with no significant differences. CONCLUSION: Despite the anatomical and functional alterations that impair vitamin B12 absorption after gastric bypass, oral vitamin B12 supplementation was as effective as intramuscular in this population.

Diagnóstico de aciduria metilmalónica en el periodo 2013-2018 / Diagnosis of Methyl Malonicaciduria from 2013 to 2018

RESUMEN Fundamento: la aciduria metilmalónica es una de las acidurias orgánicas más frecuentes y agrupa un conjunto de defectos genéticos caracterizados por la excreción de niveles elevados de ácido metilmalónico en la orina. La excreción de este metabolito puede ir acompañada o no de niveles elevados de homocisteína en dependencia de la ruta metabólica afectada. Objetivo describir la implementación de una metodología de laboratorio que combina el ácido metilmalónico y la homocisteína en el diagnóstico diferencial y seguimiento de la aciduria metilmalónica en el periodo de 2013 a 2018. Métodos: a los pacientes con incremento de ácido metilmalónico en el perfil de ácidos orgánicos, se les cuantificó homocisteína en plasma y orina. La identificación del ácido metilmalónico se realizó por cromatografía gaseosa/ espectrometría de masas, mientras que la cuantificación de homocisteína por cromatografía líquida de alta resolución. Resultados: los métodos cromatográficos permitieron la identificación y cuantificación del ácido metilmalónico y la homocisteína, respectivamente. La homocisteína se cuantificó en siete pacientes con niveles incrementados de aciduria metilmalónica. Los niveles de homocisteína en cuatro de ellos fueron superiores a los valores normales, sugiriendo una aciduria combinada con homocistinuria. Tres de los pacientes con aciduria metilmalónica combinada bajo tratamiento mostraron una disminución en los niveles de ambos metabolitos, correspondiendo con una satisfactoria evolución. Conclusiones: la metodología implementada con los análisis de la determinación simultánea de ambos marcadores permitió el diagnóstico diferencial y seguimiento bioquímico de la aciduria metilmalónica.

ABSTRACT Foundation: methylmalonic aciduria is one of the most frequent organic acidurias and groups together a set of genetic defects, characterized by the excretion of elevated levels of urinemethyl malonic acid. The excretion of this metabolite may or may not be accompanied by elevated homocysteine ​​levels depending on the affected metabolic pathway. Objective: to describe the implementation of a laboratory methodology that combines methylmalonic acid and homocysteine ​​in the differential diagnosis and monitoring of methylmalonic aciduria in the period from 2013 to 2018. Methods: for patients with an increase in methylmalonic acid in the organic acid profile, homocysteine ​​was quantified in plasma and urine. The identification of methylmalonic acid was performed by gas chromatography / mass spectrometry, while the homocysteine ​​quantification by high performance liquid chromatography. Results: chromatographic methods allowed the identification and quantification of methylmalonic acid and homocysteine, respectively. Homocysteine ​​was quantified in seven patients with increased levels of methylmalonic aciduria. Homocysteine ​​levels in four of them were higher than normal values, suggesting aciduria combined with homocystinuria. Three of the patients with combined methylmalonic aciduria under treatment showed a decrease in the levels of both metabolites, corresponding to a satisfactory evolution. Conclusions: simultaneous determination of both markers allowed differential diagnosis and biochemical monitoring of this disease.

Assessment of cellular cobalamin metabolism in Gaucher disease.

BACKGROUND: Gaucher disease (GD) is a lysosomal disorder caused by biallelic pathogenic mutations in the GBA1 gene that encodes beta-glucosidase (GCase), and more rarely, by a deficiency in the GCase activator, saposin C. Clinically, GD manifests with heterogeneous multiorgan involvement mainly affecting hematological, hepatic and neurological axes. This disorder is divided into three types, based on the absence (type I) or presence and severity (types II and III) of involvement of the central nervous system. At the cellular level, deficiency of GBA1 disturbs lysosomal storage with buildup of glucocerebroside. The consequences of disturbed lysosomal metabolism on biochemical pathways that require lysosomal processing are unknown. Abnormal systemic markers of cobalamin (Cbl, B12) metabolism have been reported in patients with GD, suggesting impairments in lysosomal handling of Cbl or in its downstream utilization events. METHODS: Cultured skin fibroblasts from control humans (n = 3), from patients with GD types I (n = 1), II (n = 1) and III (n = 1) and an asymptomatic carrier of GD were examined for their GCase enzymatic activity and lysosomal compartment intactness. Control human and GD fibroblasts were cultured in growth medium with and without 500 nM hydroxocobalamin supplementation. Cellular cobalamin status was examined via determination of metabolomic markers in cell lysate (intracellular) and conditioned culture medium (extracellular). The presence of transcobalamin (TC) in whole cell lysates was examined by Western blot. RESULTS: Cultured skin fibroblasts from GD patients exhibited reduced GCase activity compared to healthy individuals and an asymptomatic carrier of GD, demonstrating a preserved disease phenotype in this cell type. The concentrations of total homocysteine (tHcy), methylmalonic acid (MMA), cysteine (Cys) and methionine (Met) in GD cells were comparable to control levels, except in one patient with GD III. The response of these metabolomic markers to supplementation with hydroxocobalamin (HOCbl) yielded variable results. The content of transcobalamin in whole cell lysates was comparable in control human and GD patients. CONCLUSIONS: Our results indicate that cobalamin transport and cellular processing pathways are overall protected from lysosomal storage damage in GD fibroblasts. Extending these studies to hepatocytes, macrophages and plasma will shed light on cell- and compartment-specific vitamin B12 metabolism in Gaucher disease.

Ilex paraguariensis Attenuates Changes in Mortality, Behavioral and Biochemical Parameters Associated to Methyl Malonate or Malonate Exposure in Drosophila melanogaster.

Methylmalonic acidemia is a genetic disease characterized by accumulation of organic acids, such as methylmalonic (MMA) and malonic (MA) acids. Considering that the accumulation of MMA and MA causes several damages due to oxidative stress, antioxidants are thought to play a pivotal role in preventing deleterious effects associated with exposure to such compounds. Ilex paraguariensis (IP) was used here to test the hypothesis that supplementation with the aqueous extract of this plant could exert protective effect against MMA or MA induced mortality, behavioral and/or biochemical changes in Drosophila melanogaster (DM). Initially, a curve time- and dose-response to MMA (1-10 mM), MA (1-10 mM) and IP (63-500 µM) was performed. Thereafter, flies were concomitantly exposed to MA (5 mM), MMA (5 mM) and/or IP (250 µg/mL) during 15 days for survival assay, and for 48 hs to MA (1 or 5 mM), MMA (1 or 5 mM) and/or IP (250 µg/mL) for subsequent investigations. Both MMA and MA exposure resulted in higher incidence of mortality, a worse performance in the negative geotaxis assay and increased locomotion in open-field test as compared with control group. Furthermore, a marked increase in non-protein thiol (NPSH) and in thiobarbituric acid reactive substances (TBARS) levels, decrease in superoxide dismutase (SOD), catalase and acetylcholinesterase (AChE) activities, and decrease in MTT and resazurin reduction were noted in MMA or MA treated groups. IP treatment offered significant protection against all alterations associated to MMA or MA exposure. This study confirm the hypothesis that supplementation with IP offers protection against changes associated to MMA or MA exposure in DM, due, at least in part, to its antioxidant effect.

Degeneración combinada subaguda en un paciente sin anemia y con hipertensión severa / Subacute combined degeneration in a patient without anemia but with severe hypertension

RESUMEN La degeneración combinada subaguda, es una patología de tipo neuropsiquiatrica asociada al déficit de vitamina B12. Se manifiesta clínicamente por ataxia sensorial, neuropatía periférica, disfunción cognitiva y neuropatía óptica; estas manifestaciones generalmente son atribuidas a la síntesis anormal de mielina. Puede tener una presentación clínica inespecífica, pero la medición de los niveles de vitamina B12, algunos metabolitos séricos, y el uso de métodos de neuroimagen, ayudan a confirmar el diagnóstico ante su sospecha. A continuación se describe el caso de un paciente con un cuadro de degeneración combinada subaguda, quien consultó por síntomas neurológicos e hipertensión severa, quien luego del tratamiento presentó mejoría de su sintomatologia neurológica y vascular.

SUMMARY Sub-acute combined degeneration is a neuropsychiatrical pathology associated with vitamin B12 deficiency It is clinically manifested through sensorial ataxia, peripheral neuropathy, cognitive dysfunction and optical neuropathy; these manifestations are generally attributed to the abnormal synthesis of myelin. It can have a nonspecific clinical presentation but the measurement of the levels of vitamin B12, some serum metabolites, and the use of neuroimaging methods help to confirm the diagnose when suspected. The case of a patient with sub-acute combined degeneration is described below. The patient was attended because of neurological symptoms and severe hypertension, and after the treatment, the patient's neurological and vascular symptomatology improved.

Is Serum Methylmalonic Acid a Reliable Biomarker of Vitamin B12 Status in Children with Short Bowel Syndrome: A Case Series.

We describe 3 patients with short bowel syndrome who had persistently elevated serum methylmalonic acid (MMA) levels while being treated for vitamin B12 deficiency. Following treatment for presumed small bowel bacterial overgrowth, MMA levels normalized. Among patients with short bowel syndrome, MMA levels may have limited specificity for vitamin B12 deficiency.

Hampered Vitamin B12 Metabolism in Gaucher Disease?

Abstract Untreated vitamin B12 deficiency manifests clinically with hematological abnormalities and combined degeneration of the spinal cord and polyneuropathy and biochemically with elevated homocysteine (Hcy) and methylmalonic acid (MMA). Vitamin B12 metabolism involves various cellular compartments including the lysosome, and a disruption in the lysosomal and endocytic pathways induces functional deficiency of this micronutrient. Gaucher disease (GD) is characterized by dysfunctional lysosomal metabolism brought about by mutations in the enzyme beta-glucocerebrosidase (Online Mendelian Inheritance in Man (OMIM): 606463; Enzyme Commission (EC) 3.2.1.45, gene: GBA1). In this study, we collected and examined available literature on the associations between GD, the second most prevalent lysosomal storage disorder in humans, and hampered vitamin B12 metabolism. Results from independent cohorts of patients show elevated circulating holotranscobalamin without changes in vitamin B12 levels in serum. Gaucher disease patients under enzyme replacement therapy present normal levels of Hcy and MMA. Although within the normal range, a significant increase in Hcy and MMA with normal serum vitamin B12 was documented in treated GD patients with polyneuropathy versus treated GD patients without polyneuropathy. Thus, a functional deficiency of vitamin B12 caused by disrupted lysosomal metabolism in GD is a plausible mechanism, contributing to the neurological form of the disorder but this awaits confirmation. Observational studies suggest that an assessment of vitamin B12 status prior to the initiation of enzyme replacement therapy may shed light on the role of vitamin B12 in the pathogenesis and progression of GD.

Vitamin B-12 treatment of asymptomatic, deficient, elderly Chileans improves conductivity in myelinated peripheral nerves, but high serum folate impairs vitamin B-12 status response assessed by the combined indicator of vitamin B-12 status.

BACKGROUND: It is uncertain whether vitamin B-12 supplementation can improve neurophysiologic function in asymptomatic elderly with low vitamin B-12 status or whether folate status affects responses to vitamin B-12 supplementation. OBJECTIVE: We assessed the effects of a single intramuscular injection of 10 mg vitamin B-12 (which also contained 100 mg vitamin B-6 and 100 mg vitamin B-1) on vitamin B-12 status and neurophysiologic function in elderly community-dwelling Chileans with low serum vitamin B-12 concentrations who were consuming bread fortified with folic acid. DESIGN: A pretreatment and posttreatment study was conducted in 51 participants (median ± SD age: 73 ± 3 y; women: 47%) with serum vitamin B-12 concentrations <120 pmol/L at screening. Vitamin B-12 status was defined by combining vitamin B-12, plasma total homocysteine (tHcy), methylmalonic acid (MMA), and holotranscobalamin into one variable [combined indicator of vitamin B-12 status (cB-12)]. The response to treatment was assessed by measuring cB-12 and neurophysiologic variables at baseline and 4 mo after treatment. RESULTS: Treatment increased serum vitamin B-12, holotranscobalamin, and cB-12 (P < 0.001) and reduced plasma tHcy and serum MMA (P < 0.001). Treatment produced consistent improvements in conduction in myelinated peripheral nerves; the sensory latency of both the left and right sural nerves improved on the basis of faster median conduction times of 3.1 and 3.0 ms and 3.3 and 3.4 ms, respectively (P < 0.0001). A total of 10 sensory potentials were newly observed in sural nerves after treatment. Participants with high serum folate at baseline (above the median, ≥33.9 nmol/L) had less improvement in cB-12 (P < 0.001) than did individuals whose serum folate was less than the median concentration (i.e., with a concentration <33.9 nmol/L). CONCLUSION: Asymptomatic Chilean elderly with poor vitamin B-12 status displayed improved conductivity in myelinated peripheral nerves after vitamin B-12 treatment and an interaction with folate status, which was detected only with the use of cB-12. This trial was registered at www.controlled-trials.com as ISRCTN02694183.

Long-term intermittent hypoxia elevates cobalt levels in the brain and injures white matter in adult mice.

STUDY OBJECTIVES: Exposure to the variable oxygenation patterns in obstructive sleep apnea (OSA) causes oxidative stress within the brain. We hypothesized that this stress is associated with increased levels of redox-active metals and white matter injury. DESIGN: Participants were randomly allocated to a control or experimental group (single independent variable). SETTING: University animal house. PARTICIPANTS: Adult male C57BL/6J mice. INTERVENTIONS: To model OSA, mice were exposed to long-term intermittent hypoxia (LTIH) for 10 hours/day for 8 weeks or sham intermittent hypoxia (SIH). MEASUREMENTS AND RESULTS: Laser ablation-inductively coupled plasma-mass spectrometry was used to quantitatively map the distribution of the trace elements cobalt, copper, iron, and zinc in forebrain sections. Control mice contained 62 ± 7 ng cobalt/g wet weight, whereas LTIH mice contained 5600 ± 600 ng cobalt/g wet weight (P < 0.0001). Other elements were unchanged between conditions. Cobalt was concentrated within white matter regions of the brain, including the corpus callosum. Compared to that of control mice, the corpus callosum of LTIH mice had significantly more endoplasmic reticulum stress, fewer myelin-associated proteins, disorganized myelin sheaths, and more degenerated axon profiles. Because cobalt is an essential component of vitamin B12, serum methylmalonic acid (MMA) levels were measured. LTIH mice had low MMA levels (P < 0.0001), indicative of increased B12 activity. CONCLUSIONS: Long-term intermittent hypoxia increases brain cobalt, predominantly in the white matter. The increased cobalt is associated with endoplasmic reticulum stress, myelin loss, and axonal injury. Low plasma methylmalonic acid levels are associated with white matter injury in long-term intermittent hypoxia and possibly in obstructive sleep apnea.

Chronic administration of methylmalonate on young rats alters neuroinflammatory markers and spatial memory.

The methylmalonic acidemia is an inborn error of metabolism (IEM) characterized by methylmalonic acid (MMA) accumulation in body fluids and tissues, causing neurological dysfunction, mitochondrial failure and oxidative stress. Although neurological evidence demonstrate that infection and/or inflammation mediators facilitate metabolic crises in patients, the involvement of neuroinflammatory processes in the neuropathology of this organic acidemia is not yet established. In this experimental study, we used newborn Wistar rats to induce a model of chronic acidemia via subcutaneous injections of methylmalonate (MMA, from 5th to 28th day of life, twice a day, ranged from 0.72 to 1.67 µmol/g as a function of animal age). In the following days (29th-31st) animal behavior was assessed in the object exploration test and elevated plus maze. It was performed differential cell and the number of neutrophils counting and interleukin-1 beta (IL-1ß) and tumor necrosis factor-alpha (TNF-α) levels in the blood, as well as levels of IL-1ß, TNF-α, inducible nitric oxide synthase (iNOS) and 3-nitrotyrosine (3-NT) in the cerebral cortex were measured. Behavioral tests showed that animals injected chronically with MMA have a reduction in the recognition index (R.I.) when the objects were arranged in a new configuration space, but do not exhibit anxiety-like behaviors. The blood of MMA-treated animals showed a decrease in the number of polymorphonuclear and neutrophils, and an increase in mononuclear and other cell types, as well as an increase of IL-1ß and TNF-α levels. Concomitantly, MMA increased levels of IL-1ß, TNF-α, and expression of iNOS and 3-NT in the cerebral cortex of rats. The overall results indicate that chronic administration of MMA increased pro-inflammatory markers in the cerebral cortex, reduced immune system defenses in blood, and coincide with the behavioral changes found in young rats. This leads to speculate that, through mechanisms not yet elucidated, the neuroinflammatory processes during critical periods of development may contribute to the progression of cognitive impairment in patients with methylmalonic acidemia.