RESUMO
La seudomicroangiopatía trombótica o síndrome de Moschcowitz es una manifestación infrecuente del déficit de vitamina B12. Se caracteriza por anemia hemolítica con características microangiopáticas, reticulocitos e índices hematimétricos normales o con ligera megaloblastosis, asociados a manifestaciones neurológicas. La vitamina B12 está presente en alimentos proteicos de origen animal. La lactancia materna es una fuente adecuada para los niños cuando los niveles maternos son normales. Se presenta a una paciente de 16 meses que se internó por anemia hemolítica con requerimiento transfusional, plaquetopenia, mal progreso pondoestatural y retraso neuromadurativo. Durante su internación se arribó al diagnóstico de seudomicroangiopatía trombótica secundaria a déficit de vitamina B12.
Pseudo-thrombotic microangiopathy, or Moschcowitz syndrome, is a rare manifestation of vitamin B12 deficiency. It is characterized by microangiopathic hemolytic anemia, reticulocytes, and hematimetric indices that can be normal or that might present a mild megaloblastosis, and which are associated with neurological manifestations. Vitamin B12 can be found in animal-based protein foods. Breastfeeding is an adequate source of this vitamin for children, when maternal serum levels are normal. The case of a 16-month-old infant is presented. She was admitted for hemolytic anemia with transfusion requirement, thrombocytopenia, failure to thrive and developmental delay. During her hospitalization, she was diagnosed with pseudothrombotic microangiopathy caused by vitamin B12 deficiency.
Assuntos
Humanos , Feminino , Lactente , Deficiência de Vitamina B 12/complicações , Microangiopatias Trombóticas/diagnóstico , Deficiência de Vitamina B 12/terapia , Anemia Hemolítica/sangueRESUMO
During the past decade the role of folate and vitamin B12 in human nutrition have been under constant re-examination. Basic knowledge on the metabolism and interactions between these essential nutrients has expanded and multiple complexities have been unraveled. These micronutrients have shared functions and intertwined metabolic pathways that define the size of the "methyl donor" pool utilized in multiple metabolic pathways; these include DNA methylation and synthesis of nucleic acids. In Chile, folate deficiency is virtually nonexistent, while vitamin B12 deficiency affects approximately 8.5-51% depending on the cut-off value used to define deficiency. Folate is found naturally mainly in vegetables or added as folic acid to staple foods. Vitamin B12 in its natural form is present only in foods of animal origin, which is why deficit is more common among strict vegetarians and populations with a low intake of animal foods. Poor folate status in vulnerable women of childbearing age increases the risk of neural tube birth defects, so the critical time for the contribution of folic acid is several months before conception since neural tube closure occurs during the first weeks of life. The absorption of vitamin B12 from food is lower in older adults, who are considered to have higher risk of gastric mucosa atrophy, altered production of intrinsic factor and acid secretion. Deficiency of these vitamins is associated with hematological disorders. Vitamin B12 deficiency can also induce clinical and sub-clinical neurological and of other disorders. The purpose of this review is to provide an update on recent advances in the basic and applied knowledge of these vitamins relative to human health.
Assuntos
Deficiência de Ácido Fólico , Ácido Fólico , Deficiência de Vitamina B 12 , Vitamina B 12 , Dieta , Ácido Fólico/administração & dosagem , Ácido Fólico/química , Ácido Fólico/metabolismo , Deficiência de Ácido Fólico/diagnóstico , Deficiência de Ácido Fólico/etiologia , Deficiência de Ácido Fólico/terapia , Alimentos Fortificados , Humanos , Vitamina B 12/administração & dosagem , Vitamina B 12/química , Vitamina B 12/metabolismo , Deficiência de Vitamina B 12/diagnóstico , Deficiência de Vitamina B 12/etiologia , Deficiência de Vitamina B 12/terapiaAssuntos
Deficiência de Vitamina B 12 , Adolescente , Distribuição por Idade , Fatores Etários , Criança , Ingestão de Alimentos , Ácido Fólico/uso terapêutico , Alimentos Fortificados , Humanos , Prevalência , Fatores de Risco , Vitamina B 12/metabolismo , Vitamina B 12/uso terapêutico , Deficiência de Vitamina B 12/diagnóstico , Deficiência de Vitamina B 12/epidemiologia , Deficiência de Vitamina B 12/etiologia , Deficiência de Vitamina B 12/metabolismo , Deficiência de Vitamina B 12/terapiaRESUMO
Na faixa etaria pediatrica, a carencia alimentar se constitui na causa mais comum de anemia, particularmente nos paises em desenvolvimento. O acesso irregular a uma alimentacao balanceada, a elevada incidencia de parasitoses intestinais e o requerimento continuo e elevado de nutrientes devido ao crescimento, tornam as criancas propensas a desenvolver anemia carencial. Apesar de ser um problema clinico de resolucao relativamente facil apos instalado, estaria nos esforcos de prevencao a atitude mais correta dos pontos de vista medico, social e politico. Os autores fazem uma revisao da literatura abordando as tres principais deficiencias alimentares que resultam em anemia (ferropenia e as deficiencias de vitamina B12 e folato), com especial enfase as suas causas, manifestacoes clinicas, diagnostico tratamento
Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Anemia/classificação , Deficiências de Ferro/etiologia , Anemias Nutricionais/diagnóstico , Ácido Fólico/uso terapêutico , Anemia Megaloblástica/etiologia , Anemia Megaloblástica/terapia , Anemia Ferropriva , Anemia/diagnóstico , Anemia/terapia , Deficiência de Ácido Fólico/fisiopatologia , Distúrbios do Metabolismo do Ferro/terapia , Complexo Ferro-Dextran/administração & dosagem , Complexo Ferro-Dextran/uso terapêutico , Transferrina/metabolismo , Deficiência de Vitamina B 12/terapia , Vitamina B 12/uso terapêuticoRESUMO
The authors present a case of dietary vitamin B12 deficiency in a patient with multiple sclerosis. A simple schemata for evaluating patients for vitamin B12 deficiency is included as a clinical aid for physicians.
Assuntos
Transtornos da Alimentação e da Ingestão de Alimentos/complicações , Esclerose Múltipla/complicações , Deficiência de Vitamina B 12/etiologia , Adulto , Protocolos Clínicos , Árvores de Decisões , Transtornos da Alimentação e da Ingestão de Alimentos/diagnóstico , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Transtornos da Alimentação e da Ingestão de Alimentos/terapia , Humanos , Masculino , Anamnese , Psicoterapia , Vitamina B 12/uso terapêutico , Deficiência de Vitamina B 12/diagnóstico , Deficiência de Vitamina B 12/terapiaRESUMO
OBJECTIVE: To measure the prevalence of cobalamin (vitamin B12) deficiency in geriatric outpatients as documented by both low serum cobalamin levels and elevations of serum methylmalonic acid and homocysteine and to determine the response to cobalamin treatment. DESIGN: Prospective study screening elderly subjects for cobalamin deficiency using radiodilution cobalamin assays as well as stable isotope dilution gas chromatography-mass spectrometry methylmalonic acid and homocysteine assays. In patients with serum cobalamin levels < or = 300 pg/mL, the response to cobalamin treatment in the group with levels of methylmalonic acid and/or homocysteine > 3 standard deviations (SD) above the mean for normals was compared with that of those without such elevations. SETTING: Outpatient geriatric clinics at the VA Medical Center and University Health Sciences Center, Denver, CO. PATIENTS: One-hundred and fifty-two consecutive outpatients, ages 65 to 99, were screened. Twenty-nine subjects with serum cobalamin levels < or = 300 pg/mL were prospectively evaluated and treated with cobalamin. MAIN OUTCOME MEASURES: Cobalamin, methylmalonic acid, homocysteine, complete blood counts, neurologic examination, and neuropsychological testing. RESULTS: The prevalence of cobalamin deficiency as defined by a serum cobalamin level < or = 300 pg/mL and levels of serum methylmalonic acid and/or homocysteine elevated to > 3 SD was 14.5% of the screened outpatients. A similar proportion of patients with low normal serum cobalamin levels (between 201 and 300 pg/mL) demonstrated elevated metabolites > 3 SD (56%) compared with patients with low serum cobalamin levels (< or = 200 pg/mL) (62%). Cobalamin therapy caused a marked fall or complete correction of the elevated methylmalonic acid and homocysteine levels in each patient who was treated prospectively. Results for complete blood count, lactate dehydrogenase, bilirubin, baseline neurologic score, and baseline neuropsychologic scores did not differ in the group of patients with elevated metabolites compared with those with normal metabolites. The mean red cell volume fell significantly in the patients with elevated metabolites after 6 months of cobalamin treatment. One patient with elevated metabolites had marked improvement in his neurologic abnormalities after 6 months of cobalamin treatment. CONCLUSION: There was a high (14.5%) prevalence of cobalamin deficiency as demonstrated by elevations in serum methylmalonic acid and homocysteine in addition to low or low normal serum cobalamin levels in elderly outpatients. The serum cobalamin level was insensitive for screening since similar numbers of patients with low normal serum cobalamin levels of 201-300 pg/mL compared with patients with low cobalamin levels (< or = 200 pg/mL) had markedly elevated metabolites which fell with cobalamin treatment. Additional studies will be required to define the full clinical benefit from treatment with Cbl in elderly subjects.
Assuntos
Deficiência de Vitamina B 12/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Assistência Ambulatorial , Colorado/epidemiologia , Feminino , Homocisteína/sangue , Humanos , Masculino , Programas de Rastreamento , Ácido Metilmalônico/sangue , Exame Neurológico , Testes Neuropsicológicos , Prevalência , Estudos Prospectivos , Vitamina B 12/administração & dosagem , Vitamina B 12/sangue , Deficiência de Vitamina B 12/sangue , Deficiência de Vitamina B 12/diagnóstico , Deficiência de Vitamina B 12/terapiaRESUMO
A review of the clinical findings in six infants with nutritional vitamin B12 deficiency seen during the last 10 years was undertaken and an attempt made to obtain long-term neurologic follow-up. There was a consistent clinical pattern in vitamin B12-deficient infants; irritability, anorexia, and failure to thrive were associated with marked developmental regression and poor brain growth. Two of the four patients who qualified for long-term review had a poor intellectual outcome. Although early response to treatment is satisfying, the long-term consequences of nutritional vitamin B12 deficiency in infants emphasize the need for prevention or early recognition of this syndrome.