| Revue: | Jornal brasileiro de patologia e medicina laboratorial |
| Base de datos: | PERIÓDICA |
| Número de sistema: | 000297221 |
| ISSN: | 1676-2444 |
| Autores: | Paniz, Clovis1 Grotto, Denise Schmitt, Gabriela Cristina Valentini, Juliana Schott, Karen Lilian Pomblum, Valdeci Juarez Garcia, Solange Cristina2 |
| Instituciones: | 1Universidade Federal de Santa Maria, Hospital Universitario de Santa Maria, Santa Maria, Rio Grande do Sul. Brasil 2Universidade Federal de Santa Maria, Departamento de Analises Clinicas e Toxicologicas, Santa Maria, Rio Grande do Sul. Brasil |
| Año: | 2005 |
| Periodo: | Oct |
| Volumen: | 41 |
| Número: | 5 |
| Paginación: | 323-334 |
| País: | Brasil |
| Idioma: | Portugués |
| Tipo de documento: | Artículo |
| Enfoque: | Experimental |
| Resumen en inglés | INTRODUCTION: The vitamin B12 is a water soluble vitamin, not synthetized by humans organisms, found in foods of animal origin. Its deficiency is very frequent among old people, vegetarians, subjects who use a low protein diet, or who present gastrointestinal absorption failure. PHYSIOPATHOLOGY: The vitamin B12 deficiency leads to hematologic, neurophatologic and cardiovascular disorders, mainly by interfering in the homocysteine (Hcy) metabolism and in the methylation reactions of organism. Often, the deficiency can remain without symptoms for long time, leading to a chronic deficiency that, if not treated, may yield irreversible neurologic manifestations. METHODOLOGY: Efficient methodologies that allow the early diagnosis are essential. However, a gold standard method is not consensus yet. The vitamin B12 serum measurement presents some restrictions for problems of sensitivity and specificity, being able to occur deficiencys symptoms even the serum vitamin B12 being in normal range or, in another way, occurring low levels of serum vitamin B12 without, however, showing low levels of vitamin B12 fraction really available for the cells and without showing symptoms. New alternatives come appearing, as the transcobalamin II measurement, the only vitamin B12 fraction available for the cells or the methylmalonic acid and Hcy measurement, metabolites that increase when intracellular vitamin B12 decreases. These tests present some advantages, but also important limitations for use in the routine. CONCLUSION: In the sub clinical cases, a correct and early diagnosis represents still a challenge and further studies are needed to define the best method for routine laboratorial diagnosis of vitamin B12 deficiency |
| Resumen en portugués | Estes testes apresentam algumas vantagens, mas também limitações importantes para uso rotineiro. CONCLUSÃO: Em casos subclínicos, um diagnóstico correto e precoce representa ainda um desafio, e futuros estudos são necessários para definir um método padrão para diagnóstico laboratorial da deficiência de vitamina B12 |
| Disciplinas: | Medicina |
| Palabras clave: | Diagnóstico, Metabolismo y nutrición, Transcobalamina, Acido metilmalónico, Hiperhomocisteinemia, Suero, Vitamina B12 |
| Keyword: | Medicine, Diagnosis, Metabolism and nutrition, Transcobalamin, Methylmalonic acid, Hyperhomocysteinemia, Serum, Vitamin B12 |
| Texte intégral: | Texto completo (Ver HTML) |
