RESUMEN
BACKGROUND: Serum free light chain (FLC) analysis with ratio and urine immunofixation electrophoresis (IFE) are both available for routine use in helping to detect plasma cell dyscrasia and related diseases. CASES: Case reports showing one serum positive for serum FLC but that showed a hook effect and overestimated the amount of monoclonal FLC while urine IFE was negative for Bence Jones protein, and a second serum that showed elevated FLC κ and λ but a normal κ/λ ratio, while urine IFE was positive for Bence Jones protein. CONCLUSIONS: These two techniques complement one another. Neither of the techniques is truly quantitative, and both exhibit methodological defects.
Asunto(s)
Electroforesis de las Proteínas Sanguíneas/métodos , Cadenas Ligeras de Inmunoglobulina/sangre , Cadenas Ligeras de Inmunoglobulina/orina , Paraproteinemias/diagnóstico , Insuficiencia Renal/diagnóstico , Anciano , Anciano de 80 o más Años , Amiloidosis/complicaciones , Amiloidosis/diagnóstico , Amiloidosis/inmunología , Anemia Macrocítica/sangre , Anemia Macrocítica/complicaciones , Anemia Macrocítica/diagnóstico , Anemia Macrocítica/orina , Proteína de Bence Jones/análisis , Humanos , Inmunoglobulina G/sangre , Cadenas kappa de Inmunoglobulina/sangre , Cadenas kappa de Inmunoglobulina/orina , Cadenas lambda de Inmunoglobulina/sangre , Cadenas lambda de Inmunoglobulina/orina , Masculino , Mieloma Múltiple/sangre , Mieloma Múltiple/complicaciones , Mieloma Múltiple/diagnóstico , Mieloma Múltiple/orina , Proteínas de Mieloma/análisis , Paraproteinemias/sangre , Paraproteinemias/complicaciones , Paraproteinemias/orina , Insuficiencia Renal/sangre , Insuficiencia Renal/complicaciones , Insuficiencia Renal/orinaRESUMEN
Urinary methylmalonic acid (MMA) excretion in megaloblastic anemia due to vitamin B12 (B12) deficiency was studied using a colorimetric method. Average MMA excretion in 20 patients with untreated B12 deficiency was 164 mg/day, whereas it increased to 518 mg/day following oral administration of 10 g L-valine. Urinary MMA correlated significantly with platelet number, erythroblast percentage and deoxyuridine suppression test, while no correlation was found with hemoglobin, leukocyte number, reticulocyte, serum LDH, serum B12 and folate concentration. Patients with neurological disturbances excreted significantly larger amounts of MMA than those without neurological disorders. The results also indicated that MMA could be a useful adjunct for differentiation of megaloblastic anemia from myelodysplastic syndromes showing marked megaloblastic changes.
Asunto(s)
Anemia Macrocítica/orina , Anemia Megaloblástica/orina , Malonatos/orina , Ácido Metilmalónico/orina , Deficiencia de Vitamina B 12/complicaciones , Adolescente , Adulto , Anciano , Anemia Megaloblástica/etiología , Femenino , Humanos , Masculino , Persona de Mediana EdadAsunto(s)
Malonatos/orina , Anemia Macrocítica/etiología , Anemia Macrocítica/metabolismo , Anemia Macrocítica/orina , Anemia Perniciosa/metabolismo , Anemia Perniciosa/orina , Cromatografía por Intercambio Iónico , Humanos , Métodos , Espectrofotometría , Temperatura , Factores de Tiempo , Valina/metabolismo , Deficiencia de Vitamina B 12/complicaciones , Deficiencia de Vitamina B 12/metabolismo , Deficiencia de Vitamina B 12/orinaAsunto(s)
Anemia Macrocítica/sangre , Ácido Fólico/sangre , Adulto , Anciano , Anemia Macrocítica/etiología , Anemia Macrocítica/orina , Anemia Perniciosa/sangre , Proteínas Sanguíneas/análisis , Infecciones por Cestodos/complicaciones , Cromatografía , Cromatografía en Gel , Femenino , Ácido Fólico/orina , Deficiencia de Ácido Fólico/sangre , Humanos , Síndromes de Malabsorción/sangre , Masculino , Persona de Mediana Edad , Unión ProteicaAsunto(s)
Quelantes/orina , Deferoxamina/orina , Hierro/orina , Adulto , Anemia Hipocrómica/orina , Anemia Macrocítica/orina , Autoanálisis , Composición Corporal , Deferoxamina/administración & dosificación , Femenino , Hemocromatosis/orina , Hemoglobinas/análisis , Humanos , Inyecciones Intramusculares , Hierro/análisis , Isótopos de Hierro , Leucemia/orina , Masculino , Persona de Mediana Edad , Talasemia/orina , Factores de TiempoAsunto(s)
Malonatos/orina , Metano/orina , Deficiencia de Vitamina B 12/orina , Adulto , Anciano , Anemia Macrocítica/orina , Anemia Perniciosa/orina , Biotransformación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Síndromes Posgastrectomía/orina , Vitamina B 12/genética , Vitamina B 12/uso terapéutico , Deficiencia de Vitamina B 12/diagnósticoRESUMEN
A rapid technique suitable for routine pathology laboratories has been used to estimate methylmalonic acid excretion in a 24-hour urine collection following a 10g. valine load. Levels above 40 mg./24 hours were found only in patients with vitamin B(12) deficiency. Patients with pernicious anaemia treated more than 24 hours before urine collection and patients with other types of anaemia had methylmalonic acid levels below 25 mg./24 hours.This method of demonstrating vitamin B(12) deficiency can be applied rapidly in debilitated patients so that specific treatment can be instituted within 36 hours of admission.