RESUMO
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.
Assuntos
Eletroforese das Proteínas Sanguíneas/métodos , Cadeias Leves de Imunoglobulina/sangue , Cadeias Leves de Imunoglobulina/urina , Paraproteinemias/diagnóstico , Insuficiência Renal/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Amiloidose/complicações , Amiloidose/diagnóstico , Amiloidose/imunologia , Anemia Macrocítica/sangue , Anemia Macrocítica/complicações , Anemia Macrocítica/diagnóstico , Anemia Macrocítica/urina , Proteína de Bence Jones/análise , Humanos , Imunoglobulina G/sangue , Cadeias kappa de Imunoglobulina/sangue , Cadeias kappa de Imunoglobulina/urina , Cadeias lambda de Imunoglobulina/sangue , Cadeias lambda de Imunoglobulina/urina , Masculino , Mieloma Múltiplo/sangue , Mieloma Múltiplo/complicações , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/urina , Proteínas do Mieloma/análise , Paraproteinemias/sangue , Paraproteinemias/complicações , Paraproteinemias/urina , Insuficiência Renal/sangue , Insuficiência Renal/complicações , Insuficiência Renal/urinaRESUMO
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.
Assuntos
Anemia Macrocítica/urina , Anemia Megaloblástica/urina , Malonatos/urina , Ácido Metilmalônico/urina , Deficiência de Vitamina B 12/complicações , Adolescente , Adulto , Idoso , Anemia Megaloblástica/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeAssuntos
Malonatos/urina , Anemia Macrocítica/etiologia , Anemia Macrocítica/metabolismo , Anemia Macrocítica/urina , Anemia Perniciosa/metabolismo , Anemia Perniciosa/urina , Cromatografia por Troca Iônica , Humanos , Métodos , Espectrofotometria , Temperatura , Fatores de Tempo , Valina/metabolismo , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/metabolismo , Deficiência de Vitamina B 12/urinaAssuntos
Anemia Macrocítica/sangue , Ácido Fólico/sangue , Adulto , Idoso , Anemia Macrocítica/etiologia , Anemia Macrocítica/urina , Anemia Perniciosa/sangue , Proteínas Sanguíneas/análise , Infecções por Cestoides/complicações , Cromatografia , Cromatografia em Gel , Feminino , Ácido Fólico/urina , Deficiência de Ácido Fólico/sangue , Humanos , Síndromes de Malabsorção/sangue , Masculino , Pessoa de Meia-Idade , Ligação ProteicaRESUMO
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.