RESUMO
BACKGROUND AND AIMS: Cystinosis is an inborn error of metabolism, clinically characterised by severe renal involvement and development of corneal cystine deposits, especially in the adult form of the disease. Cystinosis is a treatable condition. Therefore, an early diagnosis is necessary to start therapy. For biochemical confirmation of the condition it is necessary to quantify intracellular cystine concentrations. For this, different methods have been described with variations in cell isolation strategies and the amino acid quantification techniques used. In order to improve confirmatory biochemical diagnosis in our setting, a protocol for intraleukocitary cystine quantification was established. METHODS: A high performance liquid chromatography based method for cystine quantification in polymorphonuclear cells was implemented. Evaluation of the best anticoagulant to use and temperature stability of the sample at 4ÌC were performed. In addition, we established reference values for our population. RESULTS: It was determined that intraleukocitary cystine quantification must be performed in blood samples containing acid-citrate-dextrose as anticoagulant. Samples must be processed immediately due to their poor stability even when refrigerated. Based on the results from 50 healthy individuals, the cut-off point established for our population was 0.34nmol 1/2 cystine/mg. CONCLUSION: The adaptation performed to the cystine quantification method here presented the highest control population that has been reported in the literature so far. Our results highlight the need for making available a cystine quantification method locally and confirm the convenience for each laboratory to establish its own reference values to provide greater reliability for interpreting results.
Assuntos
Cistina/sangue , Cistinose/diagnóstico , Neutrófilos/química , Anticoagulantes , Cromatografia Líquida de Alta Pressão , Ácido Cítrico , Temperatura Baixa , Colômbia , Síndrome de Fanconi/etiologia , Glucose/análogos & derivados , Humanos , Valores de ReferênciaRESUMO
Objetivo : alertar os pediatras para as diferentes apresentacoes clinicas da cistonose nefropatica. Descricao : relado da historia, exame fisico e dos principais...
Assuntos
Humanos , Lactente , Pré-Escolar , Criança , Cistinose , Nefropatias , Síndrome de Fanconi/etiologia , Cisteamina , CistinoseRESUMO
La cistinosis nefropática, rara afección recesiva, se produce por defecto en el transporte lisosomal de cistina, y depósitos de cristales intracelulares en riñón, córnea, y otros tejidos. Constituye la primera causa congénita de síndrome de Fanconi, y evoluciona en la primera década de la vida a insuficiencia renal crónica. El diagnóstico se confirma por una detección de cistina en leucocitos y linfoblastos circulantes. Su tratamiento consiste en la reposición de las pérdidas por la tubolopatía, administración de cisteamina, que depleta cistina y favorece su transporte por la pared lisosomal. El objetivo de la presentación es dar a conocer el primer caso de cistinosis documentado y tratado en Chile. Se presenta el caso de un menor hospitalizado a los quince meses de vida, con desnutrición avanzada, raquitismo clínico, deshidratación severa, acidosis metabólica, hipokalemia e hipofosfemia severas, comprobándose tubulopatía de Fanconi. Se detectó concentración elevada de cistina en polimorfonucleares, confirmando diagnóstico de cistinosis. En tratamiento desde hace dos años con cisteamina oral, muestra excelente evolución pondoestatural y conservación de la función renal, persistiendo la tubulopatía
Assuntos
Humanos , Masculino , Lactente , Cistinose/complicações , Insuficiência Renal Crônica/etiologia , Síndrome de Fanconi/etiologia , Cisteamina/uso terapêutico , Cistinose/diagnóstico , Cistinose/tratamento farmacológico , Cistinose/urina , Hipofosfatemia Familiar/etiologiaRESUMO
A male infant with clinical and radiological manifestations of hypophosphatemic rickets is presented. He had dysfunction of the renal tubular mechanisms of reabsorption manifested by: glycosuria, hyperaminoaciduria, hyperphosphaturia and high alkaline phosphatase plasma levels; associated with hepatic cirrhosis. Biochemical screening discarded most of the main known causes of Toni-Debré-Fanconi syndrome. Unfortunately, due to the low incidence of the syndrome and the patient's death, it was impossible to reach an accurate diagnosis. A review of the syndrome is presented.
Assuntos
Síndrome de Fanconi/complicações , Cirrose Hepática/etiologia , Síndrome de Fanconi/etiologia , Glicosúria/etiologia , Humanos , Lactente , Túbulos Renais Proximais/fisiopatologia , Masculino , Fosfatos/urina , Raquitismo/etiologiaRESUMO
A permature male infant required intravenous alimentation for six weeks following extensive surgery for ileal and cecal necrosis. At 3 months he developed evidence of hepatitis. Subsequently osteoporosis and the Fanconi syndrome appeared. Urine phosphate clearance was 83 percent of creatinine clearance at a serum phosphate concentration of 1.6 mg/dl. Concentration of plasma immunoreactive parathyroid hormone was elevated at 550 pg/ml. 25-Hydroxycholecalciferol was given at 240 mug/day. Aminoaciduria disappeared and bone healing occurred. Serum phosphate rose to 6.5 mg/dl and phosphate clearance fell to 2 percent of creatinine clearance. Upon cessation of 25-OHCC therapy, the Fanconi syndrome recurred despite administration of vitamin D2. 25-OHCC was then administered at 40 mug/day, and the urine abnormalities were reversed. The patient probably developed hyperparathyroidism, secondary malabsorption, and hepatitis. The Fanconi syndrome was the consequence of the hyperparathyroidism. 25-OHCC therapy was more effective than vitamin D in reversing the disordered state, possibly because of impaired hepatic metabolism of vitamin D2.