RESUMO
High plasma ferritin has been found in all three classes of malnutrition. The aim of this study was to determine whether or not the high ferritin is the result of high iron stores or of some other condition whereby ferritin escapes into the plasma from damaged tissue. Normal plasma ferritin is largely glycosylated whereas tissue ferrritin in not. Twenty-six malnourished children (9, kwashiorkor; 7, marasmic-Kwashiorkor; 10, marasmus) were injected intramuscularly with 500 mg desferrioxamine and the urinary iron output over twenty-four hours determined (urinary iron in response to desferrioxamine is an index of the size of iron stores). Total plasma ferritin was measured by an Enzyme Labeled Immunosorbent Assay and plasma glycosylated ferritin by measuring the ferritin remaining in the supernatant after incubating with concanavalin A. Urinary iron excretion correlated significantly with total plasma ferritin and plasma glycosylated ferritin. It was significantly higher in children with oedema. The extent of glycosylation suggests secretion into the plasma via the normal pathway and not by leakage from damaged tissue. The elevation of plasma ferritin in malnutrition can therefore be interpreted as an indicator of high levels or storage iron. This study was supported by the Wellcome Trust (AU)
Assuntos
Humanos , Criança , Distúrbios Nutricionais/metabolismo , Ferritinas/sangue , Ferritinas/metabolismo , Ferro/metabolismo , Jamaica , Kwashiorkor , Desnutrição Proteico-Calórica , DesferroxaminaRESUMO
The HemoCue system utilizes the principle of oxidation of haemoglobin to hemiglobin by sodium nitrite and the subsequent conversion of hemiglobin to hemiglobinazide by sodium azide. The reagents for these reactions are contained within a small disposable microcuvette of approximately 10 æ\ in volumne. A venous or capillary sample is introduced into the microcuvette by capillary action and, after reaction with the reagents, the absorbance is read in the HemoCue photometer at 565 and 880nm. The haemoglobin concentration is then displayed as a digital reading, in either g/dl or mmol/l in 15-45 seconds. We compared haemolgobin values obtained by the HemoCue system with those from the Coulter Counter S-Plus IV in 366 pregnant women in urban Jamaica, and found a highly significant correlation (r = 0.78, P < 0.01). However, because of the convenience and erase of use of this instrument and considering the relatively high cost, we recommend it for use only as a research tool in field studies where accurate and rapid haemoglobin dterminationas are required (AU)