RESUMO
We measured the levels of thyroxine-binding prealbumin (TBPA), C-reactive protein (CRP), and interleukin-6 (IL-6) in sera from protein-energy undernourished and control children either without or with associated clinical infections. Levels of TBPA were significantly lower in undernourished than in control children without clinical infections. Mean serum TBPA concentration was also significantly lower in both clinically infected undernourished and control children than in those of the same nutritional status but without overt infections. Significant positive correlations were observed between the concentration of TBPA and the Z-scores of weight for age, height for age, and weight for height in all children without clinical infections, which disappeared in clinically infected children. CRP and IL-6 increased to approximately similar levels in sera from undernourished and control children with overt infections. An inverse correlation between the levels of TBPA and CRP and a significant positive correlation between the concentration of CRP and IL-6 were observed in children with associated clinical infections. Serum IL-6 and TBPA showed a small negative relationship in patients with overt infections. Thus, TBPA is a sensitive marker of undernutrition only in the absence of clinical infections, and the capacity to increase production of IL-6 and CRP during infections is preserved in protein-energy undernutrition.
Assuntos
Proteína C-Reativa/análise , Doenças Transmissíveis/sangue , Interleucina-6/sangue , Desnutrição Proteico-Calórica/sangue , Proteínas de Ligação a Tiroxina/análise , Estudos de Casos e Controles , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunodifusão , Técnicas Imunoenzimáticas , Lactente , Modelos Lineares , MasculinoRESUMO
The spontaneous as well as mitogen-induced in vitro production of interleukin-6 (IL-6) was studied in cultures of peripheral blood mononuclear cells (PBMC) from 14 children with marginal protein-energy malnutrition, 43 children with definite protein-energy malnutrition and 38 eutrophic controls of similar age, sex, race and socioeconomical condition. PBMC were cultured without added mitogen or stimulated with either lipopolysaccharide (LPS) or phytohemagglutinin (PHA). After 48 h incubation, cell-free culture supernatants were collected and stored at -70 degrees C. The amount of IL-6 in the supernatants was determined by a specific bioassay based on the proliferation of B9 hybridoma cells using human rIL-6 as standard. The mean level of IL-6 was significantly increased in supernatants from nonstimulated PBMC cultures from definitely malnourished children as compared with that observed in those of the controls. Stimulation with either LPS or PHA induced a rise in cytokine bioactivity in the supernatants of PBMC cultures from the different nutritional groups tested. Interestingly, IL-6 was significantly increased in the supernatants of PHA-stimulated cultures from malnourished children as compared with those of the controls.
Assuntos
Interleucina-6/biossíntese , Leucócitos Mononucleares/metabolismo , Desnutrição Proteico-Calórica/sangue , Células Cultivadas , Pré-Escolar , Feminino , Humanos , Lipopolissacarídeos/farmacologia , Masculino , Fito-Hemaglutininas/farmacologiaRESUMO
Due to its short half life and high tryptophan content, prealbumin has been considered a sensitive indicator of protein and/or energy deficiency. In addition, prealbumin diminishes during the acute phase response elicited by either infection or tissue injury. Serum levels of prealbumin were determined in undernourished children with or without associated clinical infection and in their infected or non-infected controls matched for age, sex, race and socioeconomical conditions. Serum levels of prealbumin were significantly lower in undernourished than in control children without overt infections. On the other hand, the concentrations of serum prealbumin diminished significantly and to similar levels both in undernourished and control children with associated clinical infection as compared with those observed in non infected children belonging to the similar nutritional status. A positive correlation was found between prealbumin level and the Z-scores of weight-for-age, height-for-age and weight-for height in children without associated infections, which disappeared in clinically infected patients. Thus, prealbumin is a marker of undernutrition in the absence of infection and could be an earlier and more sensitive indicator of actual undernutrition caused by the metabolic effects of acute phase cytokines, than the anthropometrical measurements used here.