thymic-factor--circulating and Protein-Energy-Malnutrition

Zinc is a trace metal essential for human health and its deficiency is found to cause severe growth retardation in children. Information on the zinc status of Indian children is meagre perhaps due to lack of a reliable parameter. However, in view of the role of zinc in promoting growth, it has become common practice to prescribe zinc supplements to young children and newborns, particularly preterm infants. It is now clearly established that zinc confers no additional benefits to an individual with adequate zinc status while it can potentially lead to harmful effects by disturbing the milieu of other trace metals in the body. Estimation of thymulin levels in circulation is found to be a sensitive indicator of zinc status and using this parameter we found that apparently normal children have adequate zinc status. Children suffering from severe protein energy malnutrition however had very low levels of the hormone besides low leukocyte and plasma zinc levels indicating zinc deficiency. Such children showed improvement in their zinc status when zinc supplements were provided along with rehabilitation diets. Pregnant women and term newborns showed no evidence of zinc deficiency. Preterm infants had higher leukocyte zinc levels during early infancy and the breast milk of their mothers also had higher zinc content which could cater to the higher requirements of the rapidly growing preterm infant. All breast-fed infants showed decline in the zinc status gradually over the initial 4 months of life and regained adequate zinc status after appropriate weaning. These studies thus do not support the view of routine zinc supplements to pregnant women or children. However, Infants solely fed formula milk from birth had significantly impaired zinc status till the time of weaning. The functional significance of severe zinc inadequacy in such infants needs to be established.

Topics: Child, Preschool; Diet; Female; Food, Fortified; Growth Disorders; Humans; India; Infant; Infant, Newborn; Male; Nutrition Assessment; Nutritional Requirements; Pregnancy; Protein-Energy Malnutrition; Thymic Factor, Circulating; Zinc

This work investigates how thymic dysfunction contributes to the depression of cell-mediated immunity in protein-energy malnutrition (PEM). In Bolivian children hospitalized for severe PEM, the size of the thymus was measured by echography, and the lymphocyte subpopulations were detected by using monoclonal antibodies. These data were compared with those obtained from healthy control subjects. Regardless of the clinical form of PEM, our results show a high degree of T lymphocyte immaturity in severely malnourished children, which correlates with a severe involution of the thymus. Before in vitro incubation with thymulin, this significant increase in the percentage of circulating immature T lymphocytes was concomitant with a decrease in mature T lymphocytes and a slight increase in cytotoxic T subpopulations. After in vitro incubation with thymulin, immature T lymphocytes decreased and mature T lymphocytes increased.

Topics: Anthropometry; BCG Vaccine; Child, Preschool; Erythrocyte Count; Female; Hemoglobins; Humans; Hypersensitivity, Delayed; Immunity, Cellular; Infant; Kwashiorkor; Leukocyte Count; Lymphocyte Subsets; Male; Protein-Energy Malnutrition; Thymic Factor, Circulating; Thymus Gland

The combined effects of protein-energy malnutrition (PEM) and infection on thymic function evaluated by specific plasma thymulin activity were studied in Senegalese children: 29 hospitalized in Dakar for severe malnutrition and various diseases; 9 infected without sign of severe PEM, living in Dakar; 13 apparently healthy, uninfected, living in Dakar; and 7 apparently healthy, uninfected, living in Paris. Most of the free-living children in Dakar suffered from mild to moderate PEM. The specific thymulin activity (total plasma activity minus the activity recorded after adsorption of the plasma with a monoclonal antithymulin antibody) was almost undetectable in the infected children and was normal only in the children living in Paris. Such activity might be decreased by moderate and severe PEM and severe malnutrition may not be the only underlying cause of depressed level of thymulin in malnourished children from the Third World. Concurrent infections are important factors.

Topics: Blood Proteins; Child, Preschool; Communicable Diseases; Humans; Infant; Lymphokines; Paris; Protein-Energy Malnutrition; Senegal; T-Lymphocytes; Thymic Factor, Circulating; Thymus Gland; Thymus Hormones; Urban Population

Protein-energy malnutrition (PEM) leads to an immune deficiency, which is now well documented. Some investigators have suggested that the associated zinc deficiency is important in thymic involution and changes in cellular immunity. To evaluate the respective roles of nutritional deficiency, infection, and zinc in the alteration of thymic function, we measured the amounts of thymulin (facteur thymic serique, or FTS) and of Zn in the thymus glands of 58 Senegalese children who died in various stages of malnutrition. In the severe forms (marasmus, kwashiorkor, and marasmic kwashiorkor) the thymus was tiny and contained very little thymulin. The Zn content of the thymus was high whatever the nutritional state of the subject and was related significantly only to the presence of infections. In Senegalese children thymic atrophy and depleted thymulin content are associated with severe PEM but not systemic infection or depleted thymic Zn content.

Topics: Animals; Cattle; Child, Preschool; Female; Humans; Infant; Infections; Kwashiorkor; Male; Mice; Protein-Energy Malnutrition; Swine; Thymic Factor, Circulating; Thymus Gland; Thymus Hormones; Zinc

Topics: B-Lymphocytes; Child, Preschool; DNA Nucleotidylexotransferase; Female; Hemolytic Plaque Technique; Humans; Hydrocortisone; Immunoglobulin G; Infant; Leukocyte Count; Male; Protein-Energy Malnutrition; Rosette Formation; T-Lymphocytes, Helper-Inducer; Thymic Factor, Circulating

Facteur thymique sérique activity was evaluated in relation to different types of malnutrition in Senegalese children aged 5 to 42 months. They were classified in four groups: controls, moderate malnutrition, marasmus, and kwashiorkor, according to anthropometric measurements and clinical examination. The two latter groups were characterized by very depressed levels of total protein, album in, transferrin and prealbumin, and by high cortisol concentrations. Zinc status was marginal in all children. Facteur thymique sérique activity, determined by the rosette assay, was normal in the malnourished patients suggesting that moderate as well as severe malnutrition is not necessarily associated with depressed levels of circulating thymic hormone. These results are discussed in relation to zinc status and infections.

Topics: Blood Proteins; Child, Preschool; Humans; Hydrocortisone; Kwashiorkor; Nutrition Disorders; Protein-Energy Malnutrition; Rosette Formation; Senegal; Thymic Factor, Circulating; Thymus Hormones; Zinc