Protein-energy malnutrition and
micronutrient deficiencies may down-regulate
immune response and increase
morbidity and
mortality due to
infection. In this study, a murine model was used to study the effects of
protein,
iron and
zinc deficiencies on the
immune response to
Leishmania (Leishmania) chagasi infection.
Mice were initially fed a standard
diet or with a
diet containing 3 percent
casein but deficient in
zinc and
iron. After
malnutrition was established,
mice were inoculated with L. chagasiand sacrificed four weeks later in order to evaluate
liver and
spleen parasite loads and
serum biochemical
parameters. Significant decreases in
liver and
spleen weight, an increase in the
parasite loads in these organs and decreases in
serum protein and
glucose concentrations in malnourished
animals were observed. Furthermore, the
production of
interferon-gamma by
spleen cells from infected malnourished
mice stimulated by Leishmaniaantigen was significantly lower compared with that in control
diet mice. These data suggest that
malnutrition alters the
immune response to L. chagasiinfection in the BALB/c model and, in
association with the effects on biochemical and anatomical
parameters of the host, favored increases in the
parasite loads in the spleens and
livers of these
animals.