Obesity and immunity

The immunological processes involved in the collaborative defence of organisms are affected by nutritional status. Thus, a positive chronic imbalance between energy intake and expenditure leads to situations of obesity, which may influenceunspecific and specific immune responses. the incidence and severity of specific types of infectious illnesses are higher in obese persons as compared to lean individuals, as well as poor antibody responses to vaccinations in overweight subjects. leptin may act as a link between the nutritional status and T cell function. Moreover, there is evidence that hyperleptinaemia induced by cytokines is an integral part of the acute phase response. Leptin deficiency in animal studies associated with a lower phagocyte activity، lymphopenia, lower lymphocyte and NK cell numbers as well as decreased cytotoxic activity. In human studies have been showed delayed cutaneous hypersensitivity, abnormal lymphoproliferative responses to mitogens and a reduction in intracellular bacterial killing capacity. obesity diminishes the immune response, but the mechanisms implicated in this process remain unclear. Obesity are associated with impaired immunity. Several factors, including nutritional, metabolic and endocrine, seem to be involved. There is evidence that obesity alters several functions of the immune defense mechanisms and thus, increases susceptibility to infections, diabetes and cancer development among other chronic diseases. Further research in this interesting area would be of help in predicting obesity-prone populations and so, development of prevention strategies and new pharmacological therapies.