The effects of total parenteral nutrition on immunodepression due to malnutrition.

An experimental study was performed in 16 dogs to investigate the effects of sub-acute malnutrition on humoral and cellular immunity and phagocytic functions and, subsequently, to investigate the ability of total parenteral nutrition (TPN) to restore abnormal immunological variables. Deficiencies of IgG, C3, primary immune response to sheep red blood cells (SRBC),lymphocyte counts, lymphocyte response to phytohemagglutinin (PHA), and neutrophi chemotaxis were found to be caused by malnutrition. Nutritional repletion by means of TPN resulted in a return to normal or supranormal serum concentrations of IgG, IgM, and C3, and the primary immune response to SRVC was prompter and higher. Moreover, TPN resulted in restoration of normal neutrophil chemotactic responses. TPN did not improve lymphocyte response to PHA in these experiments. The study demonstrates that subacute malnutrition results in broad based deficiencies of the immunological response of the type that predispose to infection and that the proper use of TPN can correct most of these abnormalities.