Genetic and nutritional variations in antigen handling and disease

Low function (deficiency), within the 'normal range', of each of five immunity functions is associated with immunopathological disease, and/or defective antigen handling. These are probably genetically determined, either polygenic or single gene, but environmental factors such as diet influence them greatly, and the vulnerability may be especially great in the newborn period. The relevant systems are those involved in the immune elimination of antigen (antibody and macrophages) and those possibly involved in the immune exclusion of antigen (IgA, the alternative pathway of complement, and cilial action). The gut has an especially complicated role in antigen-handling, and feeding influences its capacity to do so. Eczema was prevented by a regimen of neonatal antigen avoidance, which was largely breast-feeding, and it is likely that other immunopathological diseases result from antigen contact during periods of malnutrition. The mechanisms of such effects are likely to be complicated, but adjustment of the environment to suit the genetically vulnerable, particularly in the newborn period, can lead to the prevention of disease.