Serum levels of immunoglobulins A, G and M in New Zealand and Tokelauan children.
Serum levels of immunoglobulins A, G and M are described in a group of New Zealand (NZ) children of European descent. These findings are used as reference standards for three groups of Tokelauan children, atoll residents, migrants in NZ, and NZ-born Tokelauan children. All three Tokelauan groups had high levels of IgA, IgG, and IgM. Breast feeding was diminished and morbidity was higher in the NZ-born group. The IgG level was negatively correlated with duration of breast feeding in this group. In the atoll group IgG was related to present illness but no other consistent relationships were found between present illness status and the immunoglobulin levels. It remains unclear whether the high Tokelauan immunoglobulin levels are genetically or environmentally determined.