Monoclonal antibody-defined T-cell surface phenotypes in human breast milk.

The distribution of T-lymphocyte subsets in human early milk was determined by immunofluorescence analysis of reactivity with monoclonal antibodies of the OKT series. A novel finding was that the T-lymphocyte population in human milk contains both OKT4 (helper/inducer phenotype) and OKT8 (suppressor/cytotoxic phenotype)-positive subsets. The relative ratio of OKT4 to OKT8-positive T-cell subsets in milk, however, was generally higher than that observed for peripheral blood T cells.