Transfer Factor

A transfer factor is a substance that is produced by sensitized lymphocytes when incubated with an allergen. Administration of a transfer factor to an intact recipient may impart increased sensitivity to the corresponding allergen.

The transfer factor is secreted by activated T lymphocytes after contact with an allergen to which they are sensitized. This occurs during cell-mediated delayed-type hypersensitivity. Transfer factor is a soluble protein that can circulate in the blood and lymph.

When a transfer factor is administered to another organism, that organism develops hypersensitivity to the same allergen as the lymphocyte donor. Thus, with the help of a transfer factor it is possible to induce an allergic reaction to certain substances. This is important for studying the mechanisms of allergy development.