Transfer factor: failure to transfer reactivity in normal human subjects.

Transfer factor was prepared from highly selected normal donors. One lot was made from donors strongly reactive to coccidioidin and negative to Dharmendra antigen in in vivo and in vitro testing. The other lot was made from donors without reactivity to coccidioidin and strongly reactive to Dharmendra. Aliquots of each lot were injected into eight normal recipients. Eight additional normal recipients were given placebo injections. Before and after injection, skin test reactivity and in vitro testing were evaluated by an individual who did not know which preparation the patient received. Changes in immunologic reactivity in subjects receiving transfer factor could not be distinguished from those in subjects receiving placebo. I conclude that transfer factor does not cause enhancement of immunologic reactivity in normal subjects. A well designed, critical study is needed to determine whether or not it does, in fact, cause enhancement of immunologic reactivity in patients with impaired cellular immune reactivity.