Transfer of Allergic Contact-Type Delayed Sensitivity in Man1

In guinea pigs it has been possible to transfer allergic contact sensitivity regularly, using peritoneal exudates (1), minced spleen (2), lymph nodes (2) and other leukocyte sources (3, 4). Mononuclear cells, most likely lymphocytes, are thought to be the cells containing the transfer factor (5). In man, on the other hand, instances of successful transfer have been so few that most workers are not persuaded that this phenomenon has been...