Transfer of Delayed Hypersensitivity: The Role of Blood Transfusions in Humans

Passive transfer of delayed skin hypersensitivity to purified protein derivative of tuberculin (tuberculin PPD) in five recipients who previously had negative reactions to tuberculin after receiving transfusions of whole blood from donors with known positive reactions has been observed. This reactivity has persisted for eight months, the period of observation. Similar passive transfer was also observed in one patient who received fresh plasma but this patient's skin reactivity disappeared after two months while his leukocytes remained "sensitive" to tuberculin. Passive transfer may occur with a variety of diseases and disease states which involve cell-mediated hypersensitivity. In the evaluation of conversion of tuberculin reactivity, one must consider the possibility of passive transfer by prior whole-blood transfusion.