Adoptive transfer of delayed skin hypersensitivity to PPD, Varidase, monilia, or mumps with "immune" R N A extracted from the sensitized lymphoid cells, injected intradermally a few centimeters away from the site of skin test, or on the opposite forearm, was demonstrated in patients with a variety of neoplastic diseases, including Hodgkin's disease, which is classically known to have impaired cellular immune mechanisms. "Immune" R N A was found to be antigenspecific and systemically active. There was a good correlation between the outcome of "immune" RNA-mediated transfer a n d the clinical features of these patients. T h e transfer was successful in a higher percentage of patients with localized disease, in remission, receiving no antitumor therapy, or with positive skin test response, as compared to those with generalized disease, in active state of disease, receiving antitumor therapy, or with negative skin test response, respectively.
DOPTIVE TRANSFER OF DELAYED SKIN HYPER-
A sensitivity to tuberculin, in nonsensitive guinea pigs and man, by injection of intact leukocytes obtained from the peripheral blood of sensitive donors, was first described by Chase4 and Lawrenceg. T h e dialyzable, low molecular weight transfer factor has also been found to be capable of transferring skin reactivity in man,l~Q~lO.ll in the rhesus monkey,l2 and in vitro cell-mediated immunity as assayed hy the macropliage migration inhibition test o r by the lymphocyte transformation test in r n a n . ~~1 ~ It has also been demonstrated that in vitro humoral and cellular immunity and in vivo allograft and tumor-specific immunity can be passively transferred by tlie "immune" ribonucleic acid (RNA) extracted from sensitized