Search

C57BL/6J mice were treated with ALS, ALG, normal rabbit serum (NRS) or IgG of the rabbit for a period of 6 days. To study the xenogeneic antigenicity of ALG and its antilymphocytic effect separately, half the mice were made tolerant to IgG of the rabbit. While a short schedule of injections of ultracentrifuged IgG induced tolerance to IgG, this tolerance was eliminated by the subsequent treatment with ALG. A prolonged injection schedule over 44 days did, however, lead to a tolerance which persisted after ALG treatment. [131I]IgG elimination proved to be a more sensitive control of tolerance than immunodiffusion.

Cytology and histology of recipients of allogeneic bone marrow were studied 13. 20, 24, 30 and 34 days after transplantation. The developing chronic secondary disease was characterized by increased numbers of myeloid cells, by lymphopenia and by erythroblastopenia in the bone marrow and the spleen. Erythroblastopenia together with lymphopenia and augmented myeloid cells also occurred in irradiated F1-hybrids suffering from a chronic homologous disease. The latter model eliminated the following as a cause of erythroblastopenia in secondary disease: (1) host-versus-graft reaction against donor-type erythroblasts for immunogenetical reasons, and (2) graft-versus-host reaction against recipient-type erythroblasts since they had already been destroyed by irradiation. Treatment of the donor with ALS resulted in a suppression of homologous disease in F1-hybrids with a cytology resembling that of recipients of syngeneic spleen cells. The same treatment only delayed the onset of chronic secondary disease in recipients of allogeneic bone marrow. These allogeneic recipients, in contrast to the F1-hybrid recipients, died with the typical morphology of a chronic secondary disease.

Leukocytes from sensitive donors (between 18,000,000 and 20,000,000 viable cells) were injected subcutaneously into six patients with malignant lymphomas and 13 with lepromatous leprosy. In three of the patients with malignant lymphomas previously negative tuberculin reactions (old tuberculin, 1:10 dilution), became positive and remained so for at least eight months. In patients with lepromatous leprosy, who had previously had negative cutaneous tuberculin, lepromin and histoplasmin reactions, the response became positive in four to lepromin (Fernandez reaction, interpreted at 48 hours), in three to tuberculin and in one to both antigens. In two the reactivity persisted for approximately one year. Thus, it is possible to obtain partial reversal of the altered immunologic mechanisms in lepromatous patients by means of leukocyte transfer.