The Treatment of Aplastic Anæmia With Phytohæmagglutinin

Impairment of Phytohaemagglutinin-Induced Blastic Transformation in Lymphnodes from Thymectomized Mice

“…Under suitable conditions the substance is capable of increasing the number of antigen-sensitive cells (18) and of inhibiting (18,25,42) or promoting antibody production to certain antigens both in vitro (5,7,30,32) and in vivo (18,31,42). Remarkably enough, however, the mitogenic and cell-stimulating action of PHA is not confined only to immunologically reactive target cells, but also extends to erythropoietic and myelopoietic elements (37,38,39,50), amoebae (1), and epithelial cells (11,34,69).…”

The Action of Phytohemagglutinin in Rabbits

“…PHA has been used in the treatment of various hematological disorders in man in a strictly arbitrary fashion (11)(12)(13)(14)(15)(16)(17). The absence of experimental models upon which to base optimal injection schedules including the dose and route of injection has accentuated the need for a precise investigation of the effects of PHA in animals.…”

“…The use of PHA in humans has initially been limited to the treatment of aplastic anemia, with controversial results (11)(12)(13)(14)(15)(16)(17). Recently, I srael et al (28) reported that the intravenous injection of PHA into 27 cancer patients on chemotherapy permitted the administration of a greater dose of antimetabolitc drugs without the accompanying leucopenia.…”

“…In the ensuing years, these in vitro effects of PHA have been substantiated many times with human lymphocytes (4)(5)(6)(7) and those of rabbits, guinea pigs, mice and rats (8)(9)(10). Recently, PHA has been utilized therapeutically in the treatment of apparently intractable idiopathic and druginduced aplastic anemias (11)(12)(13)(14)(15)(16)(17), with encouraging results. How ever, the basis for its therapeutic use has not yet been experimentally validated in animals, nor has it been demonstrated that the mito genic and blastogénie properties of PHA can be reproduced in vivo.…”

<i>In vivo</i> Effect of Phytohaemagglutinin on Mouse Haemopoietic Tissue

“…One of these [1] was improving be fore PHA treatment began and should be excluded. One was affected only to the extent of showing a slight reticulocytosis (no information about the bone marrow was given) [11], and only one [2] showed any sig-nificant improvement. In many of the case reports of patients who re sponded to PHA, reticulocyte counts were not mentioned.…”