Study of Immunologic Reactivity in Hemoblastosis. Circulating Antibody Formation as a Response to Antigenic Stimulus

N INCREASED SUSCEPTIBILITY to infections in leukemia and in primary malignant disorders of the reticuloendothelial system. especially in some forms, is generally admitted. The nature of the defects in host resistance to bacterial infections in these diseases has not been clearly defined. One possible cause which has been considered is a decrease in the ability to form circulating antibodies. In patients with malignant blood disorders, this power has usually been investigated by determining the circulating antibodies arising as a response to an artificially induced antigenic stimulus. Acute leukemia, chronic lymphatic leukemia and Hodgkin’s disease in particular were investigated in this way. The results, however, show certain discrepancies.4’10’ ’12’ 14,15,25,26,28 Various authors used different antigens, and sufficient attention was not always paid to the stage of the neoplastic process, or to complications and other factors different for each patient-e.g., the manner of treatment. The study of the ability to form circulating antibodies in leukemia is important from still another aspect. In recent years, immunologic patterns of defense of the animal organism have already been demonstrated in some experimental leukemias. It cannot he ruled out, though evidence is still lacking, that a similar mechanism may also be operative in cases of human hemoblastosis. Certain spontaneous remissions might well be interpreted as the result of successful immunologic defense. In defense of this nature, circulating antibodies may also play a role. If the chemoand immunotherapy of leukemia become a practical possibility at some time in the future, it will certainly he important to know whether organisms affected by hemoblastosis (which frequently invades the RES and lymphoid system-known to he closely related to antibody formation), are still capable of immunologic response. With experimental tumors the question has already been raised in contemporary literature of whether the increased susceptibility of certain mouse strains to tumors of viral origin is not due to an inborn-deficient capacity to form circulating antibodies.31 We have studied several factors of immunologic reactivity in patients suf-