Auto‐immunization with acute leukemia cells: Demonstration of increased lymphocyte responsiveness

Nine patients with adult acute leukemia were autoimmunized with 10⁸ and/or 10⁶ non‐irradiated leukemia cells during remission. Six of nine receiving 10⁸ cells demonstrated a 100% or greater increase in in vivo lymphocyte blastogenic response to their own leukemia cells measured 7 days after immunization. In four responders, increased blastogenesis was noted only in autologous serum, but not in allogeneic serum. Only one of four demonstrated increased lymphocyte blastogenic response in autologous serum after immunization with 10⁶ cells. The increased immune response was always accompanied by significantly increased blastogenic response to phytohemagglutinin (PHA) and/or Streptolysin‐O (SLO). Three patients studied 28–42 days following immunization showed a persistent increase in lymphocyte blastogenic response to leukemia cells, but the response to PHA and SLO had returned to pre‐immunization levels.