On Auto-antibody Formation and Antihemolysis.1

While a great deal has been learned within recent years regarding the defensive reaction on the part of the body against foreign cells and foreign cell products, introduced from without, our knowledge of the reactions of the body against its own cell derivatives, and as a matter of fact against its own cells is as yet very meager. I use the expression " against its own cells " advisedly, as there is abundant evidence to show that the body actually possesses forces which control not only normal, but also abnormal cell proliferation. In studying the protective mechanism of the animal body against its own cells and cell derivatives we naturally look for the same or similar methods by which it reacts to the introduction of foreign cells, and we may accordingly consider the possibility of auto-phagocytosis and auto-antibody formation. Both indeed seem to occur. From the evidence at hand, however, it does not appear probable that autophagocytosis represents an important method of defence, for in those cases in which it is observed the process seems purposeless, and rather a secondary result, the outcome of some other process which itself may indeed be obscured. I have thus noted phagocytosis of red cells by large mononuclear leucocytes in two cases of epidemic cerebro-spinal meningitis, where the corresponding organisms could be directly demonstrated in the circulating blood. In both cases