While it is recognized that the course and outcome in any individual case of lobar pneumonia is probably determined by the ability of the body to overcome the disease by the elaboration of substances antagonistic to the progress of the infection, it is not definitely known what the relative importance of the various immunity principles involved is, nor what factors serve to tip the balance favorably or otherwise in the struggle between antigen and antibody.
It has been known for some time that natural recovery from pneumonia is attended by the development of certain humoral antibodies which appear shortly before or at the time of crisis. In 1891 G. and F. Klemperer1 showed that the blood of patients who had recovered from the disease might protect rabbits against infection with the pneumococcus. This fact was confirmed by Neufeld and Händel,2 who also showed that similar protection might be afforded to
BLAKE FG. ANTIGEN-ANTIBODY BALANCE IN LOBAR PNEUMONIA. Arch Intern Med (Chic). 1918;XXI(6):779-790. doi:10.1001/archinte.1918.00090110076004