Abstract: | The effect on donor leukocyte migration of serum obtained from the patients with tuberculosis of the lungs, chronic pneumonia and healthy persons was studied after subcutaneous or intradermal injection of the microbial antigen (PPD, streptococcus and staphylococcus antigen). A factor inhibiting donor leukocyte migration appeared in the blood serum of sensitized individuals after the antigen injection. This factor proved to be localized in the serum fraction III obtained after the gel-filtration of sephadex G-200, and is sorbed by leukocytes. |