The Inhibitory Nature of Lymphocytic Leukemic Serum on Microorganisms.

all behaved similarly (i.e., the organism tested exhibited a relatively consistent high respiratory activity in their presence). The finding of serum-inhibitors (bactericidins) dates back to the early days of microbiology (see review of Skarnes and Watson [4]). However, it appears that specific studies on the inhibitory activity of sera from patients afflicted with leukemia have not been reported. In the present study sera obtained from patients with either acute or chronic lymphocytic leukemia (ALL or CLL) have been found to inhibit the respiratory activity of Bacillus subtilis and, to a lesser extent, Micrococcus pyogenes var attnts, M. pyogenes var aureus, and some strains of Escherichia coli. The inhibitory factor was found to be most active against gram-positive organisms. It is the purpose of this paper to report on the presence and nature of a substance(s) found in the serum of patients with acute and/or chronic lymphocytic leukemia that will inhibit the respiratory activity of different microorganisms.