idiolysin

[ĭd′ē-ŏlĭ-sĭn, ĭd′ē-ə-līsĭn]
n.
  1. A lysin that occurs in the blood of a person or an animal without the injection of a stimulating antigen or the passive transfer of antibodies.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.