idioheterolysin

[ĭd′ē-ō-hĕt′ə-rŏlĭ-sĭn, -rō-līsĭn]
n.
  1. An idiolysin occurring in the blood of one species, but capable of combining with the red blood cells of another species, thereby causing hemolysis when complement is present.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.