51Chromium survival of Yt(a+) red cells as a determinant of the in vivo significance of anti-Yta.

A case is presented in which anti-Yta produced a moderately accelerated removal of chromium-labeled Yt(a+) red blood cells (T1/2, 96 hours). Other reported examples of anti-Yta either have rapidly removed transfused Yt(a+) red blood cells or have permitted apparently normal survival of these cells. In light of this wide variation in in vivo potency of anti-Yta, it is recommended that chromium red blood cell survival studies be done before transfusion of Yt(a+) red blood cells in sensitized individuals.