"Spontaneous" blastogenic transformation was measured 203 times in 39 individuals including 20 renal allograft recipients. A value that could be considered unusually high (2,100 disintegrations per minute) was determined statistically. Such elevated values were shown to be produced by antigenic stimulation. In the transplant recipient, an elevation indicated escape from immunosuppressive therapy. When no evidence of infection existed, an elevation usually heralded a rejection crisis. It can be cautiously used to indicate need for increased immunosuppressive therapy.
McDonald JC, Lee JH. "Spontaneous" Blastogenic TransformationA Monitor of Immunosuppression. Arch Surg. 1974;109(2):320-325. doi:10.1001/archsurg.1974.01360020180035