Correlation of IFN-mediated pSTAT3 duration and proliferation with cytogenetic lesions. (A) Circulating CLL cells from 47 consecutive patients presenting to the CLL clinic at Sunnybrook Health Sciences Center, as described in Table 1, were isolated and stimulated with IFN-α2b. After 4 hours, levels of pSTAT3 relative to total STAT3 were determined by immunoblotting and densitometry as described in “Western blot analysis.” This number was then plotted as a function of the highest-risk cytogenetic abnormality.38 The median value for each subgroup is shown.*P < .001 (B) Cell cultures were continued for another 4 days. Viable cells were then counted in a hemocytometer and the ratio of the numbers obtained with and without IFN-α2b was plotted against the pSTAT3 to pSTAT1 ratio after 4 hours. Median values for the 2 groups are indicated. *P < .01).
