Recently developed molecular prognostic tests in patients with early Binet stage 
chronic lymphocytic leukemia (B-CLL) are costly and often require a high level 
of technologic expertise. Recent data give evidence for the prognostic relevance 
of the percentage of smudge cells in B-CLL. In our study we analysed the 
prognostic potential of this novel marker in a cohort of 100 CLL patients. The 
percentage of smudge cells ranged from 0% to 70% (median 21%). Patients with 
<or=20% smudge cells (according to ROC analysis) had a significantly shorter 
time to first treatment and overall survival than patients with >20% smudge 
cells. Multivariate Cox regression analysis identified percentages of smudge 
cells, stage according to Binet and CD38 expression as independent prognostic 
markers. The percentage of smudge cells was significantly lower in CD38+, 
ZAP-70+ and unmutated IgVH patients. Combined analysis of smudge cell 
percentages with CD38 expression provided complementary prognostic information 
identifying three patient subgroups with good, intermediate and poor prognosis. 
Comparing gene expression profiles in a subset of 12 patients we identified 
eight differentially expressed genes in groups with high vs. low percentage of 
smudge cells suggesting a role of these differentially expressed genes, 
especially for Tribbles homolog 2 (Trib2), in the disease progression of high 
risk CLL patients. In conclusion, our data confirm previous studies showing that 
the simple and inexpensive microscopic detection of smudge cells on blood smears 
prepared for routine diagnostic purposes is a novel independent factor 
predicting overall survival in CLL.