Increased expression of angiopoietin-2 characterizes early B-cell chronic lymphocytic leukemia with poor prognosis.

We measured the angiopoietin-2 (Ang-2) expression in early chronic lymphocytic leukemia (CLL) patients, pointing our attention on the association with immunoglobulin (IgV(H)) mutational status, CD38 expression and clinical outcome. Our results indicate that Ang-2 expression is heterogeneous among Binet stage A CLL patients. CLL patients can be divided into two subgroups (Ang-2 positive and Ang-2 negative CLL) with 30% of them displaying Ang-2 RNA levels above the cut off. A shorter progression-free survival was observed in Ang-2 positive CLL subset (p=0.032). Abnormal Ang-2 expression was also associated with unmutated IgV(H) genes (p<0.0001) and increased bone marrow angiogenesis (p=0.028), suggesting a role of Ang-2 in disease-progression of early CLL patients.