Clinical relevance of intracellular vascular endothelial growth factor levels in B-cell chronic lymphocytic leukemia

Strong evidence exists for an association between high vascular endothelial growth factor (VEGF) levels and poor prognoses in patients with solid tumo rs and acute leukemia. Using Western blot analysis and solid-phase radioimm unoassay, we measured cellular VEGF levels in B-cell chronic lymphocytic le ukemia (CLL) samples from 225 patients and correlated these levels with dis ease characteristics and prognoses. The median VEGF level in CLL samples wa s 7.26 times the median level detected in normal peripheral blood mononucle ar cells. Patients with lower levels of VEGF protein showed a trend toward shorter survival (P = .07), However, in a subgroup of CLL patients with goo d prognoses or early-stage disease (Rai stages 0-11, Binet stages A,B; beta 2-M less than or equal to 2.8 mg/dL), lower levels of VEGF were associated with shorter survival times. For the entire group of patients, no correlat ion was found between VEGF levels and beta 2-M levels or Rai and Binet stag e. Most samples from patients with CLL expressed the 43-kd VEGF isoform in addition to the commonly expressed 45-kd isoform. It remains to be seen whe ther the expression of the 43-kd isoform is responsible for this reversed c orrelation with outcome.