Abstract
CLL is a frequent and usually indolent disease that require only follow-up in about 2/3 of patients while the rest 1/3 of patients are symptomatic, have a worse outcome and need to be treated. The role of angiogenesis in CLL prognosis remains unclear. It has been shown that CLL plasma promotes von Willebrand factor (vWF) secretion, and expression in human umbilical vein endothelial cell cultures (HUVECs) [1]. Therefore, we investigated whether serum vWF levels in CLL patients at diagnosis could provide prognostic information.
Patients and methods: 33 CLL patients were studied of whom 55%, 32% and 13% were Binet staged A, B and C respectively. 45% never required treatment while 55% required treatment either at the time of diagnosis or during their follow-up. The time to first treatment (TFT) was 34 months. Serum vWF was measured by ELISA (R&D Quantiquine, duo Set) in frozen sera drawn at patients' diagnosis and in 10 healthy individuals (HI). Measurements were performed in duplicate according to the manufacturer's instructions. Statistical analysis was performed by conventional methods, using the SPSS v.22 software. P values below 0,05 were considered statistically significant.
Results: Serum vWF levels ranged from 178,5 to 14353,5 pg/ml (median 1028,5) in patients and from 374,6 to 1141,3 pg/ml (median 528,5) in HI, the difference being statistically significant (p< 0,05). Patients with Serum vWF levels above 528,5 pg/ml (median normal value) had a significantly shorter TFT than the others (p=0,01) as shown in figure. Otherwise, serum vWF levels correlated only with hypogammaglobulinemia (p=0,04).
Conclusion: Serum vWF levels were increased in CLL patients. Importantly, we showed for the first time, to our knowledge, that higher vWF levels correlated with a shorter TFT, suggesting that increased vWF levels reflect active neoangiogenesis that in turn, contributes to a more aggressive disease behavior.
[1] Shahidi M et al, Induction of endothelial cell proliferation and von Willebrand factor expression and secretion by leukemic plasma of patients with chronic lymphocytic leukemia before and after inhibition of NF-κB. Blood Coagul Fibrinolysis. 2016 Sep;27(6):711-6.
No relevant conflicts of interest to declare.
