The comparison between the cytokine profiles of ET and PV patients showed a statistically significant increase of interleukin (IL)-4, IL-8, granulocyte macrophage-colony stimulating factor, interferon -γ, monocyte chemotactic protein -1, platelet derived growth factor-BB, and vascular endothelial growth factor in the ET group.
VEGF expression parallelled VEGFR-1 and resulted increased in Ph- MPNs (NCs: 0.08±0.04; ET: 0.13±0.06; PV: 0.29±0.2; PMF: 0.31±0.15) and higher in post-polycythaemic myelofibrosis and in the fibrotic stage of PMF than in the non-fibrotic phases of both diseases.
We found significantly higher levels of vascular endothelial growth factor (VEGF) and markedly decreased levels of placental growth factor in untreated patients with ET with respect to control subjects.