The Significance of non Correlation Between Interleukin-8 Serum Levels with Bone Marrow Microvascular Density in Patients with Myeloma Multiple

In multiple myeloma (MM), angiogenesis plays a substantial role in disease progression. Interleukin-8 (IL-8), a pro-inflammatory chemokine with potent pro-angiogenic properties, has been implicated in the pathophysiology of MM. The aim of the study is to measure serum levels of IL-8 in MM patients and to correlate them with markers of angiogenesis, such as circulating levels of platelet derived growth factor-AB (PDGF-AB) and angiogenin (Ang), and bone marrow microvascular density (MVD). Fifty-three newly diagnosed MM patients, 23 of them, who reached plateau phase after effective treatment and 20 healthy controls, were studied. Serum levels of PDGF-AB, Ang and IL-8 were measured by ELISA, whereas bone marrow MVD was estimated by immunohistochemical staining of vessels with anti-CD31. All measured parameters were higher in MM patients compared to controls and in increased disease stages. They all also significantly decreased in plateau phase. IL-8 correlated positively with Ang and PDGF-AB, but not with MVD. The circulating levels of IL-8, PDGF-AB and Ang are elevated in patients with MM. The lack of correlation between IL-8 with MVD suggests that its levels represent the inflammatory element of MM disease and the participation in angiogenesis process is rather complex with multifactorial mechanisms.