[Relation of serum levels of the soluble cytoadhesion molecules sVCAM-1 and sICAM-1 to selected factors in the cytokine network in multiple myeloma].

BACKGROUND: Contemporary, not very frequent studies have brought only few and often inconsistent findings about the significance of cytoadhesive molecules (CAM) type "vascular cell adhesion molecule-1" (VCAM-1) and "intercellular cell adhesion molecule-1" (ICAM-1) at multiple myeloma (MM). The aim of the study was to interpret relations among levels of soluble forms of VCAM-1 and ICAM-1 in serum of the peripheral blood (SPB) and in serum of the aspirated bone marrow (SABM) to concentrations of selected elements of the cytokine network (IL-2, sIL-2R, IL-6, sIL-6R, and TNF-alpha) during different phases of MM disease and to recognise whether there are some specific relations of these factor in both tissue fluids.

METHODS AND RESULTS: Two groups of patients with MM were analysed: the group of 64 patients examined in different phases of MM disease and group of 39 patients examined when the disease was diagnosed (age median was 63 and 64 years, male to female relation was 1.6 and 1.3 to 1.0). CAM, cytokine and their soluble receptor levels were estimated using ELISA method. Increased levels of sVCAM-1 in APB were found in 87.5 and 87% of patients; in both groups sVCAM-1 medians almost twice exceeded the upper limits of normality (1180 and 1295 ng/ml). Levels in SABM were always higher (1347 and 1546 ng/ml) than that in SPB. Higher values of sICAM-1 in SPB had 35 and 33% of patients; sICAM-1 medians in SPB and in SABM did not exceed in either group the upper limits of normality (691 ng/ml) and they did not differ significantly (519 vs 476 and 518 vs 500 ng/ml). Statistical analysis (Pearson's correlation quotient, p < 0.05) has shown in both groups significant relation among sVCAM-1 in SPB and SABM levels (p-0.0001 and p-0.0012) and sICAM-1 level (p-0.0002 and p-0.0011) in both types of tissues fluids. In the larger group the statistically significant relation of sVCAM-1 in SPK to sIL-2R (0.0001), sIL-6R (0.0001), TNF-alpha (0.0003), and sICAM-1 (0.042) was found as well as to IL-2 (0.034, sIL-6R (0.044), and sICAM-1 (0.007) in SABM. In the group of 39 patients examined when the MM disease was diagnosed, relation of sVCAM-1 in SPB to levels of sIL-6R (0.0002) and TNF-alpha (0.0001), and in SABM only to sIL-2R (0.009). Evaluation of sICAM-1 revealed relation only to levels of sVCAM-1 both in SPK (0.042) and in SABM (0.007) in the larger group of patients.

CONCLUSIONS: The described concentration changes of soluble CAM in serum of the peripheral blood and in serum of the aspirated bone marrow as well as identified relations to levels of various elements of the cytokine network indicate that CAM and especially sVCAM-1, together with elements of the cytokine network play a role in the complicated MM pathology. Particular activity of serum soluble forms sVCAM-1 and sICAM-1 in the pathogenesis of myeloma has not been clarified. It shows that analysis of soluble cytoadhesive molecules sVCAM-1 and sICAM-1 and selected elements of the cytokine network (IL-2, sIL-2R, IL-6, sIL-6R and TNF-alpha) in serum of the aspirated bone marrow has no advantage to analysis of the peripheral blood serum.