Serum oncostatin M in multiple myeloma: association with prognostic factors.

The serum concentration of oncostatin M (OSM) was measured in 40 multiple myeloma patients at diagnosis. Serum OSM level exceeded the sensitivity limit of the ELISA assay in eight (20%) of these patients (OSM+ patients). The serum levels of IL-6, another member of the gp180 cytokine family and C-reactive protein (CRP) as a surrogate of IL-6 were significantly higher in OSM+ patients. There was a trend towards higher serum beta 2M concentration in OSM+ patients, whereas there was no difference in the serum sIL-6R level or clinical data (age, gender, myeloma protein or stage) between the two groups. Two human myeloma cell lines secreted OSM and IL-6, but not IL-11 or leukaemia inhibitory factor (LIF), which suggests an important role for OSM and IL-6 in supporting growth of myeloma cells.