SERUM ONCOSTATIN-M IN MULTIPLE-MYELOMA - ASSOCIATION WITH PROGNOSTIC FACTORS

The serum concentration of oncostatin M (OSM) was measured in 40 multi ple myeloma patients at diagnosis. Serum OSM level exceeded the sensit ivity limit of the ELISA assay in eight (20%) of these patients (OSM() patients). The serum levels of IL-6, another member of the gp130 cyt okine family, and C-reactive protein (CRP) as a surrogate of IL-6 were significantly higher in OSM(+) patients. There was a trend towards hi gher 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 inhibitor y factor (LIF), which suggests an important role for OSM and IL-6 in s upporting growth of myeloma cells.