A low serum level of soluble tumor necrosis factor receptor p55 predicts response to thalidomide in advanced multiple myeloma.

BACKGROUND AND OBJECTIVES Thalidomide modulates the production of tumor necrosis factor (TNF-alpha). Soluble TNF receptors, TNFR p55 and TNFR p75, modify TNF-alpha activity. In this study, we explored the relation between soluble TNF receptors and outcome in patients with advanced multiple myeloma treated with thalidomide. DESIGN AND METHODS The levels of soluble TNF receptor p55 and p75 were assessed in serum from 34 myeloma patients with relapsed or refractory disease before starting thalidomide treatment. Serial measurements were performed for 16 patients in serum collected during treatment. RESULTS The pre-treatment serum level of soluble TNFR p55 in thalidomide responders was significantly lower than that in non-responders (median 1.75 ng/mL (range 1.19-2.84) vs. 2.79 ng/mL (1.36-5.51), p=0.004). The levels of p55 declined significantly during treatment. The levels of p75 showed the same pattern as p55, but the differences were not significant. The median survival of myeloma patients with pre-treatment levels of p55 < 2.79 ng/mL was 404 days; the median survival of patients with pre-treatment levels >or= 2.79 ng/mL was shorter (65 days, log-rank test p=0.02). INTERPRETATION AND CONCLUSIONS We conclude that soluble TNFR p55 is an adverse prognostic factor in myeloma patients with relapsed or refractory disease treated with thalidomide. Patients with a low pre-treatment level of this receptor have a better response rate and a longer overall survival.