Serum-soluble fas level determines clinical symptoms and outcome of patients with aggressive non-Hodgkin's lymphoma

Soluble Fas (sFas) blocks apoptosis induced by Fas ligand in vitro. The serum concentration of sFas is elevated in lympho-proliferative diseases. We hypothesized that higher levels of sFas worsen the clinical symptoms and outcome of patients with aggressive non-Hodgkin's lymphoma (NHL). We prospectively measured the serum concentrations of sFas in 67 consecutive patients with aggressive NHL (59 with diffuse large cell lymphoma and 8 with diffuse small cleaved cell lymphoma). sFas was significantly elevated in patients with aggressive NHL compared to healthy controls (N = 36, P< 0.005), while sFas in patients with B symptoms (4.20 +/- 2.12 microg/l) was significantly higher than in those without B symptoms (2.66 +/- 1.08 microg/l, P < 0.005). No significant difference was observed between B-cell lymphoma and T-cell lymphoma or between patients with clinical stage I or II and those with clinical stage III or IV. Significant correlations were found between sFas concentration and both soluble interleukin-2 receptor (R = 0.400, P < 0.001) and C-reactive protein (R = 0.340, P < 0.01) levels in patients with aggressive NHL. No correlation was observed between sFas and either white blood cell count or lactate dehydrogenase. Generalized Wilcoxon analysis revealed that NHL patients with sFas less than 4 microg/l had better overall survival than those with sFas above 4 microg/l (P < 0.001). The serum concentration of sFas might be associated with clinical symptoms and the prognosis of patients with aggressive NHL.