SDF-1 kinetics and B-cell recovery. (A) The kinetics of circulating SDF-1 following DA-EPOCH-R in 19 mantle cell patients is shown. Compared with before treatment, SDF-1 levels are significantly higher at 3 (P = .006), 9 (P = .02), and 18 (P = .02) months after treatment. Horizontal bars represent median values. (B) Circulating SDF-1 levels at 3 months directly correlated with the recovery of B cells at 9 months after treatment (R = 0.65; P = .015). (C) Between 3 and 9 months after treatment, the change (Δ) in B cells inversely correlated with a reduction in circulating SDF-1 levels, indicating that SDF-1 levels decline as B cells recover (R = –0.67; P = .013). • designates the 2 patients with LON.