Kaplan-Meier estimated overall and event-free survival after first HSCT. Overall survival (A) and event-free survival (B) were significantly better in the group of 50 patients in which the DC was always >30% (solid line) than in the group of 53 patients in which the lowest DC level was ≤30% (dashed line). The respective hazard ratios were 3.5 and 4.6. An event was defined as systemic or isolated CNS reactivation, partial flare, death, or second HSCT.