DC analysis in peripheral blood. (A) Percentages of donor CD15⁺ neutrophils at last follow-up (n = 25). (B) Percentages of donor CD3⁺ T cells at last follow-up (n = 25). (C) Longitudinal analysis of DC in CD15⁺ neutrophils in the first year after HSCT (n = 14). UPN9 with continuous decrease of neutrophil DC. (D) Longitudinal analysis of DC in CD3⁺ T cells in the first year after HSCT (n = 14). UPN9 with continuous increase of CD3⁺ T-cell DC. CD3⁺ T-cell DC <20% after 6 months (gray area) increases the risk for relapse of HLH.³⁴  Each symbol depicts 1 patient.