T-cell and NK cell recovery by alemtuzumab exposure at day of HSCT. Kaplan-Meier estimates for patients stratified based on the median estimated alemtuzumab concentration at day of HSCT (0.77 μg/mL) into high-exposure (>0.77 μg/mL, represented in red) or low-exposure (≤0.77 μg/mL, represented in blue) groups. Dotted black lines represent the median recovery time for each exposure group. (A) CD4⁺ T-cell recovery (>0.05 × 10⁹/L), median time: 45 days (95% CI, 28-62, low exposure) vs 96 days (95% CI, 77-100 days, high exposure). (B) CD8⁺ T-cell recovery (>0.05 × 10⁹/L), median time: 28 days (95% CI, 27-89, low exposure) vs 137 days (95% CI, 91-167, high exposure). (C) NK cell recovery (>0.05 × 10⁹/L), median time: 29 days (95% CI, 22-35 days, low exposure) vs 36 days (95% CI, 32-43, high exposure).