Patient characteristics

Table 1 illustrates the characteristics of the patients enrolled in this study. The median age of patients at the time of CBT was 46.5 years. Acute myeloid leukemia accounted for the majority of cases, comprising 51% of the total. The predominant conditioning regimens employed were myeloablative regimens based on TBI with a dose of ≥ 10 Gy (78%), while CSP plus MTX were the most commonly utilized GVHD prophylaxis (78%).

Table 1 Patient characteristicsCrCl values and ARC at each time point following CBT

The median CrCl values at various time points after CBT were as follows: 133.6 ml/min (Interquartile range [IQR], 104.4–165.8 ml/min) at 1 day, 118.0 ml/min (IQR, 88.6–147.6 ml/min) at 15 days, and 105.1 ml/min (IQR, 74.1–132.8 ml/min) at 29 days. ARC was observed in 100 (52.9%) of the 189 assessable patients at 1 day, 77 (39.8%) of the 193 assessable patients at 15 days, and 50 (26.5%) of the 188 assessable patients at 29 days after CBT.

Among adult patients who received allogeneic HCT from a matched sibling donor (n = 22), a matched unrelated donor (n = 18), or a haploidentical donor (n = 1) during the study period in our hospital, ARC was observed in 19 (48.7%) of the 39 assessable patients at 1 day, 13 (32.5%) of the 40 assessable patients at 15 days, and 9 (22.5%) of the 40 assessable patients at 29 days after HCT. The incidences of ARC at each time point were comparable between CBT and HCT from adult donors (Table 2).

Table 2 The incidences of ARC according to donor typeVCM, TEIC, and CSP trough levels according to ARC

VCM were administered, and VCM trough levels were evaluated within 4 days at 1 day (n = 92), 15 days (n = 136), and 29 days (n = 57) after CBT. TEIC was administered, and TEIC trough levels were evaluated within 4 days at 1 day (n = 12), 15 days (n = 32), and 29 days (n = 9) after CBT. CSP was administered, and CSP trough levels were evaluated within 4 days at 1 day (n = 183), 15 days (n = 170), and 29 days (n = 159) after CBT.

The patient group exhibiting ARC at 29 days displayed slightly lower VCM (P = 0.112) and TEIC (P = 0.190) trough levels compared to those without ARC, although these differences did not reach statistical significance (Fig. 1a, b). The patient group exhibiting ARC did not affect VCM and TEIC trough levels at 1 day or 15 days (Fig. 1a, b). There were no significant associations between ARC and CSP trough levels at each time point (Fig. 1c).

Fig. 1

VCM (a), TEIC (b), and CSP (c) trough levels between augmented renal clearance (ARC) and no ARC groups at 1 day, 15 days, and 29 days after CBT. The lines represent the median value. Group comparisons were conducted using the Mann–Whitney U test

Impact of ARC on BSI, acute GVHD, and VOD/SOS

The patient group exhibiting ARC at 1 day displayed a slightly higher proportion of BSI compared to those without ARC (19.0% vs. 10.1%, P = 0.102), although this difference did not reach statistical significance. Additionally, there were no significant associations between ARC at each time point and the occurrence of BSI, acute GVHD, or VOD/SOS (Table 3).

Table 3 Post-transplant complications according to ARC at each time pointImpact of ARC on OS, NRM, and relapse

Univariate analysis demonstrated that ARC at 1 day, 15 days, and 29 days post-CBT was not associated with the probability of OS or the cumulative incidences of NRM and relapse (Fig. 2). In the multivariate analysis, ARC following CBT at each time point was also not significantly associated with the probabilities of OS, NRM, or relapse rates (Table 4).

Fig. 2

The impact of augmented renal clearance (ARC) on the overall survival (OS), non-relapse mortality (NRM), and relapse rate in adult patients who underwent single-unit cord blood transplantation (CBT). Kaplan–Meier survival curves were employed to depict OS, while cumulative incidence curves were used to represent NRM and relapse. These curves were plotted both without landmark (a–c) and with a conditional landmark analysis conducted at both 14 (d–f) and 28 days (g–i) after CBT. Group comparisons were conducted using the log-rank test for OS and Gray's test for NRM and relapse

Table 4 Multivariable analysis of overall mortality, non-relapse mortality (NRM), and relapse rate