Raw data of this study (SPSS).

Background
The optimal dose of anti-thymocyte globulin (ATG) as an induction regimen in Asian living-donor kidney recipients is unclear.
Methods
This is a pilot study in which 36 consecutive patients undergoing living-donor kidney transplantation were randomly assigned to receive either 4.5 mg/kg (n = 19) or 6.0 mg/kg (n = 17) of ATG; all patients had corticosteroid withdrawal within 7 days. The primary end point was a composite of biopsy-proven acute rejection, de novo donor-specific antibody formation, and graft failure.
Results
At 12 months post-transplant, biopsy-proven acute rejection was more common in the ATG4.5 group (21.1%) than in the ATG6.0 group (0%)(P = .048). Importantly, the rate of the composite end point was significantly higher in the ATG4.5 group (36.8% vs 0%)(P = .006). There were significant differences in neither the renal function nor adverse events between the two groups. One case of death-censored graft failure occurred in the ATG4.5 group and no mortality was observed overall. Compared with pre-transplantation, T cells, natural killer (NK) cells, and natural killer T (NKT) cells were significantly decreased in the first week post-transplantation except for B cells. Although T and NKT cells in both groups and NK cells in the ATG4.5 group had recovered to the pre-transplant levels, NK cells in the ATG6.0 group remained suppressed until six months post-transplant.
Conclusions
Compared with ATG 6.0 mg/kg, ATG 4.5 mg/kg with early corticosteroid withdrawal and low dose maintenance regimen was associated with higher rates of acute rejection in non-sensitized Asian living-donor kidney recipients.
Trial registration
ClinicalTrials.gov: NCT02447822.

Background
抗胸腺细胞球蛋白（anti-thymocyte globulin, ATG）作为亚洲活体供肾肾移植受者诱导治疗方案的最优剂量目前尚不明确。
Methods
本研究为一项先导性研究，共纳入36例连续接受活体供肾肾移植的患者，按随机分配至ATG 4.5 mg/kg组（n=19）与ATG 6.0 mg/kg组（n=17）；所有患者均在术后7天内完成糖皮质激素撤除。本研究的主要终点为活检证实的急性排斥反应、新发供者特异性抗体形成及移植物失功的复合终点。
Results
移植术后12个月时，活检证实的急性排斥反应在ATG4.5组发生率为21.1%，显著高于ATG6.0组的0%（P=0.048）。值得关注的是，ATG4.5组的复合终点发生率显著更高（36.8% vs 0%，P=0.006）。两组患者的肾功能及不良事件发生率均无显著差异。ATG4.5组发生1例死亡校正移植物失功病例，整体研究未观察到死亡病例。与移植术前相比，术后第一周患者的T细胞、自然杀伤（natural killer, NK）细胞及自然杀伤T（natural killer T, NKT）细胞水平均显著下降，B细胞除外。尽管两组的T细胞、NKT细胞以及ATG4.5组的NK细胞均恢复至术前水平，但ATG6.0组的NK细胞在术后6个月时仍处于抑制状态。
Conclusions
与6.0 mg/kg ATG方案相比，采用早期糖皮质激素撤除联合低剂量维持治疗的4.5 mg/kg ATG方案，在非致敏亚洲活体供肾肾移植受者中，急性排斥反应发生率更高。
Trial registration
临床试验注册：ClinicalTrials.gov: NCT02447822.