To the Editor We read with interest the systematic review and meta-analysis by Gagelmann and colleagues.¹ This is an important synthesis of the literature on the emerging topic of haploidentical donor transplantation using posttransplant cyclophosphamide for graft-vs-host disease prophylaxis. One of the purported strengths of this study is the large number of patients (N = 22 974) included in the meta-analysis; however, we wish to point out that there were likely fewer unique patients, as some patients appear to be reported in more than 1 of the 30 included studies. For example, the 2016 single-center retrospective review by Bashey and coauthors² (N = 475 patients with hematologic cancers; time horizon, February 2005 to February 2014) appears to include almost all the patients included in the 2013 retrospective review at the same center by Bashey and colleagues³ (N = 271 patients with hematologic cancers; time horizon, February 2005 to October 2010), except for 14 patients in the 2013 paper who received matched unrelated donor transplant with a donor matched at 9 of 10 HLA loci (all matched unrelated donors in the 2016 paper were matched at 10 of 10 loci). Similarly, the 2019 retrospective review of Center for International Blood and Marrow Transplant Research data by Rashidi and coauthors⁴ examining outcomes after matched sibling vs haploidentical donor transplants for patients with acute myeloid leukemia (n = 336 haploidentical transplant recipients; time horizon, 2005 to 2015) appears to include all patients with acute myeloid leukemia who underwent haploidentical donor transplant and were included in the 2016 single-center retrospective review by Rashidi and colleagues⁵ that compared outcomes vs matched unrelated donor transplants (n = 52 haploidentical transplant recipients; time horizon, January 2010 to August 2015). In these 2 examples, we identified 309 patients who appear to have been counted twice in the meta-analysis, and we also identified several other examples.

致编辑我们感兴趣地阅读了Gagelmann及其同事的系统评价和荟萃分析。¹这是关于使用移植后环磷酰胺预防移植物抗宿主疾病的单倍体供体移植这一新兴主题的重要文献综述。这项研究的据称优势之一是荟萃分析中包括的大量患者（N = 22974）。但是，我们希望指出的是，独特患者可能更少，因为在纳入的30项研究中，有1例报告了某些患者。例如，Bashey和合着者2016年的单中心回顾性研究²（N = 475名血液系统癌症患者；时间范围，2005年2月至2014年2月）似乎包括了Bashey及其同事在同一中心2013年回顾性回顾中纳入的几乎所有患者³（N = 271名血液系统癌症患者；时间地平线，2005年2月至2010年10月），但2013年论文中有14位患者接受了匹配的无关供体移植，且供血者匹配了10个HLA基因座中的9个（2016年论文中所有匹配的不相关供体匹配了10个基因位点中的10个） 。同样，拉希迪及其合着者对国际血液和骨髓移植研究中心数据进行的2019年回顾性回顾⁴在同胞与单倍体供体移植配对后检查急性髓性白血病患者的结果（n = 336个单倍体移植接受者；时间范围，2005年至2015年）似乎包括所有接受单倍体供体移植的急性髓性白血病患者，并被纳入2016年Rashidi及其同事进行的单中心回顾性研究⁵，比较了结果与匹配的不相关供体移植（n = 52个单倍体移植受者；时间范围，2010年1月至2015年8月）。在这两个示例中，我们确定了309例似乎在荟萃分析中被计数两次的患者，并且还确定了其他几个示例。