通过血液制品输注相关的被动免疫，具有CMV阳性血清学结果的异基因造血细胞移植受者（allo-HCTR）可能会出现假阳性结果。本文是一项单中心队列研究，纳入连续接受成年allo-HCTR的患者（2018年1月1日至2022年12月31日），其术前CMV血清学结果为阴性（在造血系统恶性肿瘤诊断时）且为不定性或低阳性（CMV-IgG滴度：≥0.6-<50 U/mL）预移植CMV血清学结果，同时术前血浆CMV DNAemia结果为阴性。这些患者的CMV血清学状态从R+重新分类为R-（CMVR- 重新分类组）。我们将这些患者与术前CMV IgG血清学结果为阴性（CMVR- 组）的allo-HCTR进行比较。我们描述了预移植CMV血清学状态从不定性/阳性重新分类为阴性的患者的数量和类型。此外，我们回顾了两组在移植后首6个月进行的所有血浆CMV DNAemia检测，以评估这种方法的安全性。在被鉴定为CMVR+术前的291名移植患者中，有246名（占84.5%）患者被重新分类为CMV血清学不定性（N:10）或低阳性（N:50）至R-。在CMVR- 重新分类组中，只有1/60（1.67%）患者在移植后的6个月随访期内发生了CMV-DNAemia，而在CMVR- 组中有3/44（6.8%；p=0.30）。两组之间在进行CMV-DNAemia检测次数、CMV-DNAemia范围和移植后时间方面没有显著差异。四分之一的allo-HCT CMVR+患者可能被错误地标记为R+，这对供体选择和预防性治疗的影响是显著的。在allo-HCTR候选者的造血系统恶性肿瘤诊断时，应采用两步方法，包括进行CMV血清学检测，并仔细审查术前CMV IgG滴度，以正确分类CMV血清学状态。© 2023作者。牛津大学出版社代表美国传染病协会发表。保留所有权利。如需权限，请发送电子邮件至journals.permissions@oup.com。

Allogeneic hematopoietic cell transplant recipients (allo-HCTR) with positive CMV serology may have false positive results due to blood product transfusions associated passive immunity.This is a single-center cohort study including consecutive adult allo-HCTR (01.01.2018-31.12.2022) with negative baseline (at hematologic malignancy diagnosis) and indeterminate or low-positive (CMV-IgG-titer: ≥ 0.6-<50 U/mL) pretransplant CMV-serology with negative pretransplant plasma CMV DNAemia. The CMV serology status of those patients was reclassified from R + to R- (CMVR- reclassification group). We compared those patients to allo-HCTR with negative (CMV-IgG-titer < 0.6 U/mL) pretransplant CMV IgG serology (CMVR- group). We describe the number and type of patients, whose pretransplant CMV serology status was reclassified from indeterminate/positive to negative. Moreover, we reviewed all plasma CMV DNAemia tests performed during the first 6 months posttransplant in both groups, to assess the safety of this approach.Amongst 246 (84.5%) of 291 transplanted patients identified as CMVR + pretransplant, 60/246 (24.4%) were reclassified from CMV serology indeterminate (N:10) or low-positive (N:50) to R-. Only 1/60 (1.67%) patient in the CMVR- reclassification group vs 3/44(6.8%; p = 0.30) in the CMVR- group developed CMV-DNAemia during the 6-month posttransplant follow-up period. There were no significant differences in the number of CMV-DNAemia tests performed, CMV-DNAemia range and time posttransplant between the two groups.One out of four allo-HCT CMVR + may be falsely flagged as R+, with significant impact on donor selection and prophylaxis administration. A 2-step approach including CMV-serology testing at hematologic malignancy diagnosis in allo-HCTR candidates and careful review of pretransplant CMV IgG-titers may help correctly classify CMV-serology status.© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.