[Effect of HCMV infection on immune reconstitution of CD8T cells in children with allogeneic hematopoietic stem cell transplantation].

To investigate the risk factors for human cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation in children and the impact of human cytomegalovirus infection on post-transplant immune reconstitution. A Retrospective Co-Hort study design was used to include 81 children treated with allo-HSCT from January 2020 to March 2022 at the Department of Hematology, Capital Institute of Pediatrics, Beijing, China, and followed up for 1 year. Real-time quantitative PCR was used to detect positive detection of HCMV in children after allo-HSCT, multifactorial logistic regression modeling was used to analyze the risk factors leading to HCMV infection, and generalized estimating equation modeling was used to analyze the effect of HCMV infection on the T-cells of the children who received allo-HSCT. The age (, ) of 81 children was 5.1 years (10 months, 13.8 years), and 50 (61.7%) were male. By the endpoint of follow-up, a total of 50 HCMV-positive cases were detected, with an HCMV detection rate of 61.7%; The results of multifactorial logistic regression modeling showed that children with grade 2-4 aGVHD had a higher risk of HCMV infection compared with grade 0-1 after transplantation [ (95%) 2.735 (1.027-7.286)]. The results of generalized estimating equation modeling analysis showed that the number of CD3T cells in HCMV-positive children after transplantation was higher than that in the HCMV-negative group [ (95%) 1.34 (1.008-1.795)]; the ratio of CD4T/CD8T cells was smaller than that in the HCMV-negative group [ (95%) 0.377 (0.202-0.704)]; the number of CD8T cells was higher than that in the HCMV-negative group [RR (95%) 1.435 (1.025-2.061)]; the number of effector memory CD8T cells was higher than that in the HCMV-negative group [ (95%) 1.877 (1.089-3.236)]. Acute graft-versus-host disease may be a risk factor for HCMV infection in children after allo-HSCT; post-transplant HCMV infection promotes proliferation of memory CD8+T-cell populations and affects immune cell reconstitution.