Objective:To investigate the significance and value of peripheral blood lymphocyte subset characteristics in patients following allogeneic hematopoietic stem cell transplantation (allo-HSCT) for distinguishing cytomegalovirus (CMV) infection.Methods:This retrospective study gathered data from allo-HSCT patients treated at Beijing Ludaopei Hospital between May 2021 and January 2023. This study included 50 patients in the CMV infection group and 47 patients in the non-CMV infection group. Flow cytometry was used to detect peripheral blood lymphocyte subsets 1 month after the allo-HSCT. The absolute lymphocyte count and their subsets were analyzed to assess their predictive significance in the occurrence of CMV infection. Mamn-whiney U test and χ 2 test were used. Indicators with statistical significance in univariate analysis were further subjected to binary logistic regression analysis and receiver operating characteristic (ROC) curves construction. The generation of survival curves for different outcomes was conducted using the Kaplan-Meier method, and the Log-rank test was applied. A two-sided P-value of<0.05 was considered statistically significant. Results:1. Among patients in the CMV infection group, 22% (11/50) were diagnosed with CMV viremia combined with CMV disease. The maximum CMV viral load in peripheral whole blood in these patients was 1 600 (1 400, 5 800) copies/ml, which was significantly higher than that in patients without confirmed CMV disease 970 (670, 2 300) copies/ml, with a statistically significant difference ( Z=-2.281, P=0.029). 2. The overall survival (OS) at the follow-up endpoint was 80% (40/50) in the CMV infection group and 87.2% (41/47) in the non-CMV infection group. There was no statistically significant difference in OS between the two groups at the follow-up endpoint ( χ2=0.231, P=0.630). 3. In the binary logistic regression model, the number of CD34 cells transfused into the patient, the percentage of CD3+CD38+T cells in CD3+T cells, and the percentage of CD4+CD38+T cells in CD4+lymphocytes were identified as important independent risk factors for infection. The ROC curve analysis demonstrated that the area under the curve (AUC) for these independent risk factors of CMV infection was 0.914 (>0.7, P<0.001), with a decision value of 0.702, a sensitivity of 0.857, and a specificity of 0.844. Conclusion:Followingallo-HSCT, the immune subsets in the CMV infection group exhibited a diminished proportion of T cells and CD4+T cells in comparison to the non-CMV infection group. In terms of T cell differentiation, there was an increase in TEM cells and a decrease in Naive T cells. Additionally, the expression level of the activation marker CD38 on T cells exhibited a high degree of predictive value for the occurrence of CMV infection. Understanding the immune characteristics of post-transplant CMV-infected patients is beneficial for the analysis of their immune reconstitution status, providing valuable insights for clinicians in the diagnosis and treatment of CMV infection after transplantation.

Objective:To investigate the significance and value of peripheral blood lymphocyte subset characteristics in patients following allogeneic hematopoietic stem cell transplantation (allo-HSCT) for distinguishing cytomegalovirus (CMV) infection.Methods:This retrospective study gathered data from allo-HSCT patients treated at Beijing Ludaopei Hospital between May 2021 and January 2023. This study included 50 patients in the CMV infection group and 47 patients in the non-CMV infection group. Flow cytometry was used to detect peripheral blood lymphocyte subsets 1 month after the allo-HSCT. The absolute lymphocyte count and their subsets were analyzed to assess their predictive significance in the occurrence of CMV infection. Mamn-whiney U test and χ 2 test were used. Indicators with statistical significance in univariate analysis were further subjected to binary logistic regression analysis and receiver operating characteristic (ROC) curves construction. The generation of survival curves for different outcomes was conducted using the Kaplan-Meier method, and the Log-rank test was applied. A two-sided P-value of<0.05 was considered statistically significant. Results:1. Among patients in the CMV infection group, 22% (11/50) were diagnosed with CMV viremia combined with CMV disease. The maximum CMV viral load in peripheral whole blood in these patients was 1 600 (1 400, 5 800) copies/ml, which was significantly higher than that in patients without confirmed CMV disease 970 (670, 2 300) copies/ml, with a statistically significant difference ( Z=-2.281, P=0.029). 2. The overall survival (OS) at the follow-up endpoint was 80% (40/50) in the CMV infection group and 87.2% (41/47) in the non-CMV infection group. There was no statistically significant difference in OS between the two groups at the follow-up endpoint ( χ2=0.231, P=0.630). 3. In the binary logistic regression model, the number of CD34 cells transfused into the patient, the percentage of CD3+CD38+T cells in CD3+T cells, and the percentage of CD4+CD38+T cells in CD4+lymphocytes were identified as important independent risk factors for infection. The ROC curve analysis demonstrated that the area under the curve (AUC) for these independent risk factors of CMV infection was 0.914 (>0.7, P<0.001), with a decision value of 0.702, a sensitivity of 0.857, and a specificity of 0.844. Conclusion:Followingallo-HSCT, the immune subsets in the CMV infection group exhibited a diminished proportion of T cells and CD4+T cells in comparison to the non-CMV infection group. In terms of T cell differentiation, there was an increase in TEM cells and a decrease in Naive T cells. Additionally, the expression level of the activation marker CD38 on T cells exhibited a high degree of predictive value for the occurrence of CMV infection. Understanding the immune characteristics of post-transplant CMV-infected patients is beneficial for the analysis of their immune reconstitution status, providing valuable insights for clinicians in the diagnosis and treatment of CMV infection after transplantation.