Quantification of Torque Teno Virus and Epstein-Barr Virus Is of Limited Value for Predicting the Net State of Immunosuppression After Lung Transplantation

Nordén, Rickard; Magnusson, Jesper; Lundin, Anna; Tang, Ka-Wei; Nilsson, Staffan; Lindh, Magnus; Andersson, Lars-Magnus; Riise, Gerdt C; Westin, Johan

Comparisons on group level for numerical variables were performed using the Mann-Whitney U test. Pearson's correlation and linear regression were used to evaluate the relationship between the real-time PCR and ddPCR measurements. Cox regression with TTV, EBV, and both as time-dependent covariates was used to analyze the relationship between the 2 biomarkers and the outcomes VRTI, fungal infection, bacterial infection, CMV viremia, or any infectious event. Each patient was treated as a cluster to handle multiple infections occurring in a single individual. Univariable logistic regression was used in each of 4 periods, q1 (1-3 months), q2 (3-6), q3 (6) (7) (8) (9) (10) (11) (12) , and q4 (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) , with the outcomes VRTI, fungal infection, bacterial infection, CMV viremia infection, or acute rejection and the predictors age, treatment, CMV mismatch, log TTV (beginning of period), or log EBV (beginning of the period). A P value <.05 was considered significant. R software, version 3.3.1 (R core team, 2016, R Foundation for Statistical Computing, Vienna, Austria; http://www.R-project.org/), was used for all statistical analyses except for Pearson's correlation analysis, which was performed using GraphPad Prism 6 software (GraphPad Software Inc., San Diego, CA).