Basal characteriwstics of patients.

Data are summarized as frequencies and percentage for categorical variables and as mean±SD for continuous variables. A total of 670 peripheral blood samples (mean of 6±3 samples per patient, range: 2–14) were obtained during the first 24 months following transplantation. Yr: year; M: male; F: female; EBV: empstein barr virus; CMV: cytomegalovirus; CN-a: calcineurin activity; BOS: bronchiolitis obliterans syndrome.