Increased numbers of circulating naive T cells in the early versus late transplantation groups.

Shown are the mean (± SEM) numbers of CD3⁺, CD45RA⁺, and CD45RO⁺ cells in patients receiving transplants early (n = 20) compared with those receiving transplants late (n = 66). Data were analyzed at the following intervals: before transplantation, 1 through 30 days, 31 through 60 days, 61 through 90 days, 91 through 120 days, 121 through 180 days, 181 through 270 days, 271 through 365 days, 1 to 2 years, 2 to 3 years, 3 to 4 years, 4 to 5 years, 5 to 6 years, 6 to 9 years, and more than 9 years after transplantation. Mean values were plotted at the midpoint of each interval; n = total number of individuals analyzed in each group over the last 19.2 years. The early group had increased numbers of CD3⁺ cells at 271 days to 1 year, 1 to 2 years, and 2 to 3 years after transplantation (P < .05). The early group had increased numbers of CD45RA⁺ T cells at 91 through 120 days, 1 to 2 years, and 2 to 3 years after transplantation (P < .05). These numbers gradually declined and were comparable to the late group by 6 years after transplantation.