Figure 1. Calcineurin activity and acute rejection.

(A) Calcineurin activity (CN-a) was measured before lung transplantation in 52 of the 107 patients enrolled in the participating center. The results are presented as box plots and 10–90 percentile whiskers. We compared CN-a expression prior to transplantation in patients with or without cystic fibrosis (CF) since it is the main initial end-stage lung disease that led to lung transplantation in this cohort of patients and a similar dispersion of the CN-a values was found in CF+ and CF- patients (p = 0.77, Mann-Whitney test). Subsequently, a relationship between extreme values of calcineurin activity and acute rejection was investigated. (B) Comparison across time of the median CN-a levels in patients displaying or not acute rejection: Kernel smoothing curves were generated. The 2 groups of patients displayed similar profiles of CN-a which consist of a phase of enzyme inhibition within the first 10 weeks after transplantation followed by a phase in which enzyme activity is restored. The phase of CN-a inhibition tended to be faster and more marked in patients who had developed acute rejection as compared to patients who were free of acute rejection. Similarly, the increase of enzyme activity to baseline levels tended to be faster and more pronounced in patients who had developed acute rejection.