Background: Suboptimal MPA, MPAG levels are associated with significant
increases in graft loss. Purpose: to assess the influence of MPA, MPAG - Co
levels on GFR level and histological changes in the protocol biopsies in kidney allograft recipients.
Material/Methods: In a prospective study of 42 low-risk patients receiving MMF,
prednisone and a low or normal CsA dose we performed histological assessment according to Banff'97 classification in protocol biopsies before Tx and then at 3, 12, 36 months after Tx, we also assessed GFR at 1, 3, 12, 36 and 60 months after Tx and MPA (ELISA), MPAG (HPLC/UV) Co levels at day 7 and at 1, 3, 12, 36 months after Tx. Statistical analysis was performed with the aid of Generalized Additive Models (SAS System) and Spearman correlation.
Results: We observed significant relationships between MPA, MPAG Co levels and the subclinical rejection episodes (SCR), ci, ct, ah, CAN in the protocol biopsies at 36 month after Tx. In detail: MPA Co level at day 7 after Tx below 1.5 μg/mL was associated with increased risk of SCR (pnl<0.03), ci ≥2 (pnl<0.05), CAN ≥2 (pnl <0.04) and with ah ≥2 (pnl<0.07). MPAG Co level at day 7 after Tx above 100-150 μg/mL was associated with decreased risk of ct ≥2 (pnl <0.01), ci ≥2 (pnl <0.04), CAN ≥2 (pnl <0.04). We also observed significant positive correlations between MPA Co level and negative significant correlations
between MPAG Co level at 1 month after Tx and GFR at 1, 3, 12 and 36 month after Tx.
Conclusions: Optimal MPA exposure in the early post-transplant period may improve renal graft outcomes

Keywords: Immunosuppression, Kidney Transplantation