554: Donor myocardial hypoxia inducible factor (HIF)-1α expression predicts cardiac allograft dysfunction: Results of a 7-year prospective study

was more effective than TA (p 0.05). Although TO and TA treatments both markedly suppressed the cellular (IFNspots: TA and TO vs UA p 0.001; IL-4 spots: TA p 0.579 and TO p 0.001 vs UA) and humoral response (IgM: TA p 0.004 and TO p 0.001 vs UA; IgG: TA p 0.241 and TO p 0.011 vs UA), TO was far more effective. Due to the insufficient systemic cellular immunosuppression, discontinuation of TA treatment resulted in a far stronger (3.5-fold) graft infiltration on POD 8 compared to TO (p 0.001). TO animals showed reduced weight gain and, after 60 days, BUN was significantly elevated (p 0.001). Cholesterol and triglycerides were significantly higher with TO than with TA (p 0.001 and p 0.041, respectively). Interestingly, after 60 days, luminal obliteration was similarly inhibited with TO (15 3%) and TA (13 4%) vs UA (44 7%, p 0.001) and the airway epithelium was preserved (TO: 96 7%, TA 97 6% vs UA 67 26%). Conclusions: Tacrolimus aerosol inhalation provides adequate trachea tissue concentrations, reduces systemic side effects and effectively protects the airway graft from early cellular rejection as well as from chronic obliterative airway disease. However, systemic immunosuppression is inferior to oral treatment and short treatment discontinuation results in rapid graft damage by activated lymphocytes.