Background: The 2-hour post-cyclosporine (CyA) dose concentration (C2) is favored as the best single-point correlate of CyA area-under-the-concentration curve. CyA nephrotoxicity is a prominent cause of renal dysfunction that affects 38% of lung transplant (LTx) recipients at 5 years.
Methods: We assessed the utility of de novo C2 monitoring after LTx by comparing 2 sequential groups of 18 bilateral LTx recipients followed with traditional de novo trough CyA (C0) monitoring and de novo C2 monitoring, respectively. Target C0 levels were 450 microg/liter and 250 microg/liter at 1 week and 3 months (3/12). Target C2 levels were 1,200 microg/liter and 800 microg/liter. Groups were matched for anthropometrics and diagnoses. Baseline serum creatinine (Cr) was lower in the C0 group than in the C2 group (65 +/- 17 vs 81 +/- 21 micromol/liter, p = 0.02).
Results: At 3 months, survival for both groups was 100%, but the C0 group had a greater increase in Cr from baseline (90 +/- 54% vs 33 +/- 23%, p < 0.001) despite similar CyA dosage (6.6 +/- 3.8 vs 6.5 +/- 2.9 mg/kg/day, p = 0.94). There was no difference in forced expiratory volume in 1 second (% predicted) (71 +/- 16 vs 69 +/- 14, p = 0.68), mean acute vascular rejection score per patient (2.61 +/- 2.12 vs 1.44 +/- 1.72, p = 0.079), mean bronchial rejection score per patient (3.72 +/- 1.81 vs 2.83 +/- 1.58, p = 0.126) or rate of infection (1.85 vs 1.79 events per 100 patient-days).
Conclusions: De novo C2 monitoring, which reduces both the risk of CyA toxicity and the risk of sub-therapeutic dosing, is a safe and effective technique for short-term preservation of renal function after LTx.