Relation of C-2 monitoring with serum lipid profile in stable renal transplant patients.

C-2 monitoring has been proposed as a more effective strategy than C-0 to predict the risk of acute rejection in the early stages posttransplantation. However, cyclosporine (CsA) is associated with posttransplant dyslipidemia. The aim of this retrospective study was to evaluate the correlations of C-0 and C-2 levels with atherogenic risk factors in the first 6 months versus after 6 months posttransplantation. We evaluated the data from 127 stable renal transplant recipients (89 males, 38 females) of mean age 38.10 +/- 12.79 years who received Neoral-based immunosuppression to investigate the relation of C-2 levels to serum lipid profile compared with C-0 values in the early and late posttransplantation periods. Receiver operating characteristic (ROC) analyses were performed to define a C-2 cutoff level that identified subjects with hypercholesterolemia, defined as a total cholesterol (TC) >200 mg/dL. There were significant positive correlations between both C-0 and C-2 levels and TC as well as the ratio of total cholesterol/HDL cholesterol (TC/HDL) in the late period. When the C-2 levels in the late posttransplantation period were stratified, serum TC concentrations showed statistically significant differences between the groups. Whole blood C-2 levels above 850 ng/mL were associated with increased serum TC concentrations; the C-2 cutoff level leading to hypercholesterolemia was 888 ng/mL. Maintenance immunosuppressive therapy under the proposed whole blood C-2 level of 888 ng/mL seemed to preserve graft function while preventing atherogenic risks for cardiovascular diseases in the late posttransplantation period.

Evaluation of the new EMIT tacrolimus assay in kidney and liver transplant recipients.

Tacrolimus (FK506) is a potent macrolide immunosuppressant used for prevention of organ transplant rejection following transplantation. Monitoring of blood tacrolimus concentrations is essential to assess organ rejection and toxicity, because of the agent's narrow therapeutic range, wide inter- and intraindividual pharmacokinetic variability as well as drug interactions mediated by alteration in cytochrome P450. Several methods have been developed to monitor tacrolimus; immunoassays, bioassays, and HPLC/MS. The purpose of this study was to compare two analytical methods: the well-established MEIA II tacrolimus immunoassay using the IMx analyzer and the new EMIT 2000 tacrolimus immunoassay on the Cobas Integra 400 system. Tacrolimus results obtained using the two methods have been compared on 180 whole blood samples from kidney and liver transplant patients. The analytical sensitivities of both methods were defined as 1.2 ng/mL for EMIT and 1.5 ng/mL for MEIA II. The within-run CVs (n = 15) obtained with four-level controls were 9.08%, 9.41%, 5.23% and 4.4% for EMIT 2000. The comparison showed the following relationship between two methods: MEIA = 1.08.EMIT + 0.20 (r =.893). In conclusion, the EMIT 2000 tacrolimus immunoassay is a reliable alternative for the MEIA II method to monitor tacrolimus in organ transplant recipients. It provides a valid quantitative measurement of tacrolimus with comparable % CVs in quality-control as well as patient blood samples. Additionally, the EMIT 2000 method provides a rapid analysis of a large number of samples in one run with a low turnaround time and possibilities to reanalyze critical samples.