Leszek Paczek
Medical University of Warsaw, Poland
Title: Liquid Chromatography coupled with Mass Spectrometry (LC/MS) for monitoring of immunosuppressive drugs and their metabolites
Biography
Biography: Leszek Paczek
Abstract
Statement of the Problem: The immunosuppressive drugs and their metabolites may often be toxic. Advances in laboratory methods enable measurement of real levels of both; a specific immunosuppressive drug and their metabolites. Older, but still widely used immunoassays yield fluctuating results and what is more, results that are often about 25-30% higher than the actual levels. On the other side, novel liquid chromatography combined with mass spectrometry (LC/MS) method obtains accurate drug level measurements.
Methodology & Theoretical Orientation: LC/MS and immunoassays (IA) were applied to assess levels of both parent drugs and its metabolites in the cohort of 834 patients after kidney transplantation (KTX), mean age: 49.13 years, median: 64.95 months after KTX. 256 (30.7%) patients were treated with cyclosporine A (CsA) and 449 (53.8%) patients were given tacrolimus (Tac).
Findings: Results of analyses of immunosuppressive drugs and their metabolites as well as differences between IA and LC/MS are presented in Table 1. Tac LC/MS to IA mean difference was 1.78 ng/ml; 89.9% of IA results overestimated real Tac levels. CsA LC/MS to IA mean was 28.8 ng/ml; 94.3% of IA results overestimated real CsA levels.
Conclusion & Significance: This preliminary study warrants the initiation of multi-centre studies of serum drug levels and metabolite pharmacokinetics. Future studies should include the analysis of large data sets, as well as long-term follow-up of patients and grafts.
