Measurement of lymphocyte cyclosporine levels in transplant patients

Liquid chromatography–tandem mass spectrometry method for simultaneous determination of cyclosporine A and its three metabolites AM1, AM9 and AM4N in whole blood and isolated lymphocytes in renal transplant patients

“…Figure 2 presents data of through concentrations of all tested substances expressed in fg bounded to one lymphocyte in the same group of patients. Masri et al correlated blood and lymphocytes CsA concentration to obtain the same parameter (binding to one lymphocyte), but concentration of CsA was measured with Abbott FPIA immunological sets based on the use of anti-CsA monoclonal antibodies [4]. As is known this immunological method is less specific with higher metabolites cross-reactivity and the overestimation is about 20-40% [16].…”

“…This dependence may be an important indicator of CsA immunosuppressive effect resulting in an inhibition of cytokine production (mainly IL-2 and INF-g), which is necessary for proliferation of lymphocyte. According to their results, only low blood and high lymphocytes concentrations of CsA were optimal for both survival of transplant organ and toxicity, which was in good correlation with clinical status of patients [4]. Falck et al measured CsA concentration in T-lymphocytes in the group of early renal transplant patients and found that rejection is accompanied by significantly lower intracellular level of CsA approximately 1 wk before an acute rejection episode has occurred [8].…”

“…For TDM in transplant patient's blood c0 and c2 of CsA are routinely measured and sparse sampling AUC is used [1][2][3]. Methods evaluating CsA effect in lymphocytes as the target site of action have been used less often [4][5][6][7][8]. However, measurement of intracellular CsA concentration in lymphocytes may give the same relevant information on the efficacy of CsA as compared with whole blood concentration.…”

Quantification of cyclosporine A in peripheral blood mononuclear cells by liquid chromatography-electrospray mass spectrometry using a column-switching approach

“…This active transporter might influence CsA levels in the target compartment. Masri et al have proposed to measure CsA directly in human peripheral blood mononuclear cells (PBMCs) using an immunoassay [29]. Interestingly, no correlation between whole blood and intracellular CsA levels was obtained.…”

“…Interestingly, no correlation between whole blood and intracellular CsA levels was obtained. Furthermore, lower intracellular drug amounts have been observed in patients with acute rejection, however, no differences were seen between patients with or without rejection in whole blood concentrations [29][30][31][32][33]. Intracellular CsA concentration measurements could correlate better with clinical events than in whole blood and offer an attractive perspective in TDM of this drug.…”