Determination of blood everolimus concentrations in kidney and liver transplant recipients using the sirolimus antibody conjugated magnetic immunoassay (ACMIA).

Background: The aim of our study was to evaluate the possible determination of everolimus concentrations using the newly-introduced sirolimus antibody conjugated magnetic immunoassay (ACMIA).

Methods: Everolimus concentrations were determined in 100 blood samples from kidney (n = 47) and liver (n = 53) transplant recipients using the IMx sirolimus microparticle enzyme immunoassay (MEIA) from Abbott as previously described (Clin Biochem 2007;40:132-36) and sirolimus ACMIA from Siemens Healthcare Diagnostics Ltd.

Results: The ACMIA everolimus values were significantly higher than those of MEIA (p < 0.

Macromolecular complexes of cystatin C with circulating liver plasma membrane fragments and determination of serum cystatin C using the particle enhanced nephelometric immunoassay (PENIA) in kidney and liver transplantation and biliary obstruction.

Background: In a patient with biliary obstruction, a macromolecular complex of cystatin C with liver plasma membrane fragments, which also contain several membrane-bound enzymes, which may be removed by butanol extraction, has recently been characterised. This could lead to an underestimation of the glomerular filtration rate (GFR) from serum cystatin C concentration.

Methods: Using the particle enhanced nephelometric immunoassay (PENIA), serum cystatin C concentration was determined in 50 healthy controls, 43 patients with renal insufficiency, 68 kidney and 88 liver transplant recipients, and 60 patients with biliary obstruction.

A limited sampling strategy for estimation of the area under the curve (0 to 8 hours) of mycophenolic acid administered three times daily to liver transplant recipients.

Objectives: Gastrointestinal side-effects caused by mycophenolic acid (MPA) are frequent in liver transplant recipients, and in these cases a switch from two to three daily doses is usually recommended. However, a limited sampling strategy for the estimation of MPA area under the curve from 0 to 8 hours (AUC(0-8h)) has not been made.

Design And Methods: In 22 liver transplant patients who were administered MPA three times daily, the trapezoidal extrapolated MPA AUC(0-8h) values using a sampling time from 0 to 2 hours were calculated.

Sirolimus and everolimus clearance in maintenance kidney and liver transplant recipients: diagnostic efficiency of the concentration/dose ratio for the prediction of trough steady-state concentrations.

Objectives: Therapeutic monitoring of sirolimus and everolimus is necessary in order to minimize adverse side-effects and to ensure effective immunosuppression. A sirolimus-dosing model using the concentration/dose ratio has been previously proposed for kidney transplant patients, and the aim of our study was the evaluation of this single model for the prediction of trough sirolimus and everolimus concentrations.

Methods: Trough steady-state sirolimus concentrations were determined in several blood samples from each of 7 kidney and 9 liver maintenance transplant recipients, and everolimus concentrations from 20 kidney, 17 liver, and 3 kidney/liver maintenance transplant recipients.

Glomerular filtration rate estimation using the Cockcroft-Gault and modification of diet in renal disease formulas for digoxin dose adjustment in patients with heart failure.

Objective: The aim of this study was to compare the estimated glomerular filtration rate (GFR) using the Cockcroft-Gault and the 4-, 5-, and 6-variable Modification of Diet in Renal Disease (MDRD) formulas for digoxin dose adjustment.

Methods: Steady-state serum digoxin concentrations were determined in 100 patients with heart failure and normal to severely impaired renal function. Total clearance (CL) and predicted average concentrations of digoxin were calculated using general pharmacokinetic principles.

Determination of blood sirolimus concentrations in liver and kidney transplant recipients using the Innofluor fluorescence polarization immunoassay: comparison with the microparticle enzyme immunoassay and high-performance liquid chromatography-ultraviolet method.

Background: Although high-performance liquid chromatography (HPLC) is the method of choice for blood sirolimus determination, the microparticle enzyme immunoassay (MEIA) run on the IMx analyser is widely used in therapeutic monitoring of this immunosuppressant agent. The aim of our study was to evaluate the possible determination of sirolimus using the fluorescence polarization immunoassay (FPIA) commercialized for everolimus quantification.

Methods: Sirolimus concentrations were determined in whole-blood samples from liver and kidney transplant recipients using the Innofluor Certican FPIA (Seradyn Inc.

LDL cholesterol estimation using the Anandaraja's and Friedewald's formulas in schizophrenic patients treated with antipsychotic drugs.

Objectives: The use of new antipsychotic drugs is associated with an increased risk of diabetes and metabolic syndrome, and the routine monitoring of blood lipids during treatment has been recommended. Recently, a new formula for the estimation of low-density lipoprotein (LDL) cholesterol from total cholesterol and triglycerides has been proposed by Anandaraja et al. (Int J Cardiol 2005; 102: 117), and the aim of our study was its evaluation in schizophrenic patients treated with antipsychotic drugs.

Evaluation of three dosing models for the prediction of steady-state trough clozapine concentrations.

Objective: Therapeutic drug monitoring of clozapine may be useful for the clinical management of schizophrenic patients treated with this atypical antipsychotic drug. The aim of our study was the evaluation of three models for the prediction of steady-state trough clozapine concentration.

Patients And Methods: The trough serum concentrations of clozapine and norclozapine were determined by high-performance liquid chromatography in 296 samples from a group of 21 schizophrenic patients selected for their good therapeutic compliance.

Effect of the hematocrit and its correction on the relationship between blood tacrolimus concentrations obtained using the microparticle enzyme immunoassay (MEIA) and enzyme multiplied immunoassay technique (EMIT).

The Abbott microparticle enzyme immunoassay (MEIA) and the Dade Behring enzyme multiplied immunoassay technique (EMIT) are the most frequently used methods in the therapeutic drug monitoring of tacrolimus; however, a hematocrit-dependent interference for the MEIA has been described. In 244 whole blood samples from patients with liver (n=152) and kidney (n=92) transplants, the MEIA/EMIT ratio presented a highly significant negative correlation with the hematocrit (r = -0.482, p < 0.

Chitotriosidase activity in pleural effusions.

Chitotriosidase (ChT) is mainly secreted by monocyte-derived macrophages, and is considered a useful marker of macrophage activation. Macrophages represent the first line of defence against Mycobacterium tuberculosis, and consequently the study of ChT activity in pleural effusions (PE) would be of clinical value in the laboratory characterization of tuberculous pleurisy. ChT and adenosine deaminase (ADA) activities were determined in 12 tuberculous PE, 26 non-tuberculous lymphocytic PE and 25 neutrophilic PE.

Determination of everolimus in whole blood using the Abbott IMx sirolimus microparticle enzyme immunoassay.

Objectives: Everolimus (Certican) is a new immunosuppressant derived from sirolimus (Rapamune) with a 2-hydroxyethyl chain at position 40 of the macrolide ring. The aim of our study was to evaluate the possible determination of everolimus in whole blood using a commercialized microparticle enzyme immunoassay for sirolimus determination.

Design And Methods: Everolimus concentrations were determined in blood samples from 11 kidney transplant patients (n=51) and different control materials (n=35) using the Seradyn Innofluor Certican fluorescence polarization immunoassay (FPIA) and the Abbott IMx sirolimus microparticle enzyme immunoassay (MEIA).

Effect of analytical inaccuracy on dose adjustment for gentamicin using the Abbottbase Pharmacokinetic Systems.

We studied the effect of analytical inaccuracy on the determination of gentamicin for estimation of the recommended dose regime (RDR) using the Abbottbase Pharmacokinetic System programme (PKS). The study was carried out in a group of 26 adult patients, determining their serum levels of gentamicin (Cmin and one hour after completing infusion, C1h) and these concentrations were processed using the PKS in order to establish the RDR (dose, posologic interval and infusion time) for each patient. Various simulations were made for each patient, adding and subtracting the clinically acceptable error (CAE) once, twice and three times to the experimentally determined Cmin and the estimated Cmax.

Chitotriosidase activity in plasma and mononuclear and polymorphonuclear leukocyte populations.

In the general population, about 5% of individuals are homozygotic and 35% are heterozygotic carriers for chitotriosidase (ChT) deficiency. Activated macrophages are considered to be the main source of plasma ChT activity, which permits the biochemical characterization of homozygote deficients. However, in the case of detecting heterozygotic carriers, the results are often inconclusive.