scholarly journals Immunomonitoring of Tacrolimus in Healthy Volunteers: The First Step from PK- to PD-Based Therapeutic Drug Monitoring?

2019 ◽  
Vol 20 (19) ◽  
pp. 4710 ◽  
Author(s):  
Aliede E. in ‘t Veld ◽  
Hendrika W. Grievink ◽  
Mahdi Saghari ◽  
Frederik E. Stuurman ◽  
Marieke L. de Kam ◽  
...  

Therapeutic drug monitoring is routinely performed to maintain optimal tacrolimus concentrations in kidney transplant recipients. Nonetheless, toxicity and rejection still occur within an acceptable concentration-range. To have a better understanding of the relationship between tacrolimus dose, tacrolimus concentration, and its effect on the target cell, we developed functional immune tests for the quantification of the tacrolimus effect. Twelve healthy volunteers received a single dose of tacrolimus, after which intracellular and whole blood tacrolimus concentrations were measured and were related to T cell functionality. A significant correlation was found between tacrolimus concentrations in T cells and whole blood concentrations (r = 0.71, p = 0.009), while no correlation was found between tacrolimus concentrations in peripheral blood mononuclear cells (PBMCs) and whole blood (r = 0.35, p = 0.27). Phytohemagglutinin (PHA) induced the production of IL-2 and IFNγ, as well as the inhibition of CD71 and CD154 expression on T cells at 1.5 h post-dose, when maximum tacrolimus levels were observed. Moreover, the in vitro tacrolimus effect of the mentioned markers corresponded with the ex vivo effect after dosing. In conclusion, our results showed that intracellular tacrolimus concentrations mimic whole blood concentrations, and that PHA-induced cytokine production (IL-2 and IFNγ) and activation marker expression (CD71 and CD154) are suitable readout measures to measure the immunosuppressive effect of tacrolimus on the T cell.

1996 ◽  
Vol 42 (12) ◽  
pp. 1943-1948 ◽  
Author(s):  
K L Napoli ◽  
B D Kahan

Abstract During phase I/II clinical trials of sirolimus (rapamycin; SRL), therapeutic drug monitoring was performed with a multistep liquid-liquid extraction of 1-mL aliquots of whole blood followed by reversed-phase HPLC with ultraviolet detection. Blood was sampled according to a standardized protocol and clinical status. SRL concentrations were interpolated from calibration curves with a linear range of 0-50 micrograms/L and 1 microgram/L lower limit of quantification. Quality control was monitored over 68 consecutive analytical runs by using frozen aliquots of SRL-supplemented pooled whole blood at 4, 12, and 32 micrograms/L. These samples showed mean concentrations of 3.7 +/- 0.6, 10.9 +/- 1.1, and 29.6 +/- 2.6 micrograms/L, respectively. This method for therapeutic drug monitoring of SRL permits one full-time technician to analyze 100 clinical specimens per week with a 24-h turnaround time. With this method, a strong linear relation (r2 = 0.946, Sy/x = 0.41, n = 115) between the average SRL concentration over a 24-h period and the SRL concentration at the 24th h was revealed.


2021 ◽  
Vol 45 (3) ◽  
pp. 183-187
Author(s):  
Dao-Hai Cheng ◽  
Zhen-Guang Huang ◽  
Jing-Bing Zhu

Abstract Objectives Heat treatment is a convenient measure for pathogens inactivation. The authors investigated the effects of this method on blood concentrations of six commonly therapeutic drugs. Methods Plasma and whole blood were pretreated with or without heating at 56 °C for 30 min, and drug concentrations of vancomycin, methotrexate, valproic acid, digoxin, carbamazepine, and cyclosporine were examined. Results Increased valproic acid levels after plasma heating (63.2 ± 30.2 vs. 62.1 ± 29.8 mg/L, mean recovery 102.0%) and whole blood heating (64.5 ± 30.5 vs. 62.1 ± 29.8 mg/L, mean recovery 104.6%) were observed (both p<0.05), but these differences were not considered clinically important. Recoveries of vancomycin in heat treatments varied widely, with an average and significant decrease of 15.8% in value after whole blood heating (11.7 ± 8.1 vs. 13.7 ± 8.6 mg/L, p<0.05). Conclusions Plasma or whole blood heating at 56 °C for 30 min are feasible in pathogens inactivation during monitoring methotrexate, valproic acid, digoxin, carbamazepine, and cyclosporine. However, such pretreatment seems inappropriate in monitoring vancomycin concentrations. Those results highlight the need for caution when applying heat treatment for pathogens inactivation in therapeutic drug monitoring.


2011 ◽  
pp. 238-261 ◽  
Author(s):  
G. Camps-Valls ◽  
J. D. Martin-Guerrero

Recently, important advances in dosage formulations, therapeutic drug monitoring (TDM), and the emerging role of combined therapies have resulted in a substantial improvement in patients’ quality of life. Nevertheless, the increasing amounts of collected data and the non-linear nature of the underlying pharmacokinetic processes justify the development of mathematical models capable of predicting concentrations of a given administered drug and then adjusting the optimal dosage. Physical models of drug absorption and distribution and Bayesian forecasting have been used to predict blood concentrations, but their performance is not optimal and has given rise to the appearance of neural and kernel methods that could improve it. In this chapter, we present a complete review of neural and kernel models for TDM. All presented methods are theoretically motivated, and illustrative examples in real clinical problems are included.


1994 ◽  
Vol 40 (12) ◽  
pp. 2247-2253 ◽  
Author(s):  
M Winkler ◽  
B Ringe ◽  
J Baumann ◽  
M Loss ◽  
K Wonigeit ◽  
...  

Abstract By retrospective analysis of 13,000 blood samples obtained from 248 patients receiving FK 506 therapy, we compared the suitability of plasma with that of whole blood as the matrix for therapeutic drug monitoring of FK 506. The plasma concentrations did not correlate with the concentrations in whole blood (r = 0.56). In contrast to plasma samples (analyzed by enzyme immunoassay), FK 506 was detectable in all whole-blood samples (analyzed by enzyme immunoassay/microparticle enzyme immunoassay). The inter- and intraindividual variations of FK 506 measurements were greater in plasma than in whole blood. Moreover, plasma concentrations correlated only poorly with clinical events. There was a tendency to greater plasma concentrations being measured during episodes of toxicity, but no clear difference was evident between stable course and rejection. In whole-blood specimens, a correlation between reduced or increased FK 506 concentrations and rejection or toxicity, respectively, was observed. The discriminatory power of whole-blood values was greater for the differentiation between toxicity and stable course than between rejection and stable course. We therefore recommend whole blood rather than plasma as the matrix for therapeutic monitoring of FK 506 concentrations.


2004 ◽  
Vol 1031 (1-2) ◽  
pp. 265-273 ◽  
Author(s):  
Miguel Angel Campanero ◽  
Ernesto Cardenas ◽  
Belén Sádaba ◽  
Emilio Garcı́a-Quetglas ◽  
Maria Jose Muñoz-Juarez ◽  
...  

2020 ◽  
Author(s):  
Edgar Ong ◽  
Ruo Huang ◽  
Richard Kirkland ◽  
Stefan Westin ◽  
Jared Salbato ◽  
...  

<p>Two fast (<5 min), time-resolved fluorescence resonance energy transfer (FRET)-based immunoassays (Procise IFX™ and Procise ADL™) were developed for the quantitative detection of infliximab (IFX), adalimumab (ADL), and their respective biosimilars for use in therapeutic drug monitoring (TDM) using 20 µL of finger prick whole blood at the point-of-care or whole blood/serum in a central lab. Studies were performed to characterize analytical performance of the Procise IFX and the Procise ADL assays on the ProciseDx™ analyzer.</p> <p><br></p><p>The Procise IFX and Procise ADL assays both showed good analytical performance with respect to sensitivity, specificity, linearity, and precision suitable for routine clinical use as well as excellent correlation to current commercial ELISA IFX and ADL measurement methods.</p> <p><br></p><p>Results indicated that the Procise IFX and Procise ADL assays are sensitive, specific, and precise yielding results in less than 5 minutes from either whole blood or serum. This indicates the Procise IFX and Procise ADL assays are useful for obtaining fast and accurate IFX or ADL quantitation, thus avoiding delays inherent to current methods and enabling immediate drug level dosing decisions to be made during a single patient visit.</p>


2020 ◽  
Vol 5 (3) ◽  
pp. 516-530
Author(s):  
Michael M Mbughuni ◽  
Maria A Stevens ◽  
Loralie J Langman ◽  
Yogish C Kudva ◽  
William Sanchez ◽  
...  

Abstract Background Immunosuppressant therapeutic drug monitoring (TDM) usually requires outpatient travel to hospitals or phlebotomy sites for venous blood collection; however Mitra® Microsampling Device (MSD) sampling could allow self-collection and shipping of samples to a laboratory for analysis. This study examined the feasibility of using volumetric microsampling by MSD for TDM of tacrolimus (TaC) and cyclosporin A (CsA) in transplant patients, along with their feedback on the process. Methods MSD was used to collect TaC and CsA from venous (VB) or capillary (CB) blood. The MSDs were rehydrated, extracted, and analyzed using on-line solid phase extraction coupled to tandem mass spectrometry (SPE-MS/MS). We report an abbreviated method validation of the MSD including: accuracy, precision, linearity, carry-over, and stability using residual venous whole blood (VB) samples. Subsequent clinical validation compared serially collected MSD + CB against VB (200 µL) from transplant patients. Results Accuracy comparing VB vs. MSD+VB showed high clinical concordance (TaC = 89% and CsA = 98%). Inter- and intra-precision was ≤11.5 %CV for TaC and CsA. Samples were stable for up to 7 days at room temperature with an average difference of &lt;10%. Clinical validation with MSD+CB correlated well with VB for CsA (slope = 0.95, r2 = 0.88, n = 47) and TaC (slope = 0.98, r2 = 0.82, n = 49). CB vs. VB gave concordance of 94% for CsA and 79% for TaC. A satisfaction survey showed 82% of patients preferred having the capillary collection option. Conclusion Transplant patients favored having the ability to collect capillary samples at home for TaC/CsA monitoring. Our results demonstrate good concordance between MSD+CB and VB for TaC and CsA TDM, but additional studies are warranted.


2018 ◽  
Vol 54 (4) ◽  
pp. 195-200 ◽  
Author(s):  
Janelle Renschler ◽  
Amanda Albers ◽  
Hanna Sinclair-Mackling ◽  
Lawrence Joseph Wheat

ABSTRACT The triazole antifungal itraconazole may be cost prohibitive in brand name form; therefore, compounded and generic products are often used as alternatives. Itraconazole blood concentrations have not been studied in clinical patients receiving these formulations. Itraconazole bioassay was performed on serum/plasma from 95 dogs and 20 cats receiving itraconazole (compounded from bulk powder, generic pelletized, or brand name) for systemic mycosis treatment. Mean itraconazole concentration was lower in the compounded group (n = 42) as compared with the generic (n = 40) or brand name (n = 33) groups (0.5 µg/mL versus 8.3 µg/mL and 6.5 µg/mL, respectively; P &lt; .001). No statistical difference was observed between itraconazole concentrations in the generic and brand name groups. Forty animals (95.2%) in the compounded group had subtherapeutic (&lt;1.0 µg/mL) values. All cats in this group (n = 10) had undetectable itraconazole concentrations. Some animals in the generic and brand name groups had subtherapeutic values (12.5 and 12.1%, respectively) or potentially toxic values (&gt;10 µg/mL; 37.5 and 24%, respectively). Compounded itraconazole should be avoided, but generic itraconazole appears to serve as a reasonable alternative to brand name itraconazole. Therapeutic drug monitoring may be beneficial in all cases.


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