Home Dried Blood Spot Monitoring; a New Tool for Measuring Variability in Tacrolimus Blood Levels Over Time
Oregon Health & Science University, Portland, OR.
Meeting: 2015 American Transplant Congress
Abstract number: D209
Keywords: Kidney transplantation, Pediatric
Session Information
Session Name: Poster Session D: Pediatric Clinical Kidney Transplantation
Session Type: Poster Session
Date: Tuesday, May 5, 2015
Session Time: 5:30pm-6:30pm
Presentation Time: 5:30pm-6:30pm
Location: Exhibit Hall E
PURPOSE: The measurement of variability in Tacrolimus (TAC) blood trough levels has been proposed to reflect the consistency with medication intake and adherence. A standard deviation score (SDS) of >2 -3.5 of TAC measurements overtime in an individual patient may predict the risk for organ rejection. We have published previously the use of dried blood spots (DBS) to measure TAC trough levels at home with excellent correlation to TAC levels obtained in clinical lab. We report here on the longitudinal analysis on the variability of TAC levels done by home DBS in children post kidney transplantation.
METHODS: This is an ongoing prospective trial. Patients were asked to obtain monthly DBS samples at home over 12 months and mail them back to the laboratory. DBS were analyzed for TAC blood levels using tandem mass spectrometry. Patients were divided into 2 groups by age. We calculated the SDS for repeated TAC measurements in each patient over time and in the 2 groups.
RESULTS: 21 children were included, 13 were male. A total of 203 DBS samples were received from patients at the time of reporting. Group A (≥12 years ) included 12 patients, mean age 16.8 ±2.3 years (mean ±SD) and were 7.9 ± 3.8 years post-transplantation. Group B (<12 years) included 9 patients, ages 6.3 ±2.3 years and 1.8 ±2.4 years post-transplantation. Group A had a mean TAC trough level of 6.8 ±2 ng/ml, a mean SDS of 2.5 ±1.1. While group B had a mean TAC trough level of 8.0 ±1.75 ng/ml and a mean SDS of 2.9 ±1.1.
Figure 1 depicts the SDS for each patient over time in the 2 groups.
CONCLUSION: Home DBS monitoring is a promising method to monitor changes overtime in TAC trough levels in children. In our study, younger children in group B demonstrated high TAC SDS with repeated measurements similar to older group which may be related to variability in TAC absorption. Further prospective trials in children are required to explore the potential benefits of using frequent home DBS monitoring to detect early problems related to medication adherence and to drug absorption.
To cite this abstract in AMA style:
Al-Uzri A, Freeman K, Clark K, Bleyle L, Iragorri S, Jenkins R, Rozansky D, Koop D. Home Dried Blood Spot Monitoring; a New Tool for Measuring Variability in Tacrolimus Blood Levels Over Time [abstract]. Am J Transplant. 2015; 15 (suppl 3). https://atcmeetingabstracts.com/abstract/home-dried-blood-spot-monitoring-a-new-tool-for-measuring-variability-in-tacrolimus-blood-levels-over-time/. Accessed May 19, 2025.« Back to 2015 American Transplant Congress