Everolimus TDM using Thermo Fisher QMS immunoassay on Indiko, Beckman DxC, AU680, and AU5800 analyzers.

OBJECTIVES: Everolimus (EVR), a mTOR inhibitor immunosuppressant approved for renal, liver and cardiac transplants. This study established the appropriate TDM performances of the Thermo Scientific QMS EVR Assay by using the Beckman DxC, followed by comparison to the Thermo Scientific Indiko and a previously published LC-MS/MS assay, and Beckman AU680 and AU5800 analyzers. DESIGN AND METHODS: The study initially established acceptable linearity, precision and accuracy of the QMS EVR turbidimetric assay. Sample preparation was initiated by mixing patient whole blood with methanol and a precipitation reagent. Supernatant was transferred to sample cups. Drug in the supernatant and drug coated on microparticle compete for the limited number of antibody binding sites. If EVR is absent in the sample supernatant, EVR coated microparticles are agglutinated in the presence of antibody reagent. If EVR is present, agglutination is partially inhibited, depending on EVR concentration. Calibrators range was from 1.5 to 20ng/mL. Comparison studies data were analyzed by Deming Regression and Bland-Altman plots. RESULTS: Precision studies showed the following mean concentrations 4.00-4.72, 7.70-8.20 and 14.80-15.56ng/mL, and CVs of 3.1-8.7%, 3.4-8.9% and 2.6-4.4% respectively. Comparison of analyses of 107 de-identified transplant samples by three analyzers - Indiko, DxC and AU680 showed: EVR concentrations from <1.5 to 13.6ng/mL, slopes 1.000 to 1.076, intercepts -0.053 to 0.462, and R 0.945 to 0.981. Another series of comparison studies (n=104) of Indiko and AU680 with LC-MS/MS showed the following: slopes 1.035 to 1.086, intercepts -0.019 to -0.265, and R 0.924 to 0.980. 2013-2016 CAP survey results were acceptable. CONCLUSIONS: Based on the experience of the past 3.5years, Thermo Scientific QMS EVR Immunoassay using four different analyzers offered adequate limit of detection and acceptable accuracy and precision, suitable for monitoring renal and liver transplant recipients.

Development and validation of a questionnaire to assess fear of kidney failure following living donation.

Living kidney donors (LKDs) may feel more anxious about kidney failure now that they have only one kidney and the security of a second kidney is gone. The aim of this cross-sectional study was to develop and empirically validate a self-report scale for assessing fear of kidney failure in former LKDs. Participants were 364 former LKDs within the past 10 years at five US transplant centers and 219 healthy nondonor controls recruited through Mechanical Turk who completed several questionnaires. Analyses revealed a unidimensional factor structure, excellent internal consistency (α = 0.88), and good convergent validity for the Fear of Kidney Failure questionnaire. Only 13% of former donors reported moderate to high fear of kidney failure. Nonwhite race (OR = 2.9, P = 0.01), genetic relationship with the recipient (OR = 2.46, P = 0.04), and low satisfaction with the donation experience (OR = 0.49, P = 0.002) were significant predictors of higher fear of kidney failure. We conclude that while mild anxiety about kidney failure is common, high anxiety about future renal failure among former LKDs is uncommon. The Fear of Kidney Failure questionnaire is reliable, valid, and easy to use in the clinical setting.

Trajectories of perceived benefits in living kidney donors: association with donor characteristics and recipient outcomes.

BACKGROUND: While improved health of the recipient may serve as a primary motivating factor, living kidney donors (LDs) also may expect to accrue some personal benefit following donation. This study sought to identify trajectories of perceived benefit over the first 2 years after donation. METHODS: Prospective questionnaire data were collected from 133 LDs from three kidney transplant programs in the United States. Before surgery, LDs completed the Living Donation Expectancies Questionnaire to assess their expectations of personal growth, interpersonal benefits, and spiritual benefits from the donation experience. This report then assessed the degree to which these expectations were met at 1, 6, 12, and 24 months post-donation. RESULTS: Analyses revealed four (Interpersonal Benefit) and five (Personal Growth, Spiritual Benefit) distinct trajectories over time. For some LDs, pre-donation expectancies about benefit were met or exceeded over the 2 years, while for others the anticipated benefits were either short-lived or not met at all. Trajectory group assignment was associated with some donor characteristics (e.g., age, gender, and relationship to recipient). Also, LDs whose recipients had functioning grafts and who reported improved health status following transplantation were more likely to have their pre-donation personal growth and interpersonal benefit expectations consistently met or exceeded. CONCLUSIONS: Longitudinal trajectory analysis can help to identify different outcomes patterns for LDs and factors associated with them. The relevance of these findings is discussed in the context of LD education, follow-up care, and future research on donation benefits.

Tubular expression of KIM-1 does not predict delayed function after transplantation.

Injured epithelial cells of the proximal tubule upregulate the glycoprotein kidney injury molecule 1 (KIM-1), suggesting its potential as a biomarker of incipient kidney allograft injury. It is unknown whether KIM-1 expression changes in kidney allografts with delayed graft function (DGF), which often follows ischemia-reperfusion injury. Here, we prospectively measured KIM-1 RNA and protein expression in preperfusion biopsies of 30 living- and 85 deceased-donor kidneys and correlated the results with histologic and clinical outcomes after transplantation. We detected KIM-1 expression in 62% of deceased-donor kidneys and only 13% of living-donor kidneys (P < 0.0001). The level of KIM-1 expression before reperfusion correlated inversely with renal function at the time of procurement and correlated directly with the degree of interstitial fibrosis. Surprising, however, we did not detect a significant correlation between KIM-1 staining intensity and the occurrence of DGF. Our findings are consistent with a role for KIM-1 as an early indicator of tubular injury but do not support tissue KIM-1 measurement before transplantation to identify kidneys at risk for DGF.