Targeted Quantification of Proteoforms in Complex Samples by Proteoform Reaction Monitoring.

Existing mass spectrometric assays used for sensitive and specific measurements of target proteins across multiple samples, such as selected/multiple reaction monitoring (SRM/MRM) or parallel reaction monitoring (PRM), are peptide-based methods for bottom-up proteomics. Here, we describe an approach based on the principle of PRM for the measurement of intact proteoforms by targeted top-down proteomics, termed proteoform reaction monitoring (PfRM). We explore the ability of our method to circumvent traditional limitations of top-down proteomics, such as sensitivity and reproducibility. We also introduce a new software program, Proteoform Finder (part of ProSight Native), specifically designed for the easy analysis of PfRM data. PfRM was initially benchmarked by quantifying three standard proteins. The linearity of the assay was shown over almost 3 orders of magnitude in the femtomole range, with limits of detection and quantification in the low femtomolar range. We later applied our multiplexed PfRM assay to complex samples to quantify biomarker candidates in peripheral blood mononuclear cells (PBMCs) from liver-transplanted patients, suggesting their possible translational applications. These results demonstrate that PfRM has the potential to contribute to the accurate quantification of protein biomarkers for diagnostic purposes and to improve our understanding of disease etiology at the proteoform level.

Correction to: Trends and predictors of multidimensional health-related quality of life after living donor kidney transplantation.

In its original publication, an erroneous version of Fig. 2d was included in the manuscript. The corrected figure has now been added.

Trends and predictors of multidimensional health-related quality of life after living donor kidney transplantation.

PURPOSE: Living donor kidney transplant (LDKT) imparts the best graft and patient survival for most end-stage kidney disease (ESKD) patients. Yet, there remains variation in post-LDKT health-related quality of life (HRQOL). Improved understanding of post-LDKT HRQOL can help identify patients for interventions to maximize the benefit of LDKT. METHODS: For 477 LDKT recipients transplanted between 11/2007 and 08/2016, we assessed physical, mental, social, and kidney-targeted HRQOL pre-LDKT, as well as 3 and 12 months post-operatively using the SF-36, Kidney Disease Quality of Life-Short Form (KDQOL-SF), and the Functional Assessment of Cancer Therapy-Kidney Symptom Index 19 item version (FKSI-19). We then examined trajectories of each HRQOL domain using latent growth curve models (LGCMs). We also examined associations between decline in HRQOL from 3 months to 12 months post-LDKT and death censored graft failure (DCGF) using Cox regression. RESULTS: Large magnitude effects (d > 0.80) were observed from pre- to post-LDKT change on the SF-36 Vitality scale (d = 0.81) and the KDQOL-SF Burden of Kidney Disease (d = 1.05). Older age and smaller pre- to post-LDKT decreases in serum creatinine were associated with smaller improvements on many HRQOL scales across all domains in LGCMs. Higher DCGF rates were associated with worse physical [e.g., SF-36 PCSoblique hazard ratio (HR) 1.18; 95% CI 1.01-1.38], mental (KDQOL-SF Cognitive Function HR 1.27; 95% CI 1.00-1.62), and kidney-targeted (FKSI-19 HR: 1.18; 95% CI 1.00-1.38) HRQOL domains. CONCLUSION: Clinical HRQOL monitoring may help identify patients who are most likely to have failing grafts and who would benefit from post-LDKT intervention.

Transplant regimen adherence for kidney recipients by engaging information technologies (TAKE IT): Rationale and methods for a randomized controlled trial of a strategy to promote medication adherence among transplant recipients.

BACKGROUND: Several studies report a high prevalence of non-adherence to prescribed immunosuppressive (IS) medications among kidney transplant recipients (KTRs), yet few interventions have been effective for helping patients sustain appropriate post-transplant adherence. We describe a multifaceted, evidence-based, medication adherence monitoring strategy ('TAKE IT') that leverages available transplant center resources to identify potential medication non-adherence and other concerns earlier to prevent complications that could result from inadequate IS adherence. METHODS: The TAKE IT strategy includes: 1) medication adherence mobile application; 2) routine, online patient self-reported adherence assessments; 3) care alert notifications via the electronic health record (EHR) directed to transplant coordinators; 4) quarterly adherence reports to monitor IS values and summarize adherence trends; 5) deployment of adherence support tools tailored to specific adherence concerns. To test the TAKE IT intervention, we will conduct a two-arm, patient-randomized controlled trial at two large, diverse transplant centers (Northwestern University, Mayo Clinic, AZ) with planned recruitment of 450 KTRs (n = 225 per site) within 2 years of transplantation and 2 years of follow-up. Study assessments will take place at baseline, 6 weeks, 6, 12, 18 and 24 months. The primary effectiveness outcome is medication adherence via pill count, secondary outcomes include self-reported adherence and clinical outcomes. Process outcomes and cost-effectiveness will also be examined. CONCLUSION: The TAKE IT trial presents an innovative approach to monitoring and optimizing medication adherence among a population taking complex medication regimens. This trial seeks to evaluate the effectiveness and feasibility of this strategy compared to usual care.

Immune reconstitution/immunocompetence in recipients of kidney plus hematopoietic stem/facilitating cell transplants.

Nineteen subjects have more than 18 months' follow-up in a phase IIb tolerance protocol in HLA-mismatched recipients of living donor kidney plus facilitating cell enriched hematopoietic stem cell allografts (FCRx). Reduced intensity conditioning preceded a kidney allograft, followed the next day by FCRx. Twelve have achieved stable donor chimerism and have been successfully taken off immunosuppression (IS). We prospectively evaluated immune reconstitution and immunocompetence. Return of CD4 and CD8 T central and effector memory cell populations was rapid. T-cell receptor (TCR) Excision Circle analysis showed a significant proportion of chimeric cells produced were being produced de novo. The TCR repertoires posttransplant in chimeric subjects were nearly as diverse as pretransplant donors and recipients, and were comparable to subjects with transient chimerism who underwent autologous reconstitution. Subjects with persistent chimerism developed few serious infections when off IS. The majority of infectious complications occurred while subjects were still on conventional IS. BK viruria and viremia resolved after cessation of IS and no tissue-invasive cytomegalovirus infections occurred. Notably, although 2 of 4 transiently or nonchimeric subjects experienced recurrence of their underlying autoimmune disorders, none of the chimeric subjects have, suggesting that self-tolerance is induced in addition to tolerance to alloantigen. No persistently chimeric subject has developed donor-specific antibody, and renal function has remained within normal limits. Patients were successfully vaccinated per The American Society for Blood and Marrow Transplantation guidelines without loss of chimerism or rejection. Memory for hepatitis vaccination persisted after transplantation. Chimeric subjects generated immune responses to pneumococcal vaccine. These data suggest that immune reconstitution and immunocompetence are maintained in persistently chimeric subjects.