Nested Semi-Transparent Isosurface Simulated Volume-Rendering (NESTIS-VR) - An efficient on-device rendering approach for Augmented Reality headsets increasing surgeon confidence of kidney donor arterial anatomy.

Background And Objective: Volume-renderings of computed tomography or magnetic resonance angiograms (MRAs) are routinely used by surgeons in the preoperative assessment of vascular anatomy in kidney donors. Stereoscopic headsets (OST-HMD) like Microsoft HoloLens allow intuitive interaction with three-dimensional content for more intuitive comprehension, but do not allow real-time ray-casting volume-rendering of medical volume datasets on-device due to computational limitations.

Methods: We introduce NEsted Semi-Transparent Isosurface Simulated Volume-Rendering (NESTIS-VR), as an on-device alternative to ray-casting volume-rendering and developed an application for HoloLens to render kidney donor MRAs with interactive control of fundamental rendering parameters.

The Medical Costs of Determining Eligibility and Waiting for a Kidney Transplantation.

Background: Recent efforts to increase access to kidney transplant (KTx) in the United States include increasing referrals to transplant programs, leading to more pretransplant services. Transplant programs reconcile the costs of these services through the Organ Acquisition Cost Center (OACC).

Objective: The aim of this study was to determine the costs associated with pretransplant services by applying microeconomic methods to OACC costs reported by transplant hospitals.

Obinutuzumab Effectively Depletes Key B-cell Subsets in Blood and Tissue in End-stage Renal Disease Patients.

Unlabelled: The THEORY study evaluated the effects of single and multiple doses of obinutuzumab, a type 2 anti-CD20 antibody that induces antibody-dependent cell-mediated cytotoxicity and direct cell death, in combination with standard of care in patients with end-stage renal disease.

Methods: We measured B-cell subsets and protein biomarkers of B-cell activity in peripheral blood before and after obinutuzumab administration in THEORY patients, and B-cell subsets in lymph nodes in THEORY patients and an untreated comparator cohort.

Results: Obinutuzumab treatment resulted in a rapid loss of B-cell subsets (including naive B, memory B, double-negative, immunoglobulin D transitional cells, and plasmablasts/plasma cells) in peripheral blood and tissue.

Cellular and humoral immune response to SARS-CoV-2 vaccination and booster dose in immunosuppressed patients: An observational cohort study.

Background: Humoral and cellular immune responses to SARS-CoV-2 vaccination among immunosuppressed patients remain poorly defined, as well as variables associated with poor response.

Methods: We performed a retrospective observational cohort study at a large Northern California healthcare system of infection-naïve individuals fully vaccinated against SARS-CoV-2 (mRNA-1273, BNT162b2, or Ad26.COV2.

SARS-CoV-2 Neutralizing Monoclonal Antibodies for the Treatment of COVID-19 in Kidney Transplant Recipients.

Background: Morbidity and mortality associated with coronavirus disease 2019 (COVID-19) infection in kidney transplant recipients are high and early outpatient interventions to prevent progression to severe disease are needed. SARS-CoV-2 neutralizing mAbs, including bamlanivimab and casirivimab-imdevimab, received emergency use authorization in the United States in November 2020 for treatment of mild to moderate COVID-19 disease.

Methods: We performed a retrospective analysis of 27 kidney transplant recipients diagnosed with COVID-19 between July 2020 and February 2021 who were treated with bamlanivimab or casirivimab-imdevimab and immunosuppression reduction.

Development of immunosuppressive myeloid cells to induce tolerance in solid organ and hematopoietic cell transplant recipients.

Replacement of failed organs followed by safe withdrawal of immunosuppressive drugs has long been the goal of organ transplantation. We studied changes in the balance of T cells and myeloid cells in the blood of HLA-matched and -mismatched patients given living donor kidney transplants followed by total lymphoid irradiation, anti-thymocyte globulin conditioning, and donor hematopoietic cell transplant to induce mixed chimerism and immune tolerance. The clinical trials were based on a conditioning regimen used to establish mixed chimerism and tolerance in mice.

Influence of immunosuppression on seroconversion against SARS-CoV-2 in two kidney transplant recipients.

Solid organ transplant recipients are at risk for infectious complications due to chronic immunosuppression. The outbreak of coronavirus disease 2019 (COVID-19) in the United States has raised growing concerns for the transplant patient population. We seek to add to the current limited literature on COVID-19 in transplant recipients by describing the clinical course of two kidney transplant recipients with SARS-CoV-2 infection monitored by both RT-PCR and serology.

Mixed chimerism and acceptance of kidney transplants after immunosuppressive drug withdrawal.

Preclinical studies have shown that persistent mixed chimerism is linked to acceptance of organ allografts without immunosuppressive (IS) drugs. Mixed chimerism refers to continued mixing of donor and recipient hematopoietic cells in recipient tissues after transplantation of donor cells. To determine whether persistent mixed chimerism and tolerance can be established in patients undergoing living donor kidney transplantation, we infused allograft recipients with donor T cells and hematopoietic progenitors after posttransplant lymphoid irradiation.

Safety, pharmacokinetics, and pharmacodynamic activity of obinutuzumab, a type 2 anti-CD20 monoclonal antibody for the desensitization of candidates for renal transplant.

The limited effectiveness of rituximab plus intravenous immunoglobulin (IVIG) in desensitization may be due to incomplete B cell depletion. Obinutuzumab is a type 2 anti-CD20 antibody that induces increased B cell depletion relative to rituximab and may therefore be more effective for desensitization. This open-label phase 1b study assessed the safety, pharmacokinetics, and pharmacodynamics of obinutuzumab in highly sensitized patients with end-stage renal disease.

Efficacy and Safety of a Tofacitinib-based Immunosuppressive Regimen After Kidney Transplantation: Results From a Long-term Extension Trial.

Background: Tofacitinib is an oral Janus kinase inhibitor. This open-label, long-term extension (LTE) study (NCT00658359) evaluated long-term tofacitinib treatment in stable kidney transplant recipients (n = 178) posttransplant.

Methods: Patients who completed 12 months of cyclosporine (CsA) or tofacitinib treatment in the phase IIb parent study (NCT00483756) were enrolled into this LTE study, evaluating long-term tofacitinib treatment over months 12 to 72 posttransplant.

A new approach to kidney wait-list management in the kidney allocation system era: Pilot implementation and evaluation.

Kidney transplant wait-list management is becoming increasingly complex. We introduced a novel wait-list management strategy at our center, the Transplant Readiness Assessment Clinic (TRAC), whereby patients whose Kidney Allocation Scores surpass a threshold are actively managed. From January 1, 2016 through June 30, 2017, we evaluated 195 patients through TRAC.

Native kidney cytomegalovirus nephritis and cytomegalovirus prostatitis in a kidney transplant recipient.

We present a case of cytomegalovirus (CMV) native kidney nephritis and prostatitis in a CMV D+/R- kidney transplant recipient who had completed six months of CMV prophylaxis four weeks prior to the diagnosis of genitourinary CMV disease. The patient had a history of benign prostatic hypertrophy and urinary retention that required self-catheterization to relieve high post-voiding residual volumes. At 7 months post-transplant, he was found to have a urinary tract infection, moderate hydronephrosis of the transplanted kidney, and severe hydroureteronephrosis of the native left kidney and ureter, and underwent native left nephrectomy and transurethral resection of the prostate.

Macrochimerism and clinical transplant tolerance.

Current theory holds that macrochimerism is essential to the development of transplant tolerance. Hematopoietic cell transplantation from the solid organ donor is necessary to achieve macrochimerism. Over the last 10-20 years, trials of tolerance induction with combined kidney and hematopoietic cell transplantation have moved from the preclinical to the clinical arena.

Longitudinal study of living kidney donor glomerular dynamics after nephrectomy.

Background: Over 5,000 living kidney donor nephrectomies are performed annually in the US. While the physiological changes that occur early after nephrectomy are well documented, less is known about the long-term glomerular dynamics in living donors.

Methods: We enrolled 21 adult living kidney donors to undergo detailed long-term clinical, physiological, and radiological evaluation pre-, early post- (median, 0.

The association of predonation hypertension with glomerular function and number in older living kidney donors.

The effect of preexisting hypertension on living donor nephron number has not been established. In this study, we determined the association between preexisting donor hypertension and glomerular number and volume and assessed the effect of predonation hypertension on postdonation BP, adaptive hyperfiltration, and compensatory glomerular hypertrophy. We enrolled 51 living donors to undergo physiologic, morphometric, and radiologic evaluations before and after kidney donation.

A preconditioning regimen with a PKCɛ activator improves islet graft function in a mouse transplant model.

Transplantation of islets isolated from deceased donor pancreata is an attractive method of β-cell replacement therapy for patients with type 1 diabetes (T1D). However, the loss of islet cell viability and function during the peritransplant period is a limiting factor to long-term islet engraftment. Activation of the isoenzyme PKCɛ may improve islet survival and function.

Evaluating deceased donor registries: identifying predictive factors of donor designation.

The objectives of this study were to evaluate and compare the performance of the deceased donor registries of the 50 states and the District of Columbia and to identify possible predictive factors of donor designation. Data were collected retrospectively by Donate Life America using a questionnaire sent to Donor Designation Collaborative state teams between 2007 and 2010. By the end of 2010, there were 94,669,081 designated donors nationwide.

Incidental kidney stones: a single center experience with kidney donor selection.

The presence of kidney stones has been a relative contraindication for living donation. With the widespread use of more sensitive imaging techniques as part of the routine living donor workup, kidney stones are more frequently detected, and their clinical significance in this setting is largely unknown. Records from 325 potential kidney donors who underwent MRA or CT-angiography were reviewed; 294 proceeded to donation.

Validity of surrogate measures for functional nephron mass.

Background: Transplanted nephron mass is an important determinant of long-term allograft survival, but accurate assessment before organ retrieval is challenging. Newer radiologic imaging techniques allow for better determination of total kidney and cortical volumes.

Methods: Using volume measurements reconstructed from magnetic resonance or computed tomography imaging from living donor candidates, we characterized total kidney (n=312) and cortical volumes (n=236) according to sex, age, weight, height, body mass index (BMI), and body surface area (BSA).

C1q-fixing human leukocyte antigen antibodies are specific for predicting transplant glomerulopathy and late graft failure after kidney transplantation.

Background: Human leukocyte antigen (HLA) antibodies, especially those that fix complement, are associated with antibody-mediated rejection and graft failure. The C1q assay on single antigen beads detects a subset of HLA antibodies that can fix complement and precede C4d deposition. The aim of this study was to determine whether C1q-fixing antibodies distinguish de novo donor-specific antibodies (DSA) that are clinically relevant and harmful.

Living donor evaluation and exclusion: the Stanford experience.

Background: The proportion of prospective living donors disqualified for medical reasons is unknown. The objective of this study is to delineate and quantify specific reasons for exclusion of prospective living donors from kidney donation.

Methods: All adult prospective kidney donors who contacted our transplant program between October 1, 2007 and April 1, 2009 were included in our analysis (n = 484).

Population pharmacokinetic analysis of mycophenolic acid coadministered with either tasocitinib (CP-690,550) or tacrolimus in adult renal allograft recipients.

Tasocitinib (CP-690,550) is an orally active Janus kinase inhibitor that is in development for prophylaxis of acute rejection after kidney transplantation and for the treatment of select autoimmune diseases. The current study was conducted to evaluate the systemic exposure of mycophenolic acid (MPA) in de novo kidney transplant patients when coadministered with tasocitinib compared with exposure in patients receiving tacrolimus, which has no effect on MPA pharmacokinetics. Plasma MPA concentrations were obtained from 17 adult patients who received either 15 mg or 30 mg tasocitinib twice daily (eight patients) or tacrolimus (nine patients) after kidney transplantation.