Application of Combined Donor-Derived Cell-Free DNA and Transcriptome in Diagnosis of Kidney Transplant Rejection.

BACKGROUND: Transcriptomic kidney profile testing and donor-derived cell-free DNA (dd-cfDNA) testing are new methods shown to provide early markers of graft inflammation during the post-transplant period. This study focused on utilizing clinical data to evaluate the application of these tests in detecting transplant rejection by comparing tests results to biopsy reports. MATERIAL AND METHODS: We conducted a retrospective analysis of a prospectively collected database of all adult kidney transplant patients at SUNY Upstate Medical Hospital from 1 January 2014 to 1 December 2022. Inclusion criteria were patients with concurrent transcriptomic kidney profile test and kidney biopsy results. RESULTS: Biopsies identified 33 kidney transplant rejections. For diagnosis of kidney rejection, transcriptomic kidney profile testing had a 52.83% positive predictive value and 92.77% negative predicative value, while dd-cfDNA testing had a 54.83% positive predictive value and 86.45% negative predictive value. Transcriptomic kidney profile testing showed an 82.35% sensitivity and 75.49% specificity, while dd-cfDNA testing showed a 56.66% sensitivity and 85.56% specificity. Positive transcriptomic kidney profile and dd-cfDNA tests detected 51.51% of rejections. Combined negative tests were observed in 70.21% of biopsies without rejection. CONCLUSIONS: Despite certain discrepancies and limitations, we believe transcriptomic profile testing and dd-cfDNA testing are useful for detecting early-stage rejections and can guide patient care. Additionally, dd-cfDNA testing avoids invasive screening biopsies. Following negative test results, the probability patients are not having rejection is 86.45%. The transcriptomic profile test's high sensitivity and specificity allow possible detection of transplant rejections that may have otherwise not been identified by biopsy.

Coupled Broad Ion Beam-Scanning Electron Microscopy (BIB-SEM) for polishing and three dimensional (3D) serial section tomography (SST).

Here we describe the first automated fully integrated in-microscope broad ion beam (BIB) system. Ar+-BIB has several advantages over Ga+ focused ion beam (FIB) and Xe+ plasma-FIB (PFIB) methods inducing less beam damage, especially for ion beam sensitive materials. It can mill areas several orders of magnitude larger (up to millimetre scale), and is not confined to the edge of the sample with associated curtaining issues. BIB is shown to have sputter rates up to five times higher than comparable FIB techniques. This new coupled BIB-SEM system (commercial name 'iPrep™II') enables in-microscope surface polishing to remove contaminants or damage for two dimensional (2D) imaging, as well as automated serial section tomography (SST) by milling and imaging hundreds of slices, cost and time efficiently. The milled slice thickness can be controlled from a few nanometers up to a micrometre. A novel sample transfer, handling and interlock system allows automated and sequential BIB polishing, scanning electron microscopy (SEM) and analysis by secondary electron (SE) imaging, electron back scatter diffraction (EBSD) and energy dispersive spectroscopy (EDS) for 3D microstructure analysis. Furthermore, insulating surfaces can be sputter coated after milling each slice to reduce charging during SEM analysis. The performance of the instrument is demonstrated through a series of case studies across the materials, earth and life sciences exploiting the imaging, crystallographic and chemical mapping capabilities. These include the study of butterfly defects in bearing steels, meta-stable intermetallic phases in bronze bearings, shale gas rock, aluminium plasma electrolytic oxide (PEO) coatings as well as liver and mouse brain tissues.

State of the Art Compendium: Canadian Thoracic Society recommendations for the management of chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a common cause of disability and death in Canada. Moreover, morbidity and mortality from COPD continue to rise, and the economic burden is enormous. The main goal of the Canadian Thoracic Society's evidence-based guidelines is to optimize early diagnosis, prevention and management of COPD in Canada. The main message of the guidelines is that COPD is a preventable and treatable disease. Targeted spirometry is strongly recommended to expedite early diagnosis in smokers and former smokers who develop respiratory symptoms, and who are at risk for COPD. Smoking cessation remains the single most effective intervention to reduce the risk of COPD and to slow its progression. Education, especially self-management plans, are key interventions in COPD. Therapy should be escalated on an individual basis in accordance with the increasing severity of symptoms and disability. Long-acting anticholinergics and beta-2-agonist inhalers should be prescribed for patients who remain symptomatic despite short-acting bronchodilator therapy. Inhaled steroids should not be used as first line therapy in COPD, but have a role in preventing exacerbations in patients with more advanced disease who suffer recurrent exacerbations. Acute exacerbations of COPD cause significant morbidity and mortality and should be treated promptly with bronchodilators and a short course of oral steroids; antibiotics should be prescribed for purulent exacerbations. Patients with advanced COPD and respiratory failure require a comprehensive management plan that incorporates structured end-of-life care. Management strategies, consisting of combined modern pharmacotherapy and nonpharmacotherapeutic interventions (eg, pulmonary rehabilitation and exercise training) can effectively improve symptoms, activity levels and quality of life, even in patients with severe COPD.