Elevation of Donor-derived Cell-free DNA Before Biopsy-proven Rejection in Kidney Transplant

BACKGROUND

Standard-of-care biomarkers for renal allograft rejection are lagging indicators, signaling existing organ injury. This precludes early intervention, when immunological cascades leading to rejection are most susceptible. Donor-derived cell-free DNA (dd-cfDNA) shows promise as an early indicator of rejection, allowing earlier and possibly more effective treatment. This analysis was designed to assess this promise using real-world dd-cfDNA testing evidence.

METHODS

This retrospective analysis of the prospective, observational ProActive registry study (NCT04091984) assessed dd-cfDNA and serum creatinine levels before biopsy in 424 patients with ≥1 dd-cfDNA test (n = 1013) in the 6 mo before biopsy.

RESULTS

Of 4667 enrolled patients, 1631 patients had ≥18 mo of follow-up data, of which 424 had a biopsy and were included in this analysis. Twenty-six biopsies showed antibody-mediated rejection (ABMR), 62 showed T cell-mediated rejection, and 336 showed nonrejection; each from a unique patient. dd-cfDNA fractions were significantly elevated 5 mo before ABMR biopsies, and 2 mo before T cell-mediated rejection biopsies, compared with nonrejection biopsies. In contrast, serum creatinine did not discriminate between rejection and nonrejection in advance, or concurrent with biopsy. Among patients with nonrejection biopsies, estimated glomerular filtration rate was significantly lower in cases with ≥2 increased dd-cfDNA results (≥1%), compared with those with 0 or 1 increased dd-cfDNA result.

CONCLUSIONS

These data indicate that dd-cfDNA is an early indicator of biopsy-proven rejection, especially ABMR, suggesting a greater role for dd-cfDNA in surveillance to identify patients at high risk of ongoing or future rejection, thus requiring closer monitoring, biopsy, or other management changes.

The Clinical Utility of Genetic Testing in the Diagnosis and Management of Adults with Chronic Kidney Disease

SIGNIFICANCE STATEMENT

Accurate diagnosis of a patient's underlying cause of CKD can influence management and ultimately overall health. The single-arm, interventional, prospective Renasight Clinical Application, Review, and Evaluation study assessed the utility of genetic testing with a 385 gene kidney disease panel on the diagnosis and management of 1623 patients with CKD. Among 20.8% of patients who had positive genetic findings, half resulted in a new or reclassified diagnosis. In addition, a change in management because of genetic testing was reported for 90.7% of patients with positive findings, including treatment changes in 32.9%. These findings demonstrate that genetic testing has a significant effect on both CKD diagnosis and management.

BACKGROUND

Genetic testing in CKD has recently been shown to have diagnostic utility with many predicted implications for clinical management, but its effect on management has not been prospectively evaluated.

METHODS

Renasight Clinical Application, Review, and Evaluation RenaCARE (ClinicalTrials.gov NCT05846113 ) is a single-arm, interventional, prospective, multicenter study that evaluated the utility of genetic testing with a broad, 385 gene panel (the Renasight TM test) on the diagnosis and management of adult patients with CKD recruited from 31 US-based community and academic medical centers. Patient medical history and clinical CKD diagnosis were collected at enrollment. Physician responses to questionnaires regarding patient disease categorization and management were collected before genetic testing and 1 month after the return of test results. Changes in CKD diagnosis and management after genetic testing were assessed.

RESULTS

Of 1623 patients with CKD in 13 predefined clinical disease categories (ages, 18-96; median, 55 years), 20.8% ( n =338) had positive genetic findings spanning 54 genes. Positive genetic findings provided a new diagnosis or reclassified a prior diagnosis in 48.8% of those patients. Physicians reported that genetic results altered the management of 90.7% of patients with a positive genetic finding, including changes in treatment plan, which were reported in 32.9% of these patients.

CONCLUSIONS

Genetic testing with a CKD-focused 385 gene panel substantially refined clinical diagnoses and had widespread implications for clinical management, including appropriate treatment strategies. These data support the utility of broader integration of panels of genetic tests into the clinical care paradigm for patients with CKD.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

ClinicalTrials.gov, NCT05846113 .

Genetic Counseling in Kidney Disease: A Perspective

As genetic testing is increasingly integrated into nephrology practice there is a growing need for partnership with genetic experts. Genetic counselors are ideally suited to fill this role. The value of genetic counseling is born out of the clinical value of genetic test results against the backdrop of the complexity of genetic testing. Genetic counselors who specialize in nephrology are trained to understand and explain the potential effects of genes on kidney disease, which can enable patients to make informed decisions about proceeding with genetic testing, navigating variants of uncertain significance, educating on extrarenal features of hereditary kidney disease, facilitating cascade testing, providing post-test education about testing results, and assisting with family planning. Genetic counselors can partner with the nephrologist and provide the knowledge needed to maximize the use of genetic testing for patients for nephrology consultation. Genetic counseling is more than an element or extension of genetic testing; it is a dynamic, shared conversation between the patient and the genetic counselor where concerns, sentiments, information, and education are exchanged, and value-based decision making is facilitated.

Combining Donor-derived Cell-free DNA Fraction and Quantity to Detect Kidney Transplant Rejection Using Molecular Diagnoses and Histology as Confirmation

BACKGROUND

Donor-derived cell-free DNA (dd-cfDNA) fraction and quantity have both been shown to be associated with allograft rejection. The present study compared the relative predictive power of each of these variables to the combination of the two, and developed an algorithm incorporating both variables to detect active rejection in renal allograft biopsies.

METHODS

The first 426 sequential indication biopsy samples collected from the Trifecta study ( ClinicalTrials.gov # NCT04239703) with microarray-derived gene expression and dd-cfDNA results were included. After exclusions to simulate intended clinical use, 367 samples were analyzed. Biopsies were assessed using the molecular microscope diagnostic system and histology (Banff 2019). Logistic regression analysis examined whether combining dd-cfDNA fraction and quantity adds predictive value to either alone. The first 149 sequential samples were used to develop a two-threshold algorithm and the next 218 to validate the algorithm.

RESULTS

In regression, the combination of dd-cfDNA fraction and quantity was found to be significantly more predictive than either variable alone ( P = 0.009 and P < 0.0001). In the test set, the area under the receiver operating characteristic curve of the two-variable system was 0.88, and performance of the two-threshold algorithm showed a sensitivity of 83.1% and specificity of 81.0% for molecular diagnoses and a sensitivity of 73.5% and specificity of 80.8% for histology diagnoses.

CONCLUSIONS

This prospective, biopsy-matched, multisite dd-cfDNA study in kidney transplant patients found that the combination of dd-cfDNA fraction and quantity was more powerful than either dd-cfDNA fraction or quantity alone and validated a novel two-threshold algorithm incorporating both variables.

Donor-derived Cell-free DNA Shows High Sensitivity for the Diagnosis of Pancreas Graft Rejection in Simultaneous Pancreas-kidney Transplantation

BACKGROUND

Pancreas graft status in simultaneous pancreas-kidney transplant (SPKTx) is currently assessed by nonspecific biochemical markers, typically amylase or lipase. Identifying a noninvasive biomarker with good sensitivity in detecting early pancreas graft rejection could improve SPKTx management.

METHODS

Here, we developed a pilot study to explore donor-derived cell-free DNA (dd-cfDNA) performance in predicting biopsy-proven acute rejection (P-BPAR) of the pancreas graft in a cohort of 36 SPKTx recipients with biopsy-matched plasma samples. dd-cfDNA was measured using the Prospera test (Natera, Inc.) and reported both as a fraction of the total cfDNA (fraction; %) and as concentration in the recipient's plasma (quantity; copies/mL).

RESULTS

In the absence of P-BPAR, dd-cfDNA was significantly higher in samples collected within the first 45 d after SPKTx compared with those measured afterward (median, 1.00% versus 0.30%; median, 128.2 versus 35.3 cp/mL, respectively with both; P  = 0.001). In samples obtained beyond day 45, P-BPAR samples presented a significantly higher dd-cfDNA fraction (0.83 versus 0.30%; P  = 0.006) and quantity (81.3 versus 35.3 cp/mL; P  = 0.001) than stable samples. Incorporating dd-cfDNA quantity along with dd-cfDNA fraction outperformed dd-cfDNA fraction alone to detect active rejection. Notably, when using a quantity cutoff of 70 cp/mL, dd-cfDNA detected P-BPAR with a sensitivity of 85.7% and a specificity of 93.7%, which was more accurate than current biomarkers (area under curve of 0.89 for dd-cfDNA (cp/ml) compared with 0.74 of lipase and 0.46 for amylase).

CONCLUSIONS

dd-cfDNA measurement through a simple noninvasive blood test could be incorporated into clinical practice to help inform graft management in SPKTx patients.

Genetic Etiologies for Chronic Kidney Disease Revealed through Next-Generation Renal Gene Panel

INTRODUCTION

Chronic kidney disease (CKD) is a major public health issue in the USA. Identification of monogenic causes of CKD, which are present in ∼10% of adult cases, can impact prognosis and patient management. Broad gene panels can provide unbiased testing approaches, which are advantageous in phenotypically heterogeneous diseases. However, the use and yield of broad genetic panels by nephrologists in clinical practice is not yet well characterized.

METHODS

Renal genetic testing, ordered exclusively for clinical purposes, predominantly by general and transplant nephrologists within the USA, was performed on 1,007 consecutive unique patient samples. Testing was performed using a commercially available next-generation sequencing-based 382 gene kidney disease panel. Pathogenic (P) and likely pathogenic (LP) variants were reported. Positive findings included a monoallelic P/LP variant in an autosomal dominant or X-linked gene and biallelic P/LP variants in autosomal recessive genes.

RESULTS

Positive genetic findings were identified in 21.1% (212/1,007) of cases. A total of 220 positive results were identified across 48 genes. Positive results occurred most frequently in the PKD1 (34.1%), COL4A5 (10.9%), PKD2 (10.0%), COL4A4 (6.4%), COL4A3 (5.9%), and TTR (4.1%) genes. Variants identified in the remaining 42 genes comprised 28.6% of the total positive findings, including single positive results in 26 genes. Positive results in >1 gene were identified in 7.5% (16/212) of cases.

CONCLUSIONS

Use of broad panel genetic testing by clinical nephrologists had a high success rate, similar to results obtained by academic centers specializing in genetics.

Genetic Testing for Chronic Kidney Diseases: Clinical Utility and Barriers Perceived by Nephrologists

Rationale & Objective

The identification of pathogenic variants in genes associated with chronic kidney disease can provide patients and nephrologists with actionable information to guide diagnoses and therapeutic plans. However, many nephrologists do not use genetic testing despite costs decreasing over time and more widespread availability.

Study Design

We conducted a survey to uncover the perceptions of general adult nephrologists about the utility of and barriers to genetic testing in clinical practice.

Setting & Participants

The online survey was administered to board-certified nephrologists (n = 10,054) in the United States.

Analytical Approach

We analyzed demographic characteristics of the survey respondents and their responses in the context of their use of genetic testing in routine clinical practice.

Results

A total of 149 nephrologists completed the survey, with 72% (107 of 149) reporting genetic test use in their practice. On average, tests were ordered for 3.8% of their patient population. Thirty-five percent of responses from nephrologists without a history of genetic test use ranked perceived barriers as "extremely significant" compared with 23% of responses from those who had previously used genetic tests. However, both users and nonusers of genetic tests indicated high cost (users: 46%, 49 of 107; nonusers 69%, 29 of 42) and poor availability or lack of ease (users: 33%, 35 of 107; nonusers: 57%; 24 of 42) of genetic testing as the most significant perceived barriers to implementation.

Limitations

The survey used in this study was not previously validated; additionally, because of the relatively small number of responses, there might have been a selection bias among the responders.

Conclusions

Although most nephrologists reported using genetic tests in clinical practice, high costs and poor availability or the lack of ease of use were perceived as the most important barriers to routine adoption. These observations indicate that educational programs that cover a range of topics, from genetics of chronic kidney disease to selection of the test, may help mitigate these barriers and enhance the use of genetic testing in nephrology practice.

Incorporation of Donor-derived Cell-free DNA Into Clinical Practice for Renal Allograft Management

BACKGROUND

Donor-derived cell-free DNA (dd-cfDNA) in plasma is an established noninvasive biomarker for allograft injury and rejection. A single-nucleotide polymorphism (SNP)-based massively multiplexed polymerase chain reaction methodology can be used to quantify dd-cfDNA in kidney transplant recipients. In this study we describe our clinical experience in using a SNP-based dd-cfDNA assay for the management of active rejection in renal transplant recipients.

METHODS

To assess the clinical utility of a clinically available SNP-based massively multiplexed polymerase chain reaction dd-cfDNA assay, we analyzed biopsy data contemporaneous to dd-cfDNA results at 33 participating clinics and calculated the rate of rejection in dd-cfDNA-matched biopsy results.

RESULTS

A total of 1347 dd-cfDNA test samples from 879 patients were accessioned from October 3, 2019, to November 2, 2020. The dd-cfDNA testing classified 25.2% (340/1347) of samples as high-risk (dd-cfDNA fraction ≥ 1%). Clinical follow-up was available for 32.1% (109/340) of the high-risk results, which included samples from 28 patients with definitive biopsy results within 2 weeks of dd-cfDNA testing. Pathology reports indicated a 64% (18/28) rate of active rejection in biopsy result-matched samples. Total cfDNA measurements indicated a skewed distribution and a correlation with dd-cfDNA-derived patient risk classification.

CONCLUSIONS

This is the first report showing the impact of dd-cfDNA on patient management in a multicenter real-world clinical cohort. The data indicate that incorporating dd-cfDNA testing into practice may improve physician decision making regarding renal allograft recipients.

Cardiac risk assessment for end-stage renal disease patients on the renal transplant waiting list

Cardiovascular disease is a leading cause of morbidity and mortality and is becoming more prevalent as the population ages and risk factors increase. This is most apparent in the end-stage renal disease (ESRD) patient population. In part, this is due to cofactors such as diabetes and hypertension commonly predisposing to progressive renal disease, as well as being a direct consequence of having renal failure. Of all major organ failures, kidney failure is the most likely to be managed chronically using renal replacement therapy and, ultimately, transplant. However, lack of transplant organs and a large renal failure cohort means waiting lists are often quite long and may extend to 5-10 years. Due to the cardiac risk factors inherent in patients awaiting transplant, many succumb to cardiac issues while waiting and present an increased per-procedural cardiac risk that extends into the post-transplant period. We aim to review the epidemiology of coronary artery disease in this population and the etiology as it relates to ESRD and its associated co-factors. We also will review the current approaches, recommendations and evidence for management of these patients as it relates to transplant waiting lists before and after the surgery. Recommendations on how to best manage patients in this cohort revolve around the available evidence and are best customized to the institution and the structure of the program. It is not clear whether the revascularization of patients without symptoms and with a good functional status yields any improvement in outcomes. Therefore, each individual case should be considered based on the risk factors, symptoms and functional status, and approached as part of a multi-disciplinary assessment program.

Chronic kidney disease, kidney transplantation and oxidative stress: a new look to successful kidney transplantation

Oxidative stress plays a key role in the pathophysiological process of uremia and its complications, particularly in cardiovascular disease. The level of oxidative stress markers is known to increase as chronic kidney disease progresses and correlates significantly with the level of renal function. Hemodialysis and peritoneal dialysis are major modes of renal replacement therapy for end-stage renal disease patients, but unfortunately they are also accompanied by increased oxidative stress. Successful kidney transplantation, however, results in near normalization of the antioxidant status and lipid metabolism by eliminating free radicals despite the surge of oxidative stress caused by the surgical procedure and ischemic injury to the organ during the operation. This success is associated with both improved renal function, reduced cardiovascular complications and overall improved morbidity and mortality. Measuring oxidative stress markers such as malondialdehyde is promising in predicting allograft survival and delayed graft function.

Minocycline-induced renal polyarteritis nodosa

Minocycline is a bacteriostatic, long-acting, lipid-soluble tetracycline that is generally well tolerated, but has been associated with polyarteritis nodosa (PAN). This is a case report of a 21-year-old woman presented to her primary care physician with several months of fatigue, mylagias, weight loss and intermittent severe bi-temporal headaches without changes in vision. Her medications included an Ortho-Tri-Cyclen Lo and Minocycline, which she started 2 years prior for acne. On presentation, she was tachycardic and severely hypertensive. Initial laboratory evaluation showed hyponatraemia and hypokalaemia as well as elevation of inflammatory markers. Autoimmune work-up was positive for perinuclear antineutrophil cytoplasmic antibodies. Renal arteriogram was characteristic of PAN and along with her other symptoms, she fulfilled the necessary criteria of American College of Rheumatology for diagnosis of PAN. Minocycline as a possible causative agent was discontinued since it was reported to cause cutaneous PAN in the literature. Cyclophosphamide and prednisone were initiated for treatment of her vasulculitis. Her symptoms and hypertension improved over the next several months. This is the first report of the minocycline-induced renal PAN.

Web based provider education for competency of scope of practice (Best Practice): Medicine Department Safe training is a computer based review program (de' medri)

Medicine Department Safe training is a computer based review program named de'medici and it is an employee training program. This annual review packet serves as a generic training tool. All health-care providers with direct patient care are required by state law to complete a group of 11 modules and pass a mandatory training test to assess proficiency in these areas. They include emergency preparedness, life and fire safety, electrical safety, working safety with hazardous materials, back safety, violence in the workplace, latex allergy prevention, preventing TB in the workplace, preventing AIDS and hepatitis B and C in the workplace, radiation safety, and age related care for health-care workers.

Web Based Health Education, E-learning, for Weight Management

Obesity is a major health problem across the United States and becoming a progressive world wide problem. An overweight person could access the weight management program and develop a personalized weight reduction plan. The customer enters specific data to personalize the program and in the future an artificial intelligence program can evaluate customer behavior and adjust accordingly. This is an on-line program with class room support, offered as back up when desired by the patient.

Database application of digital medical X-rays and labs: computerization, storage, retrieval, interpretation, and distribution

Stenter lets the health care worker order an X-ray that is produced as a computer image rather than on flat film. The health care provider can be in any location with the correct equipment, and view the digital image. The dimensions of this discussion are extensive. The cost savings because of reduced media and storage cost is substantial. Health care quality can be improved because of the ability to obtain consultation via telemedicine and the enhanced ability to track medical problems over time via trends. The major downside is the limited cost imbursement system to pay for technology. Unfortunately, this may impact on the improved quality of care. In simple terms someone needs to pay for the technology and the quality of health care needs to be maintained or improved. The real cost to the health care systems needs to be correctly calculated and inappropriate charging kept to a minimum. Specific costs need to be kept in mind and the first is the cost for new staff or staff training. The number of health care providers that are able to read the X-ray can be enlarged remembering that only American Board Certified Radiologists are allowed to give the final recommendation. How do we view the cost of missing something? It could be argued that this risk will be reduced because of improved technology for obtaining the digital X-ray and improved enhancement software. One way to view this situation is to include technology, management, and organization. The cost and benefits occur through the interplay of all three dimensions. The development of digital imaging hardware and artificial intelligence software will demand change in the management and organization. The organization will require changes in its design to accommodate the technology as to support and resources. Management will evolve to include methods for control and monitoring this technology. Business processes and standard operating procedures will change to integrate the technology into the organization in the most effective and efficient manner.

Mini medical record application: annual register for flu shot vaccinations

This application is an Intranet-based system. A database has been established utilizing patient information on the basis of age, medical diagnosis and employment history. If a health care provider or support staff states that a patient is over 65 years of age or has been diagnosed with a chronic disease and this limits the patient's ability to fight off infection, the need for preventive care is activated. In this situation the preventive care is the administration of an annual flu shot. For anyone over 65 years of age or with a chronic illness, a bulk mail of reminder cards with the dates of availability of injection is generated and mailed. All health care workers are notified at work of vaccination sites that they can use. In addition, should a patient have an appointment with a provider and a preventive flu injection is indicated, a reminder appears on the registration form. This reminder indicates a flu shot is needed as well as other preventive intervention.

Drug therapies for mesenteric vascular disease

Mesenteric vascular disease has been increasingly diagnosed in the past 25 years. This rise in incidence has been attributed to the advanced mean age of the population and increasing number of critically ill patients, and to a greater clinical recognition of the condition. While surgical revascularization and resection has long been the standard of treatment, medical management also plays an important role. Early diagnosis before irreversible bowel damage, which may occur within 6 to 8 hours after insult, is the goal of successful medical treatment without surgical intervention. Even in the presence or irreversible bowel ischemia, perioperative medical treatment may reduce the progression of further ischemia, and bowel resection may be limited. This article outlines the appropriate medical management of ischemic disorders of the intestine, with an emphasis on the drug treatments presently used in clinical practice and those being studied in the laboratory.