Outcomes in Living Donor Kidney Transplantation: The Role of Donor's Kidney Function.

INTRODUCTION: Living donor kidney transplant (LDKT) is one of the best therapeutic options for end-stage kidney disease (ESKD). Guidelines identify different estimated glomerular filtration rate (eGFR) thresholds to determine the eligibility of donors. The aim of our study was to evaluate whether pretransplant donor eGFR was associated with kidney function in the recipient. METHODS: We retrospectively studied LDKT recipients who received a kidney graft between September 1, 2005, and June 30, 2016 in the same transplant center in France and that had eGFR data available at 3, 12, 24, and 36 months posttransplant. RESULTS: We studied 90 donor-recipient pairs. The average age at time of transplant was 51.47 ± 10.95 for donors and 43.04 ± 13.52 years for recipients. Donors' average eGFR was 91.99 ± 15.37 mL/min/1.73 m2. Donor's age and eGFR were significantly correlated (p < 0.0001, r2 0.023). Donor's age and eGFR significantly correlated with recipient's eGFR at 3, 12, and 24 months posttransplant (age: p < 0.001 at all intervals; eGFR p = 0.001, 0.003, and 0.016, respectively); at 36 months, only donor's age significantly correlated with recipient's eGFR. BMI, gender match, and year of kidney transplant did not correlate with graft function. In the multivariable analyses, donor's eGFR and donor's age were found to be associated with graft function; correlation with eGFR was lost at 36 months; and donor's age retained a strong correlation with graft function at all intervals (p < 0.001). CONCLUSIONS: Donor's eGFR and age are strong predictors of recipient's kidney function at 3 years. We suggest that donor's eGFR should be clinically balanced with other determinants of kidney function and in particular with age.

COVID-19 Vaccine Hesitancy in Patients on Dialysis in Italy and France.

INTRODUCTION: Patients on dialysis (HDPs) are a category at high risk from COVID-19 and thus a high-priority group for vaccination. COVID-19 vaccine hesitancy has been a concern since the availability of the first vaccine. The objective of this study was to determine hesitancy rates and factors associated with hesitancy toward COVID-19 vaccination in HDP. METHODS: HDP were surveyed with an ad hoc questionnaire in 4 large dialysis facilities in Europe: Le Mans and Paris, in France, and Cagliari and Pavia, in Italy. The questionnaire explored different domains associated with vaccine hesitancy, such as perception of disease severity, sources of information about the vaccine and the disease, and confidence in the health care system. RESULTS: A total of 417 patients (average age 69 years, 60% men) agreed to answer the questionnaire. Hesitancy was associated with younger age (P = 0.003), lower perception of disease severity (P < 0.001) and vaccine efficacy (P < 0.001), and lower trust in vaccination (P < 0.001) and in the health care system and scientists (P < 0.001) in the univariate analysis. In the multivariate models, concerns about side effects (P = 0.004) and vaccine efficacy (P < 0.001) and living in France (P = 0.04) remained associated with higher vaccine hesitancy, whereas having received an influenza vaccine (P = 0.032) and trusting scientists (P = 0.032) were associated with a more positive attitude toward vaccination. CONCLUSIONS: HDPs have a good understanding of the risks associated with COVID-19. Vaccine hesitancy was not associated with educational level, age, or gender but rather with lack of confidence in vaccine efficacy and concerns about safety. HDPs were quite skeptical about the health care system but generally trusted scientists.

Smart Flow for the evaluation of the hemodialysis arteriovenous fistula.

BACKGROUND: Smart Flow is an innovative tool available on the Carestream Touch Prime Ultrasound machines, which provides automated blood flow measurement and shows the vectors that form the blood flow in the vessel. We compared the use of Smart Flow with traditional Duplex Doppler Ultrasound to evaluate blood flow of arteriovenous fistulas in prevalent hemodialysis patients. METHODS: A total of 31 chronic patients on hemodialysis were enrolled. Blood flow was measured on the brachial artery with Smart Flow and duplex Doppler ultrasound. In a subset of 26 patients, a video of the juxta-anastomotic efferent vein was recorded and analyzed to calculate an index of flow turbulence. RESULTS: We enrolled 21 males and 10 females aged 68.52 ± 11.64 years at the time of evaluation with an average arteriovenous fistulas vintage of 50.23 ± 47.42 months and followed them up for 18.03 ± 5.18 months. Smart Flow and Duplex Doppler Ultrasound blood flow measurements positively correlated (p < 0.0001) in the same patient but Smart Flow gave higher blood flow values (995.0 vs 730.3 mL/min, p < 0.0001), and the Duplex Doppler Ultrasound blood flow standard deviation was similar to Smart Flow (125.4 vs 114.4 mL/min, p < 0.0001). The time needed to evaluate arteriovenous fistulas with Smart Flow was significantly shorter than Duplex Doppler Ultrasound (67.58 ± 19.89 vs 146.3 ± 26.35 s, p < 0.0001). No correlation was found between blood flow turbulence and the subsequent access failure. CONCLUSION: Smart Flow is reliable, reproducible, and faster than traditional duplex ultrasound. However, the additional information given by the Smart Flow technique does not seem to add any further benefits in terms of prediction of the access failure.

Costimulatory pathways in kidney transplantation: pathogenetic role, clinical significance and new therapeutic opportunities.

Costimulatory pathways play a key role in immunity, providing the second signal required for a full activation of adaptive immune response. Different costimulatory families (CD28, TNF-related, adhesion and TIM molecules), characterized by structural and functional analogies, have been described. Costimulatory molecules modulate T cell activation, B cell function, Ig production, cytokine release and many other processes, including atherosclerosis. Patients suffering from renal diseases present significant alterations of the costimulatory pathways, which might make them particularly liable to infections. These alterations are further pronounced in patients undergoing kidney transplantation. In these patients, different costimulatory patterns have been related to distinct clinical features. The importance that costimulation has gained during the last years has led to development of several pharmacological approaches to modulate this critical step in the immune activation. Different drugs, mainly monoclonal antibodies targeting various costimulatory molecules (i.e. anti-CD80, CTLA-4 fusion proteins, anti-CD154, anti-CD40, etc.) were designed and tested in both experimental and clinical studies. The results of these studies highlighted some criticisms, but also some promising findings and now costimulatory blockade is considered a suitable strategy, with belatacept (a CTLA-4 fusion protein) being approved as the first costimulatory blocker for use in renal transplantation. In this review, we summarize the current knowledge on costimulatory pathways in the setting of kidney transplantation. We describe the principal costimulatory molecule families, their role and clinical significance in patients undergoing renal transplantation and the new therapeutic approaches that have been developed to modulate the costimulatory pathways.

Hemodialysis vascular access: everything you always wanted to know about it (but were afraid to ask).

Vascular accesses are essential for effective dialysis treatment. Arteriovenous fistulas, grafts and central venous catheters are the options available to the nephrologist, but they all have their pros and cons. All of the 3 types of vascular access share the same complications but at different rates, and their costs vary enormously, with on balance the arteriovenous fistula being the best choice. Nevertheless, recently the number of incident patients starting dialysis treatment with a venous catheter as vascular access has been steadily increasing. This is true even for more advanced countries such as the United States, where despite the efforts made to promote the use of fistulas, their prevalence is still low compared with Europe. Moreover, nowadays nephrologists are required to master technical skills that once were those of surgeons and to perform interventions to preserve the patency of the access. The aim of this paper is to review the prevalence, benefits and complications of the different vascular accesses in light of the most recent findings.