Race-Free Estimated Glomerular Filtration Rate Equation in Kidney Transplant Recipients: Development and Validation Study

OBJECTIVE: To compare the performance of a newly developed race-free kidney recipient specific glomerular filtration rate (GFR) equation with the three current main equations for measuring GFR in kidney transplant recipients. DESIGN: Development and validation study SETTING: 17 cohorts in Europe, the United States, and Australia (14 transplant centres, three clinical trials). PARTICIPANTS: 15 489 adults (3622 in development cohort (Necker, Saint Louis, and Toulouse hospitals, France), 11 867 in multiple external validation cohorts) who received kidney transplants between 1 January 2000 and 1 January 2021. MAIN OUTCOME MEASURE: The main outcome measure was GFR, measured according to local practice. Performance of the GFR equations was assessed using P RESULTS: The study included 15 489 participants, with 50 464 mGFR and eGFR values. The mean GFR was 53.18 mL/min/1.73m2 (SD 17.23) in the development cohort and 55.90 mL/min/1.73m2 (19.69) in the external validation cohorts. Among the current GFR equations, the race-free CKD-EPI 2021 equation showed the lowest performance compared with the MDRD and CKD-EPI 2009 equations. When race was included in the kidney recipient specific GFR equation, performance did not increase. The race-free kidney recipient specific GFR equation showed significantly improved performance compared with the race-free CKD-EPI 2021 equation and performed well in the external validation cohorts (P30 ranging from 73.0% to 91.3%). The race-free kidney recipient specific GFR equation performed well in several subpopulations of kidney transplant recipients stratified by race (P30 73.0-91.3%), sex (72.7-91.4%), age (70.3-92.0%), body mass index (64.5-100%), donor type (58.5-92.9%), donor age (68.3-94.3%), treatment (78.5-85.2%), creatinine level (72.8-91.3%), GFR measurement method (73.0-91.3%), and timing of GFR measurement post-transplant (72.9-95.5%). An online application was developed that estimates GFR based on recipient’s creatinine level, age, and sex (https://transplant-prediction-system.shinyapps.io/eGFR_equation_KTX/). CONCLUSION: A new race-free kidney recipient specific GFR equation was developed and validated using multiple, large, international cohorts of kidney transplant recipients. The equation showed high accuracy and outperformed the race-free CKD-EPI 2021 equation that was developed in individuals with native kidneys

Race-free estimated glomerular filtration rate equation in kidney transplant recipients:development and validation study

OBJECTIVE: To compare the performance of a newly developed race-free kidney recipient specific glomerular filtration rate (GFR) equation with the three current main equations for measuring GFR in kidney transplant recipients.DESIGN: Development and validation study SETTING: 17 cohorts in Europe, the United States, and Australia (14 transplant centres, three clinical trials).PARTICIPANTS: 15 489 adults (3622 in development cohort (Necker, Saint Louis, and Toulouse hospitals, France), 11 867 in multiple external validation cohorts) who received kidney transplants between 1 January 2000 and 1 January 2021.MAIN OUTCOME MEASURE: The main outcome measure was GFR, measured according to local practice. Performance of the GFR equations was assessed using P 30 (proportion of estimated GFR (eGFR) within 30% of measured GFR (mGFR)) and correct classification (agreement between eGFR and mGFR according to GFR stages). The race-free equation, based on creatinine level, age, and sex, was developed using additive and multiplicative linear regressions, and its performance was compared with the three current main GFR equations: Modification of Diet in Renal Disease (MDRD) equation, Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2009 equation, and race-free CKD-EPI 2021 equation. RESULTS: The study included 15 489 participants, with 50 464 mGFR and eGFR values. The mean GFR was 53.18 mL/min/1.73m 2 (SD 17.23) in the development cohort and 55.90 mL/min/1.73m 2 (19.69) in the external validation cohorts. Among the current GFR equations, the race-free CKD-EPI 2021 equation showed the lowest performance compared with the MDRD and CKD-EPI 2009 equations. When race was included in the kidney recipient specific GFR equation, performance did not increase. The race-free kidney recipient specific GFR equation showed significantly improved performance compared with the race-free CKD-EPI 2021 equation and performed well in the external validation cohorts (P 30 ranging from 73.0% to 91.3%). The race-free kidney recipient specific GFR equation performed well in several subpopulations of kidney transplant recipients stratified by race (P 30 73.0-91.3%), sex (72.7-91.4%), age (70.3-92.0%), body mass index (64.5-100%), donor type (58.5-92.9%), donor age (68.3-94.3%), treatment (78.5-85.2%), creatinine level (72.8-91.3%), GFR measurement method (73.0-91.3%), and timing of GFR measurement post-transplant (72.9-95.5%). An online application was developed that estimates GFR based on recipient's creatinine level, age, and sex (https://transplant-prediction-system.shinyapps.io/eGFR_equation_KTX/). CONCLUSION: A new race-free kidney recipient specific GFR equation was developed and validated using multiple, large, international cohorts of kidney transplant recipients. The equation showed high accuracy and outperformed the race-free CKD-EPI 2021 equation that was developed in individuals with native kidneys.TRIAL REGISTRATION: ClinicalTrials.gov NCT05229939.</p

Varicella zoster infection in renal transplant recipients: prevalence, complications and outcome

Varicella zoster virus (VZV) is an important pathogen after renal transplantation. In the present study, we examined the prevalence, clinical presentation and outcome of VZV infections in renal transplant recipients. Charts and medical records of adult renal allotransplant recipients were investigated to find patients with VZV infection. From December 1972 until July 2010, 1,139 patients received kidney allograft at our institution. VZV infection was diagnosed in 40 patients (3.51%). 28 patients (70%) had intensified immunosuppression prior to VZV infection occurrence. Median time of onset was 2.13 years after transplantation (range 9 days to 19.2 years). 35 patients developed VZV during the first post-transplant year (median 0.61 years). Four patients developed VZV infection more than 12 years after transplantation. 33 patients (82.5%) had dermatomal distribution, 5 (12.5%) disseminated herpes zoster (HZ), and 2 patients (5%) who were VZV IgG-negative before transplantation, developed chickenpox. Immunosuppression was reduced and patients received acyclovir. Cutaneous scarring was recorded in 7 cases (17.5%). Two patients developed post-herpetic neuralgia, which was accompanied by scarring and skin depigmentation in 1 of them. Five patients (12.5%) experienced relapse of HZ. Timely initiation of therapy may prevent development of complications and the visceral form of disease. Based on our experience with development of chickenpox, we suggest active immunization for all seronegative patients before organ transplantation

Octogenarians on hemodialysis: a prospective study

Octogenarians represent the fastest growing group of patients on hemodialysis. These patients were previously treated with conservative measures, while they were believed to have too poor prognosis on renal replacement therapy. We investigated clinical characteristics and outcome of patients prospectively after at least 2 years of follow-up. Six male and six female patients who were older than 80 years at the start of hemodialysis were followed up. Their clinical characteristics, comorbidities, etiology of renal disease, nutritional status, complications, vascular access, hospitalizations, compliance and outcome were recorded. The primary renal disease was unknown in 42.8% of patients. All patients had one or more comorbid conditions. Dialysis was initiated in an emergency situation in 64.3%. Vascular access was long-term hemodialysis catheter in 71.4%. Only 14.2% of them received erythropoietin. There were no major bleedings with reduced doses of heparin. The most common complications were catheter-related ones (infections, ruptures). All patients together required seven hospitalizations per year (0.58 per patient). The octogenarians tended to be underdialyzed with the mean adequacy of dialysis (Kt/V) 0.92. The 1-year survival was 71.4%, and 2-year survival was 50%, i.e., they had good survival on hemodialysis. Most of them died from causes that were not related to the uremia. Their treatment requires a careful planning of renal service expansion while more octogenarians who need renal replacement treatment may be expected