Suzanne M. Boyle

Chronic Renal Insufficiency Cohort Study (CRIC): Overview and Summary of Selected Findings

The Chronic Renal Insufficiency Cohort (CRIC) Study is a United States multicenter, prospective study of racially and ethnically diverse patients with CKD. Although the original aims of the study were to identify novel predictors of CKD progression and to elucidate the risk and manifestations of cardiovascular disease among nearly 4000 individuals with CKD, the CRIC Study has evolved into a national resource for investigation of a broad spectrum of CKD-related topics. The study has produced >90 published scientific articles, promoted many young investigative careers in nephrology, and fostered international collaborations focused on understanding the global burden of CKD. The third phase of the CRIC Study will complete enrollment of 1500 additional study participants in 2015 and is designed to answer questions regarding morbidity and mortality in mild-to-moderate CKD and to assess the burden of CKD in older persons. This review highlights some of the salient findings of the CRIC Study in the areas of race and ethnicity, CKD progression, CKD and cognition, and cardiovascular disease outcomes; it also outlines the ongoing and forthcoming opportunities for the global nephrology community to enhance its understanding of CKD and related complications through the study.

Low rates of vaccination in listed kidney transplant candidates.

Despite clear consensus and strong recommendations, vaccination rates of kidney transplant (KT) recipients have remained below targets. As vaccination is most effective if it is given prior to transplantation and the initiation of immunosuppression, patients should ideally have their vaccination status assessed and optimized in the pre‐transplant period. We performed a retrospective chart review to characterize vaccination rates and factors associated with gaps in vaccination in a single‐center population of waitlisted patients being evaluated for kidney transplantation. We evaluated 362 KT patients. Three‐quarters were receiving dialysis at the time of evaluation. Immunization rates were low with 35.9% of patients having completed vaccination for Pneumococcus, 55% for influenza, 6.9% for zoster, and 2.5% for tetanus. On multivariable analysis, patients who received other vaccines, including influenza, tetanus, or zoster vaccine (odds ratio [OR] 10.55, 95% confidence interval [CI] 5.65–19.71) were more likely to receive pneumococcal vaccine. Blacks (OR 0.24, 95% CI 0.12–0.47) were less likely to receive pneumococcal vaccine compared to whites. Patients on dialysis, and those active on the waiting list were more likely to receive pneumococcal vaccine than other groups (OR 2.81, 95% CI 1.44–5.51, and OR 1.84, 95% CI 1.08–3.14, respectively). We found that the overall immunization rate against common vaccine‐preventable infections was low among patients evaluated for kidney transplantation. A significant gap remains between recommendations and vaccine uptake in clinical practice among this high‐risk population.

ASSOCIATION OF ALTERNATIVE APPROACHES TO NORMALIZING PERITONEAL DIALYSIS CLEARANCE WITH MORTALITY AND TECHNIQUE FAILURE: A RETROSPECTIVE ANALYSIS USING THE UNITED STATES RENAL DATA SYSTEM-DIALYSIS MORBIDITY AND MORTALITY STUDY, WAVE 2.

♦ Background: Total body water (V) is an imprecise metric for normalization of dialytic urea clearance (Kt). This poses a risk of early mortality/technique failure (TF). We examined differences in the distribution of peritoneal Kt/V when V was calculated with actual weight (AW), ideal weight (IW), and adjusted weight (ADW). We also examined the associations of these Kt/V measurements, Kt/body surface area (BSA), and non-normalized Kt with mortality and TF. ♦ Methods: This is a retrospective cohort study of 534 incident peritoneal dialysis (PD) patients from the Dialysis Morbidity and Mortality Study Wave 2 linked with United States Renal Data System through 2010. Using Cox-proportional hazard models, we examined the relationship of several normalization strategies for peritoneal urea clearance, including Kt/VAW, Kt/VIW, Kt/VADW, Kt/BSA, and non-normalized Kt, with the outcomes of mortality and TF. Harrells c-statistics were used to assess the relative predictive ability of clearance metrics for mortality and TF. The distributions of Kt/VAW, KT/VIW, and KT/VADW were compared within and between body mass index (BMI) strata. ♦ Results: Median patient age: 59 (54% male; 72% white; 91% continuous ambulatory PD [CAPD]). Median 24-hour urine volume: 700 mL; median estimated glomerular filtration rate (eGFR) at initiation: 7.15 mL/min/1.73 m2. Technique failure and transplant-censored mortality at 5 years: 37%. Death and transplant-censored TF at 5 years: 60%. There were no significant differences in initial eGFR and 24-hour urine volume across BMI strata. There were statistically significant differences in each Kt/V calculation within the underweight, overweight, and obese strata. After adjustment, there were no significant differences in the hazard ratios (HRs) for TF/mortality for each clearance calculation. Harrells c-statistics for mortality for each clearance calculation were 0.78, and for TF, 0.60 – 0.61. ♦ Conclusions: Peritoneal urea clearances are sensitive to subtle changes in the estimation of V. However, there were no detectable significant associations of Kt/VAW, Kt/VIW, Kt/VADW, Kt/BSA, or Kt with TF or mortality.

HIV in the dialysis population: Current issues and future directions

Antiretroviral therapy has significantly reduced mortality due to HIV infection, but the aging HIV‐positive patient population now faces a growing burden of comorbidity. This review describes the changing epidemiology of chronic kidney disease and end‐stage renal disease in this population, and highlights recent advances in antiretroviral therapy and kidney transplantation that directly impact the care of patients with HIV infection and end‐stage renal disease.

Donor-Derived Metastatic Melanoma and Checkpoint Inhibition

Donor-derived malignancy, particularly melanoma, is a rare but known complication of organ transplantation. Here we describe a case of metastatic melanoma in a deceased-donor kidney transplant recipient. After diagnosis, the patient was successfully treated with cessation of immunosuppression, explantation of the renal allograft, and novel melanoma therapies, including the mutation-targeted agents dabrafenib and trametinib and the immune checkpoint inhibitor nivolumab. These 2 new classes of melanoma therapy have revolutionized the course of metastatic melanoma, altering it from one of nearly certain mortality to one of potential cure. This case reviews the mechanisms of action of these therapies and reports our experience with them in the rare setting of donor-derived melanoma in a dialysis-dependent patient.

Association of tenofovir disoproxil fumarate with primary allograft survival in HIV-positive kidney transplant recipients

Tenofovir disoproxil fumarate (TDF) is an antiretroviral agent frequently used to treat human immunodeficiency virus (HIV). There are concerns regarding its potential to cause acute kidney injury, chronic kidney disease, and proximal tubulopathy. Although TDF can effectively suppress HIV after kidney transplantation, it is unknown whether use of TDF‐based antiretroviral therapy (ART) after kidney transplantation adversely affects allograft survival.

Barriers to listing for HIV-infected patients being evaluated for kidney transplantation

Human immunodeficiency virus (HIV)‐infected patients have excellent outcomes following kidney transplantation (KT) but still might face barriers in the evaluation and listing process. The aim of this study was to characterize the patient population, referral patterns, and outcomes of HIV‐infected patients who present for KT evaluation. We performed a single‐center retrospective cohort study of HIV‐infected patients who were evaluated for KT. The primary outcome was time to determination of eligibility for KT. Between 2011 and 2015, 105 HIV‐infected patients were evaluated for KT. Of the 105 patients, 73 were listed for transplantation by the end of the study period. For those who were deemed ineligible, the most common reasons cited were active substance abuse (n = 7, 22%) and failure to complete the full transplant evaluation (n = 7, 22%). Our cohort demonstrated a higher proportion of HIV‐infected patients eligible for KT than in previous studies, likely secondary to advances in HIV management. Among those who were denied access to transplantation, we identified that many were unable to complete the evaluation process, and that active substance abuse was common. Future prospective studies should examine reasons and potential interventions for the lack of follow‐through and drug use we observed in this population.

Management of the Dialysis Patient with Sickle Cell Disease.

While patients with sickle cell disease currently constitute a very small minority of the US dialysis population (0.1%), there is anticipated growth of this group as the life expectancy of those with sickle cell disease (SCD) increases. SCD patients suffer a high burden of morbidity, which is enhanced by the presence of end‐stage renal disease (ESRD). In this review, we discuss the pathophysiology of SCD and the basic tenets of its management with focus on the dialysis patient with SCD. Anemia in dialysis patients with SCD is a unique challenge. The hemoglobin target in SCD dialysis patients with ESRD should not exceed 10 g/dl. SCD patients, and particularly those on dialysis, are likely to be poorly responsive to erythropoietin‐stimulating agent (ESA) therapy and might be at increased risk for vaso‐occlusive crisis (VOC) with ESA. Iron chelation and hydroyxurea therapy require special considerations and modifications in dialysis patients with SCD. There are theoretical advantages to both hemodialysis (HD) and peritoneal dialysis (PD) in SCD patients. With HD, there is a secure vascular access available for both standard and exchange blood transfusion in patients who need them. With PD, the absence of an acute rise in hematocrit with ultrafiltration (UF) might offer lower risk of VOC. During VOC, reduction in UF goals should be considered but administration of intravenous fluids should be reserved only for clear cases of volume depletion. Finally, renal transplantation appears to confer a survival advantage to dialysis in SCD patients and should be pursued when possible.

Association of the kidney allocation system with dialysis exposure before deceased donor kidney transplantation by preemptive wait-listing status

It is unknown whether the new kidney transplant allocation system (KAS) has attenuated the advantages of preemptive wait‐listing as a strategy to minimize pretransplant dialysis exposure.

Kidney Transplantation in HIV-Positive Patients: A Single-Center, 16-Year Experience

Hahnemann University Hospital has performed 120 kidney transplantations in human immunodeficiency virus (HIV)-positive individuals during the last 16 years. Our patient population represents ∼10% of the entire US population of HIV-positive kidney recipients. In our earlier years of HIV transplantation, we noted increased rejection rates, often leading to graft failure. We have established a multidisciplinary team and over the years have made substantial protocol modifications based on lessons learned. These modifications affected our approach to candidate evaluation, donor selection, perioperative immunosuppression, and posttransplantation monitoring and resulted in excellent posttransplantation outcomes, including 100% patient and graft survival at 1 year and patient and graft survival at 3 years of 100% and 96%, respectively. We present key clinical data, including a granular patient-level analysis of the associations of antiretroviral therapy regimens with long-term survival, cellular and antibody-mediated rejection rates, and the causes of allograft failures. In summary, we provide details on the evolution of our approach to HIV transplantation during the last 16 years, including strategies that may improve outcomes among HIV-positive kidney transplantation candidates throughout the United States.