Remnant cholesterol is prospectively associated with cardiovascular disease events and all-cause mortality in kidney transplant recipients: the FAVORIT study.

BACKGROUND: The cholesterol content of circulating triglyceride-rich lipoproteins is characterized as remnant cholesterol, although little is known about its role in the development of cardiovascular disease (CVD) outcomes, all-cause mortality or transplant failure in kidney transplant recipients (KTRs). Our primary aim was to investigate the prospective association of remnant cholesterol and the risk of CVD events in renal transplant recipients with secondary aims evaluating remnant cholesterol and renal graft failure and all-cause mortality among participants in the Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) trial. METHODS: Among 4110 enrolled participants, 98 were excluded for missing baseline remnant cholesterol levels and covariates. Nonfasting remnant cholesterol levels were calculated based on the lipid profiles in 3812 FAVORIT trial participants at randomization. A Wilcoxon-type test for trend was used to compare baseline characteristics across remnant cholesterol quartiles. Cox proportional hazards regression was used to evaluate the association of baseline remnant cholesterol levels with time to primary and secondary study outcomes. RESULTS: During a median follow-up of 4.0 years we documented 548 CVD incident events, 343 transplant failures and 452 all-cause deaths. When comparing the highest quartile (quartile 4) to quartile 1, proportional hazard modeling revealed a significant increase in CVD risk {hazard ratio [HR] 1.32 [95% confidence interval (CI) 1.04-1.67]} and all-cause mortality risk [HR 1.34 (95% CI 1.01-1.69)]. A nonsignificant increase in transplant failure was seen as well [HR 1.20 (95% CI 0.87-1.64)]. CONCLUSIONS: Remnant cholesterol is associated with CVD and all-cause mortality in long-term KTRs. A randomized controlled clinical trial in KTRs that assesses the potential impact of remnant cholesterol-lowering therapy on these outcomes may be warranted.

Elevated Tacrolimus Levels at Time of Diagnosis of COVID-19 Compared to Baseline Among Hospitalized Organ Transplant Recipients.

BACKGROUND: The effect of COVID-19 on immunosuppressant drug levels in organ transplant recipients (OTRs) has not been adequately studied. OBJECTIVE: To study the effect of COVID-19 on tacrolimus trough levels (primary outcome) in OTRs and the association of the later with acute kidney injury, bacterial infection, and oxygen requirements. METHODS: We studied adult (>18-year-old) hospitalized OTRs with COVID-19, who were receiving tacrolimus between 3/1 and 12/16/2020. RESULTS: Among 30 OTRs, 67% were men, 90% had a kidney transplant. Median age was 60.5 (interquartile range [IQR]: 45-68) years, median time from transplant 36 (IQR: 20-84) months. Tacrolimus troughs were higher on admission for COVID-19 than baseline (average over 6 months prior) (P = .001). Eighteen patients (60%) had admission tacrolimus trough >10, 5 (17%) >20 ng/mL. Patients with diarrhea had borderline higher tacrolimus troughs, compared to those without diarrhea (P = .09). Organ transplant recipients with a tacrolimus trough >10 ng/mL were more likely to have elevated aspartate aminotransferase on admission (P = .01) and require supplemental oxygen. (P = .026). CONCLUSION AND RELEVANCE: Tacrolimus trough levels were elevated in most OTRs with COVID-19 at the time of hospital admission, compared to baseline. Potential mechanisms are diarrhea and hepatic involvement in COVID-19. In OTRs with COVID-19, including outpatients, immunosuppressant drug levels should be closely followed; management of immunosuppression should be individualized.

Successful recovery from COVID-19 in three kidney transplant recipients who received convalescent plasma therapy.

Novel coronavirus disease 2019 (COVID-19) is a highly infectious, rapidly spreading viral disease that typically presents with greater severity in patients with underlying medical conditions or those who are immunosuppressed. We present a novel case series of three kidney transplant recipients with COVID-19 who recovered after receiving COVID-19 convalescent plasma (CCP) therapy. Physicians should be aware of this potentially useful treatment option. Larger clinical registries and randomized clinical trials should be conducted to further explore the clinical and allograft outcomes associated with CCP use in this population.

A single-center analysis of early readmission after renal transplantation.

BACKGROUND: Thirty-day readmission rates (early hospital readmission, EHR) are an important benchmark for quality improvement. Nationally, patients undergoing renal transplantation incur a 31% EHR rate. While national databases provide useful data, the impact of EHR on individual centers has received little attention. We proposed that an institutional review of EHR after renal transplantation may provide a benchmark for individual transplant programs and identify modifiable program-specific issues to reduce EHR. METHODS: We reviewed 269 consecutive kidney transplant recipients over a five-year period (2012-2016). Early hospital readmission was modeled using generalized linear modeling assuming a binary distribution. RESULTS: About 21% of patients were readmitted within 30 days. Deceased kidney donation (DD), delayed graft functioning (DGF), anti-thymocyte globulin (ATG) induction, diabetes, public insurance, weekend discharge, and low glomerular filtration rate (eGFR) at discharge were all identified as risk factors for readmission. Early hospital readmission was not correlated with risk of death (5.4% at 44 months: HR 2.2 (95% CI [0.7, 6.6]; P = 0.1473) or graft loss. CONCLUSIONS: EHR after renal transplantation is common. Certain factors may predict an increased risk for EHR. A multi-disciplinary approach to discharge planning may limit some EHR, but most complications and adverse events are unpredictable and require hospital-level of care.

Serum Calcification Propensity and Fetuin-A: Biomarkers of Cardiovascular Disease in Kidney Transplant Recipients.

BACKGROUND: "T50," shortened transformation time from primary to secondary calciprotein particles may reflect deranged mineral metabolism predisposing to vascular calcification and cardiovascular disease (CVD). The glycoprotein fetuin-A is a major T50 determinant. METHODS: The Folic Acid For Vascular Outcome Prevention In Transplantation (FAVORIT) cohort is a completed, large, multiethnic controlled clinical trial cohort of chronic, stable kidney transplant recipients (KTRs). We conducted a longitudinal case-cohort analysis using a randomly selected subcohort of patients, and all individual cases who developed CVD. Serum T50 and fetuin-A were determined in this total of n = 685 FAVORIT trial participants at randomization. RESULTS: During a median surveillance of 2.18-years, 311 incident or recurrent CVD events occurred. Shorter T50 (minutes) or reduced fetuin-A concentrations (g/L) were associated with CVD after adjustment for treatment assignment, systolic blood pressure, age, sex, race, preexisting CVD and diabetes, smoking, body mass index, total cholesterol/HDL cholesterol, kidney allograft vintage and type, calcineurin inhibitor, or lipid-lowering drug use, estimated glomerular filtration rate, and urinary albumin/creatinine: tertile 1 (lowest) to tertile 3 (highest) comparisons, T50, (hazard ratio [HR] 1.86; 95% CI 1.20-2.89); fetuin-A, (HR 2.25; 95% CI 1.38-3.69). Elevated high sensitivity c-reactive protein (hsCRP) was an effect modifier of both these associations. CONCLUSIONS: Shortened T50, as well as reduced fetuin-A levels, ostensible promoters of vascular calcification, remained associated with greater risk for CVD outcomes, after adjustment for major CVD risk factors, measures of kidney function and damage, and KTR clinical characteristics and demographics, in a large, multiethnic cohort of long-term KTRs. Increased hsCRP was an effect modifier of these CVD risk associations.

Serum Phosphorus and Risk of Cardiovascular Disease, All-Cause Mortality, or Graft Failure in Kidney Transplant Recipients: An Ancillary Study of the FAVORIT Trial Cohort.

BACKGROUND: Mild hyperphosphatemia is a putative risk factor for cardiovascular disease [CVD], loss of kidney function, and mortality. Very limited data are available from sizable multicenter kidney transplant recipient (KTR) cohorts assessing the potential relationships between serum phosphorus levels and the development of CVD outcomes, transplant failure, or all-cause mortality. STUDY DESIGN: Cohort study. SETTING & PARTICIPANTS: The Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) Trial, a large, multicenter, multiethnic, controlled clinical trial that provided definitive evidence that high-dose vitamin B-based lowering of plasma homocysteine levels did not reduce CVD events, transplant failure, or total mortality in stable KTRs. PREDICTOR: Serum phosphorus levels were determined in 3,138 FAVORIT trial participants at randomization. RESULTS: During a median follow-up of 4.0 years, the cohort had 436 CVD events, 238 transplant failures, and 348 deaths. Proportional hazards modeling revealed that each 1-mg/dL higher serum phosphorus level was not associated with a significant increase in CVD risk (HR, 1.06; 95% CI, 0.92-1.22), but increased transplant failure (HR, 1.36; 95% CI, 1.15-1.62) and total mortality risk associations (HR, 1.21; 95% CI, 1.04-1.40) when adjusted for treatment allocation, traditional CVD risk factors, kidney measures, type of kidney transplant, transplant vintage, and use of calcineurin inhibitors, steroids, or lipid-lowering drugs. These associations were strengthened in models without kidney measures: CVD (HR, 1.14; 95% CI, 1.00-1.31), transplant failure (HR, 1.72; 95% CI, 1.46-2.01), and mortality (HR, 1.34; 95% CI, 1.15-1.54). LIMITATIONS: We lacked data for concentrations of parathyroid hormone, fibroblast growth factor 23, or vitamin D metabolites. CONCLUSIONS: Serum phosphorus level is marginally associated with CVD and more strongly associated with transplant failure and total mortality in long-term KTRs. A randomized controlled clinical trial in KTRs that assesses the potential impact of phosphorus-lowering therapy on these hard outcomes may be warranted.

Unexpected Medical Conditions Discovered During Live Donor Kidney Evaluation: Single Center Study.

OBJECTIVES: Living donor kidney transplantation (LDKT) is the preferred method of treatment for patients with end-stage kidney disease. Potential living kidney donors (PLKD) are evaluated through a thorough medical, psychological and surgical work-up to ensure successful transplantation with minimal risks to all parties involved. The transplant center at Rhode Island Hospital has noticed an increasing number of PLKDs excluded from donation due to conditions newly diagnosed during the screening process. Our objective is to understand the local trends underlying the high PLKD exclusion rates in the context of newly diagnosed conditions, age, race, and sex of the excluded donors. STUDY DESIGN AND METHODS: Our study is a retrospective electronic medical record review of the 429 PLKDs screened at Rhode Island Hospital Kidney Transplant Center between December 2012 and April 2023. Age, race, gender, relationship to recipient, and reasons for exclusion were collected from the medical record for each PLKD. CONCLUSION: 115 of the 429 total PLKDs screened were excluded for newly diagnosed conditions, the most common of which were renal issues (49%), diabetes mellitus (33%), and hypertension (13%), with many comorbid diagnoses. While these donors were able to receive proper treatment after their diagnosis, the earliest intervention possible yields the best prognosis. The high prevalence of treatable yet undiagnosed conditions raise many public health concerns, such as primary care gaps or discontinuous healthcare, and increases awareness about the importance of follow-up care for the excluded PLKDs.

Obstructive Uropathy due to Bilateral Sliding Hernia in a Renal Transplant Patient with Incidental RCC in Native Kidney.

BACKGROUND: Ureteral obstruction is a common complication after kidney transplantation. Ureteral obstruction caused by inguinal hernia, however, is a rare complication of transplantation and requires urgent surgical repair to prevent allograft loss.  Case presentation: A 58-year-old man presented with allograft dysfunction 18-years after renal transplant. He was compliant with medications and given the long duration of allograft survival, a primary renal etiology was suspected. Thus, the initial work-up included allograft biopsy that was unremarkable. Three months later, worsening allograft function prompted further evaluation. At this time, allograft ultrasound and computed tomography led to the diagnosis of ureteral obstruction due to uretero-inguinal herniation of left kidney transplant secondary to bilateral sliding inguinal hernias. The patient was also found to have incidental renal cell carcinoma of the left native kidney. A percutaneous nephrostomy tube was placed and then followed by surgical repair with ureteral reimplantation, herniorrhaphy with mesh, and left native nephrectomy. CONCLUSIONS: Mechanical obstruction can occur years after kidney transplantation. Even though it is uncommon, ureteral obstruction due to inguinal herniation is critical. Early detection of this complication and surgery can salvage the allograft and prolong function. ABBREVIATIONS: RCC: renal cell carcinoma; PCN: Percutaneous Nephrostomy; ACKD: Acquired Cystic Kidney Disease.

Hypertension: Are Current Guidelines Inclusive of Sex and Gender?

Background: Hypertension (HTN) accounts for one in five deaths of American women. Major societies worldwide aim to make evidence-based recommendations for HTN management. Sex- or gender-based differences exist in epidemiology and management of HTN; in this study, we aimed to assess sex- and gender-based language in major society guidelines. Materials and Methods: We reviewed HTN guidelines from four societies: the American College of Cardiology (ACC), the American College of Emergency Physicians (ACEP), the European Society of Cardiology (ESC), and the Eighth Joint National Committee (JNC8). We quantified the sex- and gender-based medicine (SGBM) content by word count in each guideline as well as identified the gender of guideline authors. Results: Two of the four HTN guidelines (ACC, ESC) included SGBM content. Of these two guidelines, there were variations in the quantity and depth of content coverage. Pregnancy had the highest word count found in both guidelines (422 words in ACC and 1,523 words in ESC), which represented 2.45% and 3.04% of the total words in each guideline, respectively. There was minimal coverage, if any, of any other life periods. The number of women authors did not impact the SGBM content within a given guideline. Conclusions: Current HTN management guidelines do not provide optimal guidance on sex- and gender-based differences. Inclusion of sex, gender identity, hormone therapy, pregnancy and lactation status, menopause, and advanced age in future research will be critical to bridge the current evidence gap. Guideline writing committees should include diverse perspectives, including cisgender and transgender persons from diverse racial and ethnic backgrounds.

Low-Dose Valganciclovir Prophylaxis Is Safe and Cost-Saving in CMV-Seropositive Kidney Transplant Recipients.

Introduction: Observational studies suggest that low-dose valganciclovir prophylaxis (450 mg daily for normal renal function) is as effective as and perhaps safer than standard-dose valganciclovir (900 mg daily) in preventing CMV infection among kidney transplant recipients. However, this practice is not supported by current guidelines due to concerns for breakthrough infection from resistant CMV, mainly in high-risk CMV donor-seropositive/recipient-seronegative kidney transplant recipients. Standard-dose valganciclovir is costly and possibly associated with higher incidence of neutropenia and BKV DNAemia. Our institution adopted low-dose valganciclovir prophylaxis for intermediate-risk (seropositive) kidney transplant recipients in January 2018. Research Question: To analyze the efficacy (CMV DNAemia), safety (BK virus DNAemia, neutropenia, graft loss, and death), and cost savings associated with this change. Design: We retrospectively compared the above outcomes between CMV-seropositive kidney transplant recipients who received low-dose and standard-dose valganciclovir, transplanted within our institution, between 1/19/2014 and 7/15/2019, using propensity score-adjusted competing risk analyses. We also compared cost estimates between the two dosing regimens, for 3 months of prophylaxis, and for different percentage of patient-weeks with normal renal function, using the current average wholesale price of valganciclovir. Results: We studied 179 CMV-seropositive kidney transplant recipients, of whom 55 received low-dose and 124 standard-dose valganciclovir. The majority received nonlymphocyte depleting induction (basiliximab). Low-dose valganciclovir was at least as effective and safe as, and more cost-saving than standard-dose valganciclovir. Conclusion: This single-center study contributes to mounting evidence for future guidelines to be adjusted in favor of low-dose valganciclovir prophylaxis in CMV-seropositive kidney transplant recipients.

Coronavirus Disease 2019 in Kidney Transplant Recipients: Single-Center Experience and Case-Control Study.

BACKGROUND: Kidney transplant recipients (KTR) are considered high-risk for morbidity and mortality from coronavirus disease 2019 (COVID-19). However, some studies did not show worse outcomes compared to non-transplant patients and there is little data about immunosuppressant drug levels and secondary infections in KTR with COVID-19. Herein, we describe our single-center experience with COVID-19 in KTR. METHODS: We captured KTR diagnosed with COVID-19 between March 1, 2020 and May 18, 2020. After exclusion of KTR on hemodialysis and off immunosuppression, we compared the clinical course of COVID-19 between hospitalized KTR and non-transplant patients, matched by age and sex (controls). RESULTS: Eleven KTR were hospitalized and matched with 44 controls. One KTR and 4 controls died (case fatality rate: 9.1%). There were no significant differences in length of stay or clinical outcomes between KTR and controls. Tacrolimus or sirolimus levels were >10 ng/mL in 6 out of 9 KTR (67%). Bacterial infections were more frequent in KTR (36.3%), compared with controls (6.8%, P = .02). CONCLUSIONS: In our small case series, unlike earlier reports from the pandemic epicenters, the clinical outcomes of KTR with COVID-19 were comparable to those of non-transplant patients. Calcineurin or mammalian target of rapamycin inhibitor (mTOR) levels were high. Bacterial infections were more common in KTR, compared with controls.

Undiagnosed fibromuscular dysplasia in a deceased donor kidney transplant successfully treated with angioplasty.

A 41-year-old man with end-stage renal disease received a deceased donor kidney transplant without complication. Maintenance immunosuppression consisted of tacrolimus, mycophenolate and prednisone. Two months after transplantation, his creatinine did not improve beyond 2-2.3 mg/dL, which prompted allograft biopsy. His biopsy showed tubular epithelial injury without rejection, and given concern for possible calcineurin-inhibitor toxicity, his tacrolimus was changed to sirolimus. Renal function improved, but 1 month later he presented to the hospital with seizure activity, severe hypertension, acute kidney injury and MRI findings suggestive of posterior reversible encephalopathy syndrome. Blood pressure was difficult to control, which had not been the case in the immediate posttransplant period, and addition of lisinopril worsened his renal function. Transplant renal artery stenosis was suspected, and allograft ultrasound with doppler confirmed our suspicion. The patient underwent an angiogram, showing 60% stenosis of the mid-distal transplanted renal artery. Interventional radiology successfully stented this lesion, with subsequent improvement in allograft function and blood pressure control. He did not require further intervention in follow-up.

Management of uncommon disorders in pregnancy: Von Hippel-Lindau disease, Gitelman syndrome, and Nutcracker syndrome.

Uncommon renal disorders in pregnancy can be challenging to manage given limited evidence in the literature to guide management. We present a series of three uncommon renal disorders in pregnancy: Von Hippel-Lindau disease, Gitelman syndrome, and Nutcracker syndrome. Previously published case reports with differing outcomes offer some guidance to the management of these disorders in pregnancy. In this case series, we address the management of these syndromes during pregnancy and discuss the maternal and fetal outcomes. All three of our patients had good maternal and fetal outcomes, which will contribute to current data on maternal and fetal outcomes in these rare diseases, which is limited.

Proliferative glomerulonephritis with monoclonal IgG deposits in two kidney allografts successfully treated with rituximab.

Proliferative glomerulonephritis with monoclonal immunoglobulin G deposit (PGNMID), a recently described pathologic entity in native kidneys, has been recognized in kidney transplant patients, where it can present as either recurrent or de novo disease. There is no definitive treatment to date, in either population. Here, we present two cases of PGNMID in kidney allografts that illustrate the challenges of diagnostic approach and highlight the allograft outcome after treatment with rituximab as a potential treatment of this condition.

Does size matter? Kidney transplant donor size determines kidney function among living donors.

BACKGROUND: Kidney donor outcomes are gaining attention, particularly as donor eligibility criteria continue to expand. Kidney size, a useful predictor of recipient kidney function, also likely correlates with donor outcomes. Although donor evaluation includes donor kidney size measurements, the association between kidney size and outcomes are poorly defined. METHODS: We examined the relationship between kidney size (body surface area-adjusted total volume, cortical volume and length) and renal outcomes (post-operative recovery and longer-term kidney function) among 85 kidney donors using general linear models and time-to-chronic kidney disease data. RESULTS: Donors with the largest adjusted cortical volume were more likely to achieve an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 over a median 24-month follow-up than those with smaller cortical volumes (P <0.001), had a shorter duration of renal recovery (1.3-2.2 versus 32.5 days) and started with a higher eGFR at pre-donation (107-110 versus 91 mL/min/1.73 m2) and immediately post-nephrectomy (∼63 versus 50-51 mL/min/1.73 m2). Similar findings were seen with adjusted total volume and length. CONCLUSIONS: Larger kidney donors were more likely to achieve an eGFR ≥60 mL/min/1.73 m2 with renal recovery over a shorter duration due to higher pre-donation and initial post-nephrectomy eGFRs.

More than skin deep? Potential nicotinamide treatment applications in chronic kidney transplant recipients.

Non-melanoma cutaneous carcinomas, or skin cancers, predominantly squamous cell carcinomas (SCCs), are the most common malignancies occurring in kidney transplant recipients (KTRs). Squamous cell carcinoma risk is dramatically elevated in KTRs, occurring at rates of up 45-250 times those reported in general populations. New non-melanoma skin cancers in KTRs with a prior non-melanoma skin cancer also develop at 3-times the rate reported in non-KTRs with the same clinical history. The unique aggressiveness of SCCs in KTRs increases patient morbidity, due to the high rate of new lesions requiring treatment, frequently surgical excision. Oral nicotinamide shows promise in the chemoprevention of the especially aggressive non-melanoma skin cancers which occur in KTRs. This benefit might be conferred via its inhibition of sirtuin enzymatic pathways. Nicotinamide's concurrent hypophosphatemic effect may also partially ameliorate the disturbed calcium-phosphorus homeostasis in these patients-a putative risk factor for mortality, and graft failure. Conceivably, a phase 3 trial of nicotinamide for the prevention of non-melanoma skin cancers in KTRs, lasting at least 12-mo, could also incorporate imaging and laboratory measures which assess nicotinamide's impact on subclinical cardiovascular and chronic kidney disease risk, and progression.

Role for urinary biomarkers in diagnosis of acute rejection in the transplanted kidney.

Despite the introduction of potent immunosuppressive medications within recent decades, acute rejection still accounts for up to 12% of all graft losses, and is generally associated with an increased risk of late graft failure. Current detection of acute rejection relies on frequent monitoring of the serum creatinine followed by a diagnostic renal biopsy. This strategy is flawed since an alteration in the serum creatinine is a late clinical event and significant irreversible histologic damage has often already occurred. Furthermore, biopsies are invasive procedures that carry their own inherent risk. The discovery of non-invasive urinary biomarkers to help diagnose acute rejection has been the subject of a significant amount of investigation. We review the literature on urinary biomarkers here, focusing on specific markers perforin and granzyme B mRNAs, FOXP3 mRNA, CXCL9/CXCL10 and miRNAs. These and other biomarkers are not yet widely used in clinical settings, but our review of the literature suggests that biomarkers may correlate with biopsy findings and provide an important early indicator of rejection, allowing more rapid treatment and better graft survival.