Effect of glecaprevir/pibrentasvir on weight-adjusted tacrolimus trough/dose ratios in heart and kidney transplant recipients.

OBJECTIVE: The pharmacokinetic implications of direct-acting antiviral (DAA) use on tacrolimus posttransplant are unknown. This study sought to investigate the effects of glecaprevir/pibrentasvir (G/P), a CYP3A4 substrate and inhibitor, on weight-adjusted tacrolimus (FK) trough/dose ratio (T/D) following heart or kidney transplantation. MATERIAL AND METHODS: This was a single-center, retrospective analysis of hepatitis C virus (HCV) viremic donors to HCV negative heart or kidney transplant recipients who received 12 weeks of G/P therapy. Weight-adjusted T/D was assessed while patients were at steady-state before, during, and after G/P treatment. Forty-one HCV negative recipients (three heart, 38 kidney) were evaluated. RESULTS: The weight-adjusted T/D significantly increased during G/P treatment (119.31, IQR 88-173.8) compared to before G/P treatment (67.4, IQR 53.4-115.9) (p < 0.01), but decreased after completion of treatment (90.1, IQR 52.9-122.7) (p < 0.01). There was no difference in weight-adjusted T/D before and after G/P treatment (p = 0.42). Four patients experienced acute rejection. CONCLUSION: Initiation of G/P in heart or kidney transplant recipients induces a reversible change in tacrolimus metabolism. A 33%-50% tacrolimus dose reduction may be considered at the time of G/P initiation. Regardless of tacrolimus dose adjustment, tacrolimus trough levels should be monitored 3 days after initiation of G/P. No clear relationship between HCV viremic organ transplantation and rejection risk was found. Larger studies are warranted to validate these findings.

Commercial insurance delays direct-acting antiviral treatment for hepatitis C kidney transplantation into uninfected recipients.

INTRODUCTION: The advent of direct-acting antivirals (DAAs) has created an avenue for transplantation of hepatitis C virus (HCV)-infected donors into uninfected recipients (D+/R-). The donor transmission of HCV is then countered by DAA administration during the post-operative period. However, initiation of DAA treatment is ultimately dictated by insurance companies. METHODS: A retrospective chart review of 52 D+/R- kidney recipients who underwent DAA treatment post-transplant was performed. Patients were grouped according to their prescription coverage plans, managed by either commercial or government pharmacy benefit managers (PBMs). RESULTS: Thirty-nine patients had government PBMs and 13 had commercial PBMs. Demographics were similar between the two groups. All patients developed HCV viremia, but cleared the virus after treatment with DAA. Patients with government PBMs were treated earlier compared to those with commercial PBMs (11 days vs 26 days, P = .01). Longer time to DAA initiation resulted in higher peak viral loads (ß = 0.39, R2  = .15, P = .01) and longer time to HCV viral load clearance (ß = 0.41, R2  = .17, P = .01). CONCLUSIONS: D+/R- transplantation offers patients an alternative strategy to increase access. However, treatment can be profoundly delayed by a third-party payer authorization process that may be subjecting patients to unnecessary risks and worsened outcomes.

COVID-19 infection in kidney transplant recipients at the epicenter of pandemics.

We investigated the prevalence and clinical outcomes of COVID-19 in recipients of kidney transplants in the Bronx, New York, one of the epicenters of the pandemic. Between March 16 and June 2, 2020, 132 kidney transplant recipients tested positive by SARS-CoV-2 RT-PCR. From May 3 to July 29, 2020, 912 kidney transplant recipients were screened for SARS-CoV-2 IgG antibodies during routine clinic visits, of which 16.6% tested positive. Fifty-five of the 152 patients had previously tested positive by RT-PCR, while the remaining 97 did not have significant symptoms and had not been previously tested by RT-PCR. The prevalence of SARS-CoV-2 infection was 23.4% in the 975 patients tested by either RT-PCR or SARS-CoV-2 IgG. Older patients and patients with higher serum creatinine levels were more likely diagnosed by RT-PCR compared to SARS-CoV-2 IgG. Sixty-nine RT-PCR positive patients were screened for SARS-CoV-2 IgG antibodies at a median of 44 days post-diagnosis (Inter Quartile Range 31-58) and 80% were positive. Overall mortality was 20.5% but significantly higher (37.8%) in the patients who required hospitalization. Twenty-three percent of the hospitalized patients required kidney replacement therapy and 6.3% lost their allografts. In multivariable analysis, older age, receipt of deceased-donor transplantation, lack of influenza vaccination in the previous year and higher serum interleukine-6 levels were associated with mortality. Thus, 42% of patients with a kidney transplant and with COVID-19 were diagnosed on antibody testing without significant clinical symptoms; 80% of patients with positive RT-PCR developed SARS-CoV-2 IgG and mortality was high among patients requiring hospitalization.

Transplantation of viral-positive hepatitis C-positive kidneys into uninfected recipients offers an opportunity to increase organ access.

The advent of direct-acting antivirals (DAAs) has provided the impetus to transplant kidneys from hepatitis C virus-positive donors into uninfected recipients (D+/R-). Thirty D+/R- patients received DAA treatment. Sustained virologic response (SVR12) was defined as an undetectable viral load in 12 weeks after treatment. An age-matched cohort of uninfected donor and recipient pairs (D-/R-) transplanted during same time period was used for comparison. The median day of viral detection was postoperative day (POD) 2. The detection of viremia in D+/R- patients was 100%. The initial median viral load was 531 copies/µL (range: 10-1 × 108 copies/µL) with a median peak viral load of 3.4 × 105 copies/µL (range: 804-1.0 × 108 copies/µL). DAAs were initiated on median POD 9 (range: 5-41 days). All 30 patients had confirmed SVR12. During a median follow-up of 10 months, patient and graft survival was 100%, and acute rejection was 6.6% with no major adverse events related to DAA treatment. Delayed graft function was significantly decreased in D+/R- patients as compared to the age-matched cohort (27% vs 60%; P = .01). D+/R- transplantation offers patients an alternative strategy to increase access.

Molecular signatures and clinical outcomes of transplant glomerulopathy stratified by microvascular inflammation and donor-specific antibody.

BACKGROUND: We investigated clinical outcomes and molecular signatures of transplant glomerulopathy (TG) stratified by microvascular inflammation (MVI) and donor-specific antibody (DSA) status. METHODS: We performed a retrospective review of 749 kidney transplant patients who received a for-cause kidney biopsy from 2009 to 2014. We classified TG as MVI positive (MVI+) or MVI negative (MVI-), and with or without DSA. We obtained gene expression profiles for 44 biopsies by Affymetrix HuGene 1.0 ST expression arrays. RESULTS: A total of 100 patients had TG; 49 were MVI+, and 51 were MVI-. After a median post-biopsy follow-up of 2.08 years (range 0.43-4.59), Kaplan-Meier survival analysis demonstrated worse allograft survival in MVI+ TG patients compared with MVI- TG patients (P = 0.01), and time to graft failure was significantly shorter in MVI+ patients (1.08 ± 1.01 years vs 2.3 ± 1.8 years; P = 0.002). DSA status did not affect graft survival within MVI+ or MVI- groups. Analysis of pathogenesis-based transcripts (PBT) showed that MVI+ TG biopsies had increased expression of gamma interferon and rejection (GRIT) and DSA-associated transcripts (DSAST), as observed in antibody-mediated rejection. MVI- TG biopsies had increased expression of cytotoxic and regulatory T cell- and B cell-associated transcripts but not GRIT or DSAST. DSA status had no effect on expression of any PBTs studied in MVI- TG biopsies. CONCLUSIONS: Graft survival in TG is significantly worse in the presence of MVI. Gene expression profiles of MVI+ TG resemble antibody-mediated rejection while gene expression profiles of MVI- TG resemble cell-mediated rejection regardless of DSA status.

Hospital readmissions in diabetic kidney transplant recipients with peripheral vascular disease.

BACKGROUND: The benefits of kidney transplantation in diabetic patients with peripheral vascular disease (PVD) are unclear. While patients may have improved survival compared to dialysis, the burden of care after transplant has not been assessed. METHODS: We performed a retrospective review of adult diabetic kidney-only transplant recipients with and without PVD transplanted from January 2012 until June 30, 2015. RESULTS: Of 203 diabetic kidney transplant recipients, 56 (27.6%) had PVD and 147 (72.4%) had no PVD. At a median of 3.14 years follow-up, there were no significant differences in 30-, 90-, or 1-year readmission rates. At 1 year after transplant, PVD patients were significantly more likely to have a greater sum of unplanned inpatient days (44.6% vs 27.9% with ≥10 inpatient days, P = .03) and at least 1 reoperation (28.6% vs. 8.7%, P < .01). At 1 year post-transplant, there were similar rates of graft-related reoperations; however, patients with PVD had significantly increased rates of non-graft-related operations of which 31.2% were PVD-related. CONCLUSIONS: Diabetic patients with PVD utilize more resources after kidney transplant, spending more time in the hospital and undergoing more post-transplant operations. The causes of readmission are predominantly related to progression of PVD rather than allograft complications.

Improving pancreas graft utilization through importation.

BACKGROUND: We analyze our outcomes utilizing imported allografts as a strategy to shorten wait list time for pancreas transplantation. METHODS: This is an observational retrospective cohort of 26 recipients who received either a locally procured (n = 16) or an imported pancreas graft (n = 10) at our center between January 2014 and May 2017. Wait list times of this cohort were compared to UNOS Region 9 (New York State and Western Vermont). Hospital financial data were also reviewed to analyze the cost-effectiveness of this strategy. RESULTS: Imported pancreas grafts had significantly increased cold ischemia times (CIT) and peak lipase (PL) levels compared to locally procured grafts (CIT 827 vs 497 minutes; P = .001, PL 563 vs 157 u/L; P = .023, respectively). There were no differences in graft or patient survival. The median wait time was significantly lower for simultaneous kidney-pancreas transplants at our center (518 days, n = 21) compared to Region 9 (1001 days, n = 65) P = .038. Despite financial concerns, the cost of transport for imported grafts was offset by lower standard acquisition costs. CONCLUSIONS: Imported pancreas grafts may be a cost-effective strategy to increase organ utilization and shorten wait times in regions with longer waiting times.

The prevalence and clinical significance of C1q-binding donor-specific anti-HLA antibodies early and late after kidney transplantation.

We aimed to determine the prevalence and clinical significance of complement-binding donor-specific antibodies (DSA) detected up to 30 years after kidney transplantation. Group 1 patients included 284 consecutive DSA negative patients who underwent kidney transplantation after 1 May 2009. Group 2 included 405 patients transplanted before this date and followed at our center with functioning allografts. DSA were tested using Luminex Single Antigen and the C1q assay. In Group 1 patients, who were monitored prospectively, 31 (11%) developed de novo DSA during a median follow-up of 2.5 (1.9, 3.6) years. Of these, 11 (4%) had C1q+ and 20 (7%) had C1q negative DSA. In Group 2 patients, 77 (19%) displayed DSA. Among these, 33 (8%) had C1q+ and 44 (11%) had C1q negative DSA. The incidence of acute antibody-mediated rejection (AMR) was significantly higher in C1q+DSA patients in both Group 1 (45%) and Group 2 (15%) compared with C1q negative DSA (5% and 2%) and DSA negative patients (1% and 3%; P < 0.001 and P = 0.001). The incidence of chronic AMR was 36% (Group 1) and 51% (Group 2) in patients with C1q+DSA. In contrast, chronic AMR occurred in 5% and 25% of C1q negative DSA, and 2% and 6% of DSA negative Group 1 and 2 patients, respectively (P < 0.001). Although the graft survival was lower in Group 1 C1q+DSA patients (73%) compared with C1q negative DSA (95%) and DSA negative (94%) patients, the difference was not statistically significant by Kaplan-Meier survival analysis (P = 0.21). Our results indicated that the presence of C1q+ DSA was associated with acute and chronic AMR.

Clinical and molecular significance of microvascular inflammation in transplant kidney biopsies.

The diagnostic criteria for antibody-mediated rejection (AMR) are continuously evolving. Here we investigated the clinical and molecular significance of different Banff microvascular inflammation (MVI) scores in transplant kidney biopsies. A total of 356 patients with clinically indicated kidney transplant biopsies were classified into three groups based on MVI scores of 0, 1, 2, or more for Groups 1-3, respectively. Gene expression profiles were assessed using arrays on a representative subset of 93 patients. The incidence of donor-specific anti-HLA antibodies was increased from 25% in Group 1 to 36% in Group 2 and to 54% in Group 3. Acute and chronic AMR were significantly more frequent in Group 3 (15% and 35%) compared with the Group 2 (3% and 15%) and Group 1 (0% and 5%), respectively. Gene expression profiles showed increased interferon-γ and rejection-induced, cytotoxic and regulatory T-cell, natural killer cell-associated and donor-specific antibody (DSA)-selective transcripts in Group 3 compared with Groups 1 and 2. There was no significant difference in gene expression profiles between the Groups 1 and 2. Increased intragraft expression of DSA-selective transcripts was found in the biopsies of C4d- Group 3 patients. Thus, an MVI score of 2 or more was significantly associated with a histological diagnosis of acute and chronic antibody-mediated rejection. Hence, increased intragraft DSA-selective gene transcripts may be used as molecular markers for AMR, especially in C4d- biopsies.

Pregnancy in sensitized kidney transplant recipients: a single-center experience.

BACKGROUND: We aimed to examine the clinical outcomes of sensitized pregnant kidney transplant recipients. METHODS: A retrospective cohort study of female patients who received kidney transplant at Montefiore transplant center between June 1, 2009 through December 31, 2014 and had a documented pregnancy in our system. RESULTS: We found that 11 women had pregnancies during this period with a median age of 36 yr (range 22, 39). Pregnancies occurred at a median of 3.1 yr (1.1, 8.7) after transplantation. Pre-pregnancy patients' median serum creatinine levels and spot urine protein/creatinine ratio were 1.1 mg/dL (1.1, 2.1) and 0.55 g/d (0, 1.2), respectively. Eight patients were sensitized with panel reactive antibody (PRA) levels > 0% and three had PRA of 0%. The sensitized group had a higher incidence of adverse pregnancy outcomes; one stillbirth and two second trimester miscarriage. During a median follow-up of 2.3 yr (1.2, 4) after delivery, three high PRA patients (37%) developed antibody-mediated rejection that led to graft loss. CONCLUSIONS: We observed an increased risk of rejection, graft loss, and adverse pregnancy outcomes in sensitized kidney recipients.

Kidney transplant complications from undiagnosed benign prostatic hypertrophy.

BACKGROUND: It is estimated that approximately 50% of males over 50 have benign prostatic hypertrophy (BPH). BPH is underappreciated in anuric patients with end stage renal disease, and failure of diagnosis in this population can lead to complications after kidney transplantation. METHODS: A single-center retrospective review of male patients over 50 yr of age transplanted from January 1, 2010, until September 30, 2013, was performed. Outcomes assessed were as follows: graft survival, urinary retention, discharge with Foley catheter, and urinary tract infection (UTI). RESULTS: Of 147 patients, 17.0% were diagnosed with BPH before transplant, 19.0% received a BPH diagnosis after transplant, and 64% did not have BPH. Compared to those without BPH, a post-transplant BPH diagnosis was associated with urinary retention during the transplant admission (0% vs. 46.4%, p < 0.01), discharge with Foley catheter (0% vs. 21.4%, p < 0.01), readmission related to urinary retention (0% vs. 46.4%, p < 0.01), and UTI (18.0% vs. 64.3%, p < 0.01). Patients with prior diagnosis of BPH and on therapy had similar outcomes to those without BPH. CONCLUSIONS: Following kidney transplant, urinary tract complications are more common in patients with BPH; however, being on medical therapy prior to transplantation diminishes the incidence of these complications significantly.

Kidney transplantation in patients with severe preoperative hypertension.

BACKGROUND: Severe systemic hypertension (HTN) is a risk factor for perioperative cardiovascular complications; however, its impact at the time of kidney transplantation (KTX) is not well defined. METHODS: A retrospective cohort study of adult kidney-only transplant recipients between October 2009 and December 2012 was performed to examine outcomes between patients with (n = 111) and without (n = 98) severe preoperative HTN defined as SBP > 180 or DBP > 110 mmHg. RESULTS: Recipients with severe HTN were older (56.7 ± 13.0 vs. 53.5 ± 12.4 yr, p = 0.07) and significantly more likely to receive an expanded criteria donor kidney (32.7% vs. 12.2%, p = 0.02). No patients developed hypertensive crisis, intracranial hemorrhage, or life threatening ventricular arrhythmias within 30 d post-transplantation; however, three patients with severe HTN had cardiac events: two with demand ischemia and one with decompensate heart failure. Two patients in the control group had decompensated heart failure. There were no differences between the groups in terms of cardiac event (2.7% vs. 2.0%, p = 0.75), one-yr patient survival (98.2% vs. 98.0%, p = 0.90) or graft survival (90.1% vs. 92.9%, p = 0.48), nadir creatinine > 2 mg/dL (4.6% vs. 6.2%, p = 0.62), length of stay > 6 d (37.8% vs. 35.7%, p = 0.75), and DGF (52.3% vs. 63.3%, p = 0.11). CONCLUSIONS: Our results suggest that severe preoperative HTN should not be considered an absolute contraindication to kidney transplant in patients who are otherwise clinically stable.

Increased intragraft rejection-associated gene transcripts in patients with donor-specific antibodies and normal biopsies.

We investigated why some donor-specific antibody-positive patients do not develop antibody-mediated rejection. Of 71 donor-specific antibody-positive patients, 46 had diagnosis of antibody-mediated rejection and 25 had normal biopsies. Fifty donor-specific antibody-negative patients with normal biopsies were used as a control group. A subgroup of 61 patients with available biopsy and 64 with blood samples were analyzed by microarrays. Both donor-specific antibody-positive/antibody-mediated rejection-positive and negative biopsies showed increased expression of gene transcripts associated with cytotoxic T cells, natural killer cells, macrophages, interferon-gamma, and rejection compared to donor-specific antibody-negative biopsies. Regulatory T-cell transcripts were upregulated in donor-specific antibody-positive/antibody-mediated rejection-positive and B-cell transcripts in donor-specific antibody-positive/antibody-mediated rejection-negative biopsies. Whole-blood gene expression analysis showed increased immune activity in only donor-specific antibody-positive/antibody-mediated rejection-positive but not negative patients. During a median follow-up of 36 months, 4 donor-specific antibody-positive/antibody-mediated rejection-negative patients developed antibody-mediated rejection, 12 continued to have donor-specific antibody, but 9 lost their donor-specific antibody. Gene expression profiles did not predict the development of antibody-mediated rejection or the persistence of donor-specific antibody. Thus, donor-specific antibody-positive/antibody-mediated rejection-negative patients had increased rejection-associated gene transcripts in their allografts despite no histologic findings of rejection but not in their blood. This was found in both biopsy and blood samples of donor-specific antibody-positive/antibody-mediated rejection-positive patients.

Novel Potassium Binders for Early Postoperative Hyperkalemia in Kidney Transplant Recipients: A Single-Center Experience.

PURPOSE: Evaluate the safety/efficacy of novel potassium binders (patiromer, sodium zirconium cyclosilicate [SZ-9]) for early postoperative hyperkalemia following kidney transplantation. METHODS: Retrospective, single-center, cohort study of deceased-donor kidney recipients transplanted between 1/2018 and 12/2020. Potassium-binder use was evaluated from immediately posttransplant until discharge. Potassium binders were administered ≥2 hours before/after medications. RESULTS: A total of 179 patients were included, 24 (13%) of whom received potassium binders (16 [67%] patiromer, 7 [29%] SZ-9, 1 [4%] both) for a mean of 2.5 (±3.18) doses. Peak potassium levels were higher in the potassium-binder group (6.05 vs 5.35 mEq/L; P < .001). More patients on potassium binders transitioned to atovaquone than those on no binders (n = 21 [100%] vs n = 112 [75%], respectively; P = .005). Delayed graft function (DGF) was observed in 100 (56%) patients, with a higher proportion receiving potassium binders (18 [75%] vs 82 [53%], respectively; P = .042). There was no difference between groups in number of posttransplant dialysis sessions required in the general study population (P = .2), nor in the DGF group (P = .12). No difference was noted in the incidence of ileus (P = .2), or gastrointestinal symptoms (diarrhea, nausea, vomiting; P = .6). Of the 24 patients who received inpatient binders, 9 (37.5%) were discharged and remained on them for a mean of 46 (±49) days. CONCLUSION: Patiromer and SZ-9 appear safe in the early posttransplant period, but larger prospective trials are needed. Potassium-binder use does not appear to be associated with fewer dialysis sessions in DGF patients, however, they may be used as additional tools for lowering potassium in these patients.

Campath induction in HCV and HCV/HIV-seropositive kidney transplant recipients.

Alemtuzumab (AZ) induction in hepatitis C-seropositive (HCV+) kidney transplant (KTX) recipients may negatively affect patient survival; however, available information is scant. Using US registry data from 2003 to 2010 of adult HCV+ deceased-donor KTXs (n = 4910), we examined outcomes by induction agent - AZ (n = 294), other T cell-depleting agents, (n = 2033; T cell), IL-2 receptor blockade (n = 1135; IL-2RAb), and no induction (n = 1448). On multivariate analysis, induction therapy was associated with significantly better overall patient survival with AZ [adjusted hazards ratio (aHR) 0.64, 95% confidence interval (CI) 0.45, 0.92], T cell (aHR 0.52, 95% CI 0.41, 0.65) or IL-2RAb (aHR 0.67, 95% CI 0.53, 0.87), compared to no induction. A significant protective effect was also seen with AZ (aHR 0.63, 95% CI 0.40, 0.99), T cell (aHR 0.62, 95% CI 0.49, 0.78), and IL2R-Ab (aHR 0.62, 95% CI 0.47, 0.82) in terms of death-censored graft survival relative to no induction. There were 88 HIV+/HCV+ coinfected recipients. Compared to noninduction, any induction (i.e. three induction groups combined) was associated with similar overall patient survival (P = 0.2255) on univariate analysis. Induction therapy with AZ, other T cell-depleting agents, or IL-2RAb in HCV+ KTX is associated with better patient and death-censored graft survival compared to noninduction. In HCV/HIV coinfected patients, induction is not contraindicated.

Risks and Benefits of Kidney Transplantation during the COVID-19 Pandemic: Transplant or Not Transplant?

COVID-19 has significantly affected the transplant community, by leading to decreased transplant activity and increased waiting list time. As expected, COVID-19 causes substantial mortality in both ESKD and kidney transplant populations. This is due to underlying CKD and a high prevalence of comorbid conditions, such as diabetes mellitus, hypertension, and cardiovascular disease in this group. Transplant programs have faced the difficult decision of weighing the risks and benefits of transplantation during the pandemic. On one hand, there is a risk of COVID-19 exposure leading to infection while patients are on maximum immunosuppression. Alternatively, there are risks of delaying transplantation, which will increase waitlist times and may lead to waitlist-associated morbidity and mortality. Cautious and thoughtful selection of both the recipient's and donor's post-transplant management has been required during the pandemic, to mitigate the risk of morbidity and mortality associated with COVID-19. In this review article, we aimed to discuss previous publications related to clinical outcomes of COVID-19 disease in kidney transplant recipients, patients with ESKD on dialysis, or on the transplant waiting list, and the precautions transplant centers should take in decision making for recipient and donor selection and immunosuppressive management during the pandemic. Nevertheless, transplantation in this milieu does seem to be the correct decision, with careful patient and donor selection and safeguard protocols for infection prevention. Each center should conduct risk assessment on the basis of the patient's age and medical comorbidities, waitlist time, degree of sensitization, cold ischemia time, status of vaccination, and severity of pandemic in their region.