Utilization of HCV viremic donors in kidney transplantation: a chance or a threat?

Kidney transplantation is the treatment of choice in end-stage renal disease. The main issue which does not allow to utilize it fully is the number of organs available for transplant. Introduction of highly effective oral direct-acting antivirals (DAAs) to the treatment of chronic hepatitis C virus infection (HCV) enabled transplantation of HCV viremic organs to naive recipients. Despite an increasing number of reports on the satisfying effects of using HCV viremic organs, including kidneys, they are more often rejected than those from HCV negative donors. The main reason is the presence of HCV viremia and not the quality of the organ. The current state of knowledge points to the fact that a kidney transplant from an HCV nucleic acid testing positive (NAT+) donor to naive recipients is an effective and safe solution to the problem of the insufficient number of organs available for transplantation. It does not, however, allow to draw conclusions as to the long-term consequence of such an approach. This review analyzes the possibilities and limitations of the usage of HCV NAT + donor organs. Abbreviations: DAA: direct-acting antivirals; HCV: hepatitis C virus; NAT: nucleic acid testing; OPTN: Organ Procurement and Transplantation Network; KDIGO: Kidney Disease: Improving Global Outcomes; Ab: antigen; eGFR: estimated glomerular filtration rate; D: donor; R: recipient; CMV: cytomegalovirus; HBV: hepatitis B virus; UNOS: United Network for Organ Sharing; PHS: Public Health Service; EBR/GZR: elbasvir/grazoprevir; SVR: sustained virologic response; RAS: resistance-associated substitutions; SOF: soforbuvir; GLE/PIB: glecaprevir/pibrentasvir; ACR: acute cellular rejection; AR: acute rejection; DSA: donor-specific antibodies; KTR: kidney transplant recipients; AASLD: American Association for the Study of Liver Disease; IDSA: Infectious Diseases Society of America; PPI: proton pump inhibitors; CKD: chronic kidney disease; GN: glomerulonephritis; KAS: The Kidney Allocation system.

Lung transplant after 6 months on ECMO support for SARS-CoV-2-induced ARDS complicated by severe antibody-mediated rejection.

There have been a few reports of successful lung transplantation (LTx) in patients with SARS-CoV-2-induced acute respiratory distress syndrome (ARDS); however, all reports were with rather short follow-up. Here we present a 62-year-old man without prior lung diseases. Following SARS-CoV-2-induced ARDS and 6 months of extracorporeal membrane oxygenation, he underwent LTx. 3 months post-transplantation he developed acute hypoxia requiring emergency intubation. Chest imaging showed acute rejection, and de novo DQ8-DSA was discovered. He was treated with a high dose of corticosteroids and plasmapheresis and was extubated 4 days later, yet the de novo DQ8-DSA remained. After sessions of plasmapheresis and rituximab, the levels of de novo DQ8-DSA remained unchanged. Nine months post-transplantation the patient died of respiratory failure. We herein discuss the decision to transplant, the transplantation itself and the postoperative course with severe antibody-mediated rejection. In addition, we evaluated the histological changes of the explanted lungs and compared these with end-stage idiopathic pulmonary fibrosis tissue, where both similarities and differences are seen. With the current case experience, one might consider close monitoring regarding DSA, and gives further support that LTx should only be considered for very carefully selected patients.

Case Report: Convalescent Plasma Achieves SARS-CoV-2 Viral Clearance in a Patient With Persistently High Viral Replication Over 8 Weeks Due to Severe Combined Immunodeficiency (SCID) and Graft Failure.

We describe the unique disease course and cure of SARS-CoV-2 infection in a patient with SCID and graft failure. In absence of a humoral immune response, viral clearance was only achieved after transfusion of convalescent plasma. This observation underscores the necessity of the humoral immune response for SARS-CoV-2 clearance.

Role of CMV chemokine receptor M33 in airway graft rejection in a mouse transplant model.

BACKGROUND: Cytomegalovirus (CMV) infection is a risk factor for bronchiolitis obliterans (BO), one form of chronic lung allograft dysfunction (CLAD). The viral chemokine receptor M33 is essential for successful spread of murine CMV to host salivary glands. In the present study we investigated the impact of M33 on chronic airway rejection. METHODS: MHC I-mismatched tracheas of C·B10-H2b/LilMcdJ mice were transplanted into BALB/c (H2d) recipients and infected at different dates with wild type (WT) or M33-deleted (delM33) MCMV representing clinical settings of viral recipient (R)-donor (D)-serostatus: (D-/R+) or (D+/R-). Grafts were recovered for gene expression and histological / immunofluorescence analysis, respectively. RESULTS: Evaluations showed significantly increased signs of chronic rejection in WT-infected mice compared to uninfected allografts seen in lower epithelium/lamina propria-ratio (ELR) (ELR 0.46 ± 0.07 [WT post] vs. ELR 0.66 ± 0.10 [non-inf.]; p < 0.05). The rejection in delM33-infected groups was significantly reduced vs. WT-infected groups (0.67 ± 0.04 [delM33 post]; vs. WT post p < 0.05). Furthermore, decreased rejection was observed in WT pre-infected compared to post-infected groups (0.56 ± 0.08 [WT pre]; vs. WT post p < 0.05). CD8+ T cell infiltration was significantly higher in WT-post compared to the delM33 infected or non-infected allografts. CONCLUSIONS: These data support the role of the CMV in accelerating CLAD. The deletion of chemokine receptor M33 leads to attenuated rejection.

Acute graft rejection in a COVID-19 patient: Co-incidence or causal association?

A 32-year-old man with a clear and compact graft following a penetrating keratoplasty 6 years back, developed an episode of acute graft rejection, coinciding with the COVID-19 disease. Subsequent to the infection with the novel coronavirus, he developed symptoms of acute graft rejection concurrent with the development of respiratory distress and peak systemic symptoms. This was the phase of cytokine storm as evidenced by the raised inflammatory markers in his blood tests. Such a case of acute corneal graft rejection coinciding with SARS-CoV-2 infection has been reported only once in the literature and this unique association needs to be researched further.

Torque Teno Virus Load Is Associated With Subclinical Alloreactivity in Kidney Transplant Recipients: A Prospective Observational Trial.

BACKGROUND: Nonpathogenic torque teno viruses (TTVs) are highly prevalent in transplant recipients and associated with immunosuppression. Studies in kidney transplant patients have proposed assessment of TTV load for risk stratification of clinically overt graft rejection. The value of TTV quantification in the context of subclinical rejection has not been evaluated. METHODS: In this prospective trial, 307 consecutive kidney transplant recipients were subjected to per-protocol monitoring of plasma TTV. TTV was analyzed in the context of protocol biopsies (n = 82), scheduled 1 year posttransplantation. RESULTS: TTV load at the time of biopsy was lower in recipients with rejection (n = 19; according to Banff, including borderline changes suspicious for acute T cell-mediated rejection) than those without rejection (n = 63) whereby each log increase in TTV copies/mL decreased the risk for rejection by 9% (risk ratio 0.91, 95% confidence interval, 0.85-0.97; P = 0.004). Development of chronic lesions (cg, cv, ci, ct, ah, ptcml) was associated with the number of days with a TTV load <1 × 106 copies/mL between months 3 and 12 posttransplant (ß 0.07, 95% confidence interval, 0.01-0.14; P = 0.02). CONCLUSIONS: This trial demonstrates an association between TTV and subclinical graft rejection in kidney transplant recipients. A TTV load <1 × 106 copies/mL suggests suboptimal immunosuppression.

BK virus infection and outcome following kidney transplantation in childhood.

BK virus associated nephropathy (BKN) is an important cause of kidney allograft failure. In a cohort of paediatric kidney transplant recipients, we aimed to understand the incidence and clinical outcome associated with BKN, as well as identify risk factors for BKN and BK viraemia development. We retrospectively analysed all patients who received a kidney transplant and received follow up care in our centre between 2009-2019. Among 106 patients included in the study (mean follow up 4.5 years), 32/106 (30.2%) patients experienced BK viraemia. The incidence of BKN was 7/106 (6.6%). The median time of BK viraemia development post-transplant was 279.5 days compared to 90.0 days for BKN. Development of BKN was associated with younger age at transplantation (p = 0.013). Development of BK viraemia was associated with negative recipient serology for cytomegalovirus (CMV) at time of transplantation (p = 0.012) and a higher net level of immunosuppression (p = 0.039). There was no difference in graft function at latest follow up between those who experienced BKN and those without BKN. This study demonstrates that BK virus infection is associated with younger age at transplantation, CMV negative recipient serostatus and higher levels of immunosuppression. Judicious monitoring of BK viraemia in paediatric transplant recipients, coupled with timely clinical intervention can result in similar long-term outcomes for BKN patients compared to controls.

Incidence and risk factors of kidney allograft loss due to BK nephropathy in the pediatric population: A retrospective analysis of the UNOS/OPTN database.

BACKGROUND: BK virus infection can lead to graft dysfunction and loss in kidney transplant recipients. Risk factors for BKV and BKVN have been inadequately studied in children. Here, we evaluate the incidence and risk factors of allograft loss due to BKVN in the pediatric population of the UNOS data set. METHODS: We conducted a retrospective cohort analysis of the UNOS database and identified all pediatric recipients of kidney transplantation between 2000 and 2018. We compared donor and recipient characteristics, including cause of ESRD, among patients who lost their graft due to BKVN or other causes, and those with functioning allograft. Kaplan-Meier curve and Cox regression analysis were performed to evaluate the risk factors. RESULTS: A total of 66 patients (0.47%) suffered graft failure from BKVN. Older age, male gender, HLA mismatch, and rejection at 1 year were significantly associated with BKVN graft failure, compared to recipients with functioning allograft. In comparison with graft loss due to other causes, male gender, higher HLA mismatch, rejection in 1st year and tacrolimus use at discharge were significantly associated with BKVN graft loss. Recipients who received mycophenolate at time of discharge were at reduced risk for BKVN graft failure. Compared to graft failure from other causes, BKVN graft failure had shorter death censored graft survival [P = .001]. ESRD due to urologic causes and Alport syndrome had higher rate of BKVN graft failure. CONCLUSION: Incidence of graft loss from BKVN in the pediatric population was 10.2 per 10 000 patient-years in this study. BKVN is associated with early allograft failure in the pediatric population, compared to other causes of graft loss. Male gender, HLA mismatch, rejection in 1st year, and urological cause of ESRD are risk factors for graft failure from BKVN in children.

Kidney Transplantation in HIV-positive Patients: Current Practice and Management Strategies.

BACKGROUND: HIV-positive patients had been successfully transplanted for the last 15 y and the donor pool had successfully been expanded to also include HIV-positive donors. METHODS: We aimed to evaluate the effectiveness of transplantation in HIV-positive patients and highlight some of the important issues reported in the literature. We pooled clinical data from different cohorts to show some of the common issues encountered in HIV-positive transplantation. Furthermore, we searched MEDLINE via PubMed, EMBASE, Cochrane CENTRAL to create a comprehensive table for current evidence for different issues currently encountered when transplanting HIV-positive patients. RESULTS: We included data from 19 cohort studies and reported on outcomes of the current HIV-positive transplant programs. We made recommendations based on personal experience as well as the experience reported in the literature regarding rejection, opportunistic infection, and HIV-associated nephropathy. Opportunistic infections and malignancies are not a major problem for this population group. CONCLUSIONS: HIV-positive patients encounter very specific issues after transplantation, specifically related to drug interactions and higher rejection rates. When utilizing HIV-positive donors, the recurrence of HIV-associated nephropathy in the graft kidney is an issue which can be important. Despite some issues with high rejection rates, HIV-positive patients have similar results to HIV-negative patients posttransplantation.

Cytomegalovirus chemokine receptor M33 knockout reduces chronic allograft rejection in a murine aortic transplant model.

BACKGROUND: Numerous studies suggest that cytomegalovirus (CMV) infection may act as isolated risk factor in the development of cardiac allograft vasculopathy (CAV). Viral G protein-coupled receptors (GPCRs) are thought to contribute to the pathogenic changes associated with CMV infection. The aim of this study was to investigate the role of murine cytomegalovirus GPCR M33 in the development of CAV in a murine aortic allograft model. METHODS: MHC I-mismatched aortas of C.B10 (H2b) mice were transplanted into BALB/c (H2d) recipients, which were either mock-infected, infected with wild type (WT) MCMV or MCMV with a deleted M33-receptor gene (delM33). Persistence of cytomegalovirus infection was confirmed by qPCR and by luciferase assay to ensure active viral replication. Grafts were harvested on days 21 and 37 for intragraft mRNA expression and histological analysis. RESULTS: Active viral replication was demonstrated and MCMV presence was confirmed by PCR within spleen, liver, salivary glands, lung and the aortic transplant. Infection with delM33 resulted in significantly less intimal proliferation compared to WT-MCMV but more pronounced proliferation than in mock-infected allografts (32.19% [delM33] vs. 41.71% [WT-MCMV] vs. 24.33% [MCMV-]). Intragraft expression of most analyzed genes was significantly increased in infected mice. VCAM-1, ICAM-1, PDGFß, CXCR3 and Granzyme B were distinctly less expressed in grafts of delM33 infected compared to WT infected mice. Cellular infiltration revealed reduced dendritic cells and T cells in grafts infected with delM33 compared to WT MCMV. CONCLUSIONS: These data suggest that the MCMV encoded receptor M33 plays an important role as a viral effector mechanism contributing to the development of CAV in a murine aortic transplant model.

Renal transplantation during the SARS-CoV-2 pandemic in the UK: Experience from a large-volume center.

There is uncertainty about the safety of kidney transplantation during the SARS-CoV-2 pandemic due to the risk of donor transmission, nosocomial infection and immunosuppression use. We describe organ donation and transplant practice in the UK and assess whether kidney transplantation conferred a substantial risk of harm. Data from the UK transplant registry were used to describe kidney donation and transplant activity in the UK, and a detailed analysis of short-term, single-center, patient results in two periods: during the pre-pandemic era from 30th December 2019 to 8th March 2020 ("Pre-COVID era") and the 9th March 2020 to 19th May 2020 ("COVID era"). Donor and recipient numbers fell by more than half in the COVID compared to the pre-COVID era in the UK, but there were more kidney transplants performed in our center (42 vs. 29 COVID vs. pre-COVID respectively). Overall outcomes, including re-operation, delayed graft function, primary non-function, acute rejection, length of stay and graft survival were similar between COVID and pre-COVID era. 6/71 patients became infected with SARS-CoV-2 but all were discharged without critical care requirement. Transplant outcomes have remained similar within the COVID period and no serious sequelae of SARS-CoV-2 infection were observed in the peri-transplant period.

Impact of cytomegalovirus infection on gene expression profile in heart transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) infection has been implicated in the pathogenesis of allograft rejection in heart transplant (HT) recipients. The effect of a CMV infection on the gene expression profiling (GEP, AlloMap) scores in the absence of acute rejection is not known. METHODS: Data from 14,985 samples collected from 2,288 adult HT recipients enrolled in Outcomes AlloMap Registry were analyzed. Patients with known CMV serology at the time of HT who had at least 1 AlloMap score reported during follow-up were included. AlloMap scores for those patients with CMV (but no ongoing rejection) were compared with those who were never infected. An exploratory analysis on the impact of CMV on available donor-derived cell-free DNA (AlloSure) was also performed. RESULTS: A total of 218 patients (10%) were reported to have CMV infection after transplantation. AlloMap score in those samples with CMV infection (n = 311) had a GEP score (34; range: 29-36) significantly higher than the GEP score from samples (n = 14,674) obtained in the absence of CMV infection (30; range: 26-34; p < 0.0001). Both asymptomatic viremia and CMV disease demonstrated significantly higher AlloMap scores than no CMV infection samples (median scores: 33, 35, and 30, respectively; p < 0.0001). AlloSure levels, available for 776 samples, were not significantly different (median: 0.23% in 18 samples with CMV infection vs 0.15% in 776 samples without CMV infection; p = 0.66). CONCLUSIONS: CMV infection in HT recipients is associated with an increase in AlloMap score, whereas AlloSure results do not appear to be impacted. This information should be considered when clinically interpreting abnormal/high AlloMap scores in HT recipients.

Characteristics and outcomes among patients with community-acquired respiratory virus infections during the first year after lung transplantation.

BACKGROUND: The current study describes the spectrum of community-acquired respiratory infections (CARV) during the first year after lung transplantation (LT). Additionally, we elucidate variables associated with CARV, management strategies utilized, and impact on early and late outcomes. METHODS: This was a retrospective study among patients transplanted between 2012 and 2015 (n = 255, mean age 55.6 ± 13.5 years, M: F 152:103). The diagnosis of CARV was based on the multiplex PCR on nasopharyngeal swab samples. Baseline characteristics, post-transplant variables, and outcomes were compared among patients with and without CARV. RESULTS: Eighty CARV infections developed among a quarter of the study group (n = 62, 24.3%). Rhinovirus/enterovirus was the most commonly isolated CARV (n = 24) followed by coronavirus (n = 17) and RSV (n = 9). A significant proportion of episodes (43.8%) required hospitalization. The use of nasal corticosteroids and left single LT was independently associated with an increased risk of CARV. CARV infections did not impact the lung functions during the first year or the CLAD-free survival at 3 years. CONCLUSIONS: There is a significant burden of CARV infections during the first year after LT. The use of nasal corticosteroids may increase the risk of CARV infection. CARV infections did not impact outcomes.

Cytomegalovirus Experience in Pediatric Kidney Transplantation in 26 Years' Time.

INTRODUCTION: In this study,we investigated the presence of cytomegalovirus (CMV) infection in kidney transplanted children and its effect on kidney dysfunction. MATERIAL AND METHODS: One hundred thirty-five pediatric renal transplant patients were included in this study. The presence of CMV infection, CMV risk status, and other clinical features of the patients were evaluated retrospectively. RESULTS: Fifty-three percent of all patients and 68.8% of patients with CMV were male. The mean age was 12 years in all patients and CMV groups. According to the CMV risk classification, 40.9% of the patients with CMV infection/disease were in the high-risk group (CMV D+R-). In CMV risk groups, the presence of CMV infection/disease was similar. Cold ischemia time, male sex (patients and donors), deceased donor, higher HLA-mismatches, and cumulative antithymocyte globulin dose were found as risk factors for CMV infection/disease. Acute rejection/graft failure was observed in 27% of all patients. CMV infection has no effect on rejection/graft failure and survival. DISCUSSION: The frequency and risk factors of CMV in renal transplant children in our study were consistent with the literature. CONCLUSIONS: CMV infection was found in one-fifth of our patients and the majority (71.9%) of them developed infection in the first 6 months. In one-third of our patients acute rejection/graft failure was observed. There was no effect of CMV infection on rejection/graft failure and survival in pediatric patients with proper and effective treatment.

Cytomegalovirus infection and allograft rejection among pediatric heart transplant recipients in the era of valganciclovir prophylaxis.

CMV infection remains a significant cause of morbidity among pediatric HTx recipients We explored the implications of CMV infection on post-transplant outcomes among CMV risk-stratified pediatric HTx recipients receiving VGC prophylaxis. Children who underwent HTx between January 2010 and October 2016 were stratified according to CMV risk at time of transplant and evaluated for evidence of post-transplant CMV infection, rejection, CAV, and graft loss. Among 97 children, 41 (42%) were considered HR or IR risk for CMV infection and received VGC prophylaxis. CMV DNAemia was observed in 34% of children, including 71% HR, 40% IR, and 18% LR individuals. Median time to CMV DNAemia following VGC prophylaxis was 32D among HR vs 277D in IR subjects (P = .042). No difference in overall graft loss was noted among groups, but CMV HR children had decreased rejection-free survival (3.5 years) compared to IR (6 years, P = .015) and LR children (8 years, P = .0003). CMV was noted on EMB in 13% of children but was not associated with increased CAV, rejection or graft loss. High-risk CMV status was associated with decreased time to CMV infection despite VGC prophylaxis, compared to IR, and decreased rejection-free survival times compared to both IR and LR recipients. Detection of CMV on EMB was not associated with increased rejection, CAV or graft loss. Additional studies are needed to explore the impact of CMV infection on rejection-free survival in HTx recipients.