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1.
Post-renal transplant malignancies: Opportunities for prevention and early screening.
Turshudzhyan, A
Cancer treatment and research communications. 2021;:100283
Abstract
GOAL OF THE REVIEW While transplant recipients are aware of increased malignancy risk, there is little consensus on the preventative measures. The goal of this review is to bring available preventative measures to light and prompt more research to be done with ultimate goal of developing an individualized prevention plan for each patient based on risk factors and available screening tools. INTRODUCTION Transplant surgery offers patients with end-stage renal disease a longer life expectancy with help of immunosuppressive therapies. Nonetheless, life-long immunosuppression comes at a cost of post-renal transplant malignancies, which have become the leading cause of morbidity in this patient group. DISCUSSION Post-renal transplant cancers can develop through either de novo, by donor-related transmission, or recurrence of recipient's pre-transplant cancer. While immunosuppressive therapy is considered to be the leading cause, weakened immunosurveillance of neoplastic cells and inadequate immune response against oncogenic viruses also plays an important role. The most common cancers seen in renal transplant patients are skin cancers and post-transplant lymphoproliferative disorder (PTLD). Risk factors for skin cancers have are ultraviolet light, human papilloma virus infection, and use of cyclosporin and azathioprine. Numerous viral infections have been associated with transplant-related malignancies post-transplant. CONCLUSION While lowering of immunosuppressive therapy remains the treatment of choice, it may lead to graft failure. Given some of the presented malignancies have modifiable risk factors and options for screening, clinical outcomes can be improved. Limiting skin exposure, dermatologic screening, and prophylactic retinoids can help lower the incidence rate of skin malignancy. Endoscopic screening for renal transplant patients can help identify gastric adenocarcinoma early and improve survival rates. Some of the post-transplant malignancies have been responsive to anti-viral treatment.
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Exploring the potential effect of paricalcitol on markers of inflammation in de novo renal transplant recipients.
Pihlstrøm, HK, Ueland, T, Michelsen, AE, Aukrust, P, Gatti, F, Hammarström, C, Kasprzycka, M, Wang, J, Haraldsen, G, Mjøen, G, et al
PloS one. 2020;(12):e0243759
Abstract
Following a successful renal transplantation circulating markers of inflammation may remain elevated, and systemic inflammation is associated with worse clinical outcome in renal transplant recipients (RTRs). Vitamin D-receptor (VDR) activation is postulated to modulate inflammation and endothelial function. We aimed to explore if a synthetic vitamin D, paricalcitol, could influence systemic inflammation and immune activation in RTRs. Newly transplanted RTRs were included in an open-label randomized controlled trial on the effect of paricalcitol on top of standard care over the first post-transplant year. Fourteen pre-defined circulating biomarkers reflecting leukocyte activation, endothelial activation, fibrosis and general inflammatory burden were analyzed in 74 RTRs at 8 weeks (baseline) and 1 year post-engraftment. Mean changes in plasma biomarker concentrations were compared by t-test. The expression of genes coding for the same biomarkers were investigated in 1-year surveillance graft biopsies (n = 60). In patients treated with paricalcitol circulating osteoprotegerin levels increased by 0.19 ng/ml, compared with a 0.05 ng/ml increase in controls (p = 0.030). In graft tissue, a 21% higher median gene expression level of TNFRSF11B coding for osteoprotegerin was found in paricalcitol-treated patients compared with controls (p = 0.026). Paricalcitol treatment did not significantly affect the blood- or tissue levels of any other investigated inflammatory marker. In RTRs, paricalcitol treatment might increase both circulating and tissue levels of osteoprotegerin, a modulator of calcification, but potential anti-inflammatory treatment effects in RTRs are likely very modest. [NCT01694160 (2012/107D)]; [www.clinicaltrials.gov].
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New treatments for cytomegalovirus in transplant patients.
Coppock, GM, Blumberg, E
Current opinion in nephrology and hypertension. 2019;(6):587-592
Abstract
PURPOSE OF REVIEW The purpose of this review is to highlight novel advances in prophylaxis against and treatment of CMV in kidney transplant recipients. Current options include intravenous ganciclovir and oral valganciclovir, but use of these agents is limited by side effects, such as myelosuppression as well as evolving resistance in CMV strains. RECENT FINDINGS Advances in the field include novel drugs that have shown promise in preliminary studies and are now being tested in large-scale clinical trials. Moreover, there is a developing focus in enhancing host immune responses to better protect against viral infection using anti-CMV vaccines. Studying host immune responses to CMV has also led to improved monitoring strategies, such as the QuantiFERON assay, which will allow for improved risk stratification and targeted therapies in transplant recipients. SUMMARY In summary, although options for prophylaxis and treatment against CMV have been somewhat limited to date, a number of new strategies are currently under development with several drugs in phase 3 trials. Therefore, the landscape of CMV management in kidney transplant recipients will be changing significantly in the coming years with the ultimate goal of safer and more effective therapies to combat CMV.
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Relationship Among Viremia/Viral Infection, Alloimmunity, and Nutritional Parameters in the First Year After Pediatric Kidney Transplantation.
Ettenger, R, Chin, H, Kesler, K, Bridges, N, Grimm, P, Reed, EF, Sarwal, M, Sibley, R, Tsai, E, Warshaw, B, et al
American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2017;(6):1549-1562
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Abstract
The Immune Development in Pediatric Transplantation (IMPACT) study was conducted to evaluate relationships among alloimmunity, protective immunity, immune development, physical parameters, and clinical outcome in children undergoing kidney transplantation. We prospectively evaluated biopsy-proven acute rejection (BPAR), de novo donor-specific antibody (dnDSA) formation, viremia, viral infection, T cell immunophenotyping, and body mass index (BMI)/weight Z scores in the first year posttransplantation in 106 pediatric kidney transplant recipients. Outcomes were excellent with no deaths and 98% graft survival. Rejection and dnDSAs occurred in 24% and 22%, respectively. Pretransplant cytomegalovirus (CMV) and Epstein-Barr virus (EBV) serologies and subsequent viremia were unrelated to BPAR or dnDSA. Viremia occurred in 73% of children (EBV, 34%; CMV, 23%; BMK viremia, 23%; and JC virus, 21%). Memory lymphocyte phenotype at baseline was not predictive of alloimmune complications. Patients who developed viral infection had lower weight (-2.1) (p = 0.028) and BMI (-1.2) (p = 0.048) Z scores at transplantation. The weight difference persisted to 12 months compared with patients without infection (p = 0.038). These data indicate that there is a high prevalence of viral disease after pediatric kidney transplantation, and underweight status at transplantation appears to be a risk factor for subsequent viral infection. The occurrence of viremia/viral infection is not associated with alloimmune events.
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Intragraft transcriptional profiling of renal transplant patients with tubular dysfunction reveals mechanisms underlying graft injury and recovery.
Azevedo, H, Renesto, PG, Chinen, R, Naka, E, de Matos, AC, Cenedeze, MA, Moreira-Filho, CA, Câmara, NO, Pacheco-Silva, A
Human genomics. 2016;:2
Abstract
BACKGROUND Proximal tubular dysfunction (PTD) is associated with a decreased long-term graft survival in renal transplant patients and can be detected by the elevation of urinary tubular proteins. This study investigated transcriptional changes in biopsies from renal transplant patients with PTD to disclose molecular mechanisms underlying graft injury and functional recovery. METHODS Thirty-three renal transplant patients with high urinary levels of retinol-binding protein, a biomarker of PTD, were enrolled in the study. The initial immunosuppressive scheme included azathioprine, cyclosporine, and steroids. After randomization, 18 patients (group 2) had their treatment modified by reducing cyclosporine dosage and substituting azathioprine for mycophenolate mofetil, while the other 15 patients (group 1) remained under the initial scheme. Patients were biopsied at enrollment and after 12 months of follow-up, and paired comparisons were performed between their intragraft gene expression profiles. The differential transcriptome profiles were analyzed by constructing gene co-expression networks and identifying enriched functions and central nodes in each network. RESULTS Only the alternative immunosuppressive scheme used in group 2 ameliorated renal function and tubular proteinuria after 12 months of follow-up. Intragraft molecular changes observed in group 2 were linked to autophagy, extracellular matrix, and adaptive immunity. Conversely, gene expression changes in group 1 were related to fibrosis, endocytosis, ubiquitination, and endoplasmic reticulum stress. CONCLUSION These results suggest that molecular networks associated with the control of endocytosis, autophagy, protein overload, fibrosis, and adaptive immunity may be involved in improvement of graft function.
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Failure of Calcineurin Inhibitor (Tacrolimus) Weaning Randomized Trial in Long-Term Stable Kidney Transplant Recipients.
Dugast, E, Soulillou, JP, Foucher, Y, Papuchon, E, Guerif, P, Paul, C, Riochet, D, Chesneau, M, Cesbron, A, Renaudin, K, et al
American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2016;(11):3255-3261
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Abstract
Long-term renal transplant outcome is limited by side effects of immunosuppressive drugs, particularly calcineurin inhibitor (CNI). We assumed that some patients selected for a "low immunological risk of rejection" could be eligible and benefit from a CNI weaning strategy. We designed a prospective, randomized, multicenter, double-blind placebo-controlled clinical study (Eudract: 2010-019574-33) to analyze the benefit-risk ratio of tacrolimus weaning on highly selected patients (≥4 years of transplantation, normal histology, stable graft function, no anti-HLA immunization). The primary endpoint was improvement of renal function. Fifty-two patients were scheduled in each treatment arm, placebo compared to the CNI maintenance arm. Only 10 patients were eligible and randomized. Five patients were assigned to the placebo arm and five were assigned to the tacrolimus maintenance arm. In the tacrolimus maintenance arm, all patients maintained stable graft function and no immunological events occurred. Contrastingly, in the placebo arm, all five patients had to reintroduce a full dose of tacrolimus since three of them presented an acute rejection episode (one humoral, one mixed, and one borderline) and two displayed anti-HLA antibodies without histological lesion (one donor-specific antibodies [DSA] and one non-DSA). Clearly, tacrolimus withdrawal must be avoided even in long-term highly selective stable kidney recipients.
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Mammalian Target of Rapamycin Inhibitors and Nephrotoxicity: Fact or Fiction.
Barbari, A, Maawad, M, Kfoury Kassouf, H, Kamel, G
Experimental and clinical transplantation : official journal of the Middle East Society for Organ Transplantation. 2015;(5):377-86
Abstract
Mammalian target of rapamycin inhibitors, such as rapamycin and more recently everolimus, have substituted calcineurin inhibitors in many minimization strategies. Despite their acclaimed renal safety profile, several lines of evidence are emerging on their potential nephrotoxic effect. Predisposing conditions for nephrotoxicity involve a complex interplay between several environmental and genetic factors in the donor-recipient pair. Renal injury may be enhanced by pharmacodynamic interactions when combined with other drugs such as calcineurin inhibitors or nutrients that are predominantly related to an increase in local tissue exposure. These toxic interactions may occur within adequate doses and therapeutic blood levels. This explains the occurrence of nephrotoxicity in some but not all cases. Here, we postulated that activity of a low permeability glycoprotein efflux pump related to low protein expression and/or inhibition enhanced immunosuppressive drug entry in different cells. A rise in intracellular drug concentration increases bioactivity, leading to greater immunosuppression and more immune-related, nonrenal adverse events in the recipient and increased nephrotoxicity in the kidney graft. Under specific isolated or combined environmental and/or genetic conditions in both the recipient and donor affecting the glycoprotein efflux pump and/or the mammalian target of rapamycin pathway, these renal injuries may be aggravated by heightened drug tissue concentrations despite adherence to therapeutic drug and blood levels. Mammalian target of rapamycin inhibitors may induce predominantly a dose-dependent renal epithelial cell injury affecting either the glomerular or the renal tubular epithelial cells, leading to cell death and apoptosis. Epithelial mesenchymal transition mediated interstitial fibrosis and tubular atrophy observed with these drugs may be the result of a cumulative toxic renal tubular injury induced by the direct insult of the drug itself and/or podocytopathy-associated proteinuria. The resulting glomerular tubular damage will ultimately lead to graft failure and loss, if exposure persists.
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Pharmacokinetics of enteric-coated mycophenolate sodium in Chinese renal transplantation recipients.
Qiu, K, Tian, H, Wang, W, Hu, XP, Li, XB, Gong, LL, Luo, W, Liu, LH, Zhang, XD, Yin, H
Chinese medical journal. 2012;(23):4226-32
Abstract
BACKGROUND Mycophenolic acid (MPA) as an anti-proliferative immune-suppressive agent is used in the majority of immunosuppressive regimens in solid organ transplantation. This study aimed to investigate the pharmacokinetic (PK) characteristics of enteric-coated mycophenolate sodium (EC-MPS) and area under the curve (AUC) from 0 to 12 hours with limited sampling strategies (LSSs) in Chinese renal transplant recipients. METHODS This study was conducted in 10 Chinese renal transplant patients receiving living donor and treated with EC-MPS, cyclosporine, and corticosteroids. MPA concentrations were measured by enzyme multiplied immunoassay technique (EMIT). Whole 12-hour PK profiles were obtained on Day 4 after operation. LSSs with jackknife technique, multiple stepwise regression analysis, and Bland-Altman analysis were developed to estimate MPA AUC. RESULTS The mean maximum plasma concentration, the mean time for it to reach peak (T(max)), and the mean MPA AUC were (11.38 ± 2.49) mg/L, (4.85 ± 3.32) hours, and (63.19 ± 13.54) mg×h×L(-1), respectively. Among the 10 profiles, MPA AUC of four patients was significantly higher than that of the other six patients, and the corresponding T(max) was significantly longer than that of the other six patients. No patient exhibited a second peak caused by enterohepatic recirculation. The best models were as follows: 27.46 + 0.94C(3) + 3.24C(8) + 2.81C(10) (r(2) = 0.972), which was used to predict AUC of fast metabolizer with a mean prediction error (MPE) of -0.21% and a mean absolute prediction error (MAE) of 2.59%; 36.65 + 3.08C(8) + 5.30C(10) - 4.04C(12) (r(2) = 0.992), which was used to predict AUC of slow metabolizer with a MPE of 0.58% and a MAE of 1.95%. CONCLUSIONS The PKs of EC-MPS had a high variability among Chinese renal transplant recipients. The preliminary PK data indicated the existence of slow and fast metabolizer. These findings may be associated with the enterohepatic recirculation.
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Higher memory responses in HIV-infected and kidney transplanted patients than in healthy subjects following priming with the pandemic vaccine.
Siegrist, CA, van Delden, C, Bel, M, Combescure, C, Delhumeau, C, Cavassini, M, Clerc, O, Meier, S, Hadaya, K, Soccal, PM, et al
PloS one. 2012;(7):e40428
Abstract
BACKGROUND Memory responses require immune competence. We assessed the influence of priming with AS03-adjuvanted pandemic vaccine (Pandemrix®) on memory responses of HIV patients, kidney recipients (SOT) and healthy controls (HC). METHOD Participants (HIV: 197, SOT: 53; HC: 156) were enrolled in a prospective study and 390/406 (96%) completed it. All had been primed in 2009/2010 with 1 (HC) or 2 (patients) doses of Pandemrix®, and were boosted with the 2010/2011 seasonal influenza vaccine. Geometric mean titres and seroprotection rates were measured 12 months after priming and 4 weeks after boosting. Primary and memory responses were directly compared in 191 participants (HCW: 69, HIV: 71, SOT: 51) followed during 2 consecutive seasons. RESULTS Most participants (HC: 77.8%, HIV: 77.6%, SOT: 66%) remained seroprotected at 12 months post-priming. Persisting A/09/H1N1 titers were high in HIV (100.2) and HC (120.1), but lower in SOT (61.4) patients. Memory responses reached higher titers in HIV (507.8) than in HC (253.5) and SOT (136.9) patients. Increasing age and lack of HAART reduced persisting and memory responses, mainly influenced by residual antibody titers. Comparing 2009/2010 and 2010/2011 titers in 191 participants followed for 2 seasons indicated lower post-2010/2011 titers in HC (240.2 vs 313.9), but higher titers in HIV (435.7 vs 338.0) and SOT (136 vs 90.3) patients. CONCLUSIONS Priming with 2 doses of Pandemrix® elicited persistent antibody responses and even stronger memory responses to non-adjuvanted seasonal vaccine in HIV patients than 1 dose in healthy subjects. Adjuvanted influenza vaccines may improve memory responses of immunocompromised patients. TRIAL REGISTRATION ClinicalTrials.gov NCT01022905.
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Reinfection of cytomegalovirus in renal transplantation.
Ishibashi, K, Yamaguchi, O, Suzutani, T
Fukushima journal of medical science. 2011;(1):1-10
Abstract
Cytomegalovirus (CMV) is the most important pathogen affecting the outcome of renal transplantation. Reinfection of CMV can occur in CMV-seropositive donors and CMV seropositive recipients (D+/R+) settings because the protection against CMV conferred by preexisting immunity is limited due to its strain-dependent immune responses. To analyze the influence of CMV reinfection in renal transplantation, ELISA using fusion proteins encompassing epitope of glycoprotein H(gH) from both AD169 and Towne strains was employed before transplantation. The CMV-gH seropositive rate increased with increases in age and the rate of samples which contained antibodies against both AD169 and Towne were significantly high in the age of 50 years or over. Antibodies from HLA-DR10 and DR11 were associated with a significantly lower response rate against CMV-gH. In renal transplantation, the high degrees of antigenemia and high incidences of CMV disease are more prevalent in the CMV gH antibody-mismatched group in D+/R+ setting. The nucleotide sequence of the region of the gH epitope in the CMV-DNA extracted from the transplant recipients who showed high degree of antigenemia revealed the CMV reinfection from the donors. As a CMV indirect effect, the incidence of acute rejection in the mismatched gH antibody group was higher than that observed in the matched and D+/R- groups. The adverse events were more likely to occur in cases of D+/R+ renal transplantation with mismatched strain-specific antibodies which would indicates the risk of CMV reinfection after transplantation.