KDIGO clinical practice guideline for the care of kidney transplant recipients

The number of donor HLA-derived T cell epitopes available for indirect antigen presentation determines the risk for vascular rejection after kidney transplantation

The role of the indirect T-cell recognition pathway of allorecognition in acute T cell-mediated rejection (aTCMR) is not well defined. The amount of theoretical T-cell epitopes available for indirect allorecognition can be quantified for donor-recipient combinations by the Predicted Indirectly ReCognizable HLA Epitopes algorithm (PIRCHE-II). The PIRCHE-II score was calculated for 688 donor kidney-recipient combinations and associated with the incidence of first-time diagnosed cases of TCMR. A diagnosis of TCMR was made in 182 cases; 121 cases of tubulo-interstitial rejection cases (79 cases of borderline TCMR, 42 cases of TCMR IA-B) and 61 cases of vascular TCMR (TCMR II-III). The PIRCHE-II score for donor HLA-DR/DQ (PIRCHE-II DR/DQ) was highly associated with vascular rejection. At one year after transplantation, the cumulative percentage of recipients with a vascular rejection was 12.7%, 8.6% and 2.1% within respectively the high, medium and low tertile of the PIRCHE-II DR/DQ score (p<0.001). In a multivariate regression analysis this association remained significant (p<0.001 for PIRCHE-II DR/DQ tertiles). The impact of a high PIRCHE-II DR/DQ score was mitigated by older recipient age and a living donor kidney. In conclusion, indirect antigen presentation of donor HLA-peptides may significantly contribute to the risk for acute vascular rejection.

The effect of the very low dosage diltiazem on tacrolimus exposure very early after kidney transplantation: a randomized controlled trial

The objective of this study was to assess the effect of the very low dosage of diltiazem on tacrolimus exposure during the first week post-kidney transplantation, among cytochrome P450 (CYP) 3A5 expressers who did not receive diltiazem (EXplb), CYP3A5 expressers who received the very low dose diltiazem (EXdtz), CYP3A5 nonexpressers who did not receive diltiazem (NEplb), and CYP3A5 nonexpressers who received the very low dose diltiazem (NEdtz). Forty kidney recipients who receive tacrolimus-based immunosuppressive regimen were randomly assigned, with stratification on the CYP3A5 genotypes, to receive either diltiazem 30 mg every 12 h or a matched placebo. The observed median dose-adjusted area under the 12-h curve of tacrolimus concentration (AUC/D) at day 7 post-transplantation was lowest in the EXplb group followed by EXdtz, NEplb, and NEdtz at 34.9, 43.6, 49.4, and 71.1 ng*h/mL per mg, respectively. A Kruskal-Wallis test showed a significant difference in the mean ranks of AUC/D among groups. Significant differences between EXplb and NEplb, and between EXplb and NEdtz were demonstrated, whereas no sufficient evidence of significant differences was detected between the other pairs. In conclusion, coadministration of diltiazem 30 mg twice daily may be advantageous for increasing tacrolimus exposure early after kidney transplantation among CYP3A5 expressers.

Dynamic risk prediction of BK polyomavirus reactivation after renal transplantation

Purpose

To construct a dynamic prediction model for BK polyomavirus (BKV) reactivation during the early period after renal transplantation and to provide a statistical basis for the identification of and intervention for high-risk populations.

Methods

A retrospective study of 312 first renal allograft recipients was conducted between January 2015 and March 2022. The covariates were screened using univariable time-dependent Cox regression, and those with P<0.1 were included in the dynamic and static analyses. We constructed a prediction model for BKV reactivation from 2.5 to 8.5 months after renal transplantation using dynamic Cox regression based on the landmarking method and evaluated its performance using the area under the curve (AUC) value and Brier score. Monte-Carlo cross-validation was done to avoid overfitting. The above evaluation and validation process were repeated in the static model (Cox regression model) to compare the performance. Two patients were presented to illustrate the application of the dynamic model.

Results

We constructed a dynamic prediction model with 18 covariates that could predict the probability of BKV reactivation from 2.5 to 8.5 months after renal transplantation. Elder age, basiliximab combined with cyclophosphamide for immune induction, acute graft rejection, higher body mass index, estimated glomerular filtration rate, urinary protein level, urinary leukocyte level, and blood neutrophil count were positively correlated with BKV reactivation, whereas male sex, higher serum albumin level, and platelet count served as protective factors. The AUC value and Brier score of the static model were 0.64 and 0.14, respectively, whereas those of the dynamic model were 0.79 ± 0.05 and 0.08 ± 0.01, respectively. In the cross-validation, the AUC values of the static and dynamic models decreased to 0.63 and 0.70 ± 0.03, respectively, whereas the Brier score changed to 0.11 and 0.09 ± 0.01, respectively.

Conclusion

Dynamic Cox regression based on the landmarking method is effective in the assessment of the risk of BKV reactivation in the early period after renal transplantation and serves as a guide for clinical intervention.

Fast Tacrolimus Metabolism Does Not Promote Post-Transplant Diabetes Mellitus after Kidney Transplantation

Post-transplant diabetes mellitus (PTDM) after kidney transplantation induced by tacrolimus is an important issue. Fast tacrolimus metabolism, which can be estimated by concentration-to-dose (C/D) ratio, is associated with increased nephrotoxicity and unfavorable outcomes after kidney transplantation. Herein, we elucidate whether fast tacrolimus metabolism also increases the risk for PTDM. Data from 596 non-diabetic patients treated with tacrolimus-based immunosuppression at the time of kidney transplantation between 2007 and 2015 were retrospectively analyzed. The median follow-up time after kidney transplantation was 4.7 years (IQR 4.2 years). Our analysis was complemented by experimental modeling of fast and slow tacrolimus metabolism kinetics in cultured insulin-producing pancreatic cells (INS-1 cells). During the follow-up period, 117 (19.6%) patients developed PTDM. Of all patients, 210 (35.2%) were classified as fast metabolizers (C/D ratio < 1.05 ng/mL × 1/mg). Fast tacrolimus metabolizers did not have a higher incidence of PTDM than slow tacrolimus metabolizers (p = 0.496). Consistent with this, insulin secretion and the viability of tacrolimus-treated INS-1 cells exposed to 12 h of tacrolimus concentrations analogous to the serum profiles of fast or slow tacrolimus metabolizers or to continuous exposure did not differ (p = 0.286). In conclusion, fast tacrolimus metabolism is not associated with increased incidence of PTDM after kidney transplantation, either in vitro or in vivo. A short period of incubation of INS-1 cells with tacrolimus using different concentration profiles led to comparable effects on cell viability and insulin secretion in vitro. Consistent with this, in our patient, collective fast Tac metabolizers did not show a higher PTDM incidence compared to slow metabolizers.

Real-World Treatment Patterns of Antiviral Prophylaxis for Cytomegalovirus Among Adult Kidney Transplant Recipients: A Linked USRDS-Medicare Database Study

Limited data exist on cytomegalovirus (CMV) antiviral treatment patterns among kidney transplant recipients (KTRs). Using United States Renal Database System registry data and Medicare claims (1 January 2011-31 December 2017), we examined CMV antiviral use in 22,878 KTRs who received their first KT from 2011 to 2016. Three-quarters of KTRs started CMV prophylaxis (85.8% of high-, 82.4% of intermediate-, and 32.1% of low-risk KTRs). Median time to prophylaxis discontinuation was 98, 65, and 61 days for high-, intermediate-, and low-risk KTRs, respectively. Factors associated with receiving CMV prophylaxis were high-risk status, diabetes, receipt of a well-functioning kidney graft, greater time on dialysis before KT, panel reactive antibodies ≥80%, and use of antithymocyte globulin, alemtuzumab, and tacrolimus. KTRs were more likely to discontinue CMV prophylaxis if they developed leukopenia/neutropenia, had cardiovascular disease, or received their kidney from a deceased donor. These findings suggest that adherence to the recommended duration of CMV-prophylaxis for high and intermediate-risk patients is suboptimal, and CMV prophylaxis is overused in low-risk patients.

A CRISPR-based ultrasensitive assay detects attomolar concentrations of SARS-CoV-2 antibodies in clinical samples

CRISPR diagnostics are powerful tools for detecting nucleic acids but are generally not deployable for the detection of clinically important proteins. Here, we report an ultrasensitive CRISPR-based antibody detection (UCAD) assay that translates the detection of anti-SARS-CoV-2 antibodies into CRISPR-based nucleic acid detection in a homogeneous solution and is 10,000 times more sensitive than the classic immunoassays. Clinical validation using serum samples collected from the general population (n = 197), demonstrates that UCAD has 100% sensitivity and 98.5% specificity. With ultrahigh sensitivity, UCAD enables the quantitative analysis of serum anti-SARS-CoV-2 levels in vaccinated kidney transplant recipients who are shown to produce "undetectable" anti-SARS-CoV-2 using standard immunoassay. Because of the high sensitivity and simplicity, we anticipate that, upon further clinical validation against large cohorts of clinical samples, UCAD will find wide applications for clinical uses in both centralized laboratories and point-of-care settings.

Immune checkpoint inhibitors increase the risk of kidney transplant rejection: a real-world pharmacovigilance study

BACKGROUND

Kidney transplant recipients with cancer are at higher risk of kidney transplant rejection (KTR), and the safety of immune checkpoint inhibitors (ICIs) is unclear. The present study investigates the relationship between ICIs and KTR using data from the Food and Drug Administration Adverse Event Reporting System (FAERS).

RESEARCH DESIGN AND METHODS

Case reports of KTR inducted by ICIs in FAERS from January 1, 2011, to June 30, 2021, were collected, and a disproportionate analysis was performed to assess the correlation between ICIs and KTR.

RESULTS

A total of 99 cases of ICI-related KTR were reported in the FAERS database. Most of them were male patients (n=63, 84.0%), and more than half of patients suffered from malignant melanoma (n=46, 52.9%). The median onset time after the medication was 22 days, the withdrawal rates of ICIs were 78.0%, and the overall death rate was 29.3%. In general, there was a significant relevance between ICIs and KTR (ROR=3.92[3.21-4.79] IC025=1.56), of which PD-1 was the most prominent (n=81 ROR=5.26[4.22-6.57] IC025=1.86).

CONCLUSIONS

ICIs may increase the risk of KTR in organ transplant recipients with cancer.

Balancing B cell responses to the allograft: implications for vaccination

Balancing enough immunosuppression to prevent allograft rejection and yet maintaining an intact immune system to respond to vaccinations, eliminate invading pathogens or cancer cells is an ongoing challenge to transplant physicians. Antibody mediated allograft rejection remains problematic in kidney transplantation and is the most common cause of graft loss despite current immunosuppressive therapies. The goal of immunosuppressive therapies is to prevent graft rejection; however, they prevent optimal vaccine responses as well. At the center of acute and chronic antibody mediated rejection and vaccine responses is the B lymphocyte. This review will highlight the role of B cells in alloimmune responses including the dependency on T cells for antibody production. We will discuss the need to improve vaccination rates in transplant recipients and present data on B cell populations and SARS-CoV-2 vaccine response rates in pediatric kidney transplant recipients.

BK Virus Nephropathy in Kidney Transplantation: A State-of-the-Art Review

BK virus maintains a latent infection that is ubiquitous in humans. It has a propensity for reactivation in the setting of a dysfunctional cellular immune response and is frequently encountered in kidney transplant recipients. Screening for the virus has been effective in preventing progression to nephropathy and graft loss. However, it can be a diagnostic and therapeutic challenge. In this in-depth state-of-the-art review, we will discuss the history of the virus, virology, epidemiology, cellular response, pathogenesis, methods of screening and diagnosis, evidence-based treatment strategies, and upcoming therapeutics, along with the issue of re-transplantation in patients.

Association of Abdominal Arterial Calcification Score with Patients' Survival and Kidney Allograft Function after Kidney Transplant

BACKGROUND

Abdominal arterial calcification (AAC) is common among candidates for kidney transplant. The aim of this study is to correlate AAC score value with post-kidney transplant outcomes.

METHODS

We modified the coronary calcium score by changing the intake data points and used it to quantitate the AAC. We conducted a retrospective clinical study of all adult patients who were transplanted at our center, between 2010 and 2013, and had abdominal computed tomography scan done before transplantation. Outcomes included mortality, pulse pressure (PP) measured by 24 h ambulatory blood pressure monitoring system, and kidney allograft function measured by iothalamate clearance.

RESULTS

For each 1000 increase of AAC score value, there is an associated 1.05 increase in the risk of death (95% CI 1.02, 1.08) (p < 0.001). Overall median AAC value for all patients was 1784; Kaplan-Meier curve showed reduced survival of all-cause mortality for patients with AAC score value above median and reduced survival among patients with cardiac related mortality. The iothalamate clearance was lower among patients with total AAC score value above the median. Patients with abnormal PP (< 40 or > 60 mmHg) had an elevated median AAC score value at 4319.3 (IQR 1210.4, 11097.1) compared to patients with normal PP with AAC score value at 595.9 (IQR 9.9, 2959.9) (p < 0.001).

CONCLUSION

We showed an association of AAC with patients' survival and kidney allograft function after kidney transplant. The AAC score value could be used as a risk stratification when patients are considered for kidney transplant.

Pharmacotherapeutic options for the prevention of kidney transplant rejection: the evidence to date

INTRODUCTION

Although early rejection episodes are successfully controlled, the problem of unrecognized production of de novo anti HLA antibodies and associated chronic rejection still persists.

AREAS COVERED

In addition to the standard induction and maintenance therapy, we present a couple of new drugs as induction (Alemtuzumab), CNI free protocol (Belatacept, Sirolimus, Everolimus), maintenance treatment in transplant patients with various type of malignancies (T cell targeted immunomodulators blocking the immune checkpoints CTLA-4, PD1/PDL1) and TMA (aHUS) -eculizimab, and IL6 receptor antagonists in antibody mediated rejection (AMR).

EXPERT OPINION

There are couple of issues still preventing improvement in kidney transplant long-term outcomes with current and anticipated future immunosuppression: patient more susceptible to infection and CNI nephrotoxicity in kidneys obtained from elderly donors, highly sensitized patients with limited chances to get appropriate kidney and a higher risk for late AMR. A lower rate of CMV/BK virus infections has been observed in everolimus treated patients. Belatacept use has been justified only in EBV seropositive kidney transplants due to the increased risk of PTLD. Eculizumab upon recurrence of aHUS is a sole cost-effective option. A new IL-6 blocking drug (clazakizumab/tocilizumab) is promising option for prevention/treatment of AMR. Clinical experience in tailoring immunosuppression for as long as possible graft and patient survival is inevitable.

Medical Aspects of mTOR Inhibition in Kidney Transplantation

The advances in transplant immunosuppression have reduced substantially the incidence of kidney graft rejection. In recent years, the focus has moved from preventing rejection to preventing the long-term consequences of long-standing immunosuppression, including nephrotoxicity induced by calcineurin inhibitors (CNI), as well as infectious and neoplastic complications. Since the appearance in the late 1990s of mTOR inhibitors (mTORi), these unmet needs in immunosuppression management could be addressed thanks to their benefits (reduced rate of viral infections and cancer). However, management of side effects can be troublesome and hands-on experience is needed. Here, we review all the available information about them. Thanks to all the basic, translational and clinical research achieved in the last twenty years, we now use mTORi as de novo immunosuppression in association with CNI. Another possibility is represented by the conversion of either CNI or mycophenolate (MPA) to an mTORi later on after transplantation in low-risk kidney transplant recipients.

Transplanted kidney loss during colorectal cancer chemotherapy: A case report

BACKGROUND

The overall risk of de novo malignancies in kidney transplant recipients (KTRs) is higher than that in the general population. It is associated with long-lasting exposure to immunosuppressive agents and impaired oncological vigilance due to chronic kidney disease. Colorectal cancer (CRC), frequently diagnosed in an advanced stage, is one of the most common malignancies in this cohort and is associated with poor prognosis. Still, because of the scarcity of data concerning adjuvant chemotherapy in this group, there are no clear guidelines for the specific management of the CRCs in KTRs. We present a patient who lost her transplanted kidney shortly after initiation of adjuvant chemotherapy for colon cancer.

CASE SUMMARY

A 36-year-old woman with a medical history of kidney transplantation (2005) because of end-stage kidney disease, secondary to chronic glomerular nephritis, and long-term immunosuppression was diagnosed with locally advanced pT_4AN_1BM₀ (clinical stage III) colon adenocarcinoma G2. After right hemicolectomy, the patient was qualified to receive adjuvant chemotherapy that consisted of oxaliplatin, leucovorin and 5-fluorouracil (FOLFOX-4). The deterioration of kidney graft function after two cycles caused chemotherapy cessation and initiation of hemodialysis therapy after a few months. Shortly after that, the patient started palliative chemotherapy because of cancer recurrence with intraperitoneal spread.

CONCLUSION

Initiation of adjuvant chemotherapy for colon cancer increases the risk of rapid kidney graft loss driven also by under-immunosuppression.

Combined Analysis of HLA Class II Eplet Mismatch and Tacrolimus Levels for the Prediction of De Novo Donor Specific Antibody Development in Kidney Transplant Recipients

We investigated whether HLA class II eplet mismatch was related to dnDSA development and analyzed its combined impact with tacrolimus levels for kidney transplantation outcomes. A total of 347 kidney transplants were included. HLA Matchmaker was used for the single molecular eplet, total eplet, antibody (Ab)-verified eplet mismatch analyses, and Ab-verified single molecular analysis to identify HLA-DR/DQ molecular thresholds for the risk of dnDSA development. A time-weighted tacrolimus trough level (TAC-C0) of 5 ng/mL and a TAC-C0 time-weighted coefficient variability (TWCV) of 20% were applied to find the combined effects on dnDSA development. A high level of mismatch for single molecular eplet (DQ ≥ 10), total eplet (DQ ≥ 12), Ab-verified eplet (DQ ≥ 4), and Ab-verified single molecular eplet (DQ ≥ 4) significantly correlated with HLA class II dnDSA development. Class II dnDSA developed mostly in patients with low TAC-C0 and high eplet mismatch. In the multivariable analyses, low TAC-C0 and high eplet mismatch showed the highest hazard ratio for the development of dnDSA. No significant combined effect was observed in dnDSA development according to TWCV. In conclusion, the determination of HLA class II eplet mismatch may improve the risk stratification for dnDSA development, especially in conjunction with tacrolimus trough levels.

Peter W, Roberts G, Rangaswami J, Mottl A, Kliger AS, Harris RC, Gee PO, Fowler K, Cherney D, Brosius FC, Argyropoulos C, Quaggin SE. Moving from Evidence to Implementation of Breakthrough Therapies for Diabetic Kidney Disease

Diabetic kidney disease is the most frequent cause of kidney failure, accounting for half of all cases worldwide. Moreover, deaths from diabetic kidney disease increased 106% between 1990 and 2013, with most attributed to cardiovascular disease. Recommended screening and monitoring for diabetic kidney disease are conducted in less than half of patients with diabetes. Standard-of-care treatment with an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker is correspondingly low. Sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide 1 receptor agonists, and a nonsteroidal mineralocorticoid antagonist are highly effective therapies to reduce kidney and cardiovascular risks in diabetic kidney disease. However, <20% of eligible patients are receiving these agents. Critical barriers are high out-of-pocket drug costs and low reimbursement rates. Data demonstrating clinical and cost-effectiveness of diabetic kidney disease care are needed to garner payer and health care system support. The pharmaceutical industry should collaborate on value-based care by increasing access through affordable drug prices. Additionally, multidisciplinary models and communication technologies tailored to individual health care systems are needed to support optimal diabetic kidney disease care. Community outreach efforts are also central to make care accessible and equitable. Finally, it is imperative that patient preferences and priorities shape implementation strategies. Access to care and implementation of breakthrough therapies for diabetic kidney disease can save millions of lives by preventing kidney failure, cardiovascular events, and premature death. Coalitions composed of patients, families, community groups, health care professionals, health care systems, federal agencies, and payers are essential to develop collaborative models that successfully address this major public health challenge.

Carbon monoxide mechanism of protection against renal ischemia and reperfusion injury

Carbon monoxide is quickly moving past its historic label as a molecule once feared, to a therapeutic drug that modulates inflammation. The development of carbon monoxide releasing molecules and utilization of heme oxygenase-1 inducers have shown carbon monoxide to be a promising therapy in reducing renal ischemia and reperfusion injury and other inflammatory diseases. In this review, we will discuss the developments and application of carbon monoxide releasing molecules in renal ischemia and reperfusion injury, and transplantation. We will review the anti-inflammatory mechanisms of carbon monoxide in respect to mitigating apoptosis, suppressing dendritic cell maturation and signalling, inhibiting toll-like receptor activation, promoting anti-inflammatory responses, and the effects on renal vasculature.

Early Post-Transplant Red Blood Cell Transfusion Is Associated With an Increased Risk of Transplant Failure: A Nationwide French Study

Background

Red blood cell (RBC) transfusions are frequently required in the early period after kidney transplantation. However, the consequences of RBC transfusions on long-term outcomes are largely unrecognized.

Methods

We conducted a nationwide French cohort study involving all 31 French kidney transplant centers. Patients having received a first kidney transplant between January 1, 2002 and December 31, 2008 were identified through the national registry of the French BioMedecine Agency (Agence de BioMédecine). Number and date of RBC transfusions were collected from the national database of the French transfusion public service. The primary endpoint was transplant failure defined as graft loss or death with a functional graft.

Results

Among 12,559 patients included during the study period, 3,483 (28%) were transfused during the first 14 days post-transplant. Median follow-up was 7.6 (7.5-7.8) years. Multivariable analysis determined that post-transplant RBC transfusion was associated with an increased risk in transplant failure (HR 1.650, 95%CI [1.538;1.771] p<0.0001). Both sensitivity and propension score analyses confirmed the previous result.

Conclusions

Early red blood cell transfusion after kidney transplantation is associated with increased transplant failure.

Vascular Calcification and the Gut and Blood Microbiome in Chronic Kidney Disease Patients on Peritoneal Dialysis: A Pilot Study

Vascular calcification (VC) is a frequent condition in chronic kidney disease (CKD) and a well-established risk factor for the development of cardiovascular disease (CVD). Gut dysbiosis may contribute to CVD and inflammation in CKD patients. Nonetheless, the role of gut and blood microbiomes in CKD-associated VC remains unknown. Therefore, this pilot study aimed to explore the link between gut and blood microbiomes and VC in CKD patients on peritoneal dialysis (CKD-PD). Our results showed relative changes in specific taxa between CKD-PD patients with and without VC, namely Coprobacter, Coprococcus 3, Lactobacillus, and Eubacterium eligens group in the gut, and Cutibacterium, Pajaroellobacter, Devosia, Hyphomicrobium, and Pelomonas in the blood. An association between VC and all-cause mortality risk in CKD-PD patients was also observed, and patients with higher mortality risk corroborate the changes of Eubacterium eligens in the gut and Devosia genus in the blood. Although we did not find differences in uremic toxins, intestinal translocation markers, and inflammatory parameters among CKD-PD patients with and without VC, soluble CD14 (sCD14), a nonspecific marker of monocyte activation, positively correlated with VC severity. Therefore, gut Eubacterium eligens group, blood Devosia, and circulating sCD14 should be further explored as biomarkers for VC, CVD, and mortality risk in CKD.

A Prediction Model for Tacrolimus Daily Dose in Kidney Transplant Recipients With Machine Learning and Deep Learning Techniques

Tacrolimus is a major immunosuppressor against post-transplant rejection in kidney transplant recipients. However, the narrow therapeutic index of tacrolimus and considerable variability among individuals are challenges for therapeutic outcomes. The aim of this study was to compare different machine learning and deep learning algorithms and establish individualized dose prediction models by using the best performing algorithm. Therefore, among the 10 commonly used algorithms we compared, the TabNet algorithm outperformed other algorithms with the highest R² (0.824), the lowest prediction error [mean absolute error (MAE) 0.468, mean square error (MSE) 0.558, and root mean square error (RMSE) 0.745], and good performance of overestimated (5.29%) or underestimated dose percentage (8.52%). In the final prediction model, the last tacrolimus daily dose, the last tacrolimus therapeutic drug monitoring value, time after transplantation, hematocrit, serum creatinine, aspartate aminotransferase, weight, CYP3A5, body mass index, and uric acid were the most influential variables on tacrolimus daily dose. Our study provides a reference for the application of deep learning technique in tacrolimus dose estimation, and the TabNet model with desirable predictive performance is expected to be expanded and applied in future clinical practice.

Challenging Dermatologic Considerations Associated with Immune Checkpoint Inhibitors

Immune checkpoint inhibitors have emerged as a new paradigm in oncologic care for many malignancies. However, nonspecific immune activation has led to "collateral damage" in the form of immune-related adverse events, with skin being a commonly affected organ. Cutaneous immune-related adverse events include a wide spectrum of clinical presentations and challenging considerations, often necessitating dermatology referral to support diagnosis and management, particularly for atypical presentations or more severe, cutaneous immune-related adverse events that may require specialized dermatologic evaluations including biopsy and histopathology. Close collaborations between oncologists and dermatologists may optimize clinical decision making in the following challenging management settings: non-steroidal therapies for corticosteroid-refractory, cutaneous immune-related adverse events, immune checkpoint inhibitor rechallenge, balancing cutaneous immune-related adverse events and treatments, and immune checkpoint inhibitors in patients with pre-existing autoimmune disease, skin conditions, and organ transplants. These complex clinical decisions that often lack rigorous data should be made in close collaboration with dermatologists to minimize unnecessary morbidity and mortality. This article provides a review of approaches to challenging dermatologic considerations associated with immune checkpoint inhibitor therapies.

Approach to the Patient With Glucocorticoid-induced Adrenal Insufficiency

Glucocorticoid-induced adrenal insufficiency is caused by exogenous glucocorticoid suppression of the hypothalamic-pituitary-adrenal axis and is the most prevalent form of adrenal insufficiency. The condition is important to diagnose given the risk of life-threatening adrenal crisis and impact on patients' quality of life. The diagnosis is made with a stimulation test such as the ACTH test. Until now, testing for glucocorticoid-induced adrenal insufficiency has often been based on clinical suspicion rather than routinely but accumulating evidence indicates that a significant number of cases will remain unrecognized. During ongoing oral glucocorticoid treatment or initially after withdrawal, ~50% of patients have adrenal insufficiency, but, outside clinical studies, ≤ 1% of patients have adrenal testing recorded. More than 70% of cases are identified during acute hospital admission, where the diagnosis can easily be missed because symptoms of adrenal insufficiency are nonspecific and overlap those of the underlying and intercurrent conditions. Treatment of severe glucocorticoid-induced adrenal insufficiency should follow the principles for treatment of central adrenal insufficiency. The clinical implications and thus indication to treat mild-moderate adrenal deficiency after glucocorticoid withdrawal has not been established. Also, the indication of adding stress dosages of glucocorticoid during ongoing glucocorticoid treatment remains unclear. In patients with established glucocorticoid-induced adrenal insufficiency, high rates of poor confidence in self-management and delayed glucocorticoid administration in the acute setting with an imminent adrenal crisis call for improved awareness and education of clinicians and patients. This article reviews different facets of glucocorticoid-induced adrenal insufficiency and discusses approaches to the condition in common clinical situations.

Anaesthetic Approach to Enhanced Recovery after Surgery for Kidney Transplantation: A Narrative Review

Enhanced recovery after surgery (ERAS) protocols are designed to reduce medical complications, the length of hospital stays (LoS), and healthcare costs. ERAS is considered safe and effective for kidney transplant (KTx) surgery. KTx recipients are often frail with multiple comorbidities. As these patients follow an extensive diagnostic pathway preoperatively, the ERAS protocol can ideally be implemented at this stage. Small singular changes in a long perioperative pathway can result in significant positive outcomes. We have investigated the current evidence for an ERAS pathway related to anaesthetic considerations in renal transplant surgery for adult recipients.

Harnessing the B Cell Response in Kidney Transplantation - Current State and Future Directions

Despite dramatic improvement in kidney transplantation outcomes over the last decades due to advent of modern immunosuppressive agents, long-term outcomes remain poor. Antibody-mediated rejection (ABMR), a B cell driven process, accounts for the majority of chronic graft failures. There are currently no FDA-approved regimens for ABMR; however, several clinical trials are currently on-going. In this review, we present current mechanisms of B cell response in kidney transplantation, the clinical impact of sensitization and ABMR, the B cell response under current immunosuppressive regimens, and ongoing clinical trials for ABMR and desensitization treatment.

Dickkopf 3-A New Indicator for the Deterioration of Allograft Function After Kidney Transplantation

Evidence of tubular atrophy and interstitial fibrosis is prognostically unfavorable and associated with a premature graft loss after kidney transplantation. Recently, Dickkopf 3 (DKK3), a profibrotic glycoprotein released by stressed tubular epithelial cells, has been identified to cause IF/TA by regulating the Wnt/β-catenin signaling and seems to engage a T-cell response. The aim of our study was to determine if a correlation between DKK3 and graft function exists and if DKK3 could be a new indicator to identify patients at risk for a deterioration in graft function. Patients, transplanted between 2016 and 2018, were analyzed with regard to DKK3 in the urine and graft function (creatinine, eGFR, albuminuria). Multivariable analyzes were used including known factors influencing graft function (PRA, donor age) to stress robustness of DKK3. The 3 and 12 month DKK3 values were significant predictors for subsequent graft function up to 36 months. An increase of DKK3 from month 3 to 12 of ≥ 25% showed a higher risk of an impaired graft function, with, e.g., a reduction in eGFR of about 9–10 ml/min in contrast to patients without intensified DKK3 increase. Induction therapy has an influence on DKK3 as patients induced with a T-cell depleting therapy showed a trend toward lower DKK3 values. In summary, our study is the first investigation of DKK3 in kidney transplant recipients and was able to show that DKK3 could forecast graft function. It is recommended to investigate the potential of DKK3 as a predictor of kidney function after transplantation in further studies.

Pediatric Onco-Nephrology: Time to Spread the Word-Part II: Long-Term Kidney Outcomes in Survivors of Childhood Malignancy and Malignancy after Kidney Transplant

Onco-nephrology is a recent and evolving medical subspecialty devoted to the care of patients with kidney disease and unique kidney-related complications in the context of cancer and its treatments, recognizing that management of kidney disease as well as the cancer itself will improve survival and quality of life. While this area has received much attention in the adult medicine sphere, similar emphasis in the pediatric realm has not yet been realized. As in adults, kidney involvement in children with cancer extends beyond the time of initial diagnosis and treatment. Many interventions, such as chemotherapy, stem cell transplant, radiation, and nephrectomy, have long-term kidney effects, including the development of chronic kidney disease (CKD) with subsequent need for dialysis and/or kidney transplant. Thus, with the improved survival of children with malignancy comes the need for ongoing monitoring of kidney function and early mitigation of kidney-related comorbidities. In addition, children with kidney transplant are at higher risk of developing malignancies than their age-matched peers. Pediatric nephrologists thus need to be aware of issues related to cancer and its treatments as they impact their own patients. These facts emphasize the necessity of pediatric nephrologists and oncologists working closely together in managing these children and highlight the importance of bringing the onco-nephrology field to our growing list of pediatric nephrology subspecialties.

Nondestructive versus advanced post-transplant lymphoproliferative disorder in a single-center pediatric kidney transplant population

BACKGROUND

Pediatric kidney transplant recipients are at risk for the development of post-transplant lymphoproliferative disorders (PTLD), a group of potentially devastating diseases that present on a spectrum of severity ranging from nondestructive PTLD to more histologically destructive lesions. Currently, there is inadequate evidence to guide evaluation and management of nondestructive PTLD.

METHODS

This is a single-center case series of pediatric kidney transplant recipients between January 1, 2008 and December 31, 2019, who were diagnosed with PTLD. The aim was to describe clinical characteristics, presentation, and management of nondestructive versus advanced PTLD.

RESULTS

Eighteen patients were diagnosed with nondestructive PTLD and seven with more advanced PTLD histopathology. The majority (66.7%) of nondestructive PTLD patients (n = 16) presented with tonsillar hypertrophy and/or snoring and were managed conservatively, with minimal reduction in tacrolimus dose and no further evaluation. No patient progressed to more advanced PTLD. Advanced PTLD patients (n = 7) were more likely to present with fever, elevated creatinine, a new mass of gastrointestinal symptoms. They received workup with imaging and oncology consultation, and were managed with chemotherapy.

CONCLUSIONS

Patients with nondestructive PTLD often present with symptoms of sleep-disordered breathing and can be managed conservatively with excellent clinical outcomes. More study is needed to guide care of this under-researched population.

Pretransplant and Posttransplant Alcohol Consumption and Outcomes in Kidney Transplantation: A Prospective Multicenter Cohort Study

The impact of pretransplant and posttransplant alcohol consumption on outcomes in kidney transplant recipients (KTRs) is uncertain. Self-reported alcohol consumption was obtained at the time of transplant and 2 years after transplant in a prospective cohort study. Among 907 KTRs, 368 (40.6%) were drinkers at the time of transplant. Compared to non-drinkers, alcohol consumption did not affect the risk of death-censored graft failure (DCGF), biopsy-proven acute rejection (BPAR), cardiovascular events, or all-cause mortality. Compared to persistent non-drinkers, the development of DCGF, BPAR, cardiovascular events, all-cause mortality, or posttransplant diabetes mellitus was not affected by the alcohol consumption pattern (persistent, de novo, or stopped drinking) over time. However, de novo drinkers had a significantly higher total cholesterol (p < 0.001) and low-density lipoprotein cholesterol levels (p = 0.005) compared to persistent non-drinkers 5 years after transplant, and had significantly higher total cholesterol levels (p = 0.002) compared to the stopped drinking group 7 years after transplant, even after adjusting for the use of lipid-lowering agents, age, sex, and body mass index. Although pretransplant and posttransplant alcohol consumption were not associated with major outcomes in KTRs during the median follow-up of 6.0 years, a new start of alcohol use after KT results in a relatively poor lipid profile.

Clinical Trial Registration:clinicaltrials.gov, identifier NCT02042963.

Anti-T-Lymphocyte Immunoglobulin (Grafalon) as an Induction Agent for Renal Transplantation: A Real-World, Retrospective, Single-Center Experience

OBJECTIVES

Polyclonal antithymocyte globulins are widely used in the induction regimens of solid-organ transplant recipients; however, their doses and outcomes remain to be standardized in Indian patients. We report our clinical experience from the real-world use of Grafalon (an anti-T-lymphocyte globulin; ATG-Fresenius) as an induction agentin renal transplant recipients from India.

MATERIALS AND METHODS

In this retrospective, single- center, observational study, we analyzed the medical records of 177 consecutive, kidney-only transplant recipients who received induction therapy with Grafalon from September 2016 to March 2018 at our center. Incidences of biopsy-proven acute rejection and graft dysfunction, immunosuppression protocol, Grafalon dosage, 18-month post-transplant graft and patient survival, treatment-related adverse events, and infective complications were reported.

RESULTS

Mean age of patients was 41.46 years (range, 14-68 years), (85% were males). The average dose of Grafalon was 5.81 ± 1.95 mg/kg (range, 2.41 to 10.07 mg/kg). Graft dysfunction (ie, at least 20% increase in serum creatinine from baseline) was observed in 26 patients (14%): 11 patients (6.2%) had biopsy-proven acute rejections, 11 patients (6.2%) had acute tubular necrosis, and 4 patients (2.2%) had calcineurin inhibitor toxicity. Seven deaths were recorded: 2 each from fungal pneumonia, bacterial pneumonia, and acute coronary syndrome and 1 with urinary tract infection with septicemia. Death-censored graft survival was 100% at 12 months and 98% at 18-month follow-up; overall patient survival was 96%. Infective complications occurred in 40 patients (22.5%), with the most common being urinary tract infection in 32 patients (18%). No malignancies were reported.

CONCLUSIONS

Use of a potent induction therapy like anti-T-lymphocyte globulin (Grafalon) is often restricted by the risk of side effects and lack of local clinical evidence supporting its role in long-term graft survival. Real-world evidence support the safe and effective use of anti-T-lymphocyte globulin as an induction agent in renal transplant recipients with an individualized dosing approach.

Costs in the Year Following Deceased Donor Kidney Transplantation: Relationships With Renal Function and Graft Failure

Relationships between renal function and medical costs for deceased donor kidney transplant recipients are not fully quantified post-transplant. We describe these relationships with renal function measured by estimated glomerular filtration rate (eGFR) and graft failure. The United States Renal Data System identified adults receiving single-organ deceased donor kidneys 2012–2015. Inpatient, outpatient, other facility costs and eGFRs at discharge, 6 and 12 months were included. A time-history of costs was constructed for graft failures and monthly costs in the first year post-transplant were compared to those without failure. The cohort of 24,021 deceased donor recipients had a 2.4% graft failure rate in the first year. Total medical costs exhibit strong trends with eGFR. Recipients with 6-month eGFRs of 30–59 ml/min/1.73m² have total costs 48% lower than those <30 ml/min/1.73m². For recipients with graft failure monthly costs begin to rise 3–4 months prior to failure, with incremental costs of over $38,000 during the month of failure. Mean annual total incremental costs of graft failure are over $150,000. Total costs post-transplant are strongly correlated with eGFR. Graft failure in the first year is an expensive, months-long process. Further reductions in early graft failures could yield significant human and economic benefits.

The Feasibility and User-Experience of a Digital Health Intervention Designed to Prevent Weight Gain in New Kidney Transplant Recipients-The ExeRTiOn2 Trial

Half of kidney transplant recipients (KTRs) gain more than 5% of their body weight in the first year following transplantation. KTRs have requested support with physical activity (PA) and weight gain prevention, but there is no routine care offered. There are few high-quality studies investigating the clinical value of diet, PA or combined interventions to prevent weight gain. The development and evaluation of theoretically informed complex-interventions to mitigate weight gain are warranted. The aims of this mixed-methods randomized controlled trial (RCT) were to explore the feasibility, acceptability and user-experience of a digital healthcare intervention (DHI) designed to prevent post-transplant weight gain, in preparation for a large multi-center trial. New KTRs (<3 months) with access to an internet compatible device were recruited from a London transplant center. The usual care (UC) group received standard dietary and PA advice. The intervention group (IG) received access to a 12-week DHI designed to prevent post-transplant weight gain. Primary feasibility outcomes included screening, recruitment, retention, adherence, safety and hospitalizations and engagement and experience with the DHI. Secondary outcomes (anthropometrics, bioimpedance, arterial stiffness, 6-minute walk distance and questionnaires) were measured at baseline, 3- and 12-months. 38 KTRs were screened, of which 32 (84.2%) were eligible, and of those 20 (62.5%) consented, with 17 participants (85%) completing baseline assessment (Median 49 years, 58.8% male, Median 62 days post-transplant). Participants were randomized using a computer-generated list (n = 9 IG, n = 8 UC). Retention at 12-months was 13 (76.4%) (n = 6 IG, n = 7 UC). All a priori progression criteria were achieved. There were no associated adverse events. Reflexive thematic analysis revealed four themes regarding trial participation and experience whilst using the DHI. Halting recruitment due to COVID-19 resulted in the recruitment of 40% of the target sample size. Mixed-methods data provided important insights for future trial design. A definitive RCT is warranted and welcomed by KTRs.

Clinical Trial Registration

www.clinicalTrials.gov, identifier: NCT03996551.

Severe Bartonella henselae bone infection in a kidney transplanted young man

We present a case of a young kidney transplanted man. He was admitted with lymphadenopathy, fluctuating fever and night sweats 2 months after a cat bite. After admission, he developed severe pain around his right hip. An 18F-fluorodeoxyglucose (FDG)-positron emission tomography/CT revealed intense FDG-uptake in lymph nodes, spleen and bone, suggestive of lymphoma. An extracted lymph node showed confluent granulomas, microabscesses with neutrophils and scattered multinucleated giant cells histologically. The patient had history of latent tuberculosis and proteinase 3 -anti-neutrophil cytoplasmic antibodies associated (PR3-ANCA) vasculitis, making differential diagnostic considerations complicated. Bartonella henselae antibodies was detected in blood and B. henselae DNA in a lymph node. He was started on doxycycline and rifampicin. Due to severe drug interactions with both tacrolimus and increasing morphine doses, rifampicin was changed to azithromycin. He received 12 days of relevant antibiotic treatment and responded well. He was discharged after 16 days with close follow-up and was still in habitual condition 12 months later.

Mixed Infection of Cytomegalovirus and Pulmonary Nocardiosis Caused by Nocardia elegans Diagnosed Using Nanopore Sequencing Technology

A 69-year-old woman who had undergone renal transplantation and was receiving sulfamethoxazole/trimethoprim (ST) developed pulmonary nocardiosis. To our knowledge, this is the first report of the identification of Nocardia elegans using nanopore sequencing, supported by 16S rDNA capillary sequencing findings. Chest computed tomography performed after ST initiation revealed significant improvement of the pulmonary shadows compared to previous findings. We herein report the value of nanopore sequencing for rapid identification of rare pathogens, such as Nocardia elegans. Furthermore, our findings suggest that Nocardia may infect even patients receiving ST, which is currently the most effective prophylactic drug.

Inflammatory biomarkers in staging of chronic kidney disease: elevated TNFR2 levels accompanies renal function decline

BACKGROUND

Inflammation is a common feature in the pathogenesis of chronic kidney disease (CKD), regardless of the disease cause. Our aim was to evaluate the potential of several inflammatory biomarkers in CKD diagnosis and staging.

METHODS

A total of 24 healthy controls and 92 pre-dialysis CKD patients with diverse etiologies, were enrolled in this study and grouped according to their CKD stage. We analysed the circulating levels of inflammatory molecules, C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), tumor necrosis factor receptor 2 (TNFR2), pentraxin 3 (PTX3) and leptin, as well as the hemogram. We studied their association with parameters of kidney function and kidney injury, to evaluate their potential as early markers of the disease and/or of its worsening, as well as their interplay.

RESULTS

Compared to controls, patients in CKD stages 1-2 presented significantly higher IL-6 and TNFR2 levels, and higher neutrophil-to-lymphocyte ratio. All inflammatory cytokines and acute-phase proteins showed a trend to increase up to stage 3, stabilizing or declining thereafter, save for TNFR2, which steadily increased from stage to stage. All inflammatory molecules, apart from PTX3, were negatively and significantly correlated with eGFR, with a remarkable value for TNFR2 (r = - 0.732, p < 0.001).

CONCLUSION

TNFR2 might be useful for an early detection of CKD, as well as for disease staging/worsening. Still, the potential value of this biomarker in disease progression warrants further investigation.

Tocilizumab and Active Antibody-Mediated Rejection in Kidney Transplantation: A Literature Review

Introduction

Chronic kidney disease (CKD) is a major public-health problem that increases the risk of end-stage kidney disease (ESKD), cardiovascular diseases, and other complications. Kidney transplantation is a renal-replacement therapy that offers better survival compared to dialysis. Antibody-mediated rejection (ABMR) is a significant complication following kidney transplantation: it contributes to both short- and long-term injury. The standard-of-care (SOC) therapy combines plasmapheresis and Intravenous Immunoglobulins (IVIg) with or without steroids, with or without rituximab: however, despite this combined treatment, ABMR remains the main cause of graft loss. IL-6 is a key cytokine: it regulates inflammation, and the development, maturation, and activation of T cells, B cells, and plasma cells. Tocilizumab (TCZ) is the main humanized monoclonal aimed at IL-6R and appears to be a safe and possible strategy to manage ABMR in sensitized recipients. We conducted a literature review to assess the place of the anti-IL-6R monoclonal antibody TCZ within ABMR protocols.

Materials and Methods

We systematically reviewed the PubMed literature and reviewed six studies that included 117 patients and collected data on the utilization of TCZ to treat ABMR.

Results

Most studies report a significant reduction in levels of Donor Specific Antibodies (DSAs) and reduced inflammation and microvascular lesions (as found in biopsies). Stabilization of the renal function was observed. Adverse events were light to moderate, and mortality was not linked with TCZ treatment. The main side effect noted was infection, but infections did not occur more frequently in patients receiving TCZ as compared to those receiving SOC therapy.

Conclusion

TCZ may be an alternative to SOC for ABMR kidney-transplant patients, either as a first-line treatment or after failure of SOC. Further randomized and controlled studies are needed to support these results.

Acute kidney injury during pregnancy in kidney transplant recipients

Pregnancy-related acute kidney injury (AKI) is a public health problem and remains an important cause of maternal and fetal morbidity and mortality. The incidence of pregnancy-related AKI has increased in developed countries due to increase in maternal age and higher detection rates. Pregnancy in women with kidney transplants is associated with higher adverse outcomes like preeclampsia, preterm births, and allograft dysfunction, but limited data exist on causes and outcomes of pregnancy-related AKI in the kidney transplant population. Diagnosis of AKI during pregnancy remains challenging in kidney transplant recipients due to lack of diagnostic criteria. Management of pregnancy-related AKI in the kidney transplant population requires a multidisciplinary team consisting of transplant nephrologists, high-risk obstetricians, and neonatologists. In this review, we discuss pregnancy-related acute kidney injury in women with kidney transplants, etiologies, pregnancy outcomes, and management strategies. This article is protected by copyright. All rights reserved.

Pearls and Pitfalls in Pediatric Kidney Transplantation After 5 Decades

Worldwide, over 1,300 pediatric kidney transplantations are performed every year. Since the first transplantation in 1959, healthcare has evolved dramatically. Pre-emptive transplantations with grafts from living donors have become more common. Despite a subsequent improvement in graft survival, there are still challenges to face. This study attempts to summarize how our understanding of pediatric kidney transplantation has developed and improved since its beginnings, whilst also highlighting those areas where future research should concentrate in order to help resolve as yet unanswered questions. Existing literature was compared to our own data of 411 single-center pediatric kidney transplantations between 1968 and 2020, in order to find discrepancies and allow identification of future challenges. Important issues for future care are innovations in immunosuppressive medication, improving medication adherence, careful donor selection with regard to characteristics of both donor and recipient, improvement of surgical techniques and increased attention for lower urinary tract dysfunction and voiding behavior in all patients.

Clinical predictors of incipient vertebral fractures and bone mineral density in kidney transplant patients

PURPOSE

Kidney transplant recipients are prone to metabolic bone diseases and consequent fractures. This study aimed to evaluate the incidence of incipient vertebral fractures, osteopenia, osteoporosis, and the clinical factors associated with incipient vertebral fractures in a group of kidney transplant patients.

METHODS

Two hundred sixty-four patients (F/M 124/140, 45.3 ± 13 years) who had undergone kidney transplantation in tertiary care centers were included. Vertebral fractures were assessed semiquantitatively using conventional thoracolumbar lateral radiography in 202 of the patients.

RESULTS

Vertebral fractures were observed in 56.4% (n = 114) of the study group. The frequency of osteoporosis was 20.0% (53 of 264 patients), and osteopenia was 35.6% (94 of 264 patients). Bone mineral density (BMD) levels were in the normal range in 40.3% (n = 46) of the subjects with vertebral fractures. It was in the osteoporotic range in 20.1% (n = 23) and the osteopenic range in 40.3% (n = 46). Vertebral fractures were associated with age, duration of hemodialysis, BMI, and femoral neck Z score (R² 37.8%, p = 0.027).

CONCLUSION

As incipient vertebral fractures can be observed in patients with normal BMD levels in kidney transplant recipients, conventional X-ray screening for vertebral fractures may be beneficial for a proper therapy decision of metabolic bone disease in kidney transplant recipients.

A Three-Year Experience With Overseas Kidney Transplantation in a Tertiary Transplant Center in Saudi Arabia

Background Overseas kidney transplantation is known to be associated with adverse outcomes. In this study, we aim to present a detailed analysis of our three years of experience with overseas kidney transplantation at one of the largest kidney transplant referral sites in the Kingdom of Saudi Arabia. Materials and methods A retrospective cohort study included patients who underwent kidney transplantation overseas and were subsequently followed up at King Abdulaziz Medical City from January 2016 to July 31, 2019. In addition, we compared the outcomes of the patients who underwent kidney transplantation overseas with a cohort of patients who were transplanted locally within the same period. Patients in both cohorts had to have at least one year of follow-up post-transplantation. Results We included a total of 51 patients who underwent kidney transplantation overseas. The mean age of the cohort was 44.7 years, and 69% were male. Almost 60% of the cohort had one or no comorbidity prior to transplant, with hypertension (84%) and diabetes mellitus (37%) being the leading comorbidities. The cause of end-stage kidney disease was unknown in 55% of our patients. In those who had an identifiable cause, lupus nephropathy and diabetes were the most common causes of kidney failure. In comparison with the locally transplanted cohort, no difference was detected between these groups in their baseline characteristics, type or number of comorbidities, medical or surgical complications postoperatively, and one-year mortality. However, we found that the graft rejection rate was significantly higher in patients transplanted overseas (OR=5.4, p<0.001). In addition, the proportion of patients who received anti-thymocyte globulin (ATG) induction was also less in the group with overseas kidney transplantation (58% vs. 22%, p<0.001). Conclusion Overseas transplantation is associated with an increased risk for graft rejection. Our study suggests that overseas kidney transplantation is possibly driven by a lack of donors, especially cadaveric. Counseling patients about risks associated with overseas kidney transplantation and encouraging the public to register for organ donation after death may help curb out this practice.

Time-Dissociated Pharmacokinetic Pharmacodynamic Model of Cyclosporine Among Malaysian Renal Transplant Recipients

BACKGROUND

Cyclosporine is an essential component of many immunosuppressive regimens. However, its pharmacokinetic and pharmacodynamic (PKPD) modeling has not been widely investigated. This study aims to develop a time-dissociated PKPD model of cyclosporine in renal transplant patients.

METHODS

Medical records of renal transplant patients at Penang General Hospital were retrospectively analyzed. A time-dissociated PKPD model with covariate effects was developed using NONMEM to evaluate renal graft function response, quantified as estimated glomerular filtration rate (eGFR), toward the cyclosporine cumulative exposure (area under the concentration-time curve). The final model was integrated into a tool to predict the potential outcome. Individual eGFR predictions were evaluated based on the clinical response recorded as acute rejection/nephrotoxicity events.

RESULTS

A total of 1256 eGFR readings with 2473 drug concentrations were obtained from 107 renal transplant patients receiving cyclosporine. An Emax drug effect with a linear drug toxicity model best described the data. The baseline renal graft level (E0), maximum effect (Emax), area under the concentration-time curve achieving 50% of the maximum effect, and nephrotoxicity slope were estimated as 12.9 mL·min-1·1.73 m-2, 50.7 mL·min-1·1.73 m-2, 1740 ng·h·mL-1, and 0.00033, respectively. The hemoglobin level was identified as a significant covariate affecting the E0. The model discerned acute rejection from nephrotoxicity in 19/24 cases.

CONCLUSIONS

A time-dissociated PKPD model successfully described a large number of observations and was used to develop an online tool to predict renal graft response. This may help discern early rejection from nephrotoxicity, especially for patients unwilling to undergo a biopsy or those waiting for biopsy results.

Pregnancy Outcomes After Kidney Transplantation and Long-Term Evolution of Children: A Single Center Experience

BACKGROUND

Pregnancies in women who underwent kidney transplants are at high risk compared with the general population.

METHODS

In this study, we aimed to retrospectively assess the obstetrical complications, delivery outcomes, and impact of pregnancy on kidney allograft function in a single-center cohort of kidney transplant recipients (KTRs). We provide data regarding the long-term evolution of children.

RESULTS

Thirty-two KTRs underwent a total of 57 pregnancies between 1994 and 2010. Fourteen pregnancies (24 %) did not survive caused by miscarriages (n = 9), stillborn (n = 1), ectopic pregnancies (n = 2), and medical abortion (n = 2). Live birth occurred in 76% of pregnancies. Delivery was by cesarean in 66%. The mean gestational age was 30.45 ± 11.3 weeks and 65% of newborns were premature. A low birth weight <2500g was noted in 46%. Obstetric complications were de novo hypertension in 4%, pre-eclampsia in 9%, and gestational diabetes in 2%. The 5- and 10-year post-delivery death-censored graft loss rates were 3.1% and 12.5%, respectively. Data on 21 children were collected via a self-questionnaire. After a median follow-up time of 17 years, they appeared in good medical and psychological health. None of them suffered from chronic disease (especially uronephrological condition) or was taking chronic medication.

CONCLUSIONS

Long-term evolution of children born to women who underwent kidney transplants seems favorable. Pregnancies in KTRs are successful in two-thirds of cases but are at increased risk of prematurity, delivery by cesarean, and low birth weight.

New onset hypertension after transplantation

It has been reported that up to 90% of organ transplant recipients have suboptimal blood pressure control. Uncontrolled hypertension is a well-known culprit of cardiovascular and overall morbidity and mortality. In addition, rigorous control of hypertension after organ transplantation is a crucial factor in prolonging graft survival. Nevertheless, hypertension after organ transplantation encompasses a broader range of causes than those identified in non-organ transplant patients. Hence, specific management awareness of those factors is mandated. An in-depth understanding of hypertension after organ transplantation remains a debatable issue that necessitates further clarification. This article provides a comprehensive review of the prevalence, risk factors, etiology, complications, prevention, and management of hypertension after organ transplantation.

Development and Validation of the New Liquid Chromatography-Tandem Mass Spectrometry Method for the Determination of Unbound Tacrolimus in the Plasma Ultrafiltrate of Transplant Recipients

(1) Background: Only unbound tacrolimus particles are considered to be active and capable of crossing cellular membranes. Thus, the free-drug concentration might be better associated with clinical effects than the total drug concentration used for dosage adjustment. We propose a new, fully validated online liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for unbound tacrolimus concentration measurement. (2) Methods: The determination of the unbound tacrolimus concentration in plasma ultrafiltrate was performed with the Nexera LC system with LCMS-8050 triple quadrupole MS using ascomycin as an internal standard. Chromatographic separation was made using a HypurityC18 analytical column. MS/MS with electrospray ionization and positive-ion multiple-reaction monitoring was used. The unbound tacrolimus level was determined in 36 patients after solid organ transplantation (n = 140). (3) Results: A lower limit of quantification 0.1 pg/mL was achieved, and the assay was linear between 0.1 and 20 pg/mL (R2 = 0.991). No carry-over was detected. The within-run and between-run accuracies ranged between 97.8–109.7% and 98.3–107.1%, while the greatest imprecision was 10.6% and 10.7%, respectively. Free tacrolimus in patients’ plasma ultrafiltrate varied between 0.06 and 18.25 pg/mL (median: 0.98 pg/mL). (4) Conclusions: The proposed method can be easily implemented. The significance of the unbound tacrolimus concentration needs to be investigated. This may facilitate the individualization and optimization of immunosuppressive treatment.

Personalized immunosuppression after kidney transplantation

With advances in immunosuppressive therapy, there have been significant improvements in acute rejection rates and short-term allograft survival in kidney transplant recipients. However, this success has not been translated into long-term benefits by the same magnitude. Optimization of immunosuppression is important to improve the clinical outcome of transplant recipients. It is important to note that each patient has unique attributes and immunosuppression management should not be a one-size-fits-all approach. Elderly transplant patients are less likely to develop acute rejection but more likely to die from infectious and cardiovascular causes than younger patients. For those with post-transplant cancers and BK polyomavirus-associated nephropathy, reduction of immunosuppression can increase the risk of rejection. Therapeutic drug monitoring (TDM) is routinely used for dosage adjustment of several immunosuppressive drugs. It has been hoped that pharmacogenetics can be used to complement TDM in optimizing drug exposure. Among the various drug-genotype pairs being investigated, tacrolimus and CYP3A5 gives the most promising results. Different studies have consistently shown that CYP3A5 expressers require a higher tacrolimus dose and take longer time to achieve target blood tacrolimus levels than nonexpressers. However, for pharmacogenetics to be widely used clinically, further trials are necessary to demonstrate the clinical benefits of genotype-guided dosing such as reduction of rejection and drug-related toxicities. The development of different biomarkers in recent years may help to achieve true personalized therapy in transplant patients.

Clinically available immunosuppression averts rejection but not systemic inflammation after porcine islet xenotransplant in cynomolgus macaques

A safe, efficacious, and clinically applicable immunosuppressive regimen is necessary for islet xenotransplantation to become a viable treatment option for diabetes. We performed intraportal transplants of wild-type adult porcine islets in 25 streptozotocin-diabetic cynomolgus monkeys. Islet engraftment was good in 21, partial in 3, and poor in 1 recipient. Median xenograft survival was 25 days with rapamycin and CTLA4Ig immunosuppression. Adding basiliximab induction and maintenance tacrolimus to the base regimen significantly extended median graft survival to 147 days (p < .0001), with three animals maintaining insulin-free xenograft survival for 265, 282, and 288 days. We demonstrate that this regimen suppresses non-Gal anti-pig antibody responses, circulating effector memory T cell expansion, effector function, and infiltration of the graft. However, a chronic systemic inflammatory state manifested in the majority of recipients with long-term graft survival indicated by increased neutrophil to lymphocyte ratio, IL-6, MCP-1, CD40, and CRP expression. This suggests that this immunosuppression regimen fails to regulate innate immunity and resulting inflammation is significantly associated with increased incidence and severity of adverse events making this regimen unacceptable for translation. Additional studies are needed to optimize a maintenance regimen for regulating the innate inflammatory response.

Transplant Onconephrology in Patients With Kidney Transplants

Cancer is a leading cause of death in patients with kidney transplantation. Patients with kidney transplants are 10- to 200-times more likely to develop cancers after transplant than the general population, depending on the cancer type. Recent advances in cancer therapies have dramatically improved survival outcomes; however, patients with kidney transplants face unique challenges of immunosuppression management, cancer screening, and recurrence of cancer after transplant. Patients with a history of cancer tend to be excluded from transplant candidacy or are required to have long cancer-free wait time before wait-listing. The strategy of pretransplant wait time management may need to be revisited as cancer therapies improve, which is most applicable to patients with a history of multiple myeloma. In this review, we discuss several important topics in transplant onconephrology: the current recommendations for pretransplant wait times for transplant candidates with cancer histories, cancer screening post-transplant, post-transplant lymphoproliferative disorder, strategies for transplant patients with a history of multiple myeloma, and novel therapies for patients with post-transplant malignancies. With emerging novel cancer treatments, it is critical to have multidisciplinary discussions involving patients, caregivers, transplant nephrologists, and oncologists to achieve patient-oriented goals.

Adherence to Immunosuppressive Medication in Iraqi Kidney Transplant Recipients During the First Year of Transplant. A Single-Center Experience

OBJECTIVES

Our objective was to measure adherence to immunosuppressive medications among Iraqi renal transplant patients at a single center.

MATERIALS AND METHODS

This cross-sectional study was conducted from January to November 2020 in the outpatient unit of the Nephrology and Renal Transplantation Center in Baghdad's Medical City. Seventy-five adult Iraqi renal transplant recipients were recruited. An Arabic version of the Basel Assessment of Adherence to Immunosuppressive Medications (BAASIS) scale was used to evaluate adherence.

RESULTS

The study included 75 adult renal transplant recipients (51 men/24 women) with a mean age of 39.44 ± 12.06 years. The mean time posttransplant was 8.11 ± 3.12 months. In our patient group, 65.33% reported total adherence and 34.6% did not adhere to one (25.3%) or more (9.3%) drug. We observed a statistically significant association between nonadherence and complications (P = .015, chi-square test). Four patients had biopsy-proven acute rejection, and all 4 patients were noncompliant with medications. Binary logistic regression model P values for employment, time after transplant, and complications were .06, .06, and .08, respectively.

CONCLUSIONS

There was a high rate of nonadherence among our sample of Iraqi renal transplant recipients in the first year posttransplant. Time after transplant and transplant complications were related to nonadherence. More extensive multicenter studies are needed to define the actual rate of adherence to immune suppression in Iraq.

Lessons of the month 2: A case of inappropriate drug-drug interaction in kidney transplant

Carbamazepine remains a first-line antiepileptic medication for the treatment of partial seizures. Despite its widespread use, carbamazepine has significant neurotoxicity and hypersensitivity reactions. We report a case of a patient post-kidney transplant who was on regular carbamazepine for childhood epilepsy and developed nystagmus, diplopia and a broad-base gait after receiving diltiazem. Understanding of the interaction between diltiazem and carbamazepine is necessary to prevent the neurotoxic effects.

Panel-reactive Antibody and the Association of Early Steroid Withdrawal With Kidney Transplant Outcomes

BACKGROUND

Early steroid withdrawal (ESW) is a viable maintenance immunosuppression strategy in low-risk kidney transplant recipients. A low panel-reactive antibody (PRA) may indicate low-risk condition amenable to ESW. We aimed to identify the threshold value of PRA above which ESW may pose additional risk and to compare the association of ESW with transplant outcomes across PRA strata.

METHODS

We studied 121 699 deceased-donor kidney-only recipients in 2002-2017 from Scientific Registry of Transplant Recipients. Using natural splines and ESW-PRA interaction terms, we explored how the associations of ESW with transplant outcomes change with increasing PRA values and identified a threshold value for PRA. Then, we assessed whether PRA exceeding the threshold modified the associations of ESW with 1-y acute rejection, death-censored graft failure, and death.

RESULTS

The association of ESW with acute rejection exacerbated rapidly when PRA exceeded 60. Among PRA ≤60 recipients, ESW was associated with a minor increase in rejection (adjusted odds ratio [aOR], 1.001.051.10) and with a tendency of decreased graft failure (adjusted hazard ratio [aHR], 0.910.971.03). However, among PRA >60 recipients, ESW was associated with a substantial increase in rejection (aOR, 1.191.271.36; interaction P < 0.001) and with a tendency of increased graft failure (aHR, 0.981.081.20; interaction P = 0.028). The association of ESW with death was similar between PRA strata (PRA ≤60, aHR, 0.910.961.01; and PRA >60, aHR, 0.900.991.09; interaction P = 0.5).

CONCLUSIONS

Our findings show that the association of ESW with transplant outcomes is less favorable in recipients with higher PRA, especially those with PRA >60, suggesting a possible role of PRA in the risk assessment for ESW.