Physical Frailty Predicts Outcomes in Patients Undergoing Evaluation for Kidney Transplantation

INTRODUCTION

An increasing number of older patients are undergoing evaluation for kidney transplantation; however, older patients experience increased rates of complications compared with younger patients, leading to the study of frailty assessments. Although many centers have evaluated the Fried Frailty Phenotype (FFP), less is known about the ability of the Short Performance Physical Battery (SPPB) to predict outcomes.

METHODS

Frailty assessment by FFP and SPPB was introduced into routine outpatient evaluation for patients aged 55 years and older referred for transplantation. Transplant rate, length of stay, readmission up to 3 months posttransplant, and death were reviewed. Patients were evaluated in an initial cohort followed by a validation cohort by FFP and SPPB. Multivariate analysis correcting for demographic characteristics was applied.

RESULTS

Patient cohorts reflected the racial and ethnic diversity of our population, including approximately 40% Hispanic patients. The first cohort of 514 patients demonstrated a significant association between frailty as measured by SPPB and transplantation (odds ratio [OR], 2.27; 95% CI, 1.38-3.83; p = .002). The second cohort of 1408 patients validated the association between frailty measured by SPPB and transplantation (OR, 2.81; 95% CI, 1.83-4.48; p < .001). In addition, there was a significant association between nonfrail status measured by SPPB and death (OR, 0.16; 95% CI, 0.04-0.62; p = .006).

CONCLUSIONS

Frailty assessment is a potentially useful approach for the assessment of transplant candidates. Our real-world study examined the performance of 2 methods of frailty evaluation methods in a diverse population, demonstrating that SPPB but not FFP was predictive of clinical outcomes. Incorporation of frailty assessments into transplant evaluation may improve risk stratification and optimize outcomes for older patients.

Novel indications for referral and care for simultaneous liver kidney transplant recipients

PURPOSE OF REVIEW

Kidney dysfunction is challenging in liver transplant candidates to determine whether it is reversible or not. This review focuses on the pertinent data on how to best approach liver transplant candidates with kidney dysfunction in the current era after implementing the simultaneous liver kidney (SLK) allocation policy and safety net.

RECENT FINDINGS

The implementation of the SLK policy inverted the steady rise in SLK transplants and improved the utilization of high-quality kidneys. Access to kidney transplantation following liver transplant alone (LTA) increased with favorable outcomes. Estimating GFR in liver transplant candidates remains challenging, and innovative methods are needed. SLK provided superior patient and graft survival compared to LTA only for patients with advanced CKD and dialysis at least 3 months. SLK can provide immunological protection against kidney rejection in highly sensitized candidates. Post-SLK transplant care is complex, with an increased risk of complications and hospitalization.

SUMMARY

The SLK policy improved kidney access and utilization. Transplant centers are encouraged, under the safety net, to reserve SLK for liver transplant candidates with advanced CKD or dialysis at least 3 months while allowing lower thresholds for highly sensitized patients. Herein, we propose a practical approach to liver transplant candidates with kidney dysfunction.

Patterns of administration of antibody induction therapy and their associated outcomes

1. There was a dramatic shift in the type of induction therapy used between 1996-2000. In 2000, more than half of recipients received induction therapy. 2. The type of transplants strongly influenced the use of antibody induction. LD recipients were least likely to receive antibody induction followed by unsensitized, sensitized cadaveric and SPK recipients. 3. Pan-T antibody induction was used more frequently in patients with DGF and in high immunologic risk groups. 4. IL-2 receptor antagonists have become the dominant induction therapy; even for recipients with high immunologic risk or those with DGF. 5. We cannot demonstrate the effects of pan-T antibody induction on the resolution of DGF. Pan-T antibody induction did not improve graft survival in any cohorts, although it was associated with lower acute rejection rates in LD and unsensitized groups. 6. IL-2R antibody induction therapy was associated with lower acute rejection and graft failure at one year in LD and unsensitized groups. However, this trend cannot be demonstrated in higher immunologic risk groups ie., sensitized cadaveric and SPK.

Recent Trends in Kidney Transplant in the United States

The number of new wait list registrants has increased in the last decade but not to the same magnitude as the increase in the number of end stage renal disease patients in the United States. The number of wait list patients has increased at a much higher pace due to the lack of kidney supply. The overall number of kidney transplants only increased slightly. Paired exchange kidney transplant is a viable source of increasing the availability of kidney transplant and also offers access to transplant to patients with immunologic barriers to their intended donors. Paired donor exchange results in similar outcomes despite recipients' having a higher immunologic risk profile. The kidney allocation system (KAS) was recently implemented and so far has resulted in more access for patients with very high immunologic risk and allocation of lower kidney donor profile index organs to younger recipients. Longer follow up is needed to determine the net benefit of the KAS.

Interplay of Donor-Recipient Relationship and Donor Race in Living Liver Donation in the United States

INTRODUCTION

Living liver donation improves survival of end-stage liver disease (ESLD) patients. Yet, it continues to represent a small proportion of United States (U.S.) liver transplantation with existing racial disparities. We investigated the interplay of donor-recipient relationship and donor race to understand donor subgroups with no significant increase.

METHODS

We studied 4407 living liver donors in the U.S. from January 1, 2012, to December 31, 2022 (median age = 36 years, and 59% were biologically related to the recipient). We quantified the change in the number of donors per 3-year increment using negative binomial regression (incidence rate ratio [IRR]), stratified by donor-recipient relationship and race/ethnicity.

RESULTS

Among biologically related donors, the observed annual number of White donors increased from 146 to 253, Hispanic donors from 18 to 53, and Black donors decreased from 11 to 10. Among unrelated donors, White donors increased from 65 to 221, Hispanic donors from 4 to 25, and Black donors from 3 to 11. For the IRR of biologically related donors aged <40 and ≥40 years, White donors increased by 18% and 22%; Hispanic donors increased by 25% and 54%; and Black donors did not change. Likewise, the IRR of unrelated donors aged <40 and ≥40 years, White donors increased by 48% and 55%; Hispanic donors increased by 52% and 65%; and Black donors did not change.

CONCLUSIONS

While biologically related donors represent the majority of donors, unrelated donors have substantially risen in recent years, primarily driven by White donors. Although the rate of unrelated donations increased among Hispanic donors, the absolute number remains very small (≤25 donors/year). Interventions are needed to increase education among Hispanic and Black communities to grow unrelated living liver donations across race/ethnicity.

Pretransplant Treatment to Avoid Recurrent Membranous Nephropathy in a Kidney Transplant Recipient: A Case Report

Kidney transplant candidates with high anti-M-type phospholipase A2 receptor antibody activity may be at increased risk for early postkidney transplant recurrence and allograft loss. Pretransplant treatment to induce serological remission may be warranted to improve allograft survival. In this case report, a patient seeking their third kidney transplant, who lost 2 prior living donor transplants from early recurrent membranous nephropathy, underwent pretransplant treatment for membranous nephropathy with serological remission and no evidence of recurrent disease.

Plasma proteome perturbation for CMV DNAemia in kidney transplantation

BACKGROUND

Cytomegalovirus (CMV) infection, either de novo or as reactivation after allotransplantation and chronic immunosuppression, is recognized to cause detrimental alloimmune effects, inclusive of higher susceptibility to graft rejection and substantive impact on chronic graft injury and reduced transplant survival. To obtain further insights into the evolution and pathogenesis of CMV infection in an immunocompromised host we evaluated changes in the circulating host proteome serially, before and after transplantation, and during and after CMV DNA replication (DNAemia), as measured by quantitative polymerase chain reaction (QPCR).

METHODS

LC-MS-based proteomics was conducted on 168 serially banked plasma samples, from 62 propensity score-matched kidney transplant recipients. Patients were stratified by CMV replication status into 31 with CMV DNAemia and 31 without CMV DNAemia. Patients had blood samples drawn at protocol times of 3- and 12-months post-transplant. Additionally, blood samples were also drawn before and 1 week and 1 month after detection of CMV DNAemia. Plasma proteins were analyzed using an LCMS 8060 triple quadrupole mass spectrometer. Further, public transcriptomic data on time matched PBMCs samples from the same patients was utilized to evaluate integrative pathways. Data analysis was conducted using R and Limma.

RESULTS

Samples were segregated based on their proteomic profiles with respect to their CMV Dnaemia status. A subset of 17 plasma proteins was observed to predict the onset of CMV at 3 months post-transplant enriching platelet degranulation (FDR, 4.83E-06), acute inflammatory response (FDR, 0.0018), blood coagulation (FDR, 0.0018) pathways. An increase in many immune complex proteins were observed at CMV infection. Prior to DNAemia the plasma proteome showed changes in the anti-inflammatory adipokine vaspin (SERPINA12), copper binding protein ceruloplasmin (CP), complement activation (FDR = 0.03), and proteins enriched in the humoral (FDR = 0.01) and innate immune responses (FDR = 0.01).

CONCLUSION

Plasma proteomic and transcriptional perturbations impacting humoral and innate immune pathways are observed during CMV infection and provide biomarkers for CMV disease prediction and resolution. Further studies to understand the clinical impact of these pathways can help in the formulation of different types and duration of anti-viral therapies for the management of CMV infection in the immunocompromised host.

Multivariate analyses of antibody induction therapies

1. Between 1997-2002 a 3-fold increase in induction therapy was attributed to surging use of Simulect, Zenapax and Thymoglobulin. 2. Induction therapy reduced the hazard ratio by 8% in deceased and 13% in living donor transplants and reduced the risk of rejection by 26% in deceased and 13% in living donor allografts. 3. Thymoglobulin was used more often in sensitized and retransplanted recipients and those with delayed graft function. Zenapax was used more often in pediatric recipients and those receiving MMF. Simulect was used more often in recipients not receiving MMF. 4. Simulect was associated with increased risk of rejection, perhaps due to a negative association with MMF maintenance immunosuppression. On the other hand, recipients not given MMF had a decreased hazard ratio with Simulect induction. 5. Induction reduced the risk of rejection in deceased donor allografts with delayed graft function, and sensitized and Black recipients. However a resultant impact on hazard ratio was not observed in these high-risk cohorts. 6. When considering HLA compatibility, induction reduced the hazard ratio only for DR-mismatched deceased donor allografts. Thymoglobulin induction increased the hazard ratio for zero-haplotype-mismatched living donor transplants.

Application of diagnostic classification algorithms to identify the most common causes of post-transplant complications

ICD-9-CM diagnoses for hospitalizations occurring during the first 6 post-transplant months were summarized into Clinical Classifications System (CCS) categories. Of the 28,900 patients examined, 54% had at least one hospitalization. There were 2.39 hospitalizations per patient-year at risk. The total Medicare inpatient costs were $339 million and mean length of stay was 8.3 days. The most common and costly CCS diagnosis was complications of a kidney transplant followed by infections, circulatory system disease, gastrointestinal disease and endocrine complications. The CCS is a useful tool to summarize the complexity of claims information in the USRDS and could prove useful in further claims research.

Kidney failure requiring kidney transplantation after pancreas transplant alone

Pancreas transplant alone (PTA) is usually performed in type 1 diabetic patients with preserved renal function to correct severe metabolic complications. One of the major concerns is renal failure after PTA. Here, we reported the cumulative incidence of kidney failure requiring kidney transplantation (KF/KT) among PTA recipients in the United States. Using the Organ Procurement Transplant Network/ United Network for Organ Sharing database, all primary adult PTA recipients with estimated baseline glomerular filtration rate (by the Modification of Diet in Renal Disease equation) >or=60 mL/min/1.73m2 were selected (n=1085). KF/ KT after PTA was defined as: wait-listing for or receiving a kidney alone (KA) or simultaneous pancreas kidney (SPK) transplant. The median follow-up time was 1185 days (25-75%: 524-2183). Ten years post PTA, 120 (11.1%) patients developed KF/KT; of those, 70 (6.5%) subsequently received a KA/SPK transplant (56 received KA and 14 received SPK) and 50 (4.6%) recipients were listed without receiving a transplant. The cumulative incidence of KF/KT after PTA at 1, 3, and 5 years after PTA was 0.3, 2.5, and 9.7%, respectively. In conclusion, KF/KT after PTA was not uncommon (9.7% at 5 years), and prospective PTA recipients should be aware of the risks of kidney failure after transplantation.

Deceased Donor Kidney Nonuse: A Systematic Approach to Improvement

A large number of procured kidneys continue not to be transplanted, while the waiting list remains high.

Methods

We analyzed donor characteristics for unutilized kidneys in our large organ procurement organization (OPO) service area in a single year to determine the reasonableness of their nonuse and to identify how we might increase the transplant rate of these kidneys. Five experienced local transplant physicians independently reviewed unutilized kidneys to identify which kidneys they would consider transplanting in the future. Biopsy results, donor age, kidney donor profile index, positive serologies, diabetes, and hypertension were risk factors for nonuse.

Results

Two-thirds of nonused kidneys had biopsies with high degree of glomerulosclerosis and interstitial fibrosis. Reviewers identified 33 kidneys as potentially transplantable (12%).

Conclusions

Reducing the rate of unutilized kidneys in this OPO service area will be achieved by setting acceptable expanded donor characteristics, identifying suitable well-informed recipients, defining acceptable outcomes, and systematically evaluating the results of these transplants. Because the improvement opportunity will vary by region, to achieve a significant impact on improving the national nonuse rate, it would be useful for all OPOs, in collaboration with their transplant centers, to conduct a similar analysis.

Outcomes of small pediatric donor kidney transplants according to donor weight

A small pediatric deceased donor (SPD) weight cutoff whether to transplant as en bloc (EB) or single pediatric (SP) kidney is uncertain. Using UNOS/OPTN data (2000-2019), 27 875 SPDs were divided by (i) EB (11.4%) or SP (88.6%) and (ii) donor weight [≤10 (5.4%), >10-15 (8.3%), >15-18 (3.7%), >18-20 (2.9%), and >20 kg (79.7%)]. SP >20 kg and adult deceased donors (grouped by Kidney Donor Profile Index, KDPI, <30, 30-85, and >85) were used as references. The primary outcome was 10-year graft failure. In SP <10 kg, the hazard ratio (HR) for overall graft failure was 1.64 (1.38-2.20) compared with EB <10 kg, and 1.45 (1.18-1.80) compared with SP >20 kg. In SP >10-15 kg, HR was 1.31 (1.12-1.54) compared with EB >10-15 kg, and 1.04 (0.91-1.18) compared with SP >20 kg. In SP >15 kg, the risk was the same as SP >20 kg. Ten-year overall graft survival of SP 12 kg was comparable to SP >20 kg (62% vs. 57%). Ten-year death censored graft failure of SP >10-15 kg (70%) and SP >15-18 kg (70%) was like the adult donors with KDPI 30-85 (67%). In conclusion, we recommend single kidney transplants from SPDs with weight >12 kg to adult recipients in centers with experience in SPD transplants to optimize organ utilization.

Cytotoxic KLRG1+ IL-7R- effector CD8+ T cells distinguish kidney transplant recipients controlling cytomegalovirus reactivation

Introduction

Cytomegalovirus (CMV) viremia remains a major contributor to clinical complications in solid organ transplant (SOT) patients, including organ injury, morbidity and mortality. Given their critical role in antiviral defense, CD8+ T cells are essential for protective immunity against CMV.

Methods

Using single-cell RNA sequencing, we investigated the transcriptional signatures and developmental lineages of CD8+ T cells in eight immunosuppressed kidney transplant recipients (KTRs) who received organs from CMV-seropositive donors. Results were validated in a cohort of 62 KTRs using immunophenotyping.

Results

Our data revealed a significant influence of CMV serostatus on transcriptional variance of CD8+ memory T cells, associating with the first principal component from a global analysis of CD8+ T cells (p =0.0406), forming a continuum with five principal differentiation trajectories driven by CMV primary infection or reactivation. Following CMV primary infection, CD8+ T cells were hallmarked by restrained effector-memory differentiation. CD8+ T cells during CMV reactivation diverged non-linearly into senescent-like cells with signatures of arrested cell cycle, diminished translational activity and downregulated ZNF683 and longitudinally expanding effector cells with robust cytotoxic potential and upregulated ZNF683, acting as a reservoir for long-lived effector cells supporting long-term protection. Notably, CD28lo KLRG1hi IL-7R (CD127)lo HLA-DRhi CD8+ T cells present prior to the detection of viremia in CMV-seropositive patients emerged as a key feature distinguishing patients who did or did not undergo CMV reactivation after prophylaxis discontinuation (p =0.0163). Frequencies of these cells were also positively correlated with CMV-stimulated secretion of IFN-γ (p =0.0494), TNF-α (p =0.0358), MIP-1α (p =0.0262), MIP-1β (p =0.0043).

Discussion

These results provide insights into the transcriptional regulation that influences the generation of CD8+ T cell immunity to CMV and may inform strategics for monitoring host immune response to CMV to better identify and introduce therapeutic intervention to patients at risk of developing clinically significant CMV viremia.

629. Blood Transcriptome Variations Predict Infection and Rejection in the Older Kidney Transplant Recipient

Background

Compared with younger patients on similar immunosuppression regimens, older solid-organ transplant recipients experience increased rates of infection and death, but decreased rates of rejection. Our previous findings demonstrated increased T-cell immunosenescence and pro-inflammatory monocytes in older patients. This study sought to define the implications of transcriptome alterations for clinical outcomes. The objective of this abstract is to evaluate older vs. younger solid-organ transplant recipients for differential patterns of gene expression associated with infection and rejection.

Methods

Peripheral blood mononuclear cells were isolated from 23 older (≥age 60) and 37 matched younger (ages 30–59) kidney transplant recipients at 3 months after transplantation. RNA extraction was performed on banked PBMCs. Isolated RNA was converted to fluorescent cRNA and hybridized to Illumina Human HT-12 v4 BeadArrays. Gene expression values were quantile-normalized and log2-transformed for mixed effect linear model analyses to identify differential expression as a function of age, adjusted for induction type, donor type, and sex. Statistical analysis was performed using R software.

Results

Genes differentially expressed in older patients revealed an over-representation of pro-inflammatory genes and a down regulation of genes associated with the CD8 immune response. Patients who went on to develop infection demonstrated an increase in IRF transcription factor activation and plasmacytoid dendritic cell activity. Patients who developed rejection demonstrated an increase in myeloid lineage immune cell activity.

Conclusion

Differential patterns of gene expression were observed in patients who developed infection in the first year after kidney transplantation. These findings were distinct from the gene expression changes associated with development of rejection. These findings may explain the mechanism behind vulnerability to infection in older transplant patients. In addition, monitoring of changes in gene expression may provide an avenue for patient monitoring after transplantation as well as individualization of immune suppression after solid-organ transplantation.

Disclosures

All authors: No reported disclosures.

Overview of renal transplantation

Kidney transplantation is the treatment of choice for end stage renal disease patients. Recent advances, including newer immunosuppressants, revision of organ allocation policies, and better medical care of renal transplant recipients, have resulted in an increase number of transplants with improved outcomes. The major obstacles include the lack of improvement in long term outcomes, shortage of organs and long-term morbidity of candidates with chronic kidney disease. This review highlights transplant immunology, organ allocation, immunosuppressive medications, and complications of transplantation involving post transplantation infections, diabetes, and cardiovascular disease.

Renal Transplant Outcomes in Waitlist Candidates with a Previous Inactive Status Due to Being Temporarily Too Sick

BACKGROUND

In 2003, the United Network for Organ Sharing (UNOS) changed its policy to allow candidates with 'inactive' status to accrue time on the waitlist. In this study, we assessed the transplant outcomes among deceased donor kidney transplant (DDKT) recipients who were temporarily inactive specifically due to medical reason, i.e., being temporarily too sick (reason 7).

METHODS

Using the UNOS database, adult DDKT recipients were divided into two groups: those who had never been inactivated (active group) and those with a history of being inactive due to reason 7 (reason 7 group). Patient and graft survival, 3-year risk of death, and graft failure were examined and compared.

RESULTS

After 3 years of follow-up, patient survival in the reason 7 group was significantly lower than that of the active group (88.14% versus 91.93%, p < 0.01). The reason 7 group had a 20% increased risk of death (hazard ratio, HR 1.20, confidence interval, CI 1.04 - 1.38), a 16% increase in graft failure (HR 1.16, CI 1.06-1.28), and a 15% decrease in death-censored graft failure (HR 1.15, CI 1.01-1.31).

CONCLUSION

Recipients with a history of reason 7 have lower patient and graft survival when compared to the active group. Nonetheless, the margins of difference are minimal. Candidates with a history of reason 7 should not be discouraged from transplantation once they return to active status. Standardized criteria for placing candidates on inactive status should be developed to reduce disparities among transplant centers.

Intraoperative Mean Arterial Pressure and Postoperative Delayed Graft Function in Kidney Transplantation: Evaluating Three Commonly Used Thresholds

BACKGROUND

Delayed graft function (DGF) is a common early complication after kidney transplantation (KT) and is associated with various long-term adverse outcomes. Despite numerous studies on hemodynamic management, the optimal hemodynamic goals during KT remain unclear. In this retrospective study, we aimed to investigate if three mean artery pressure (MAP) thresholds (≤75, 80, and 85 mmHg) that were commonly used in clinical practice were associated with DGF in adult patients undergoing KT.

METHODS

We extracted de-identified data on adult patients who underwent deceased donor KT from our Discovery Data Repository. DGF was defined as the requirement for dialysis within the first 7 days after transplantation. Three MAP thresholds (≤75, 80, and 85 mmHg) and the duration of pressure below the three thresholds were recorded. Multivariable logistic analysis was used to identify risk factors for DGF.

RESULTS

We included 2301 adult KT patients. The mean age was 52.5±12.9 years and 59% were male. DGF occurred in 1066 patients (46.3%). Patients frequently experienced MAP ≤75, 80, and 85 mmHg (approximately 70%, 80%, and 90% of patients experienced 10 min of MAP ≤75, 80, and 85 mmHg, respectively). Patients with DGF spent significantly longer durations below the three MAP thresholds during surgery compared with those without DGF. Further analysis revealed that the minimal time spent on MAP ≤75, 80, and 85 mmHg that were significantly associated with DGF were 6, 23, and 37 min, respectively. After adjusting for non-hemodynamic risk factors (age, basiliximab administration, and urine output), prolonged exposure to the three MAP thresholds remained significant predictors for DGF (for MAP ≤75 mmHg, OR 1.257, 95% CI 1.017-1.554, p = 0.034; MAP ≤80 mmHg, OR 1.220, 95% CI 1.018-1.463, p = 0.031; MAP ≤85 mmHg, OR 1.253, 95% CI 1.048-1.498, p = 0.013).

CONCLUSION

Prolonged exposure to the three common MAP thresholds (≤75, 80, and 85 mmHg) occurred frequently during adult deceased donor KT and was associated with DGF.

Changing landscape of living kidney donation and the role of telemedicine

PURPOSE OF REVIEW

There has been a decline in living kidney donation over the last two decades. Donors from low-income families or racial/ethnic minorities face greater disproportionate geographic, financial, and logistical barriers to completing lengthy and complex evaluations. This has contributed to the decreased proportion of these subgroups. The authors view telemedicine as a potential solution to this problem.

RECENT FINDINGS

Since the initial decline of donors in 2005, biologically related donors have experienced a lack of growth across race/ethnicity. Conversely, unrelated donors have emerged as the majority of donors in recent years across race/ethnicity, except for unrelated black donors. Disparities in access to living kidney donation persist. Telemedicine using live-video visits can overcome barriers to access transplant centers and facilitate care coordination. In a U.S. survey, nephrologists, surgeons, coordinators, social workers, and psychologists/psychologists across transplant centers are favorably disposed to use telemedicine for donor evaluation/follow-up beyond the coronavirus disease 2019 pandemic. However, with the waning of relaxed telemedicine regulations under the Public Health Emergency, providers perceive payor policy and out-of-state licensing as major factors hindering telemedicine growth prospects.

SUMMARY

Permanent federal and state policies that support telemedicine services for living kidney donation can enhance access to transplant centers and help overcome barriers to donor evaluation.

A2/A2B Deceased Donor Kidney Transplantation Using A2 Titers Improves Access to Kidney Transplantation: A Single-Center Study

Rationale & Objective

The option for A2/A2B deceased donor kidney transplantation was integrated into the kidney allocation system in 2014 to improve access for B blood group waitlist candidates. Despite excellent reported outcomes, center uptake has remained low across the United States. Here, we examined the effect of implementing an A2/A2B protocol using a cutoff titer of ≤1:8 for IgG and ≤1:16 for IgM on blood group B kidney transplant recipients at a single center.

Study Design

Retrospective observational study.

Setting & Participants

Blood group B recipients of deceased donor kidney transplants at a single center from January 1, 2019, to December 2022.

Exposure

Recipients of deceased donor kidney transplants were analyzed based on donor blood type with comparisons of A2/A2B versus blood group compatible.

Outcomes

One-year patient survival, death-censored allograft function, primary nonfunction, delayed graft function, allograft function as measured using serum creatinine levels and estimated glomerular filtration rate at 1 year, biopsy-proven rejection, and need for plasmapheresis.

Analytical Approach

Comparison between the A2/A2B and compatible groups were performed using the Fisher test or the χ2 test for categorical variables and the nonparametric Wilcoxon rank-sum test for continuous variables.

Results

A total of 104 blood type B patients received a deceased donor kidney transplant at our center during the study period, 49 (47.1%) of whom received an A2/A2B transplant. Waiting time was lower in A2/A2B recipients compared with blood group compatible recipients (57.9 months vs 74.7 months, P = 0.01). A2/A2B recipients were more likely to receive a donor after cardiac death (24.5% vs 1.8%, P < 0.05) and experience delayed graft function (65.3% vs 41.8%). There were no observed differences in the average serum creatinine level or estimated glomerular filtration rate at 1 month, 3 months, and 1 year post kidney transplantation, acute rejection, or primary nonfunction.

Limitations

Single-center study. Small cohort size limiting outcome analysis.

Conclusions

Implementation of an A2/A2B protocol increased transplant volumes of blood group B waitlisted patients by 83.6% and decreased the waiting time for transplantation by 22.5% with similar transplant outcomes.

Kinetics of hepatitis C virus load during hemodialysis: novel perspectives

Hepatitis C virus (HCV) infection remains frequent among dialysis patients. The relationship between viral load and liver disease progression is currently a matter of debate; however, low HCV viral load (HCV RNA) is a well established predictor of successful antiviral treatment. Dialysis patients have immune compromise due to uremia; in spite of this, HCV viral load is not high and does not increase over time. A number of studies support the notion that this dynamics of HCV viral load may be related to lowering of HCV RNA titers during the HD procedure. It has been suggested that the intradialytic reduction of HCV is membrane-dependent; polysulphone (PS) and hemophan membranes appear more effective. Various mechanisms have been mentioned to explain the reduction of HCV RNA during hemodialysis (HD): adsorption of HCV onto dialysis membrane, HCV escape into spent dialysate, destruction of HCV particles or increased interferon (IFN) activity. Several investigators have noted that, at the end of the HD procedure, a virological rebound of HCV viremia occurs. Some suggestions have been made to minimize the risk for HCV escape into spent dialysate. However, controversial evidence on these issues exists: the HCV RNA reduction during HD procedures has not been seen in some studies and the relationship between the intra-dialytic reduction of HCV RNA titers and dialysis membrane is not completely understood. It is evident that additional long-term longitudinal studies by serial viral load estimations are needed to better define the dynamics of HCV viral load in the dialysis population.