Impact of Post-Transplantation Hypomagnesemia on Long-Term Graft and Patient Survival after Transplantation.

BACKGROUND: Post-transplant hypomagnesemia is commonly observed among patients prescribed calcineurin inhibitor (CNIs). METHODS: We conducted a retrospective single-center analysis (2000-2013, N = 726) to examine the association of hypomagnesemia with long-term patient and allograft outcomes in kidney transplant recipients. A median serum magnesium (Mg) level of all measured Mg levels from 1 month to 1 year posttransplant was calculated. RESULTS: For every increase in Mg of 0.1 mg/dL, the risk for either graft loss or death, overall mortality, and death with a functioning graft increased by 11%, 14%, and 12%, respectively (p < 0.01). In a multivariate model, patients with median Mg level ≥1.7 mg/dL had a reduced overall survival rate (HR 1.57, 95% CI: 1.04-2.38, p = 0.033) compared to those with median Mg level <1.7 mg/dL. This association was observed in subgroups of patients above 60 years old, in those who had a slow graft function (SGF) and in females. CONCLUSIONS: Posttransplant hypomagnesemia is associated with better patient and allograft survival up to 10 years posttransplant. This relationship remained significant after accounting for baseline allograft function, presence of SGF and CNI trough levels.

Can uric acid blood levels in renal transplant recipients predict allograft outcome?

BACKGROUND: Hyperuricemia is common after renal transplantation, especially in those receiving calcineurin inhibitors. Little, however, is known about the relationship between uric acid (UA) levels and allograft outcome. METHODS: We conducted a retrospective single-center analysis (N = 368) in order to assess UA blood levels post-transplant association with allograft outcome. For this study, a median serum UA level of all measured UA levels from 1 month to 1 year post renal transplantation was calculated. RESULTS: Patients were divided into 2 groups based on the median UA level measured between 1 and 12 months post-transplant. Those with median UA level ≥ 7 and ≥ 6 mg/dL (N = 164) versus median UA level < 7 and < 6 mg/dL for men and women respectively (N = 204) had lower GFR values at 1, 3 and 5 years posttransplant (mean GFR ± SD of 43.4 ± 20.6 and 58 ± 19.9 at 3 years post-transplant, p < 0.001). In multivariate models, UA levels were no longer significantly associated with renal allograft function. In a multivariate cox proportional hazard model, UA level was found to be independently associated with increased risk for death-censored graft loss (HR of 1.3, 95% CI 1.0-1.7, p < 0.05 for every increase of 1 mg/dL in UA level). CONCLUSION: Hyperuricemia was found to be associated with increased death- censored graft loss but not with allograft function. Increased UA levels were not found to be an independent predictor of long-term allograft function despite the known association of hyperuricemia with the progression of cardiovascular and renal disease.

Combined liver and kidney transplantation in children and long-term outcome.

Combined liver-kidney transplantation (CLKT) is a rarely performed complex surgical procedure in children and involves transplantation of kidney and either whole or part of liver donated by the same individual (usually a cadaver) to the same recipient during a single surgical procedure. Most common indications for CLKT in children are autosomal recessive polycystic kidney disease and primary hyperoxaluria type 1. Atypical haemolytic uremic syndrome, methylmalonic academia, and conditions where liver and renal failure co-exists may be indications for CLKT. CLKT is often preferred over sequential liver-kidney transplantation due to immunoprotective effects of transplanted liver on renal allograft; however, liver survival has no significant impact. Since CLKT is a major surgical procedure which involves multiple and complex anastomosis surgeries, acute complications are not uncommon. Bleeding, thrombosis, haemodynamic instability, infections, acute cellular rejections, renal and liver dysfunction are acute complications. The long-term outlook is promising with over 80% 5-year survival rates among those children who survive the initial six-month postoperative period.

Association of graft survival with tacrolimus exposure and late intra-patient tacrolimus variability in pediatric and young adult renal transplant recipients-an international CTS registry analysis.

Adolescent and young adult age is a high-risk window with an alarmingly increased likelihood of premature kidney graft loss due to immunological rejection. Using the large database of the Collaborative Transplant Study, we analyzed whether a more intense and less variable exposure to tacrolimus could counteract this young age-related enhanced immunoreactivity. Kidney graft recipients aged 12-23 years (n = 964) with a 1-year tacrolimus trough level between 4.0 and 10.9 ng/ml had a 5-year graft survival rate of 85.1%, significantly better than the poor 66.1% rate in patients with a trough level below 4.0 ng/ml who showed a 2.38-fold increased risk of graft loss in the multivariable analysis (P < 0.001). This association was not apparent in young children aged 0-11 years (n = 455) and less pronounced in adults aged 24-34 years (n = 1466). However, an intra-patient variability of tacrolimus (IPV) trough level ≥1.5 at post-transplant years 1 and 2 was associated with an increased graft loss risk in both 12- to 23-year-old and 0- to 11-year-old recipients (P < 0.001 and P = 0.045). Patients with high IPV made up as many as 30% of kidney graft recipients, indicating that a more intense and less variable exposure to tacrolimus could improve graft survival strongly in this high-risk group.

Predictors of long-term renal allograft survival after second kidney transplantation.

INTRODUCTION: Few studies investigate significant perioperative predictors for long-term renal allograft survival after second kidney transplant (SKT). We compared long-term survival following SKT with primary kidney transplant and determined predictors of renal allograft failure after SKT. METHODS: Outcomes of all primary or second kidney transplant recipients at a national kidney transplant center between 1993 and 2017 were reviewed. The primary outcomes measurements were renal allograft survival for both first and second kidney transplants. Secondary outcome measurements were incidence of delayed graft function (DGF), incidence of acute rejection (AR), and predictors for renal allograft survival in SKT recipients. RESULTS: In total, there were 392 SKTs and 2748 primary kidney transplants performed between 1993 and 2017. The 1-, 5-, and 10-year death-censored graft survival for deceased-donor recipients was 95.3%, 88.7%, and 78.2% for primary kidney transplant and 94.9%, 87.1%, and 74.9% for SKT (P = .0288). Survival of primary renal allograft <6 years (HR 0.6, P = .017), AR episodes (HR 1.6, P = .031), DGF (HR 2.0, P = .005), and HLA-DR MM (HR 1.7, P = .018) was independent predictors of long-term renal allograft failure after SKT. CONCLUSION: These findings may provide important information on long-term survival outcomes after SKT and for identifying patients at risk for long-term renal allograft failure after SKT.

Pretransplant serum BAFF levels are associated with pretransplant HLA immunization and renal allograft survival.

BACKGROUND: The essential function of B cell-activating factor (BAFF) is regulating the survival and differentiation of B cells. The link between pretransplant BAFF levels and pretransplant alloimmunization and its value to predict subsequent acute antibody-mediated rejection (AMR) and outcome after renal transplantation is not fully understood. METHODS: Objective of our retrospective single-center study was to determine, by ELISA analysis of pretransplant serum BAFF levels in 249 patients undergoing renal transplantation, association between preformed anti-human leukocyte antigen (HLA) antibodies, occurrence of acute antibody mediated rejection (AMR) and renal allograft survival. RESULTS: Pretransplant serum BAFF levels were significantly higher in presensitized recipients with anti-HLA antibodies (3262±2796pg/ml) than in recipients without occurrence of anti-HLA antibodies (2252±1425pg/ml; p<0.0001). In addition, pretransplant BAFF levels correlated with cumulative MFI values of anti-HLA antibodies (r=0.2966, p=0.0025). Patients with high pretransplant BAFF levels (≥2137pg/ml) experienced significantly lower allograft survival rates compared to low pretransplant BAFF levels (80% vs. 91%; p=0.01). Coexistence of high pretransplant BAFF levels and posttransplant AMR was associated with the worst allograft survival rates (56%). Relative risk (RR) for allograft loss was associated with high serum BAFF levels (RR 2.3; p=0.02), presence of anti-HLA antibodies (RR 2.5; p=0.007) or anti-HLA -donor-specific antibodies (DSAs) (RR 2.6; p=0.003) before transplant and AMR post transplant (RR 2.5; p=0.007). AMR was the strongest independent risk factor for allograft failure (RR 2.6; p=0.03). CONCLUSION: Elevated pretransplant serum BAFF levels negatively affect renal allograft survival and represent a risk factor for allosensitization and subsequent AMR.

Expression patterns of CD56+ and CD16+ cells in renal transplant biopsies with acute rejection: Associations with microcirculation injuries and graft survival.

BACKGROUND: The study investigated whether immunohistochemical features of interstitial and glomerular CD56 and CD16 infiltrates - NK cells markers - could be associated with microcirculation injury scores - peritubular capillaritis (ptc) and glomerulitis (g) - and graft survival. METHODS: The research analyzed the immunohistochemical pattern of CD56 and CD16 in interstitial and glomerular compartments of biopsies for-cause biopsies from 59 recipients diagnosed with acute rejection (mean = 135.5 days post-transplant). RESULTS: Interstitial CD56+ cells had an increased expression for glomerulitis (g ≥ 1) (P = 0.02) and peritubular capillaritis (ptc ≥ 2) (P = 0.003) presence. It was noted that interstitial CD56 + cells with mean above 0.56 cells/mm2 had worse allograft survival. CD56+ cells in the interstitial compartment with mean less than or equal to 0.56cells/mm2 was related with absence or mild peritubular capillaritis (P = 0.012) and mean above 0.56 cells/mm2 , respectively, with glomerulitis (P = 0.002) presence. Interstitial CD16 cells showed greater positive results in relation to peritubular capillaritis (P = 0.0001) cases. Similarly, it was observed that glomerular CD16+ cells had higher positive results in glomerulitis (P = 0.009) presence. CONCLUSIONS: The study findings showed that CD56+ cell infiltrated in the interstitial compartment was significantly associated with microcirculation injury scores, especially the glomerulitis, and graft survival.

The lack of Lazarus effect with proteasome inhibition.

There have been marked improvements in the short- and long-term outcomes for children after renal transplantation over the past two decades with superior quality and quantity of life. It is encouraging to see increased patient and renal allograft survival rates with initially lower acute renal allograft rejection rates due to improved matching and immunosuppressive regimens. Unfortunately, longer-term renal allograft survival remains unchanged with chronic allograft injury from both immune and non-immune causes, resulting in chronic allograft dysfunction, morbidity from chronic kidney disease, and eventual renal allograft loss. Acute and chronic antibody-mediated rejection remains a clinical dilemma with a growing evidence base of its treatment, including proteasome inhibition using intravenous bortezomib. The future goal is to reduce chronic allograft dysfunction and make renal transplants last longer for pediatric renal transplant recipients who may require retransplantation during their childhood and adult lives, which can become successively more difficult due to sensitization.

Association of functional genetic variants of transcription factor Forkhead Box P3 and Nuclear Factor-κB with end-stage renal disease and renal allograft outcome.

BACKGROUND: The transcription factor FOXP3 and NF-κB regulates the expression of various genes that play an important role in the regulation of renal inflammation. We investigated the association of FOXP3 (rs2232365, rs3761548, rs5902434 and rs2294021) and NF-κB1 (rs28362491 and rs696) gene variants in susceptibility and prognosis of end stage renal disease (ESRD) and renal allograft outcome. METHODS: We genotyped four common polymorphisms of FOXP3 and two-tag SNPs of NF-κB1 genes in 350 ESRD cases and 350 controls. Single marker analysis and SNP-SNP interaction model (one to six way combinations) was used for determination of clinical outcome of ESRD and acute rejection episode (ARE). RESULTS: We observed significantly higher occurrence of mutant genotypes of tag-SNPs of FOXP3 namely; rs2232365 and rs3761548 along with NF-kB1 namely; rs28362491 and rs696 in ESRD and ARE cases, suggested a risk association for ESRD and ARE. Interestingly, multifactor dimension reduction analysis suggested an increased risks of nearly 6-folds for ESRD and 23-folds for ARE cases under the six factors model which consists of tag-SNPs of FOXP3 (rs2232365, rs3761548, rs5902434 and rs2294021) and NF-kB1 (rs28362491 and rs696). Kaplan-Meier survival analysis showed the lowest overall survival for mutant genotypes compared with wild and heterozygous genotypes of rs2232365 and rs3761548 tag SNPs of FOXP3 as well as NF-kB1 tag-SNPs rs28362491 and rs696 in renal allograft recipients. The crude and adjusted hazard ratios in univariate and multivariate Cox regression models showed almost 2-folds to 3-folds risk for overall survival against mutant genotypes of tag-SNPs of FOXP3 (rs2232365 and rs3761548) and NF-kB1 (rs28362491 and rs696) genes. CONCLUSIONS: These results suggest that variants of transcription factor FOXP3 and NF-kB1 might be associated with increased risk to the clinical outcome of ESRD and renal allograft survival.

Tacrolimus confers lower acute rejection rates and better renal allograft survival compared to cyclosporine.

AIM: To compare the impact of tacrolimus (FK) and cyclosporine (CYA) on acute rejection and graft survival and to assess the predominant causes of graft loss between patients receiving these two calcineurin inhibitors (CNIs). METHODS: Retrospective review of 1835 patients who received a kidney transplant (KTX) between 1999-2012. Patients were grouped based on initial CNI utilized: 1195 in FK group, 640 in CYA group. Data on baseline characteristics, clinical outcomes, and causes of graft loss in both groups were analyzed. RESULTS: Cumulative acute rejection rates were 14% in the FK vs 24% in the CYA group. Despite more marginal donor characteristics in the FK group, these patients had better graft survival rates compared to the CYA group. Three and five year graft survival rates were 88% and 84% respectively in the FK group compared to 79% and 70% respectively in the CYA group (P < 0.001). After multivariate analysis, which controlled for confounders, FK use was a strong predictor for lower acute rejection rates [odds ratio (OR) 0.60, 95%CI: 0.45-0.79] and better renal allograft survival (OR 0.740, 95%CI: 0.58-0.94). Death with a functioning graft was the most common cause of graft loss in both groups. Common causes of death included cardiovascular disease, infections, and malignancies. Chronic allograft nephropathy was also found to be an important cause of graft loss, being more prevalent in the CYA group. CONCLUSION: The use of FK-based maintenance immunosuppression therapy is associated with a significantly lower rate of acute rejection and better graft survival compared to CYA-based regimen. Individualizing immunosuppression through risk-stratified CNI choice may lead to improved outcomes across all spectra of KTX patients.

Assessment of the relationship between ACE I/D gene polymorphism and renal allograft survival.

BACKGROUND AND OBJECTIVE: The relationship between the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and renal allograft survival after renal transplantation from the published reports are still debatable. This study was performed to evaluate the relationship between the ACE I/D gene polymorphism and renal allograft survival after renal transplantation using meta-analysis. METHOD: Eligible studies were identified from PubMed and Cochrane Library on 1 November 2014, and eligible studies were recruited and synthesized using a meta-analysis methodology. RESULTS: Twelve investigations were included in this meta-analysis for the assessment of the relationship between the ACE I/D gene polymorphism and renal allograft survival. In this meta-analysis, the ACE I/D gene polymorphism was not associated with renal allograft survival after renal transplantation for overall populations, Caucasians, Brazilians and Africans. Interestingly, the ACE D allele and DD genotype were associated with renal allograft survival after renal transplantation in the Asian population. CONCLUSIONS: ACE D allele and DD genotype were associated with renal allograft survival after renal transplantation in the Asian population. However, more studies should be performed to confirm this association.

Impact of donor and recipient age difference on long-term allograft survival after living donor renal transplantation: analysis of 478 cases.

INTRODUCTION: Either deceased or living-related renal transplantation constitutes the best therapeutic option for patients with end-stage renal disease. In this retrospective study, an attempt to identify parameters that affect allograft survival in living donor renal transplantation was made. METHODS: Between January 2000 and July 2012, 478 adult patients received a renal transplant from a living-related donor in our center and their records were retrospectively reviewed in November 2012. Data concerning donor age, recipient age, donor/recipient age difference, donor/recipient gender, and ABO compatibility/incompatibility were recorded and associated with renal allograft survival rate. RESULTS: Renal allograft survival rate was 96%, 89.5%, and 77.7% in the first, fifth, and 10th yr after transplantation, respectively. Only the difference between donor and recipient age was statistically significant in relation to graft survival. In cases with age difference >13 yr, graft survival rate was lower from the third yr onward. CONCLUSIONS: Only the age difference between donor and recipient exerts an adverse impact on graft outcome after living donor renal transplantation, whereas donor age, recipient age, donor/recipient gender, and ABO incompatibility do not significantly influence renal allograft survival.

Synergistic effect of mycophenolate mofetil and angiotensin-converting enzyme inhibitor in patients with chronic allograft nephropathy

Experimental data and few clinical non-randomized studies have shown that inhibition of the renin-angiotensin system by angiotensin-converting enzyme (ACE) associated or not with the use of mycophenolate mofetil (MMF) could delay or even halt the progression of chronic allograft nephropathy (CAN). In this retrospective historical study, we investigated whether ACE inhibition (ACEI) associated or not with the use of MMF has the same effect in humans as in experimental studies and what factors are associated with a clinical response. A total of 160 transplant patients with biopsy-proven CAN were enrolled. Eighty-one of them were on ACE therapy (G1) and 80 on ACEI_free therapy (G2). Patients were further stratified for the use of MMF. G1 patients showed a marked decrease in proteinuria and stabilized serum creatinine with time. Five-year graft survival after CAN diagnosis was more frequent in G1 (86.9 vs 67.7 percent; P < 0.05). In patients on ACEI-free therapy, the use of MMF was associated with better graft survival. The use of ACEI therapy protected 79 percent of the patients against graft loss (OR = 0.079, 95 percentCI = 0.015-0.426; P = 0.003). ACEI and MMF or the use of MMF alone after CAN diagnosis conferred protection against graft loss. This finding is well correlated with experimental studies in which ACEI and MMF interrupt the progression of chronic allograft dysfunction and injury. The use of ACEI alone or in combination with MMF significantly reduced proteinuria and stabilized serum creatinine, consequently improving renal allograft survival.

Are the current chronic allograft nephropathy grading systems sufficient to predict renal allograft survival?

A major problem in renal transplantation is identifying a grading system that can predict long-term graft survival. The present study determined the extent to which the two existing grading systems (Banff 97 and chronic allograft damage index, CADI) correlate with each other and with graft loss. A total of 161 transplant patient biopsies with chronic allograft nephropathy (CAN) were studied. The samples were coded and evaluated blindly by two pathologists using the two grading systems. Logistic regression analyses were used to evaluate the best predictor index for renal allograft loss. Patients with higher Banff 97 and CADI scores had higher rates of graft loss. Moreover, these measures also correlated with worse renal function and higher proteinuria levels at the time of CAN diagnosis. Logistic regression analyses showed that the use of angiotensin-converting enzyme inhibitor (ACEI), hepatitis C virus (HCV), tubular atrophy, and the use of mycophenolate mofetil (MMF) were associated with graft loss in the CADI, while the use of ACEI, HCV, moderate interstitial fibrosis and tubular atrophy and the use of MMF were associated in the Banff 97 index. Although Banff 97 and CADI analyze different parameters in different renal compartments, only some isolated parameters correlated with graft loss. This suggests that we need to review the CAN grading systems in order to devise a system that includes all parameters able to predict long-term graft survival, including chronic glomerulopathy, glomerular sclerosis, vascular changes, and severity of chronic interstitial fibrosis and tubular atrophy.

Outcomes of Kidney Transplantation from Spousal Donors: Comparison with Kidney Transplantation from Living-related Donors / 대한신장학회잡지

BACKGROUND: Although transplantation is the best treatment for many people with end-stage renal disease, the gap between the number of organs and the number of potential recipients continues to widen. In addition to living-related individuals, the primary source of donor kidney, the severe organ shortage has led to consideration of genetically unrelated but emotionally related persons as donor candidates. The aim of this study was to compare the results of spousal kidney transplantation with those of living-related kidney transplantation and to analyze the characteristics of spousal kidney transplantation. METHODS: Clinical data were retrospectively analyzed from 21 patients with spousal kidney transplantation and 205 patients with living-related kidney transplantation. Cumulative renal allograft survival was compared between the two groups using Kaplan-Meier curve and log-rank test. Subgroup analysis was done within the patients with spousal kidney transplantation. RESULTS: The patients were significantly older in spousal group (43.7+/-7.8 years) than in living-related group (36.2+/-10.8 years). Donor age was also significantly higher in spousal group (43.0+/-8.4 years) than in living-related group (39.8+/-13.9 years). The number of HLA mismatch was significantly larger in spousal group (3.79+/-1.03) than in living-related group (2.60+/-1.21). The episodes of acute rejection occurring within a year after the transplantation were more frequent in spousal group (5/21) than in living-related group (13/205). Kaplan-Meier curves for cumulative survival of renal allograft revealed no difference between spousal group and living-related group. Renal allograft survival rates in spousal group were 85.2% at 1 year, 75.2% at 5 years, and 67.7% at 10 years after the transplantation. In living-related group, renal allograft survival rates were 96.6% at 1 year, 85.9% at 5 years, and 69.9% at 10 years after the transplantation. Within the patients with spousal kidney transplantation, cumulative renal allograft survival was superior in cases with absent acute rejection, husband-to-wife transplantation, and the number of HLA mismatch less than 5. CONCLUSION: Spousal kidney transplantation shares comparable results with living-related kidney transplantation despite older age, poorer HLA matching and a higher rate of acute rejection. Spousal donor transplants could be a real alternative especially when the donors are husband and the number of HLA mismatch is less than 5.