Risk Factor For Acute Rejection Research Articles

Basiliximab vs. No Induction Therapy in Kidney Transplant Recipients with a Low Immunological Risk Profile Receiving Tacrolimus/Mycophenolate/Steroids Maintenance Immunosuppression.

Background: Induction therapy with basiliximab is recommended in kidney transplant (KT) recipients with a low immunological risk (LIR) profile. Whether basiliximab is associated with a decreased risk of acute rejection (AR) and graft loss is controversial. Methods: In our institution, LIR patients (absence of anti-HLA antibodies before KT) are inducted with basiliximab in case of living-donor KT, while deceased-donor KT recipients receive no induction. Maintenance immunosuppression is similar, including a combination of tacrolimus (Tac), mycophenolate (MPA) and steroids. In this single-center retrospective study, we included all adult LIR patients who underwent KT between 1 January 2015 and 31 December 2022. Results: Of the 471 patients included, 354 received no induction and 117 received basiliximab. The median (IQR) number of HLA A-B-DR mismatches was 3 (2-3) and 2 (2-4) in the no induction group and the basiliximab group, respectively. The cumulative incidences in the no induction group vs. the basiliximab group of acute rejection and graft loss over 5 years post-KT were similar at 8.9% vs. 7.8% (p = 0.8) and 8.5% vs. 4.2% (p = 0.063), respectively. In multivariable Cox regression analysis, delayed graft function emerged as an independent risk factor for acute rejection (hazard ratio [HR] 2.75, 95% confidence interval [CI] 1.23-6.13, p = 0.014) and graft loss (HR 9.32, CI 4.10-21.1, p < 0.001). Conclusions: Basiliximab did not provide any advantage in terms of rate of acute rejection and graft survival within 5 years post KT compared with a strategy without induction therapy in patients with a low immunological risk profile receiving triple maintenance immunosuppression Tac/MPA/steroids.

Multidrug resistant 1 (MDR1) C3435T and G2677T gene polymorphism: impact on the risk of acute rejection in pediatric kidney transplant recipients

BackgroundTacrolimus is the backbone drug in kidney transplantation. Single nucleotide polymorphism of Multidrug resistant 1 gene can affect tacrolimus metabolism consequently it can affect tacrolimus trough level and incidence of acute rejection. The aim of this study is to investigate the impact of Multidrug resistant 1 gene, C3435T and G2677T Single nucleotide polymorphisms on tacrolimus pharmacokinetics and on the risk of acute rejection in pediatric kidney transplant recipients.MethodsTyping of Multidrug resistant 1 gene, C3435T and G2677T gene polymorphism was done using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for 83 pediatric kidney transplant recipients and 80 matched healthy controls.ResultsIn Multidrug resistant 1 gene (C3435T), CC, CT genotypes and C allele were significantly associated with risk of acute rejection when compared to none acute rejection group (P = 0.008, 0.001 and 0.01 respectively). The required tacrolimus doses to achieve trough level were significantly higher among CC than CT than TT genotypes through the 1st 6 months after kidney transplantation. While, in Multidrug resistant 1 gene (G2677T), GT, TT genotypes and T allele were associated with acute rejection when compared to none acute rejection (P = 0.023, 0.033 and 0.028 respectively). The required tacrolimus doses to achieve trough level were significantly higher among TT than GT than GG genotypes through the 1st 6 months after kidney transplantation.ConclusionThe C allele, CC and CT genotypes of Multidrug resistant 1 gene (C3435T) and the T allele, GT and TT genotypes of Multidrug resistant 1 gene (G2677T) gene polymorphism may be risk factors for acute rejection and this can be attributed to their effect on tacrolimus pharmacokinetics. Tacrolimus therapy may be tailored according to the recipient genotype for better outcome.

HLA-DPB1 molecular mismatches are risk factors for acute rejection and low 5-year graft function in first kidney transplants.

The study aimed to investigate the impact of HLA-DPB1 allelic and molecular mismatches on the occurrence of acute rejection (AR) and low 5-year graft function (5Y-GF) in first kidney transplant (KT) recipients. This is a single center retrospective study of 130 deceased donor KT recipients transplanted between 2014 and 2016. HLA-DPB1 allelic MM and the following molecular MM (mMM) were analyzed: expression MM with the high expression G allele in the donor; T cell epitope MM (TCE MM); epitope MM (EMM), considering all six hypervariable regions (EMM-ABCDEF HVR), or only ABEF regions (EMM-ABEF HVR); eplet MM (EpMM); antibody-verified eplet MM (AbVer EpMM); and solvent accessible amino acid MM (SAMM). There was no association of allelic MM with AR or 5Y-GF. The variables independently associated (Cox regression analyses) with AR were high donor final creatinine, nonpermissive TCE MM, ABCDEF EMM load ≥6, EpMM load ≥6; SAMM load ≥5, and AbVer EpMM load ≥3. No association between any HLA-DPB1 mMM and 5Y-GF was observed when all 130 transplant recipients were considered. However, when transplants from expanded criteria donors were excluded, independent associations were detected (logistic regression analyses) with AbVerEpMM load ≥2, SAMM load ≥7, cerebro-vascular death, donor age, and AR. To our knowledge, this is the first study that shows that some HLA-DPB1 mMM are associated with AR and low 5Y-GF in a population of exclusively first kidney transplant recipients.

Risk factors for acute rejection in liver transplantation and its impact on the outcomes of recipients

ObjectiveTo determine the risk factors for acute rejection in liver transplantation and its impact on the outcomes of the recipients. MethodsClinicopathological data of 290 patients who underwent liver transplantation from January 2012 to December 2021 at our center were retrospectively evaluated. Patients were grouped into an acute rejection (AR) group and a normal (NM) group based on the confirmed histopathological diagnosis of acute rejection. Univariate and multivariate logistic regression were used to determine the risk factors for acute rejection. Results244 patients were included in the study. Acute rejection occurred in 27 (11.1%) of the patients. Warm ischemia time (P = 0.137), cold ischemia time (P = 0.064) and chronic liver failure (P = 0.001) were potential risk factors for acute rejection. Chronic liver failure (P < 0.001, OR = 8.22, 95% CI = 2.47–27.32) was the independent risk factor. There was no significant difference in overall survival between recipients with acute rejection and those without it (P = 0.985). The 1-, 3- and 5-year overall survival in the NM group was 98.1%, 85.7% and 78.6% respectively vs 88.9%, 82.5% and 82.5% respectively in the AR group. ConclusionAcute rejection does not appear to affect the long-term survival of the recipients. Only chronic liver failure was an independent risk factor for acute rejection. Our findings further illustrate that contradictions still exist on which factors influence acute rejection in liver transplant recipients. SummaryClinicopathological data of 290 liver transplant recipients at our center between January 2012 and December 2021 were retrospectively evaluated to determine the risk factors for acute rejection and its impact on the outcomes of the recipients. 244 patients were included in the analysis. 27 of the 244 experienced acute rejection. Propensity score matching was performed to reduce the confounding effect. Patients were assigned to an acute rejection group (n = 27) and a normal group (n = 54). Chronic liver failure (P < 0.001, OR = 8.22, 95% CI = 2.47–27.32) was the determined to be independent risk factor for acute rejection. Acute rejection did not appear to affect the long-term survival of the recipients and there was no significant difference in overall survival between the patients with acute rejection and those without it.

The Role of Early Sequential Biopsies in Delayed Renal Graft Function of Transplanted Kidney Is Reduced in Modern Immunosuppression Era

Background: Delayed graft function (DGF) immediately after kidney transplantation is considered a risk factor for acute rejection. According to clinical guidelines, a weekly allograft biopsy should be performed until DGF resolves. Based on clinical evidence, the first biopsy is considered appropriate. However, the recommendation for further biopsies is based on sparse evidence from era of earlier immunosuppression protocols, and the benefit of the second and further biopsies remains uncertain. The aim of this study was to reevaluate this policy. Methods: The database of a transplant medical center was retrospectively reviewed for all patients who underwent kidney transplantation in 2011–2020. Those with DGF who performed two or more graft biopsies within the first 60 days after transplantation were identified. Clinical data were collected from the medical files. The rates of diagnosis of acute rejection at the second and subsequent biopsies were analyzed relative to the previous ones. Results: Kidney transplantation was performed in 1,722 patients during the study period, of whom 225 (13.07%) underwent a total of 351 graft biopsies within 60 days after transplantation, mostly due to DGF. A second biopsy was performed in 32 patients (14.2%), and a third biopsy in 8, at weekly intervals. In 2 patients (6.25%), the diagnosis changed from the first biopsy (acute tubular necrosis or toxic damage) to acute rejection in the second biopsy. In both, the rejection was borderline. Third and fourth biopsies did not add information to the previous diagnosis. Conclusions: The common practice of performing sequential biopsies during a postoperative course of DGF seems to be of low benefit and should be considered on a case-by-case basis.

Effect of Perioperative Dexmedetomidine on Delayed Graft Function Following a Donation-After-Cardiac-Death Kidney Transplant

Delayed graft function (DGF) is a risk factor for acute rejection and graft failure after kidney transplant. Previous studies have suggested that dexmedetomidine may be renoprotective, but whether the use of dexmedetomidine would improve kidney allograft function is unknown. To investigate the effects of perioperative dexmedetomidine on DGF following a donation-after-cardiac-death (DCD) kidney transplant. This single-center, double-blind, placebo-controlled randomized clinical trial was conducted at The First Affiliated Hospital of Soochow University in Suzhou, China. Adults (18 years or older) who were scheduled for DCD kidney transplant were enrolled between September 1, 2019, and January 28, 2021, and then randomized to receive either dexmedetomidine or normal saline (placebo). One-year postoperative outcomes were recorded. All analyses were based on the modified intention-to-treat population. Patients who were randomized to the dexmedetomidine group received a 24-hour perioperative dexmedetomidine intravenous infusion (0.4 μg/kg/h intraoperatively and 0.1 μg/kg/h postoperatively). Patients who were randomized to the normal saline group received an intravenous infusion of the placebo with the same dose regimen as the dexmedetomidine. The primary outcome was the incidence of DGF, defined as the need for dialysis in the first posttransplant week. The prespecified secondary outcomes were in-hospital repeated dialysis in the first posttransplant week, in-hospital acute rejection, and serum creatinine, serum cystatin C, estimated glomerular filtration rate, need for dialysis, and patient survival on posttransplant day 30. Of the 114 patients enrolled, 111 completed the study (mean [SD] age, 43.4 [10.8] years; 64 male patients [57.7%]), of whom 56 were randomized to the dexmedetomidine group and 55 to the normal saline group. Dexmedetomidine infusion compared with normal saline reduced the incidence of DGF (17.9% vs 34.5%; odds ratio [OR], 0.41; 95% CI, 0.17-0.98; P = .04) and repeated dialysis (12.5% vs 30.9%; OR, 0.32; 95% CI, 0.13-0.88; P = .02, which was not statistically significant after multiple testing corrections), without significant effect on other secondary outcomes. Dexmedetomidine vs normal saline infusion led to a higher median (IQR) creatinine clearance rate on postoperative days 1 (9.9 [4.9-21.2] mL/min vs 7.9 [2.0-10.4] mL/min) and 2 (29.6 [9.7-67.4] mL/min vs 14.6 [3.8-45.1] mL/min) as well as increased median (IQR) urine output on postoperative days 2 (106.5 [66.3-175.6] mL/h vs 82.9 [27.1-141.9] mL/h) and 7 (126.1 [98.0-151.3] mL/h vs 107.0 [82.5-137.5] mL/h) and at hospital discharge discharge (110.4 [92.8-121.9] mL/h vs 97.1 [77.5-113.8] mL/h). Three patients (5.5%) from the normal saline group developed allograft failure by the post hoc 1-year follow-up visit. This randomized clinical trial found that 24-hour perioperative dexmedetomidine decreased the incidence of DGF after DCD kidney transplant. The findings support the use of dexmedetomidine in kidney transplants. Chinese Clinical Trial Registry Identifier: ChiCTR1900025493.

Delayed Graft Function Under the Microscope: Surveillance Biopsies in Kidney Transplantation.

Delayed graft function (DGF) is a common complication of kidney transplantation and frequently leads to the necessity of surveillance biopsies. The purpose of this study is to describe the histological findings in surveillance biopsies of deceased donor kidney transplant recipients and evaluate the risk factors for graft outcomes. This is a monocentric, retrospective study including kidney transplant recipients that underwent a graft biopsy during the DGF period between January 2006 and July 2019. 356 biopsies were performed in 335 deceased donor transplant recipients. Biopsies were analyzed according to the Banff classification. The main histological findings were: acute tubular necrosis in 150 biopsies (42.1%), acute rejection in 96 biopsies (26.9%), and borderline findings in 91 biopsies (25.5%). In the multivariate analysis, recipient age (p = 0.028) and DGF duration (p = 0.005) were associated with rejection, antibody-induction with anti-thymocyte globulin (ATG) was protective (p = 0.001). The occurrence of rejection was associated with lower death-censored graft survival (log-rank; p = 0.009). Surveillance biopsies of kidney grafts experiencing DGF remain an essential tool for the care of kidney transplant recipients. The recipient's age and duration of DGF are independent risk factors for acute rejection, while antibody-induction therapy with ATG is associated with protection from its occurrence.

Endogenous memory T cells with donor-reactivity: early post-transplant mediators of acute graft injury in unsensitized recipients.

The pretransplant presence of endogenous donor-reactive memory T cells is an established risk factor for acute rejection and poorer transplant outcomes. A major source of these memory T cells in unsensitized recipients is heterologously generated memory T cells expressing reactivity to donor allogeneic MHC molecules. Multiple clinical studies have shown that the pretransplant presence of high numbers of circulating endogenous donor-reactive memory T cells correlates with higher incidence of acute rejection and decreased graft function during the first-year post-transplant. These findings have spurred investigation in preclinical models to better understand mechanisms underlying endogenous donor-reactive memory T-cell-mediated allograft injury in unsensitized graft recipients. These studies have led to the identification of unique mechanisms underlying the activation of these memory T cells within allografts at early times after transplant. In particular, optimal activation to mediate acute allograft injury is dependent on the intensity of ischaemia-reperfusion injury. Therapeutic strategies directed at the recruitment and activation of endogenous donor-reactive memory T cells are effective in attenuating acute injury in allografts experiencing increased ischaemia-reperfusion injury in preclinical models and should be translatable to clinical transplantation.

MO982COMPARISON OF BASILIXIMAB AND R-ATG ON ACUTE REJECTION RISK IN HIGH IMMUNOLOGICAL RISK RENAL TRANSPLANT RECIPIENTS

Abstract Background and Aims High Panel Reactive Antibody (PRA) level has been widely accepted as a marker for acute rejection risk following kidney transplantation. PRA&amp;gt;/= 20% is considered a high immunological risk renal transplant. The aim of our study was to assess the risk of acute rejection in kidney transplant recipients (KTR) following Basiliximab induction compared to Rabbit Anti-Thymocyte Globulin (R-ATG) maintained on tacrolimus and mycophenolate mofetil maintenance immunotherapy. Method This was a retrospective observational cohort study using data from the United States Organ Procurement and Transplantation Network, all KTR’s with PRA =/&amp;gt; 20%, who were maintained on tacrolimus and mycophenolate mofetil between September 2017 and September 2019 were included. Follow-up was until September 2020. Data included recipient factors (age, sex, ethnicity, diabetes, body mass index), transplant factors (delayed graft function, cold ischemia time, number of previous transplants, panel reactive antibodies, HLA-mismatches, induction therapy, maintenance immunotherapy and donor factors (donor type, donor age). The cohort were divided into 2 groups; living and deceased donor renal transplants. The groups were further divided by PRA level, each group was divided into 3 subgroups: Group A (low PRA level: PRA range from 20% to 49%), Group B (moderate PRA level: PRA range from 50% to 79%), and Group C (High PRA level: PRA range from 80% to 100%). Multivariable logistic regression models were constructed to assess the effect of induction therapies (Basiliximab versus R-ATG) on acute rejection episodes at 6 months post-transplant. The multivariable model was adjusted for recipient, donor and transplant factors mentioned above. Results Among living donor KTR’s, there was no difference between Basiliximab and R-ATG in acute rejection episodes in any of the three groups, Group A (low PRA level, n=717, OR=1.17, P=0.79, 95%CI:0.34-3.95), Group B (moderate PRA level, n=618, OR=1.51, P=0.58, 95%CI:0.33-6.92) and Group C (high PRA level, n=401, OR=1.17, P=0.85, 95%CI:0.21-6.56) respectively. In contrast, among deceased donor KTR’s R-ATG was associated with lower risk of rejection compared to Basiliximab in all three groups, group A (low PRA level, n=1895, OR=0.52, P=0.03, 95%CI: 0.28-0.94), group B (moderate PRA level, n=1618, OR=0.41, P&amp;lt;0.01, 95%CI: 0.22-0.78) and group C (high PRA level, n=3973, P&amp;lt;0.01, 95%CI: 0.28-0.70). Conclusion This study shows that risk of acute rejection is no different with Basilximab induction compared to R-ATG in high immunological risk living-donor KTR’s at all levels of PRA in the current tacrolimus-mycophenolate mofetil immunosuppression era. However, risk of acute rejection seems to be lower in deceased donor KTR’s having R-ATG induction at all levels of PRA. Delayed graft function is a risk factor for acute rejection, our models did not adjust for dose of R-ATG which may explain the lower risk seen in deceased donor KTR’s, data was not available on donor specific antibodies. In summary, Basiliximab induction has similar acute rejection rates as R-ATG in living donor KTR’s whereas in deceased donor KTR’s R-ATG was found to be better.

Clinical Implications of Tacrolimus Time in Therapeutic Range and Intrapatient Variability in Urban Renal Transplant Recipients Undergoing Early Corticosteroid Withdrawal.

Background.Tacrolimus demonstrates wide intrapatient and interpatient variability requiring therapeutic drug monitoring. The utility of tacrolimus time in therapeutic range (TTR) after renal transplantation (RT) under an early corticosteroid withdrawal (ECSWD) protocol is unknown. The purpose of this study is to assess the impact of tacrolimus TTR in an ECSWD RT population.Materials.A retrospective analysis of adult RT recipients maintained on tacrolimus was conducted. Patients were excluded if they were on nonstandard protocol immunosuppression agents <12 months post-RT. Tacrolimus TTR was calculated using the Rosendaal method. Patients were divided into high (TTR-H) and low (TTR-L) TTR groups based on cohort median. The primary outcome was to compare the incidence of acute rejection 12 months post-RT. Secondary outcomes included comparing rejection subtypes, incidence of donor-specific antibody (DSA) and de novo DSA (dnDSA), risk factors for acute rejection and dnDSA development, and allograft function (serum creatinine and estimated glomerular filtration rate).Results.A total of 193 patients were analyzed (TTR-H = 98 and TTR-L = 95). There was no difference in the incidence of acute rejection (TTR-H 20.4% versus TTR-L 20.0%; P = 0.944). Positive DSA posttransplant (odds ratio [OR], 3.62; 95% confidence interval [CI], 1.41-9.26; P = 0.007) was associated with a higher acute rejection at 12 months posttransplant. Mycophenolate dose reduction (OR, 2.82; 95% CI, 1.13-6.97; P = 0.025) and acute rejection (OR, 2.99; 95% CI, 1.09-8.18; P = 0.032) were associated with dnDSA formation. No difference in serum creatinine or estimated glomerular filtration rate was observed (P > 0.05).Conclusions.Tacrolimus TTR was not significantly different with regards to acute rejection in an ECSWD population. Future studies are still needed to determine tacrolimus TTR thresholds post-RT and identify populations that may benefit from this intrapatient variability monitoring parameter.

A combination of the percentages of IFN-\u03b3+CD4+T cells and granzyme B+CD19+B cells is associated with acute hepatic rejection: a case control study

BackgroundT cells and B cells play a key role in alloimmune responses. We aimed to characterize the shift of T cell subsets and B cell subsets during acute hepatic rejection, and further determine whether they could serve as a prognostic marker.MethodsBlood samples together with the clinical data from liver transplant recipients with and without acute hepatic rejection were collected and analyzed as well as from a validation cohort.ResultsUpon activation the expression of TGF-β and granzyme B in CD19+B cells, and the expression of IL-2 and IFN-γ in CD4+T cells were higher in acute hepatic rejection. However, only the frequencies of granzyme B+CD19+B cells and IFN-γ+CD4+T cells correlated with liver function in addition to with each other. A combination of the two cell subsets as a novel marker could classify rejection versus non-rejection (area under the curve 0.811, p = 0.001) with the cut-off value of 62.93%, which was more sensitive for worse histological changes (p = 0.027). Moreover, the occurrence rate of acute rejection was higher in the group with the novel marker > 62.93% (p = 0.000). The role of the novel marker was further confirmed in a validation cohort, which was identified to be the only significant independent risk factor for acute rejection (odds ratio: 0.923; 95% CI confidence interval: 0.885–0.964; p = 0.000).ConclusionsA combination of the percentages of IFN-γ+CD4+T cells and granzyme B+CD19+B cells can distinguish rejection from non-rejection, which can be used as a potential prognostic marker for acute rejection in liver transplant recipients.

Plasma Soluble CD146 as a Potential Diagnostic Marker of Acute Rejection in Kidney Transplantation.

Previous studies have implicated the role of CD146 and its soluble form (sCD146) in the pathogenesis of inflammatory diseases. However, the association between CD146 and acute rejection in kidney transplant patients remains unexplored. In this study, fifty-six patients with biopsy-proved rejection or non-rejection and 11 stable allograft function patients were retrospectively analyzed. Soluble CD146 in plasma was detected in peripheral blood by enzyme linked immunosorbent assay (ELISA), and local CD146 expression in graft biopsy was detected by immunohistochemistry. We found that plasma soluble CD146 in acute rejection recipients was significantly higher than in stable patients without rejection, and the biopsy CD146 staining in the rejection group was higher than that of the non-rejection group. Multivariate analysis demonstrated soluble CD146 as an independent risk factor of acute rejection. The area under the receiver operating characteristic curve (AUC) of sCD146 for AR diagnosis was 0.895, and the optimal cut-off value was 75.64 ng/ml, with a sensitivity of 87.8% and a specificity of 80.8%, which was better than eGFR alone (P = 0.02496). Immunohistochemistry showed CD146 expression in glomeruli was positively correlated with the Banff-g score, and its expression in tubules also had a positive relationship with the Banff-t score. Therefore, soluble CD146 may be a potential biomarker of acute rejection. Increased CD146 expression in the endothelial or tubular epithelial cells may imply that endothelial/epithelial dysfunction is involved in the pathogenesis of immune injury.

Acute Rejection and Infectious Complications in ABO- and HLA-Incompatible Kidney Transplantations.

BackgroundPatients receiving ABO-incompatible (ABOi) or human leukocyte antigen (HLA)-incompatible (HLAi) kidney transplantation (KT) require potent immunosuppression and are thus at a higher risk of infectious complications. We evaluated the clinical outcomes of KT stratified by ABO and HLA incompatibilities and identified the factors associated with the clinical outcomes.Material/MethodsRecipients who underwent living-related KT between 2012 and 2017 were included and classified into 4 groups: ABO-compatible and HLA-compatible (ABOc/HLAc), HLA-incompatible (ABOc/HLAi), ABO-incompatible (ABOi/HLAc), and ABO-incompatible and HLA-incompatible (ABOi/HLAi). Cox proportional hazards regression analyses were carried out to evaluate the risk factors of acute rejection. Out of the 1732 patients who underwent KT, 1190, 131, 358, and 53 were in the ABOc/HLAc, ABOi/HLAc, ABOc/HLAi, and ABOi/HLAi groups, respectively.ResultsThe ABO/HLAi group showed the lowest 5-year graft survival rate (91.7%). Death-censored graft survival was not significantly different among the groups. The mortality rate from infections was significantly higher in the ABOi/HLAi group (7.5%) than the other groups. Antibody-mediated rejection-free graft survival was the lowest in the ABOi/HLAi group, with significant differences compared with the ABOi/HLAc group (P=0.02) and the ABOc/HLAi group (P=0.03). ABOi/HLAi (hazard ratio [HR], 2.63; 95% confidence interval [CI], 1.04–6.65; P<0.01) and combined infection (HR, 1.91; 95% CI, 1.45–2.51; P<0.01) were significant risk factors for acute rejection.ConclusionsPatients with both ABO and HLA incompatibilities showed inferior rates of overall patient and graft survival due to infectious complications. Infection was a prominent risk factor of acute rejection following KT after adjusting for possible confounders including ABO and HLA incompatibility.

Risk Factors for Acute Rejection in the First Year after Lung Transplant. A Multicenter Study.

Rationale: Acute rejection, manifesting as lymphocytic inflammation in a perivascular (acute perivascular rejection [AR]) or peribronchiolar (lymphocytic bronchiolitis [LB]) distribution, is common in lung transplant recipients and increases the risk for chronic graft dysfunction.Objectives: To evaluate clinical factors associated with biopsy-proven acute rejection during the first post-transplant year in a present-day, five-center lung transplant cohort.Methods: We analyzed prospective diagnoses of AR and LB from over 2,000 lung biopsies in 400 newly transplanted adult lung recipients. Because LB without simultaneous AR was rare, our analyses focused on risk factors for AR. Multivariable Cox proportional hazards models were used to assess donor and recipient factors associated with the time to the first AR occurrence.Measurements and Main Results: During the first post-transplant year, 53.3% of patients experienced at least one AR episode. Multivariable proportional hazards analyses accounting for enrolling center effects identified four or more HLA mismatches (hazard ratio [HR], 2.06; P ≤ 0.01) as associated with increased AR hazards, whereas bilateral transplantation (HR, 0.57; P ≤ 0.01) was associated with protection from AR. In addition, Wilcoxon rank-sum analyses demonstrated bilateral (vs. single) lung recipients, and those with fewer than four (vs. more than four) HLA mismatches demonstrated reduced AR frequency and/or severity during the first post-transplant year.Conclusions: We found a high incidence of AR in a contemporary multicenter lung transplant cohort undergoing consistent biopsy sampling. Although not previously recognized, the finding of reduced AR in bilateral lung recipients is intriguing, warranting replication and mechanistic exploration.

Exploratory Analysis of the Impact of an mHealth Medication Adherence Intervention on Tacrolimus Trough Concentration Variability: Post Hoc Results of a Randomized Controlled Trial.

Medication nonadherence is a leading cause of late allograft loss in kidney transplantation (KT). Tacrolimus trough coefficient of variation (CV), measured using the coefficient of variation, is strongly correlated with acute rejection, graft function, and graft loss. The objective of this study was to determine if this mobile health (mHealth) intervention aimed at improving medication adherence in a nonadherent KT population would affect high intrapatient tacrolimus variability. A 6-month, prospective, parallel-arm, randomized controlled clinical trial was conducted to determine the effects of an mHealth intervention on tacrolimus CV. Intervention arm participants utilized an electronic medication tray and an mHealth app to monitor home-based adherence. Tailored motivational reinforcement messages were delivered to promote competence for adherence. Tacrolimus CV was measured using a 12-month rolling average, assessed at monthly intervals (6-month intervention period and 6 months after completion of the study); 80 were included, 40 in each arm. At baseline, tacrolimus CV was similar between arms (37% ± 15% intervention, 37% ± 13% control, P = 0.894). Patients randomized to the intervention had a significant reduction in mean 12-month tacrolimus CVs (P = 0.046) and a significant improvement in the proportion achieving low tacrolimus CV (tacrolimus CV < 40%; P = 0.001), as compared with the control arm. High tacrolimus CV is a risk factor for acute rejection and graft loss; these results offer the potential promise of improved medication adherence and clinical outcomes through the use of innovative technology.

Evaluation and Treatment of Acute Rejection in Kidney Allografts.

Advances in immunosuppressive therapy have drastically improved acute rejection rates in kidney transplant recipients over the past five decades. Nevertheless, it should remain high on any differential diagnosis of unexplained graft dysfunction because of the potential negative effect on graft longevity. Understanding the pre- and post-transplant risk factors for acute rejection can help estimate the probability of immunologic graft damage, and accurate identification of the type and severity of acute rejection will guide appropriate treatment. Tissue biopsy remains the gold standard for evaluating immunologic graft damage, and the histologic definition of acute rejection has evolved in recent years. Intravenous steroids and T cell depletion remain the standard therapy for T cell-mediated rejection and are effective in reversing most cases. Plasma exchange and intravenous Ig, with or without rituximab, are most commonly used for the treatment of antibody-mediated rejection and several newer agents have recently been investigated for severe cases. This review aims to provide the general nephrologist caring for transplant recipients with an approach to immunologic risk assessment and a summary of recent advances in the diagnosis and treatment of acute graft rejection.

Effect of simultaneous presence of anti-blood group A/B and -HLA antibodies on clinical outcomes in kidney transplantation across positive crossmatch: a nationwide cohort study

ABO-incompatible (ABOi) and positive crossmatch (XM) kidney transplantation (KT) have been considered immunologically challenging. The present study analyzed the clinical outcomes in XM positive KT based on ABO incompatibility. We used data from the Korea Organ Transplantation Registry, a nationwide database, and a single-center registry. A total of 263 patients with positive XM were divided into an ABO compatible (ABOc) & XM positive (ABOc/XM+, n = 176) group and an ABOi & XM positive (ABOi/XM+, n = 87) group. The overall rejection rate one year after KT was significantly higher in the ABOi/XM+ group than in the ABOc/XM+ group (P < 0.01). A total of four mortalities occurred, all in the ABOi/XM+ patients (P < 0.01). There were no differences in surgical complications or the occurrence of infection-related complications, including BK virus nephropathy. Multivariate analysis indicated that female vs. male (odds ratio (OR), 2.27; P = 0.03), DSA class I (MFI/1000) (OR, 1.10; P = 0.03), DSA class II (MFI/1000) (OR, 1.10; P < 0.01), and ABOi & XM+ status (OR, 2.38; P < 0.01) were significant risk factors for acute rejection during the year after transplantation. Overall graft survival was inferior in ABOi/XM+ patients than in ABOc/XM+ patients (P = 0.02). ABO incompatibility in XM-positive KT patients was found to be a significant risk factor for the development of rejection within one year after transplantation as well as for long-term graft survival. The anti-blood group A, B and anti-HLA antibodies may show synergistic activity.

K121Q polymorphism in the Ectonucleotide Pyrophosphatase/Phosphodiesterase 1 gene is associated with acute kidney rejection.

The identification of risk factors for acute rejection (AR) may lead to strategies to improve success of kidney transplantation. Ectonucleotidases are ectoenzymes that hydrolyze extracellular nucleotides into nucleosides, modulating the purinergic signaling. Some members of the Ectonucleotidase family have been linked to transplant rejection processes. However, the association of Ectonucleotide Pyrophosphatase / Phosphodiesterase 1 (ENPP1) with AR has not yet been evaluated. The aim of this study was to evaluate the association between the K121Q polymorphism of ENPP1 gene and AR in kidney transplant patients. We analyzed 449 subjects without AR and 98 with AR from a retrospective cohort of kidney transplant patients from Southern Brazil. K121Q polymorphism was genotyped using allelic discrimination-real-time PCR. Cox regression analysis was used to evaluate freedom of AR in kidney transplant patients according to genotypes. Q allele frequency was 17.6% in recipients without AR and 21.9% in those with AR (P = 0.209). Genotype frequencies of the K121Q polymorphism were in Hardy-Weinberg equilibrium in non-AR patients (P = 0.70). The Q/Q genotype (recessive model) was associated with AR (HR = 2.83, 95% CI 1.08–7.45; P = 0.034) after adjusting for confounders factors. Our findings suggest a novel association between the ENPP1 121Q/Q genotype and AR in kidney transplant recipients.

Prevalence and Impact of De Novo Donor-Specific Antibodies During a Multicenter Immunosuppression Withdrawal Trial in Adult Liver Transplant Recipients.

The development of human leukocyte antigen (HLA) donor-specific antibody/antibodies (DSA) is not well described in liver transplant (LT) patients undergoing immunosuppression (IS) withdrawal protocols despite the allograft risk associated with de novo DSA (dnDSA). We analyzed the development of dnDSA in 69 LT patients who received calcineurin inhibitor monotherapy and were enrolled in the ITN030ST study. Of these 69 patients, 40 stable patients were randomized to IS maintenance (n = 9) or IS minimization (n = 31). Nine of the 31 IS minimization patients achieved complete withdrawal and were free of IS. Among patients who achieved stable IS monotherapy 1 year after transplantation, the prevalence of dnDSA was 18.8%. Acute rejections and the biopsy-proven findings disqualifying patients from IS withdrawal attempt were factors associated with dnDSA development (P = 0.011 and P = 0.041, respectively). Among randomized patients, dnDSA prevalence was 51.7% after IS minimization and 66.7% in IS-free patients. dnDSA prevalence in patients on IS maintenance was 44.4%. dnDSA development during IS minimization was a risk factor for acute rejection (P = 0.015). The majority of dnDSA were against HLA-DQ antigens (78.7%). Conclusion. During the first year following transplantation, acute rejections increase the risk of developing dnDSA, so dnDSA positivity should be considered for IS withdrawal eligibility; during IS minimization, dnDSA development was associated with acute rejection, which prevented further IS withdrawal attempts.

Risk Factors of Acute Rejection in Patients with BK Nephropathy After Reduction of Immunosuppression.

BackgroundBK nephropathy (BKN) affects graft function and increases the risk of graft failure. The reduction of immunosuppression is the main treatment for BKN. However, acute rejection may develop following immunosuppression reduction, and data regarding the risk factors of acute rejection during the post-reduction period are insufficient.Material/MethodsOf 758 patients who received a kidney transplantation (KT) between 2008 and 2011, 79 who underwent immunosuppression reduction as BKN treatment were enrolled. The risk factors of acute rejection after immunosuppression reduction were identified using multivariate logistic regression analysis.ResultsDuring the median follow-up period (75 months), acute rejection developed in 21.5% of study group patients and in 22.5% of KT recipients without BKN. The rejection group showed a trend of higher body mass index (24.13±3.92 vs. 22.40±3.31 kg/m2, P=0.070) and lower tacrolimus levels than the no rejection group, although mycophenolate mofetil (MMF) doses were not lower in the rejection group. The rejection group showed worse graft survival than the no rejection group (P=0.001 by the log rank test). A greater number of patients in the rejection group exhibited reduced calcineurin inhibitor (CNI) level by >20% at 1 month after initial BKV detection (34.2% vs. 7.9%, P=0.008). Multivariate analysis indicated that the peak BKV PCR level (odds ratio [OR], 0.136; 95% confidence interval [CI], 0.025–0.732; P=0.020), MMF discontinuation (vs. MMF reduction; OR, 0.112; 95% CI, 0.020–0.618; P=0.012) and CNI level reduction >20% (OR, 33.752; 95% CI, 4.263–267.251; P=0.001) were significantly associated with acute rejection.ConclusionsAcute rejection after immunosuppression reduction for BKN showed worse allograft survival than the patients without acute rejection. In addition, a CNI dose reduction >20% at 1 month after the initial BKV detection can increase the risk of acute rejection.