Acute Allograft Rejection Episodes Research Articles

#2894 pre-mRNA FOXP3 levels after transplant do not reflect risk of rejection

Abstract Background and Aims Forkhead box P3 (FOXP3) is the master gene regulator of T regulatory cells, and is crucial for their suppressive function. In kidney transplant recipients, low post-transplant levels of FOXP3 in peripheral blood has been associated with increased risk of kidney allograft rejection. However, it is unknown if low post-transplant levels of FOXP3 pre-mRNA is also associated with increased risk of kidney allograft rejection. Here we aim to test if pre-mRNA FOXP3 levels are associated with the risk of rejection post-transplant in kidney transplant recipients. Method We collected blood samples from incident kidney transplant recipients the first day after transplantation. From these, we extracted peripheral blood mononuclear cell ribonucleic acid and measured pre-mRNA FOXP3 transcripts with quantitative reverse transcription polymerase chain reaction. Pre-mRNA FOXP3 levels were normalized to β-actin, and converted to a logarithmic scale. We collected data concerning rejection episodes through medical record review. Kidney transplant recipients that had at least one recorded acute kidney allograft rejection episode within the first three months post-transplant were defined as recipients with a rejection episode. Data is presented as median [interquartile range] and tested with Wilcoxon rank sum test. Results We measured pre-mRNA FOXP3 in 515 incident kidney transplant recipients, 52 experienced a rejection episode within the first three months post-transplant. Pre-mRNA levels did not differ between recipients with vs without rejection, logarithmic value of normalized pre-mRNA FOXP3 −4.48 [−4.63 to −4.10] vs −4.41 [−4.69 to −4.11], p = 0.80. The pattern persisted regardless of donor type, deceased recipients with rejection (N = 25) vs deceased recipients without—(N = 268), −4.47 [−4.62 to −4.26] vs −4.46 [−4.71 to −4.25], p = 0.90. Living ABO-compatible recipients with rejection (N = 19) vs living ABO-compatible recipients without—(N = 139), −4.49 [−4.64 to −4.14] vs −4.35 [−4.65 to −3.93], p = 0.30. Living ABO-incompatible recipients with rejection (N = 8) vs living ABO-compatible recipients without—(N = 56), −4.13 [−4.48 vs −3.88] vs −4.20 [−4.61 to −3.88], p = 0.70. Conclusion In kidney transplant recipients, early post-transplant abundance of pre-mRNA FOXP3 transcripts were similar regardless of risk of kidney allograft rejection post-transplant.

2706. Effectiveness and Safety of Shingrix Vaccination in Solid Organ Transplant Recipients at a Large Urban Transplant Center

Abstract Background The varicella zoster virus (VZV) recombinant subunit vaccine, Shingrix, was found to be safe in solid organ transplant recipients (SOTR) and is now approved and recommended for all immunocompromised patients. Given limited efficacy data, we preferred a single center retrospective study to demonstrate safety and effectiveness of the Shingrix vaccine in solid organ transplant recipients. Methods After IRB approval, clinical data from all SOTR at Northwestern Memorial Hospital (NMH) who received the Shingrix vaccine after their transplant, between January 1, 2017 and March 1, 2022 was collected from our Enterprise Data Warehouse (EDW). Extracted data includes age, race, ethnicity, date of transplant, organ transplanted, and date(s) of vaccine administration(s). Clinical outcomes were assessed by diagnosis of acute allograft rejection and/or HZ made post-vaccine administration. Descriptive statistics were utilized. This project is supported by the IDSA G.E.R.M. program. Results 309 of 338 eligible SOTR were included in the analysis of this study (characteristics and reasons for exclusion in Table 1). Only 1 (0.32%) patient experienced a new episode of acute allograft rejection within 3 months of Shingrix administration. 18/309 (5.8%) were diagnosed with HZ after vaccination with Shingrix. This represents a reduction in VZV reactivation events compared to the 9.1% incidence found in the 2021 meta-analysis of HZ in the general solid organ transplant population [Kwon, Transpl Infect Dis., 2021].Table 1.Characteristics of 338 solid organ transplant patients who received Shingrix vaccine. Conclusion The Shingrix vaccine, when administered to SOTR post-transplant, is safe and likely effective in reducing the rate of herpes zoster. This data supports the current recommendation to vaccinate all SOTR with Shingrix. Larger, multi-center data are needed to inform the true efficacy of the vaccine in SOTRs. Disclosures All Authors: No reported disclosures

Reduction of immunosuppression for post-transplant lymphoproliferative disorder (PTLD): a single-center experience of allograft survival outcomes

Post-transplant lymphoproliferative disorder (PTLD) is a well-known complication of hematopoietic stem cell transplant and solid organ transplant. While reduction in immunosuppression (RIS) is the first-line treatment for PTLD, outcomes of allograft function as a result of RIS remain understudied. In this retrospective study, we examine rates of allograft rejection and graft failure after RIS in 141 patients diagnosed with PTLD at the University of Florida. Compared to prior literature demonstrating around 32–40% rate of allograft rejection as result of RIS, our institutional analysis revealed a much lower treatment-related allograft rejection rate of 18.4%. Out of the patients who experienced acute allograft rejection, 23.1% ultimately progressed to allograft failure. Interestingly, acute allograft rejection episodes during PTLD treatment were not statistically found to impact overall survival. RIS remains an overall beneficial treatment modality of PTLD due to its low allograft rejection rate relative to treatment rate.

Plasma CD5L and non-invasive diagnosis of acute heart rejection

Acute rejection is one of the most important direct contributors to mortality after heart transplantation. Advances in the development of novel non-invasive approaches for the early identification of allograft rejection are necessary. We conducted a non-targeted proteome characterization focused on identifying multiple plasmatic protein differences to evaluate their diagnostic accuracy for rejection episodes. We included consecutive plasma samples from transplant recipients undergoing routine endomyocardial biopsies. A liquid chromatography-tandem mass spectrometry analysis using isobaric tags (tandem mass tag 10-plex) was performed and concentrations of CD5L were validated using a specific sandwich enzyme-linked immunosorbent assay. A total of 17 altered proteins were identified as potential markers for detecting heart transplant rejection, most involved in inflammation and immunity. CD5L, an apoptosis inhibitor expressed by macrophages, showed the best results in the proteomic analysis (n = 30). We confirm this finding in a larger patient cohort (n = 218), obtaining a great diagnostic capacity for clinically relevant rejection (≥Grade 2R: area under the curve = 0.892, p < 0.0001) and preserving the accuracy at mild rejection (Grade 1R: area under the curve = 0.774, p < 0.0001). CD5L was a strong independent predictor, with an odds ratio of 14.74 (p < 0.0001), for the presence of rejection. Episodes of acute cardiac allograft rejection are related to significant changes in a key inhibitor of apoptosis in macrophages, CD5L. Because of its precision to detect acute cellular rejection, even at mild grade, we propose CD5L as a potential candidate to be included in the studies of molecule combination panel assays. This finding could contribute to improving the diagnostic and preventive methods for the surveillance of cardiac transplanted patients.

Renal Allograft Rejection: Noninvasive Ultrasound- and MRI-Based Diagnostics.

To date, allogeneic kidney transplantation remains the best available therapeutic option for patients with end-stage renal disease regarding overall survival and quality of life. Despite the advancements in immunosuppressive drugs and protocols, episodes of acute allograft rejection, a sterile inflammatory process, continue to endanger allograft survival. Since effective treatment for acute rejection episodes is available, instant diagnosis of this potentially reversible graft injury is imperative. Although histological examination by invasive core needle biopsy of the graft remains the gold standard for the diagnosis of ongoing rejection, it is always associated with the risk of causing substantial graft injury as a result of the biopsy procedure itself. At the same time, biopsies are not immediately feasible for a considerable number of patients taking anticoagulants due to the high risk of complications such as bleeding and uneven distribution of pathological changes within the graft. This can result in the wrong diagnosis due to the small size of the tissue sample taken. Therefore, there is a need for a tool that overcomes these problems by being noninvasive and capable of assessing the whole organ at the same time for specific and fast detection of acute allograft rejection. In this article, we review current state-of-the-art approaches for noninvasive diagnostics of acute renal transplant inflammation, i.e., rejection. We especially focus on nonradiation-based methods using magnetic resonance imaging (MRI) and ultrasound.

O-39 Tacrolimus intra-patient variability is an independent factor associated with the need for liver biopsy in paediatric liver transplant recipients

Background The intra-patient variability in tacrolimus exposure (TAC-IPV) after paediatric liver transplantation and its impact on patient outcomes has been poorly studied. The present study aims to investigate whether there is a trend in TAC-IPV during the first 5 years post transplantation, which variables influence IPV and wheth-er the IPV during the first year is associated with liver transplantation outcomes in paediatric patients. Methods We conducted a single centre retrospective study including 41 living paediatric patients transplanted between January 2003 and September 2016 at the Ghent University Hospital. The intra-patient variability in the dose-adjusted tacrolimus pre-dose concentrations was calculated yearly during the first five years following trans-plantation, expressed as coefficient of variation (CV%1–5) The difference in CV% in the years following transplanta-tion was analysed using the Friedman test. A linear uni-variate and multivariate regression analysis was applied to identify factors associated with TAC-IPV. The following parameters were tested: age, gender, origin, the number of missed clinic appointments as a surrogate marker for ther-apy adherence, the total number of medications, concom-itant medications potentially interfering with TAC metabo-lism-CYP3A4/A5 inductors or inhibitors and biochemical parameters. Logistic and linear regression models were fit-ted to test an association of TAC-IPV with patient outcomes: need for biopsy during year 1, 3 and 5; hypertension and renal function at 1, 3 and 5 years; acute rejection and CMV/EBV viremia during year 1 post-transplantation. Results We identified a significant decrease in TAC-IPV during the first 3 years after transplantation with the me-dian CV%1=39,4%; CV%2=30,9%; CV%3=28,5% (p=0,004), after which the CV% reaches a plateau (CV%4=23,6% en CV%5=28,9%). Multivariate analysis showed that serum albumin in the first year (p=0,029), haematocrit in the third year (p=0,019) and the number of missed clin-ic appointments in the fifth year after transplantation (p=0,009) were associated with TAC-IPV.in the 1 st, 3rd and 5th year, respectively. Univariate analysis showed that CV%1 was significantly associated with the need for bi-opsy during the first year post-transplantation (p=0.036) and the occurrence of one or more episodes of acute al-lograft rejection during the first year post-transplantation (p=0.031). In univariate analysis a trend was observed for association with hypertension one year after transplan-tation (p=0,085). Multivariate logistic regression analysis confirmed that CV%1 was an independent factor associ-ated with the need for liver biopsy in the first year follow-ing liver transplantation. (p=0.05; Exp(B)=1.045). Conclusion As expected, tacrolimus intra-patient vari-ability is higher during the first two years after transplantation. Our results suggest that while albumin and hae-matocrit are associated with TAC-IPV in the first 3 years, therapy adherence expressed as the number of missed clinic appointments is associated with TAC-IPV after a longer follow-up. A high TAC-IPV during the first year was an independent factor associated with the need for liver biopsy. Our results therefore highlight the importance of monitoring the variability of the tacrolimus trough levels.

Variations in DNA methylation of interferon gamma and programmed death 1 in allograft rejection after kidney transplantation.

BackgroundThe role of DNA methylation in the regulation of the anti-donor-directed immune response after organ transplantation is unknown. Here, we studied the methylation of two mediators of the immune response: the pro-inflammatory cytokine interferon γ (IFNγ) and the inhibitory receptor programmed death 1 (PD1) in naïve and memory CD8+ T cell subsets in kidney transplant recipients receiving immunosuppressive medication. Both recipients experiencing an episode of acute allograft rejection (rejectors) as well as recipients without rejection (non-rejectors) were included.ResultsCpGs in the promoter regions of both IFNγ and PD1 were significantly (p < 0.001) higher methylated in the naïve CD8+ T cells compared to the memory T cell subsets. The methylation status of both IFNγ and PD1 inversely correlated with the percentage of IFNγ or PD1-producing cells. Before transplantation, the methylation status of both IFNγ and PD1 was not significantly different from healthy donors. At 3 months after transplantation, irrespective of rejection and subsequent anti-rejection therapy, the IFNy methylation was significantly higher in the differentiated effector memory CD45RA+ (EMRA) CD8+ T cells (p = 0.01) whereas the PD1 methylation was significantly higher in all memory CD8+ T cell subsets (CD27+ memory; p = 0.02: CD27− memory; p = 0.02: EMRA; p = 0.002). Comparing the increase in methylation in the first 3 months after transplantation between rejectors and non-rejectors demonstrated a significantly more prominent increase in the PD1 methylation in the CD27− memory CD8+ T cells in rejectors (increase in rejectors 14%, increase in non-rejectors 1.9%, p = 0.04). The increase in DNA methylation in the other memory CD8+ T cells was not significantly different between rejectors and non-rejectors. At 12 months after transplantation, the methylation of both IFNγ and PD1 returned to baseline levels.ConclusionsThe DNA methylation of both IFNγ and PD1 increases the first 3 months after transplantation in memory CD8+ T cells in kidney transplant recipients. This increase was irrespective of a rejection episode indicating that general factors of the kidney transplantation procedure, including the use of immunosuppressive medication, contribute to these variations in DNA methylation.

OR19 Quantification of peripheral B-cell subsets in acute allograft rejection in recipients with renal transplantation

To monitor B cell subsets in peripheral circulation to find a distinctive phenotypic signature of rejection in our cohort. The study population consisted of 211 consecutive first renal allograft recipients who were followed up for 12 months post-transplant. One ml of EDTA peripheral venous blood was collected pre- transplant, 1 month, 3 months, 6 months, 12 months post-transplant and at the time of graft rejection. A multicolour flowcytometry was performed to monitor the percentage of peripheral Plasma cells (CD20-CD38+CD138+), Total B-cells (CD20+), Naïve B-cells (CD20+CD27-CD38-), Activated B-cells (CD20+CD38+CD138-) and Memory B-cells (CD20+CD138-CD27+). Of 211 cases of first kidney allograft recipients, 35 (16.58%) recipients had 38 episodes of acute allograft rejection. Percentage of activated B cells and Memory B-cells were found to be significantly higher in uremic patients (n = 78) than those of healthy persons (n = 40) (20.81 ± 0.7616 % vs. 14.37 ± 0.5972%, p < 0.0001 and 10.56 ± 0.5813% vs 7.658 ± 0.6626%, p = 0.0025 respectively). On the contrary, the percentage of naïve B- cells was found to be significantly lower in the patients than normal controls (61.04 ± 1.691% vs 73.62 ± 1.320%, p < 0.0001). Acute rejection episodes (n = 38) were associated with increase in peripheral percentage of total B-cells (19.02 ± 1.457 vs. 10.80 ± 0.6338, P < 0.0001) and activated B-cells (33.92 ± 1.756 vs. 23.26 ± 1.113, P < 0.0001). On the contrary, the percentage of plasma cells and memory B-cells and naïve B- cells was significantly lower during rejection episodes (0.7447 ± 0.09 vs. 2.363 ± 0.1529, P < 0.0001, 5.871 ± 0.6677 vs. 12.12 ± 0.6584, P < 0.0001 and 44.53 ± 2.504 vs. 52.61 ± 2.488, P = 0.0311 respectively). The percentage of activated B-cells and Memory B-cells were persistently high in uremic patients suggesting that these patients are always in a stage of immune activation. Acute rejection episodes were associated with increased percentage of activated B-cells but decrease in the percentage of plasma- and memory-B cells in the peripheral blood. Therefore, post- transplantation, periodic measurements of B-cell subsets may serve as an important marker in the prediction of acute allograft rejection.

Imaging-based diagnosis of acute renal allograft rejection.

Kidney transplantation is the best available treatment for patients with end stage renal disease. Despite the introduction of effective immunosuppressant drugs, episodes of acute allograft rejection still endanger graft survival. Since efficient treatment of acute rejection is available, rapid diagnosis of this reversible graft injury is essential. For diagnosis of rejection, invasive core needle biopsy of the graft is the "gold-standard". However, biopsy carries the risk of significant graft injury and is not immediately feasible in patients taking anticoagulants. Therefore, a non-invasive tool assessing the whole organ for specific and fast detection of acute allograft rejection is desirable. We herein review current imaging-based state of the art approaches for non-invasive diagnostics of acute renal transplant rejection. We especially focus on new positron emission tomography-based as well as targeted ultrasound-based methods.

Severe Veno-occlusive Disease/Sinusoidal Obstruction Syndrome After Deceased-donor and Living-donor Liver Transplantation

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) occurring after liver transplantation is a relatively rare complication but it often takes a life-threatening course. However, the detailed etiology and mechanism of VOD/SOS after liver transplantation (LT) remains unclear. We report two cases with rapidly progressive VOD/SOS after ABO-identical LT resistant to various therapies. In case 1, in which the patient underwent deceased-donor LT, the first episode of acute allograft rejection was triggered VOD/SOS, and the presence of donor non-specific anti-HLA antibodies was confirmed. The recipient died with graft failure on day 46 after transplantation. Case 2, in which the patient underwent living-donor LT from the mother, had neither rejection nor mechanical venous obstruction, but condition of the patient rapidly worsened and he died on day 13 after transplantation. This recipient's direct cross-match test for the donor's B lymphocyte was strongly positive, but that for T lymphocyte was negative. In both cases, neither stenosis of hepatic vein outflow tract nor C4d deposition in post-transplantation liver biopsy specimens and autopsy specimen was found. On the other hand, in both cases, the patient was transfusion unresponsive thrombocytopenia and hyperbilirubinemia persisted postoperatively, and glycoprotein Ⅰ bα was strongly stained in the neighboring centrilobular area (zone 3), especially in the space of Disse, and platelet phagocytosis was observed in Kupffer cells and hepatocytes around zone 3 such as clinical xenotransplantation of the liver in post-transplantation liver biopsy specimens. From the viewpoint of graft injury, VOD/SOS was considered that sustained sinusoidal endothelial cells injury resulted in bleeding in the space of Disse and led to around centrilobular hemorrhagic necrosis, and the fundamental cause was damage around centrilobular area including sinusoid by acute cellular rejection, antibody-mediated rejection or ischemic reperfusion injury. The extrasinusoidal platelet activation, aggregation, and phagocytosis of platelets were some of the main reasons for VOD/SOS and transfusion-resistant thrombocytopenia.

SPECT- and PET-based approaches for noninvasive diagnosis of acute renal allograft rejection.

Molecular imaging techniques such as single photon emission computed tomography (SPECT) or positron emission tomography are promising tools for noninvasive diagnosis of acute allograft rejection (AR). Given the importance of renal transplantation and the limitation of available donors, detailed analysis of factors that affect transplant survival is important. Episodes of acute allograft rejection are a negative prognostic factor for long-term graft survival. Invasive core needle biopsies are still the “goldstandard” in rejection diagnostics. Nevertheless, they are cumbersome to the patient and carry the risk of significant graft injury. Notably, they cannot be performed on patients taking anticoagulant drugs. Therefore, a noninvasive tool assessing the whole organ for specific and fast detection of acute allograft rejection is desirable. We herein review SPECT- and PET-based approaches for noninvasive molecular imaging-based diagnostics of acute transplant rejection.

Non-invasive Imaging of Acute Allograft Rejection after Rat Renal Transplantation Using &lt;sup&gt;18&lt;/sup&gt;F-FDG PET

The number of patients with end-stage renal disease, and the number of kidney allograft recipients continuously increases. Episodes of acute cellular allograft rejection (AR) are a negative prognostic factor for long-term allograft survival, and its timely diagnosis is crucial for allograft function (1). At present, AR can only be definitely diagnosed by core-needle biopsy, which, as an invasive method, bares significant risk of graft injury or even loss. Moreover, biopsies are not feasible in patients taking anticoagulant drugs and the limited sampling site of this technique may result in false negative results if the AR is focal or patchy. As a consequence, this gave rise to an ongoing search for new AR detection methods, which often has to be done in animals including the use of various transplantation models. Since the early 60s rat renal transplantation is a well-established experimental method for the examination and analysis of AR (2). We herein present in addition small animal positron emission tomography (PET) using (18)F-fluorodeoxyglucose (FDG) to assess AR in an allogeneic uninephrectomized rat renal transplantation model and propose graft FDG-PET imaging as a new option for a non-invasive, specific and early diagnosis of AR also for the human situation (3). Further, this method can be applied for follow-up to improve monitoring of transplant rejection (4).

Non-invasive Imaging of Acute Allograft Rejection after Rat Renal Transplantation Using &lt;sup&gt;18&lt;/sup&gt;F-FDG PET

The number of patients with end-stage renal disease, and the number of kidney allograft recipients continuously increases. Episodes of acute cellular allograft rejection (AR) are a negative prognostic factor for long-term allograft survival, and its timely diagnosis is crucial for allograft function 1. At present, AR can only be definitely diagnosed by core-needle biopsy, which, as an invasive method, bares significant risk of graft injury or even loss. Moreover, biopsies are not feasible in patients taking anticoagulant drugs and the limited sampling site of this technique may result in false negative results if the AR is focal or patchy. As a consequence, this gave rise to an ongoing search for new AR detection methods, which often has to be done in animals including the use of various transplantation models. Since the early 60s rat renal transplantation is a well-established experimental method for the examination and analysis of AR 2. We herein present in addition small animal positron emission tomography (PET) using 18F-fluorodeoxyglucose (FDG) to assess AR in an allogeneic uninephrectomized rat renal transplantation model and propose graft FDG-PET imaging as a new option for a non-invasive, specific and early diagnosis of AR also for the human situation 3. Further, this method can be applied for follow-up to improve monitoring of transplant rejection 4.

Acute Pancreas Allograft Rejection Is Associated With Increased Risk of Graft Failure in Pancreas Transplantation

The effect of acute allograft rejection (AR) on long-term pancreas allograft function is unclear. We retrospectively studied 227 consecutive pancreas transplants performed at our institution between January 1, 998 and December 31, 2009 including: 56 simultaneous pancreas and kidney (SPK), 69 pancreas transplantation alone (PTA); and 102 pancreas after kidney (PAK) transplants. With a median follow-up of 6.1 (IQR 3-9) years, 57 patients developed 79 episodes of AR, and 19 experienced more than one episode. The cumulative incidence for AR was 14.7%, 19.7%, 26.6% and 29.1% at 1, 2, 5 and 10 years. PTA transplant (hazards ratio [HR]=2.28, p=0.001) and donor age (per 10 years) (HR=1.34, p=0.006) were associated with higher risk for AR. The first AR episode after 3 months post PT was associated with increased risk for complete loss (CL) (HR 3.79, p<0.001), and the first AR episode occurring during 3- to 12-month and 12- to 24-month periods after PT were associated with significantly increased risk for at least partial loss (PL) (HR 2.84, p=0.014; and HR 6.25, p<0.001, respectively). We conclude that AR is associated with increased risk for CL and at least PL. The time that the first AR is observed may influence subsequent graft failure.

Biomarkers for Monitoring Therapeutic Side Effects or Various Supratherapeutic Confounders after Kidney Transplantation

Although the development of novel immunosuppressants dramatically decreased the incidence of acute allograft rejection episodes, long-term allograft survival has not improved due to various postoperative confounders. These confounders include heterologous immunity by cytomegalovirus (CMV) infection, nephrotoxicity of immunosuppressants, ureteral complications, and onset of the original renal disease in the graft, which can mislead physicians from the actual diagnosis. Early and precise discrimination of these complications by using noninvasive biomarkers will benefit the patients at high-risk and be instructive in directing effective and timely therapies whenever necessary.

Remote noninvasive allograft rejection monitoring for heart transplant recipients: study protocol for the novel evaluation with home electrocardiogram and remote transmission (NEW HEART) study

BackgroundAcute allograft rejection is a major cause of early mortality in the first year after heart transplantation in adults. Although endomyocardial biopsy (EMB) is not a perfect "gold standard" for a correct diagnosis of acute allograft rejection, it is considered the best available test and thus, is the current standard practice. Unfortunately, EMB is an invasive and costly procedure that is not without risk. Recent evidence suggests that acute allograft rejection causes delays in ventricular repolarization and thereby increases the cellular action potential duration resulting in a longer QT interval on the electrocardiogram (ECG). No prospective study to date has investigated whether such increases in the QT interval could provide early detection of acute allograft rejection. Therefore, in the Novel Evaluation With Home Electrocardiogram And Remote Transmission (NEW HEART) study, we plan to investigate the potential benefit of daily home QT interval monitoring to predict acute allograft rejection.Methods/designThe NEW HEART study is a prospective, double-blind, multi-center descriptive research study. A sample of 325 adult heart transplant recipients will be recruited within six weeks of transplant from three sites in the United States. Subjects will receive the HeartView™ ECG recorder and its companion Internet Transmitter, which will transmit the subject's ECG to a Core Laboratory. Subjects will be instructed to record and transmit an ECG recording daily for 6 months. An increase in the QTC interval from the previous day of at least 25 ms that persists for 3 consecutive days will be considered abnormal. The number and grade of acute allograft rejection episodes, as well as all-cause mortality, will be collected for one year following transplant surgery.DiscussionThis study will provide "real world" prospective data to determine the sensitivity and specificity of QTC as an early non invasive marker of cellular rejection in transplant recipients during the first post-transplant year. A non-invasive indicator of early allograft rejection in heart transplant recipients has the potential to limit the number and severity of rejection episodes by reducing the time and cost of rejection surveillance and by shortening the time to recognition of rejection.Trial RegistrationClinicalTrials.gov: NCT01365806

Sequential Monitoring of TIM-3 Gene Expression in Peripheral Blood for Diagnostic and Prognostic Evaluation of Acute Rejection in Renal Graft Recipients

Background TIM-3 is expressed on primary T effector cells, including th1, ctl, and Th17, which play essential roles in acute allograft rejection (AR). In this study we monitored sequential changes of TIM-3 gene expression among peripheral blood leukocytes (PBL) from renal transplant recipients. Methods The study consisted of an AR group (n = 24), a no AR group (n = 20), and a stable group (n = 18). Prospective serial blood samples were collected after allotransplantation and during AR episodes. The mRNA encoding for TIM-3 was quantified using real-time reverse-transcription polymerase chain reaction (RT-PCR). Statistical analyses were performed to correlate gene transcript measurements with clinical events. Results TIM-3 mRNA in PBL showed significantly higher expression in the AR compared with the no AR and stable groups: 286.72 ± 86.28 vs 126.10 ± 28.31 vs 96.91 ± 17.88, respectively ( P = .00). The receiver operating characteristic curve showed a specificity of 100% and a sensitivity of 87.5% for the utility of TIM-3 for rejection diagnosis. Antirejection therapy decreased TIM-3 mRNA expression in all AR patients. There was a positive correlation between TIM-3 mRNA expression and serum creatinine ( r 2 = 0.716; P = .00). Conclusions TIM-3 mRNA quantification by RT-PCR in PBL may be a promising tool for a noninvasive diagnosis of AR. But the utility for predicting the prognosis of AR after antirejection treatment was limited, owing to the great variations of TIM-3 mRNA expression during AR episodes.

Mammalian target of rapamycin signal inhibitors could play a role in the treatment of BK polyomavirus nephritis in renal allograft recipients

BK virus (BKV) nephropathy is a common viral infection in renal transplant patients, with a prevalence of 1-9% at approximately 12 months after surgery. While it is widely agreed that reduction of immunosuppression should be the first intervention after diagnosis of BKV infection, there is no consensus on whether calcineurin inhibitors or antiproliferative drugs should be reduced first. Furthermore, target levels of immunosuppressive drugs are poorly defined, as are criteria for replacing one immunosuppressive agent with another. We report our series of 15 renal transplant patients who underwent surgery between September 2004 and March 2010 and who developed BKV infection. The first 8 patients were treated with reduction of immunosuppression; 7 of these patients received cidofovir and 6 received intravenous immunoglobulin. The remaining 7 renal transplant recipients received mammalian target of rapamycin inhibitors (imTOR). In this group, we observed faster and more efficacious BKV clearance in plasma and urine and a steady improvement in allograft function, with no episodes of acute allograft rejection during follow-up. The polymerase chain reaction assay for BKV in urine became positive in 2 patients in whom imTOR were stopped due to severe side effects. The use of imTOR should be considered a first step in the treatment of renal transplant recipients with BKV infection. In our experience, this change in treatment was safe and resulted in viral clearance.

Antithymocyte treatment of steroid-resistant acute rejection in renal transplantation

To evaluate the outcome of early (ER <3 months) and late (LR >3 months) episodes of corticosteroid resistant acute allograft rejection (CRR) treated with anti-thymocyte globulin (ATG) in pediatric renal allograft recipients. Retrospective study of 15 children, mean age 13.2 y, who received ATG for the treatment of biopsy proven CRR over a 15 year period. Seven children received ATG for ER (median 26 days post transplantation) and 8 for LR (median 763 days). There was a significant improvement in the 3 month eGFR (70.3 ml/min/1.73m(2), SD 22.3, p = 0.018) when compared with the value prior to ATG treatment (23.3 ml/min/1.73m(2), SD 10.2) in the ER group. In the LR group (4 DSA positive) there was no improvement in the eGFR at 3 months (42 ml/min/1.73m(2), SD 10.5, p = 0.32) when compared with the value prior to ATG (38 ml/min/1.73 m(2), SD 9.7). At final review, eGFR in the ER group was 72.3 ml/min/1.73m(2) (SD 33) vs. 37.7 ml/min/1.73m(2) (SD 17.9) in the LR group after a mean follow up of 10.4 y and 1.2 y, respectively. ATG therapy in CRR is associated with reversal of rejection and excellent graft outcome in children with ER. The benefits remain uncertain in LR, the etiology of which is multifactorial.

Postoperative intensive care of biliary atresia patients treated with living donor liver transplantation

To summarize experience of pediatric intensive care and explore the incidence of complications, the involved pathogens among liver recipients to determine the effective strategies for preventing complications. Between June 2006 and July 2009, 35 children under the age of 14 yr received 35 liver transplantations (LTs) performed at the center. A retrospective review of 22 infants weighing 8.8 kg or less underwent 23 transplants was conducted. Indication for transplantation was biliary atresia. Central venous pressure and arterial blood pressure were monitored continuously and fluid monitoring was performed every 2 hours in the first postoperative week. Blood loss, ascites, and intraoperative transudate loss were primarily replaced with 5% albumin and crystalloids to maintain a central venous pressure between 4 and 6 cm H(2)O. Oral food intake was allowed as soon as possible. To identify vascular or biliary complications, liver doppler ultrasound was performed intraoperatively immediately after reperfusion and after closure of the abdominal wall and postoperatively, twice daily during the first week after surgery. Immunosuppression was initially cyclosporine based, in combination with steroids. Cyclosporine was begun one day prior to transplantation at a dose of 10 mg/(kg·d) divided into two doses, except for cases with hepatic encephalopathy and severe infection. The subsequent doses were adjusted on the basis of recommended trough blood concentrations at different stages. Steroids were eventually discontinued at a time point exceeding 6 months after transplantation. The diagnosis of rejection was confirmed by histology on needle biopsy specimens. Acute graft rejection episodes were treated with a 3-day scheme of IV methylprednisolone 10 mg/(kg·d) followed by recycling doses during the following 3 days (7.5, 5 and 2.5 mg/(kg·d). The most common postoperative complications were infections (18 cases), gastrointestinal bleeding (3 cases), and vascular complications (4 cases). Rejection occurred in 25% of patients. There was one perioperative death from primary graft non-function. The most common isolated bacteria of the pathogen spectrum were Staphylococcus epidermidis. The median length of stay (LOS) in the PICU for 22 patients (23 transplants) was 10 days (range 5 - 21) and the mean length of stay in the hospital was (18.5 ± 116) days (range, 11 - 48 days). Mean requirement for artificial ventilation was 37.6 h. Mean use of dobutamine, prostaglandin E1 and dopamine was 3.3, 7.5 and 8.8 days, respectively. Preoperatively, 3 children had gastrointestinal bleeding, 18 had ascites, 2 had encephalopathy, 22 had jaundice, and 16 had coagulopathy. There were multiple early operative complications in these infants, including one graft with primary non-function (4.5%). Two patients (9.1%) returned for a total of three times for gastrointestinal bleeding or intra-abdominal hematoma. Three patients (13.6%) had early postoperative intestinal perforations related to adhesions or enterotomy, one was associated with a bowel obstruction. There were 26 episodes of bacterial or fungal infections in 18 (81.8%) patients in the early postoperative period, and infection was the direct/contributing cause of death in one infant. These infections included pneumonia, intra-abdominal abscess or sepsis. All of the bacterial and fungal infections were successfully treated with the appropriate antibacterial and antifungal agents, except for one patient who developed overwhelming sepsis after small bowel perforation. Four (18.2%) patients developed five episodes of acute allograft rejection during the first 15 days after LT. Three of the four patients who developed rejection were transplanted before 2007. All episodes of rejection were treated successfully with intravenous steroid pulse and optimization of cyclosporine levels or FK506 conversion. Of the 20 survivors beyond the perioperative period, two cases (10%) had hypertension requiring therapy. Liver transplantation in infants with biliary atresia appears technically demanding but acceptable. There should be essentially no age or size restriction for infants and transplantation can be performed with good outcome, although the frequency of complications is much higher than that seen in older children. The improvement in medical and nursing expertise in this group of very sick infants is based on judicious preoperative donor and recipient selection, meticulous surgical technique (vascular reconstruction and abdominal closure), immediate detection and prompt intervention of complications, and keen postoperative surveillance, which reflect a learning curve for both the technical aspects of liver transplantation and post-operative care of these very small patients in our institution. Liver transplantation for infants can be technically challenging.