Cardiac magnetic resonance imaging in heart transplant recipients with biopsy-negative graft dysfunction

AIMS

Graft dysfunction (GD) after heart transplantation (HTx) can develop without evidence of cell- or antibody-mediated rejection. Cardiac magnetic resonance imaging (CMR) has an evolving role in detecting rejection; however, its role in biopsy-negative GD has not been described. This study examines CMR findings, evaluates outcomes based on CMR results, and seeks to identify the possibility of rejection missed through endomyocardial biopsy by using CMR in HTx recipients with biopsy-negative GD.

METHODS AND RESULTS

HTx recipients with GD [defined as a decrease in left ventricular ejection fraction (LVEF) by >5% and LVEF < 50%] in the absence of rejection by biopsy or allograft vasculopathy and who underwent CMR were included in the study. The primary outcome was a composite of all-cause mortality, re-transplantation, or persistent LVEF < 50%. Overall, 34 HTx recipients developed biopsy-negative GD and underwent CMR. Left ventricular late gadolinium enhancement (LGE) on CMR was observed in 16 patients with two distinct patterns: diffuse epicardial (n = 13) and patchy (n = 3) patterns. Patients with LGE developed GD later after HTx [4 (1.4-6.8) vs. 0.8 (0.3-1.2) years, P < 0.001], were more often symptomatic (88% vs. 56%, P = 0.06), and had greater haemodynamic derangement (pulmonary capillary wedge pressure: 19 ± 7 vs. 13 ± 3 mmHg, P = 0.002) as compared with those without LGE. No significant difference was observed in the primary composite outcome between patients with LGE and those without LGE (50% vs. 38% of patients with events, P = 0.515). During a median follow-up of 3.8 years, mean LVEF improved similarly in the LGE-negative (37-55%) and LGE-positive groups (32-55%) (P = 0.16).

CONCLUSIONS

Biopsy-negative GD occurs with and without LGE when assessed by CMR, indicative of possible rejection/inflammation occurring only in a subset of patients. Irrespective of LGE, LVEF improvement occurs in most GD patients, suggesting that other neurohormonal or immunomodulatory mechanisms may also contribute to GD development.

Value of blood lipid in predicting graft dysfunction after organ and tissue transplantation: A study of Mendelian randomization

Background

While immunosuppressive regimens have improved outcomes in solid organ transplantation, non-immune factors have also been identified as contributors to graft prognosis. Age, gender, hormones, heredity, and other diseases have been recognized to affect organ transplantation. However, the causal relationship between blood lipids and graft dysfunction remains unverified in human clinical investigations. In this study, we employed two-sample Mendelian randomization (MR) to examine the causality between different types of blood lipids and graft dysfunction following organ and tissue transplantation.

Methods

We conducted a two-sample MR study using available genome-wide association summary data from the online database MRBASE (http://app.mrbase.org/), which encompasses over 11 billion associations between genetic factors and health-related outcomes, enabling researchers to explore various potential determinants of poor health. The exposure factors included four types of blood lipids: high-density lipoprotein, low-density lipoprotein, cholesterol, and triglycerides. For each exposure factor, three databases were selected for analysis. The outcome factor was the failure and rejection of transplanted organs and tissues. All databases consisted of European population samples, without specific subgroups. The related studies were conducted between 2016 and 2022, and the "TwoSampleMR" R package was employed for variant selection.

Results

A total of 13 sample groups were collected and analyzed. The results revealed a causal association between blood lipids and graft dysfunction following organ and tissue transplantation. Specifically, the two-sample MR analysis confirmed that low-density lipoprotein and cholesterol levels were significant risk factors for increased graft dysfunction risk after transplantation. Moreover, high-density lipoprotein potentially reduced the risk of allograft dysfunction, while triglycerides possibly elevated the risk.

Conclusions

Our recent study provides the initial confirmation that blood lipids may initiate causal pathological processes leading to graft dysfunction after organ and tissue transplantation.

Immunosuppression in uterus transplantation: from transplant to delivery

INTRODUCTION

Uterus transplantation introduces unique challenges regarding immunosuppression, including the effects of immunosuppressive drugs on the fetus and graft rejection during pregnancy. Although immunosuppressive regimens are based on protocols used after solid organ transplantation, in recipients of uterus grafts, the physician must consider therapy modifications based on the phase of the transplant, from the intra-operative period through to delivery.

AREAS COVERED

This review discusses the current immunosuppressive rationale in uterus transplantation, focusing on the therapy in each phase of the transplant. The authors present an overview of the already approved immunosuppressive medications for solid organ transplantation, their application in uterus transplant prior to pregnancy, during pregnancy and as rejection treatment.

EXPERT OPINION

Most medications used for uterus transplant are adopted from solid organ transplantation experience, especially kidney transplantation, and rejection is treated in standard fashion. Research is needed to clarify the drugs' effects on fetal and neonatal well-being and to develop new medications to achieve better tolerance. Early markers of uterus graft rejection need to be identified, and prior rejection episodes should no longer be a cause to remove the graft during delivery in a recipient who wants a further pregnancy.

Macrophage polarization in kidney transplant patients

BACKGROUND

Macrophages can oscillate between two functionally distinct states: proinflammatory M1 and anti-inflammatory M2. Classically- activated M1 macrophages produce proinflammatory cytokines (TNF-α, IFN-ƴ, and IL-6), which ares associated with graft dysfunction/rejections. In contrast, alternatively-activated macrophages M2 produce anti-inflammatory cytokines (IL-10) that are involved in host defense, tissue repair/remodeling, debris scavenging, and immune regulation, thereby helps to improve long-term graft survival.

METHODS

In this study, we have identified graft dysfunction or rejection by biopsies using immunohistochemistry. Flow cytometry was used to detect M1 (CD163+, CD206+, and CD200R+) and M2 (CD86+, CD80+, and CD68+) macrophages. Enzyme-linked immunosorbent assay (ELISA) was used to measure a panel of cytokines.

RESULTS

Histological analysis of the kidney transplants (n = 30) was used to distinguish those with acute/chronic allograft rejection (n = 15) from those with stable kidney function (n = 15). Flow cytometry results showed that patients with graft rejection exhibited macrophages with decreased expression (33.28%) of M2 macrophage markers (CD163+, CD206+, and CD200R+) and reduced production of IL-10 (as detected using ELISA). However, 71.33% of the macrophages were found to have M1 markers (CD86+, CD80+, and CD68+; p = 0.002) and produced proinflammatory cytokines (TNF-α, IFN-ƴ, and IL-6) by ELISA (p = 0.001) when compared with the healthy control group. In contrast, stable kidney transplants had 65.58% M2 and 27.66% M1 macrophages (p = 0.03) and produced IL-10. These findings suggest that M1 macrophages dominate in kidney grafts with dysfunction or rejection, whereas M2 macrophages dominate in kidney grafts with stable function.

CONCLUSION

Our observations implicate a major shift towards M2 macrophages in stable kidney transplants, which are markedly downregulated in patients with graft dysfunction or rejection. In contrast, an increased frequency of M1 macrophages remained dominant in the pathophysiology of kidney transplants undergoing active dysfunction or rejection.

Native T1 mapping detects both acute clinical rejection and graft dysfunction in pediatric heart transplant patients

BACKGROUND

Cardiovascular magnetic resonance (CMR) is emerging as an important tool for cardiac allograft assessment. Native T1 mapping may add value in identifying rejection and in assessing graft dysfunction and myocardial fibrosis burden. We hypothesized that CMR native T1 values and features of textural analysis of T1 maps would identify acute rejection, and in a secondary analysis, correlate with markers of graft dysfunction, and with fibrosis percentage from endomyocardial biopsy (EMB).

METHODS

Fifty cases with simultaneous EMB, right heart catheterization, and 1.5 T CMR with breath-held T1 mapping via modified Look-Locker inversion recovery (MOLLI) in 8 short-axis slices and subsequent quantification of mean and peak native T1 values, were performed on 24 pediatric subjects. A single mid-ventricular slice was used for image texture analysis using nine gray-level co-occurrence matrix features. Digital quantification of Masson trichrome stained EMB samples established degree of fibrosis. Markers of graft dysfunction, including serum brain natriuretic peptide levels and hemodynamic measurements from echocardiography, catheterization, and CMR were collated. Subjects were divided into three groups based on degree of rejection: acute rejection requiring new therapy, mild rejection requiring increased ongoing therapy, and no rejection with no change in treatment. Statistical analysis included student's t-test and linear regression.

RESULTS

Peak and mean T1 values were significantly associated with acute rejection, with a monotonic trend observed with increased grade of rejection. Texture analysis demonstrated greater spatial heterogeneity in T1 values, as demonstrated by energy, entropy, and variance, in cases requiring treatment. Interestingly, 2 subjects who required increased therapy despite low grade EMB results had abnormal peak T1 values. Peak T1 values also correlated with increased BNP, right-sided filling pressures, and capillary wedge pressures. There was no difference in histopathological fibrosis percentage among the 3 groups; histopathological fibrosis did not correlate with T1 values or markers of graft dysfunction.

CONCLUSION

In pediatric heart transplant patients, native T1 values identify acute rejection requiring treatment and may identify graft dysfunction. CMR shows promise as an important tool for evaluation of cardiac grafts in children, with T1 imaging outperforming biopsy findings in the assessment of rejection.

Primary Nonfunction and Early Allograft Dysfunction after Liver Transplantation

BACKGROUND

Despite continuous progress in the field of liver transplantation, considerable proportion of patients still suffer from the postoperative graft dysfunction. Clinically, it presents as early allograft dysfunction (EAD), and its more severe form defined as primary nonfunction (PNF). Posttransplant liver dysfunction translates into significantly worse treatment outcomes.

SUMMARY

Both entities are multifactorial, with donor (graft), recipient, and procedure-related factors playing the key roles. Ischemia-reperfusion injury is a major driver of their development. So far, various noninvasive (pharmacological) and invasive strategies have been tested to mitigate its negative effects. This article pre-sents the current approach to diagnosis, prediction, and management of EAD and PNF.

KEY MESSAGES

Different pharmacological interventions may be considered to improve graft function after liver transplantation. Machine perfusion seems to be the most effective method at the moment.

Longitudinal monitoring of mRNA levels of regulatory T cell biomarkers by using non-invasive strategies to predict outcome in renal transplantation

BACKGROUND

Acute T-cell mediated rejection (aTCMR) is still an issue in kidney transplantation, for it is associated with chronic rejection, graft loss, and overall worse outcomes. For these reasons, a standard non-invasive molecular tool to detect is desirable to offer a simpler monitoring of kidney transplant recipients (KTRs). The purpose of our study was to examine, in peripheral blood before and after transplantation, the expression patterns of regulatory T cell (Treg)-related genes: the forkhead box P3 (FOXP3) and the two CTLA-4 isoforms (full-length and soluble) to predict acute rejection onset, de novo donor-specific antibodies (DSA) development and renal dysfunction 1 year after transplantation.

METHODS

We profiled by using a relative quantification analysis (qRT-PCR) circulating mRNA levels of these biomarkers in peripheral blood of 89 KTRs within the first post-transplant year (at baseline and 15, 60 and 365 days, and when possible at the acute rejection) and compared also the results with 24 healthy controls.

RESULTS

The three mRNA levels drastically reduced 15 days after transplantation and gradually recovered at 1 year in comparison with baseline, with very low levels at the time of aTCMR for FOXP3 (RQ = 0.445, IQR = 0.086-1.264, p = 0.040), maybe for the pro-apoptotic role of FOXP3 during inflammation. A multivariate Cox regression analysis evidenced a significant relation between aTCMR onset and thymoglobuline induction (HR = 6.749 p = 0.041), everolimus use (HR = 7.017, p = 0.007) and an increased risk from the solCTLA-4 expression at 15 days, mainly considering recipients treated with Mycophelolic acid (HR = 13.94 p = 0.038, 95%CI:1.157-167.87). Besides, solCTLA-4 also predisposed to graft dysfunction (eGFR< 60 mL/min/1.73m²) at 1 year (AOR = 3.683, 95%CI = 1.145-11.845, p = 0.029). On the other hand, pre-transplant solCTLA-4 levels showed a protective association with de novo DSAs development (HR = 0.189, 95%CI = 0.078-0.459, p < 0.001).

CONCLUSIONS

mRNA levels of Treg-associated genes, mainly for solCTLA-4, in peripheral blood could put forward as candidate non-invasive biomarkers of cellular and humoral alloreactivity in clinical transplantation and might help shape immunosuppression, tailor monitoring and achieve better long-term outcomes of kidney transplantation in the wake of "precision medicine".

Transit time flow measurement predicts graft patency in off-pump coronary artery bypass grafting upon 5-year angiographic follow-up

Objective

This retrospective study sought to evaluate the efficacy of transit time flow measurement (TTFM) as a means of predicting bypass graft patency as assessed by coronary artery angiography upon 5-year follow-up.

Methods

Of 311 patients undergone isolated off-pump coronary artery bypass graft surgery from January 2014 through December 2014, 202 (65%) underwent both intraoperative TTFM and angiography at follow-up. 610 grafts, 202 left internal mammary artery grafts and 408 saphenous vein grafts were checked. Any grafts that exhibited Fitzgibbon type B or O lesions upon angiographic evaluation were considered to be failing. Receiver operating characteristic curves were used to identify the optimal TTFM values for predicting graft patency.

Results

A total of 610 grafts were included in this analysis, including 202 LIMA grafts and 408 SV grafts, of which 107, 129, 129, and 43 anastomosed to DIAG, OM, PDA, and PLA, respectively. LIMA, DIAG, OM, PDA, and PLA bypass grafts had overall patency rates of 95.0%, 74.8%, 73.6%, 71.5%, and 74.4%, respectively, upon 5-year follow up. No significant differences in TTFM values (MGF, PI, and DF) were observed when comparing outcomes associated with individual or sequential SV grafting. MGF was found to be predictive of graft failure regardless of the target vessel (P < 0.05). While PI was found to predict LIMA, OM, and PDA graft failure (P < 0.05), it was not associated with the failure of grafts associated with DIAG and PLA vessels. Similarly, DF was found to predict OM and PDA graft failure (P < 0.05), but was not significantly associated with the failure of grafts associated with LIMA, DIAG, or PLA vessels.

Conclusion

LIMA bypass grafts were associated with better 5-year graft patency relative to SV bypass grafts. Similar graft patency rates were observed for both individual and sequential bypass grafts. MGF was able to predict bypass graft failure in patients that underwent off-pump CABG surgery.

Emerging monitoring technologies in kidney transplantation

Non-invasive technologies to monitor kidney allograft health utilizing high-throughput assays of blood and urine specimens are emerging out of the research realm and slowly becoming part of everyday clinical practice. HLA epitope analysis and eplet mismatch score determination promise a more refined approach to the pre-transplant recipient-donor HLA matching that may lead to reduced rejection risk. High-resolution HLA typing and multiplex single antigen bead assays are identifying potential new offending HLA antibody subtypes. There is increasing recognition of the deleterious role non-HLA antibodies play in post-transplant outcomes. Donor-derived cell-free DNA detected by next-generation sequencing is a promising biomarker for kidney transplant rejection. Multi-omics techniques are shedding light on discrete genomic, transcriptomic, proteomic, and metabolomic signatures that correlate with and predict allograft outcomes. Over the next decade, a comprehensive approach to optimize kidney matching and monitor transplant recipients for acute and chronic graft dysfunction will likely involve a combination of those emerging technologies summarized in this review.

The changes in the expression levels of β-catenin gene in pre- and post- Kidney Transplants

PURPOSE

Wnt signaling is an important pathway in kidney development and disease. We aimed to establish the levels of β-catenin expression in CD4⁺ T cells before and after renal transplantation and to associate it with the form of transplant type, rejection, and graft dysfunction.

METHODS

CD4⁺ T cells were isolated from patients before and after kidney transplantation and their purity was confirmed by flow cytometer. RNA isolation and cDNA synthesis were carried out from these cells. The expression changes of the β-catenin were investigated by real-time polymerase chain reaction (RT-PCR). Changes in the β-catenin protein levels were determined by the western blot analysis.

RESULTS

The increasing expression levels of β-catenin were detected in 60.8% of the patients 6 months after transplantation when compared to patients before transplantation result. 12 of these 14 patients had no graft rejection. It was observed that 11 of 14 patients with increased β-catenin expression had not graft dysfunction after the transplantation.

CONCLUSION

According to our results, the increased levels of β-catenin expression after transplantation may have a protective function for kidney survival. To understand this protective mechanism, further analysis of this signaling pathway is necessary.

Cardiac allograft vasculopathy after heart transplantation: Pathophysiology, detection approaches, prevention, and treatment management

Cardiac allograft vasculopathy (CAV) continues to be a significant risk factor for the recipient's long-term survival following heart transplantation. Our knowledge of its etiology is constantly changing as new imaging techniques provide direct insight into the disease's natural history. CAV identification continues to be difficult since symptoms may be varied or nonexistent. Due to the irreversible nature of the disease, early diagnosis is critical to halting development. Prognostic tools and biomarkers have proliferated as a result of advancements in diagnostic techniques. Simultaneously, pharmaceutical advancements have aided in the amelioration of the disease's progressive progression.

Impact of donor-specific antibodies on long-term graft survival with pediatric liver transplantation

BACKGROUND

In a previous paper, we reported a high prevalence of donor-specific antibody (DSA) in pediatric patients with chronic rejection and expressed the need for confirmation of these findings in a larger cohort.

AIM

To clarify the importance of DSAs on long-term graft survival in a larger cohort of pediatric patients.

METHODS

We performed a retrospective analysis of 123 pediatric liver transplantation (LT) recipients who participated in yearly follow-ups including Luminex testing for DSA at our center. The cohort was split into two groups according to the DSA status (DSA-positive n = 54, DSA-negative n = 69). Groups were compared with regard to liver function, biopsy findings, graft survival, need for re-LT and immunosuppressive medication.

RESULTS

DSA-positive pediatric patients showed a higher prevalence of chronic rejection (P = 0.01), fibrosis (P < 0.001) and re-transplantation (P = 0.018) than DSA-negative patients. Class II DSAs particularly influenced graft survival. Alleles DQ2, DQ7, DQ8 and DQ9 might serve as indicators for the risk of chronic rejection and/or allograft fibrosis. Mean fluorescence intensity levels and DSA number did not impact graft survival. Previous episodes of chronic rejection might lead to DSA development.

CONCLUSION

DSA prevalence significantly affected long-term liver allograft performance and liver allograft survival in our cohort of pediatric LT. Screening for class II DSAs in combination with assessment of protocol liver biopsies for chronic antibody-mediated rejection improved early identification of patients at risk of graft loss.

Post-transplant inflow modulation for early allograft dysfunction after living donor liver transplantation

Background

To treat small-for-size syndrome (SFSS) after living donor liver transplantation (LDLT), many procedures were described for portal flow modulation before, during, or after transplantation. The selection of the procedure as well as the best timing remains controversial.

Case presentation

A 43-year-old female with end-stage liver disease underwent LDLT with extended left with caudate lobe graft from her donor who was her 41-year-old brother (graft volume/standard liver volume (GV/SLV), 35.7%; graft to recipient weight ratio (GRWR), 0.67%). During the surgery, splenectomy could not be performed owing to severe peri-splenic adhesions to avoid the ruined bleedings. The splenic artery ligation was not also completely done because it was dorsal to the pancreas and difficult to be approached. Finally, adequate portal vein (PV) inflow was confirmed after portal venous thrombectomy. As having post-transplant optional procedures that are accessible for PV flow modulation, any other procedures for PV modulation during LDLT were not done until the postoperative assessment of the graft function and PV flow for possible postoperative modulation of the portal flow accordingly. Postoperative PV flow kept as high as 30 cm/s. By the end of the 1st week, there was a progressive deterioration of the total bilirubin profile (peak as 19.4 mg/dL) and ascitic fluid amount exceeded 1000 mL/day. Therefore, splenic artery embolization was done effectively and safely on the 10th postoperative day (POD) to reverse early allograft dysfunction as PV flow significantly decreased to keep within 20 cm/s and serum total bilirubin levels gradually declined with decreased amounts of ascites below 500 mL on POD 11 and thereafter. The patient was discharged on POD 28 with good condition.

Conclusions

SFSS can be prevented or reversed by the portal inflow modulation, even by post-transplant procedure. This case emphasizes that keeping accessible angiographic treatment options for PV modulation, such as splenic artery embolization, after LDLT is quite feasible.

Diarrhea in kidney transplant recipients: Etiology and outcome

BACKGROUND AND AIM

Diarrhea in kidney transplant recipients influences outcome of transplantation. Data from India in this regard are sparse and do not address the differential outcome of infective and non-infective diarrhea. We studied the demographic data, laboratory findings, treatment response, disease duration, and outcome of diarrhea in kidney transplant recipients, and the differential outcome between infective and non-infective diarrhea, if any.

METHODS

All kidney transplant recipients who were referred to the Division of Gastroenterology with diarrhea between June 2015 and February 2017 were prospectively included. Demographic, clinical and laboratory data, graft function, treatment administered, and outcome were noted, and the patients were followed up for 3 months.

RESULTS

Forty-seven patients (median age 45 years, range 16-78; 34 men) with 64 episodes of diarrhea were studied. Thirty-three (51.5%) episodes were attributed to infections. Eleven (17%) were immunosuppressant-induced (mycophenolate 8, tacrolimus 2, cyclosporine 1). Twenty (31%) were due to other causes (antibiotics 6, laxatives 3, irritable bowel syndrome 3, sepsis 8). Fifty-three episodes (82%) had graft dysfunction during the diarrheal episodes. Mean increase in serum creatinine was 45% in the infectious diarrhea group and 95% in the non-infectious diarrhea group (p < 0.05). Median time to resolution of diarrhea was 3 days. With improvement in diarrhea, return to pre-diarrhea creatinine levels occurred in 87% of episodes at 3 months.

CONCLUSION

One-half of episodes of diarrhea in kidney transplant recipients were non-infectious in origin. Seventeen percent were attributed to immunosuppressants, requiring dose modification. More than 80% were associated with worsening of graft function. Recovery of graft function to baseline was seen in a majority of cases with the resolution of diarrhea.

Indocyanine green dye clearance test: early graft (dys)-function and long-term mortality after liver transplant. Should we continue to use it? An observational study

Early allograft dysfunction (EAD) can be a serious complication in the immediate postoperative period following liver transplantation. Our aim was to study the prognostic role of the indocyanine green plasma disappearance rate (ICG-PDR) in predicting early and late EAD and mortality at 3 and 12 months and 5 years after liver transplantation. ICG-PDR values were also assessed for association with the Donor Risk Index (DRI). 220 patients underwent orthotopic liver transplantation. In 77 patients, ICG-PDR was assessed on the 1st post-operative (PO) day. ICG, a water-soluble dye almost entirely excreted into the bile, was measured by spectrophotometry to evaluate graft (dys)-function. DRI was calculated in all patients. The primary study outcomes were the presence (or absence) of EAD after transplant and the results of mortality risk factor analysis. EAD occurred in 18 patients. 1st PO day ICG-PDR was significantly associated with EAD (p < 0.005). A threshold ICG-PDR value < 16%/min on the 1st PO day was also associated with patient probability to survive at 3 and 12 months and 5 years. The sensitivity and specificity of the AUC was good in predicting EAD, being 83% and 56%, respectively, for a 1st PO day ICG-PDR cut-off value < 16%/min. In this study, ICG-PDR on the 1st PO day following OLT can reliably predict EAD and survival at 3 and 12 months and 5 years. ICG-PDR should, therefore, be routinely performed on the 1st PO day following OLTx in all patients in light of its important prognostic role.

Antibody-mediated rejection 16 years post-cardiac transplantation: a case report of an uncommon late presentation in a middle-aged woman

Background 

Very late antibody-mediated rejection (AMR) in heart transplant patients (over 10 years post-transplant) is very rare. It is associated with high mortality, graft dysfunction, and fulminant coronary artery vasculopathy (CAV) and should remain in the differential for patients presenting with late graft dysfunction.

Case summary 

A 57-year-old woman 16 years of post-heart transplant with a previously unremarkable post-transplant course including protocol driven biopsies showing no rejection and a recent unremarkable screening nuclear stress test presented to our institution with clinical heart failure. Echocardiogram revealed graft dysfunction and endomyocardial biopsy showed no signs of cellular rejection, but evidence of AMR. The patient was treated with steroid and immunotherapy with clinical improvement but suffered several infectious complications and renal dysfunction requiring haemodialysis related to her immunotherapy treatment. Despite aggressive AMR management, donor-specific antibodies and symptoms persisted and CAV progressed.

Discussion 

This case illustrates the poor diagnostic yield of non-invasive testing for AMR, and highlights importance to clinicians of considering AMR even if the patient over 10 years post-transplant when the diagnosis is rare.

Iliofemoral deep venous thrombosis in kidney transplant patients can cause graft dysfunction

We present a series of kidney transplant dysfunction secondary to lower extremity deep venous thrombosis (DVT). A 70-year-old man underwent living unrelated kidney transplantation and presented 2 months postoperatively with acute kidney injury (AKI) secondary to external iliac vein thrombosis. Graft function improved after endovascular intervention. A 43-year-old man underwent living unrelated kidney transplantation and presented 3 years postoperatively with AKI secondary to external iliac vein thrombosis. Graft function recovered after thrombolysis. A 42-year-old woman underwent simultaneous pancreas and kidney transplantation. Four weeks postoperatively, she had AKI secondary to common femoral vein DVT. Her graft function improved after common iliac vein stenting. A 67-year-old man underwent living unrelated kidney transplantation and presented a week later with lower extremity DVT and AKI. His graft function improved with anticoagulation. Iliofemoral DVT can cause allograft dysfunction. The cause may be multifactorial. Endovascular intervention is safe and feasible when anticoagulation fails.

[Second allogeneic hematopoietic stem cell transplant: Guidelines from the francophone Society of bone marrow transplantation and cellular therapy (SFGM-TC)]

Disease recurrence and graft dysfunction after allogeneic hematopoietic stem cell transplantation (allo-HSCT) currently remain among the major causes of treatment failure in malignant and non-malignant hematological diseases. A second allo-HSCT is a valuable therapeutic option to salvage those situations. During the 8th annual harmonization workshops of the french Society of bone marrow transplantation and cellular therapy (SFGM-TC), a designated working group reviewed the literature in order to elaborate unified guidelines on feasibility, indications, donor choice and conditioning in the case of a second allo-HSCT. In case of relapse, a second allo-HSCT with reduced intensity or non-myeloablative conditioning is a reasonable option, particularly in patients with a good performance status (Karnofsky/Lansky>80%), low co-morbidity score (EBMT score≤3), a longer remission duration after the first allo-HSCT (>6 months), and who present low disease burden at the time of second allo-HSCT. Matched related donors tend to be associated with better outcomes. In the presence of graft dysfunction (primary and secondary graft rejection), an immunoablative conditioning regimen is recommended. A donor change remains a valid option, especially in the absence of graft-versus-host disease after the first allo-HSCT.

Sequential monitoring of TIM-3 mRNA expression in blood and urine samples of renal transplant recipients

BACKGROUND

T cell immunoglobulin and mucin domain 3 (TIM-3), as a co-inhibitory receptor expressed on Th1, Th17, CD8T, FoxP3 + Treg and innate immune cells, plays an important role in suppression of T cell-mediated immune responses, tolerance induction and T cell exhaustion. In this study, we evaluated sequential alterations of TIM-3 mRNA expression level in blood and urine samples of renal transplant recipients to predict approaching clinical episodes.

METHODS

A total of 52 adult renal transplant recipients (31 male and 21 female) were enrolled in this study. All the patients received kidney transplant from living unrelated donors. TIM-3 mRNA expression in peripheral blood mononuclear cells (PBMCs) and urinary cells were quantified using Real Time TaqMan polymerase chain reaction (PCR) at 4 different time points (pre-transplantation, 2, 90 and 180 days post-transplantation).

RESULT

TIM-3 mRNA expression level on days 2, 90 and 180 after transplantation was significantly higher in blood and urine samples of patients with graft dysfunction (GD) compared with patients with well-functioning graft (WFG). Our results also showed a high correlation between blood and urinary level of TIM-3 mRNA expression. The data from Receiver Operating Characteristic (ROC) Curve Analysis showed that blood and urinary TIM-3 mRNA expression level at month 3 and 6 could discriminate graft dysfunction (GD) from well-functioning graft (WFG) with high specificity and sensitivity.

CONCLUSION

Our data suggested that serial monitoring of TIM-3 mRNA level in the blood and urine samples of renal transplant recipients could be a useful non-invasive biomarker for prediction and diagnosis of allograft dysfunction.

Graft Dysfunction and Management in Liver Transplantation

Graft dysfunction of the liver allograft manifests across a spectrum in both timing posttransplantation and clinical presentation. This can range from mild transient abnormalities of liver tests to acute liver failure potentially leading to graft failure. The causes of graft dysfunction can be divided into those resulting in early and late graft dysfunction. Although nonspecific, liver biochemistry abnormalities are still the mainstay investigation used in monitoring for dysfunction. This article provides a summary of the main causes and management strategies for liver graft dysfunction in the early through late posttransplant stages.

Expression patterns of Toll like receptor (TLR)-2, TLR-4 and myeloid differentiation primary response gene 88 (MYD88) in renal transplant patients developing allograft dysfunction; a cohort study

This cohort intends to determine the sequential dynamic changes in Toll-like receptor (TLR)-4, TLR-2, and myeloid differentiation primary response gene 88 (MYD88) mRNA expressions in PBMCs and biopsy samples from kidney allograft recipients in relation to graft function. This study enrolled 52 renal transplant patients, 27 with well functioning graft (WFG) and 25 graft dysfunction (GD). Peripheral blood samples pre- and post-transplantation (days 2, 90 and 180) were collected to analyze mRNA expression levels of TLR-2, TLR-4, and MYD88 genes in relation to allograft function during one-year follow up. The mean dynamic changes of post-transplant TLR-2, TLR-4, and MYD88 mRNA expressions were significantly higher in GD compared to WFG patients (P = .001). ROC curve analysis based on glomerular filtration rate (GFR) index showed the area under curve (AUC) values for the genes: TLR-2(0.89;P < .001), TLR-4(0.86;P < .001), and MYD88(0.75;P = .003) in the third month post-transplantation for GD diagnosis. The calculated AUCs for the expressions of genes in allograft biopsies were 0.94(TLR-2), 0.95(TLR-4), and 0.98(MYD88) in the sixth month post-transplant based on pathology report (P < .001). Our results indicate that sequential monitoring of the expression patterns of TLR-2, TLR-4, and MYD88 in PBMCs and biopsy samples could be considered as predictive biomarkers for early and late kidney allograft function.

Longer Ischemic Time is Associated with Increased Ventricular Stiffness as Measured by Pressure-Volume Loop Analysis in Pediatric Heart Transplant Recipients

BACKGROUND

The purpose of this study was to investigate the associations between clinical factors and cardiac function as measured by pressure-volume loops (PVLs) in a pediatric heart transplant cohort.

METHODS

Patients (age < 20 years) who underwent heart transplantation presenting for a clinically indicated catheterization were enrolled. PVLs were recorded using microconductance catheters (CD Leycom^®, Zoetermeer, Netherlands). Demographic data, serum B-type natriuretic peptide (BNP), time from transplant, ischemic time, presence of transplant coronary artery disease, donor-specific antibodies, and history of rejection were recorded at the time of catheterization. PVL data included contractility indices: end-systolic elastance and preload recruitable stroke work; ventricular-arterial coupling index; ventricular stiffness constant, Beta; and isovolumic relaxation time constant, tau. Associations between PVL measures and clinical data were investigated using non-parametric statistical tests.

RESULTS

A total of 18 patients were enrolled. Median age was 8.7 years (IQR 5-14 years). There were ten males and eight females. Six patients had a history of rejection and ten had positive donor-specific antibodies. There was no transplant coronary artery disease. Median BNP was 100 pg/mL (IQR 46-140). Time from transplant to PVL obtained during catheterization procedure was 4.1 years (IQR 1.7-7.8 year). No single clinical characteristic was statistically significant when correlated with PVL data. However, longer ischemic time was associated with worse Beta (r = 0.49, p = 0.05).

CONCLUSIONS

Our study found that longer ischemic times are associated with increased left ventricular stiffness. No other single clinical variable is associated with cardiac dysfunction as determined by PVL analysis.

[Simultaneous Hepatorenal Transplantation from a Brain-Dead Donor for Graft Dysfunction and Renal Insufficiency in a Liver Transplant Recipient : A Case Report]

We report a case of lethal hepatorenal insufficiency in a 52-year-old man who received successful simultaneous hepatorenal transplantation from a deceased donor. The patient had undergone live-donor liver transplantation for type-C hepatitis and liver cirrhosis 11 years before he developed graft liver dysfunction due to recurrent viral hepatitis and cirrhosis. At that instance, he also developed end-stage renal dysfunction due to calcineurin inhibitor nephropathy and hepatorenal syndrome. Although he needed three open hemostases and abundant blood transfusion, he was withdrawn from continuous hemodiafiltration on the 55th day and discharged from the hospital on the 272nd day postoperatively. Simultaneous hepatorenal transplantation was reported to be associated with more favorable outcomes of graft function, lower rejection rates, but higher perioperative complication rates compared with liver transplantation alone in patients on hemodialysis. Particularly, close attention should be paid for hemostasis since patients have a hemorrhagic tendency until the recovery of graft liver function.

Anesthesia for Lung Transplantation

Perioperative management of patients undergoing lung transplantation is challenging and requires constant communication among the surgical, anesthesia, perfusion, and nursing teams. Although all aspects of anesthetic management are important, certain intraoperative strategies (mechanical ventilation, fluid management, extracorporeal mechanical support deployment) have tremendous impact on the subsequent evolution of the lung transplant recipient, especially with respect to allograft function, and should be carefully considered. This review highlights some of the intraoperative anesthetic challenges and opportunities during lung transplantation.

Dysfunction in Patients With Small-for-Size Grafts After Living Donor Liver Transplantation. Int Surg. 2015;100:524-530. [PMID: 25785339 DOI: 10.9738/intsurg-d-14-00016.1]

The relationship between postoperative percentage fall of platelet (PLT) counts and graft dysfunction after living donor liver transplantation (LDLT) in recipients with small-for-size (SFS) graft has not been fully evaluated. We retrospectively studied 50 adult-to-adult LDLT recipients with a graft-to-recipient weight ratio of <0.8% between 1999 and 2011. Graft dysfunction was defined as the presence of hyperbilirubinemia, coagulopathy, or ascites on 3 consecutive days during the first postoperative week. Each clinical sign of dysfunction was assigned 1 point. Postoperative percentage fall in PLT counts, graft dysfunction score, and postoperative complications according to the Clavien-Dindo classification were investigated. Overall, 31 patients (62%) exhibited a PLT count fall of more than 50%, and 19 (38%) patients exhibited a PLT count fall of less than 50% at postoperative day (POD) 3. Receiver operating characteristic curve analysis indicated that at POD 3, the cutoff value of PLT count fall was 56% for a graft dysfunction score of 2 or 3 (sensitivity, 70%; specificity, 63.3%). Fourteen of 20 patients (70%) with a dysfunction score of 2 or 3 and 11 of 30 patients (37%) with a dysfunction score of 0 or 1 showed a fall in PLT count >56% at POD 3 (P = 0.021). Grade 2 to 5 complications were more observed in patients with a dysfunction score of 2 or 3 than in patients with a dysfunction score of 0 or 1 (P < 0.001). The fall of PLT count at POD 3 >56% is an ominous sign that can predict the graft dysfunction after LDLT in recipients with SFS graft.

Increased levels of CD4(+) and CD8(+) T cells expressing CCR1 in patients developing allograft dysfunction; a cohort study

BACKGROUND

Leukocyte infiltration into the graft has pivotal effects on kidney transplantation outcome. The present study sought to determine whether the expression of sequential chemokine receptors on CD4(+) and CD8(+) T cells in human renal allograft can predict clinical episodes.

METHODS

Blood samples from 52 consecutive renal transplant patients were evaluated at the time of transplantation and at three times (2, 90 and 180days) after transplantation to analyze the expression of CCR1 and CXCR3 on CD4(+) and CD8(+) T cells by flowcytometry. A total of 30 biopsies, including protocol biopsy (n=24) and cause biopsy (n=6), were investigated according to the Banff criteria.

RESULTS

The mean percentage of CD4(+) and CD8(+) T cells expressing CCR1 was significantly increased in patients with allograft dysfunction (n=25) (p=0.006, p=0.004). The mean fluorescence intensity of CXCR3 on CD4(+) and CD8(+) T cells were found to be significantly higher in graft dysfunction than that in well-functioning grafts. (p<0.001, p=0.007). Receiver Operating Characteristic (ROC) Curve Analysis showed that the calculated AUC was 0.86 at the third month for CD4(+)CCR1(+) and CD8(+)CCR1(+) (p<0.001). Multiple logistic regression analysis showed that an increase in CD4(+) expressing CXCR3 leads to a lower risk of graft dysfunction (OR=0.37), while an increase in CD8(+) expressing CCR1 results in a higher risk of graft dysfunction (OR=3.66).

CONCLUSION

During renal transplantation, CD4(+) and CD8(+) T cells expressing CCR1 were increased in patients who developed graft dysfunction. These findings may prospectively predict allograft dysfunction, and help elucidate the underlying pathogenic mechanisms.

Obesity and graft dysfunction among kidney transplant recipients: Increased risk for atherosclerosis

Weight gain after kidney transplant is common, and may be related to graft dysfunction and high cardiovascular risk. We investigated the prevalence of obesity and evaluated the relationship between obesity and graft dysfunction in kidney transplant recipients (KTRs). All patients who received kidney transplant at the Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) between January 2005 and December 2009 were recruited. Information on demographics, clinical characteristics and post-transplant care were documented. All patients underwent transthoracic echocardiography and carotid Doppler ultrasound for the assessment of cardiac status and carotid intima-media thickness (cIMT), respectively. Inferential and modelling statistics were applied. One hundred KTRs were recruited, of which 63 were males. The mean age was 42.2 ± 12.42 years with a range of 19-70 years. The mean body mass index and waist circumference of the recipients were 26.4 ± 4.81 kg/m² and 90.73 ± 14.76 cm, respectively. Twenty-nine patients (29%) were obese; of these, 24 (82.8%) had moderate obesity, 4 (13.8%) had severe obesity, and 1 (3.4%) had morbid obesity. Graft dysfunction was present in 52%. Obese patients were older (P < 0.0001), had graft dysfunction (P = 0.03), higher mean arterial blood pressure (P = 0.022), total cholesterol (P = 0.019), triglycerides (P < 0.0001), left ventricular mass index (P = 0.035) and cIMT (P = 0.036). Logistic regression showed obesity to be independently associated with graft dysfunction (P = 0.033). Obesity after kidney transplantation is common and is associated with graft dysfunction and markers of atherosclerosis.

Donor-acquired fat embolism syndrome after lung transplantation

OBJECTIVES

Fat embolism is a known complication of severe trauma and closed chest cardiac resuscitation both of which are more common in the lung transplant donor population and can lead to donor-acquired fat embolism syndrome (DAFES). The objective was to review the diagnosis and management of DAFES in the lung transplantation literature and at our centre.

METHODS

We performed a literature review on DAFES using the Medline database. We then reviewed the transplant record of Brigham and Women's Hospital, a large academic hospital with an active lung transplant programme, for cases of DAFES.

RESULTS

We identified 2 cases of DAFES in our centre, one of which required extracorporeal membrane oxygenation (ECMO) for successful management. In contrast to the broader literature on DAFES, which emphasizes unsuccessfully treated cases, both patients survived.

CONCLUSION

DAFES is a rare but likely underappreciated early complication of lung transplant as it can mimic primary graft dysfunction. Aggressive interventions, including ECMO, may be necessary to achieve a good clinical outcome following DAFES.

Biomarkers to assess graft quality during conventional and machine preservation in liver transplantation

A global rising organ shortage necessitates the use of extended criteria donors (ECD) for liver transplantation (LT). However, poor preservation and extensive ischemic injury of ECD grafts have been recognized as important factors associated with primary non-function, early allograft dysfunction, and biliary complications after LT. In order to prevent for these ischemia-related complications, machine perfusion (MP) has gained interest as a technique to optimize preservation of grafts and to provide the opportunity to assess graft quality by screening for extensive ischemic injury. For this purpose, however, objective surrogate biomarkers are required which can be easily determined at time of graft preservation and the various techniques of MP. This review provides an overview and evaluation of biomarkers that have been investigated for the assessment of graft quality and viability testing during different types of MP. Moreover, studies regarding conventional graft preservation by static cold storage (SCS) were screened to identify biomarkers that correlated with either allograft dysfunction or biliary complications after LT and which could potentially be applied as predictive markers during MP. The pros and cons of the different biomaterials that are available for biomarker research during graft preservation are discussed, accompanied with suggestions for future research. Though many studies are currently still in the experimental setting or of low evidence level due to small cohort sizes, the biomarkers presented in this review provide a useful handle to monitor recovery of ECD grafts during clinical MP in the near future.

Renal outcome in biopsy proven cases of graft pyelonephritis

The incidence, risk factors and outcome of graft pyelonephritis are variably described in literature. All patients who had been transplanted at our center between January 2002 and November 2006 and had presented with acute graft dysfunction were subjected to biopsy. Those patients who had neutrophilic casts and interstitial inflammation with predominant neutrophils were included in the study. Out of the 265 patients, 110 were transplanted in the period and underwent biopsy for graft dysfunction. Out of the 110 patients, 26 had biopsy proven acute graft pyelonephritis (AGPN). Nine patients had early AGPN (within 6 months) and the other 17 had late AGPN. Nearly 19% of patients were culture negative and five patients had no clinical features of urinary tract infection; AGPN being a surprise finding on biopsy. Among the risk factors, only hepatitis C virus infection was significantly associated with AGPN. All patients received 4-6 weeks of antibiotics with at least 3 weeks of parenteral antibiotics. Majority (75%) of our patients experienced relapse of AGPN. Graft function was significantly lower 6 months after onset when compared to baseline, portending a poor outcome for these patients. Out of 26, 7 (27%) of our patients had biopsy features of concomitant acute cellular rejection. The treatment of acute rejection, however, did not improve the outcome.

Myoglobinuria masquerading as acute rejection in a renal allograft recipient with recurrent post transplant diabetic nephropathy

Rhabdomyolysis contributes to 7-10% of total AKI cases. Myoglobinuria as a cause of acute renal allograft dysfunction is extremely uncommon. Renal allograft recipient on cyclosporine or tacrolimus can develop myoglobinuria in presence of other precipitating factors. Present case describes an interesting report of myoglobinuria in a patient with post transplant diabetic nephropathy mimicking acute graft rejection. Clinically myoglobinuria presenting as renal allograft dysfunction is diagnosis of exclusion and renal biopsy is extremely important in making a correct diagnosis and planning optimal management in such cases.

Portal flow is the main predictor of early graft dysfunction regardless of the GRWR status in living donor liver transplantation - a retrospective analysis of 134 patients. Int J Surg. 2014;12:177-180. [PMID: 24370677 DOI: 10.1016/j.ijsu.2013.12.006]

BACKGROUND

Sometimes even in adequate graft to recipient weight ratio (GRWR) settings and after ruling out all other causes, recipients still show features of the small for size syndrome. The purpose of this study was to evaluate all causative factors responsible for early graft dysfunction fulfilling the definition of the small for size syndrome, regardless of the GRWR status, and with particular emphasis on portal flow (ml/min/100 g). We also tried to establish whether a high portal flow on intraoperative Doppler study immediately after reperfusion can predict graft dysfunction.

MATERIAL AND METHODS

Early graft dysfunction was defined according to the definitions given for the small for size syndrome by the Kyushu University Group. Patients undergone living donor liver transplantations between January 2010 and December 2012 were analyzed. We routinely do Doppler ultrasound (USG) immediately after reperfusion and daily for 5 days. The portal vein flow after routine Doppler examination immediately after reperfusion was noted as the portal vein flow at day 0.

RESULTS

19 of 134 patients showed features of early graft dysfunction as defined. On univariate analysis, hepatitis C virus (HCV) and portal vein flow immediately after reperfusion were significant predictors of postoperative graft dysfunction. (p = 0.008 and p < 0.0001). On multivariate logistic regression, only portal vein flow after reperfusion (p = 0.002) remained as the significant predictor of postoperative graft dysfunction. A portal flow of greater than 190 (ml/min/100 g) was significant in predicting graft dysfunction (p < 0.0001) with an AUROC of 0.709. GRWR was not a significant predictor.

CONCLUSION

A portal vein flow immediately after reperfusion >190/ml/min/100 g. reliably predicted whether a graft would behave as small for size or not, regardless of the GRWR status. Portal vein flow was the most significant predictor of graft dysfunction.

Acute hepatitis with periportal confluent necrosis associated with human herpesvirus 6 infection in liver transplant patients

OBJECTIVES

To correlate human herpesvirus 6 (HHV-6) viral load with pathologic features in graft acute hepatitis of unknown origin.

METHODS

Liver frozen samples from 26 patients with graft hepatitis of unknown origin were available for HHV-6 DNA quantification.

RESULTS

In 10 (38.5%) of 26 liver samples, HHV-6 DNA was detectable, with a median viral load of 3.84 log10 copies/10⁶ cells. Confluent periportal necrosis was observed in 4 of 10 patients and associated with high viral load. These 4 patients responded to antiviral therapy. Mild unspecific hepatitis was observed in 4 patients with low intragraft viral load and in 2 patients with high viral load in a context of deep immunosuppression. Patients with HHV-6-negative graft hepatitis disclosed lobular necrotico-inflammatory activity without periportal necrosis.

CONCLUSIONS

Our study provides data supporting the pathogenic role of HHV-6 for liver allografts. The presence of confluent periportal necrosis could be a clue for prompt diagnosis of HHV-6-induced graft hepatitis.

CLINICAL APPLICATION OF FLOW CYTOMETRY IN LIVE RELATED DONOR RENAL TRANSPLANTATION

To monitor the activity of the humoral component in graft dysfunction following renal transplantation using live related donors, flowcytometric cross-match procedure was adopted. Antidonor antibodies were detected in the sera of both pre- and post-transplant patients using conventional serological cytotoxicity cross-match and flowcytometric cross-match assays. In the 52 pretransplant samples no significant differences were observed in flowcytometric and cytotoxicity tests except in 2 secondary transplant cases which were negative by cytotoxicity test. However, in post-transplant samples, floweytometry was found to be a more objective and useful test than cytotoxicity testing in distinguishing 6 out of 7 mild acute-graft-rejection episodes. Both tests were found to be negative in alt 5 cases of cyclosporin-A nephrotoxicity, 7 cases of acute tubular necrosis and 10 out of 11 cases of chronic rejection.