A report of a prospective randomized trial of extended-release tacrolimus versus immediate release tacrolimus after liver transplantation with anti-thymocyte induction in a steroid free protocol

PURPOSE

Our study hypothesis was that once daily dosing of extended-release tacrolimus (XRT) would be a safe and effective immunosuppression (IS) with the potential to decrease adverse events (AEs) associated with immediate release tacrolimus (IRT) after liver transplantation (LT).

METHODS

All patients receiving LT at our center received rabbit anti-thymocyte globulin (RATG) induction therapy. Eligible patients were randomized in a 1:1 fashion to receive either XRT or IRT. Antimicrobial prophylaxis was the same between arms, and both groups received an antimetabolite for the first 6 months following LT. Patients were then followed at pre-determined study intervals for the following year after LT. We administered the RAND-36SF survey to assess patient's health-related quality of life at pre-determined intervals. All analysis was performed with an intention to treat basis.

RESULTS

We screened 194 consecutive patients and enrolled 110. Our control and study arms were well matched. Transplant characteristics were similar between groups. At all timepoints, both arms had similar serum creatinine and estimated glomerular filtration rate (eGFR), calculated by MDRD6 equation, with post-transplant GFRs between 60 and 70 mL/min/1.73 m2 . Tacrolimus trough levels were similar between arms. The XRT arm had fewer AEs (166) and fewer serious AEs (70) compared to IRT (201 and 99, respectively). AEs most commonly were renal, infectious, or gastrointestinal in nature. While not statistically significant, XRT was held temporarily (25 vs. 35 cases) or discontinued (3 vs. 11 cases) less frequently than IRT and had fewer instances of rejection (7 vs. 12 cases).

CONCLUSION

This analysis showed that XRT is safe and effective as de novo maintenance IS in a steroid-free protocol with RATG.

Association between longer hospitalization and development of de novo donor specific antibodies in simultaneous liver-kidney transplant recipients

Background: De novo Donor Specific Antibodies (DSA) are considered as a risk factor for the kidney allograft outcomes in recipients after simultaneous liver-kidney transplantation (SLKT). We hypothesized that length of hospital stay (LOS) might be associated with de novo DSA development of due to the increased likelihood of receiving blood transfusions with reduced immunosuppressive regimens.Methods: This study is a single-center, retrospective cohort study consisting of 85 recipients who underwent SLKT from 2009 to 2018 in our hospital. We divided the patients into two groups according to LOS [long hospital stay (L) group (LOS >14 days) and short hospital stay (S) group (LOS ≤14 days)]. Propensity score (PS) has been created using logistic regression to predict LOS greater than median of 14 days. The association between the presence of de novo DSA and LOS was assessed by logistic regression models adjusted for PS.Results: The mean age at transplantation of the entire cohort was 55.5 ± 10.1 years. Sixty percent of the recipients were male and Caucasian. Median LOS in (L) group was three-fold longer than (S) group [L: median 30 days (IQR: 21-52), S: median 8.5 days (IQR: 7-11)]. Eight patients developed de novo DSA after SLKT (9.4%), all of them were in (L) group. Longer LOS was significantly associated with higher risk of development of de novo DSA in unadjusted (OR_{+ each 5 days}: 1.09, 95% CI:1.02-1.16) and PS adjusted (OR_{+ each 5 days}: 1.11, 95% CI:1.02-1.21) analysis.Conclusion: Longer hospitalization is significantly associated with the development of de novo DSA in SLKT.

Stricturing CMV enteritis in an adult liver transplant recipient

Cytomegalovirus (CMV) is a common posttransplant infection, most commonly seen in settings of excessive immunosuppression. Before the advent of CMV specific antiviral therapies, the standard treatment approaches for CMV disease were immunosuppression reductions to let the transplant recipient mount an immunologic response against CMV. Additionally, CMV is rarely identified as causing stricturing enteritis and has not previously been reported as causing stricturing enteritis in an adult transplant recipient. All identified reports of stricturing CMV enteritis have been reported in either pediatric patient populations or those with severe immunosuppression from human immunodeficiency virus and acquired immune deficiency syndrome. Our report presents the unusual case of an adult liver transplant recipient many years after transplant and on minimal immunosuppression with mycophenolate alone who developed stricturing CMV enteritis.

Cholecystitis and hemobilia

Hemobilia, or hemorrhage into the biliary system, is an unusual cause of gastrointestinal bleeding most commonly seen in accidental or iatrogenic trauma. We present the rare case of a 43-year-old gentleman who presents with an intrahepatic pseudoaneurysm caused by cholecystitis. The management of the hemobilia was technically challenging requiring multiple interventional procedures. We review the pathophysiology and treatment strategies for this rare case of gastrointestinal hemorrhage.

Transplantation of kidneys from hepatitis C-infected donors to hepatitis C-negative recipients: Single center experience

Our aim was to evaluate the safety of transplanting kidneys from HCV-infected donors in HCV-uninfected recipients. Data collected from 53 recipients in a single center, observational study included donor and recipient characteristics, liver and kidney graft function, new infections and de novo donor-specific antibodies and renal histology. Treatment with a direct-acting antiviral regimen was initiated when HCV RNA was detected. The mean ± SD age of recipients was 53 ± 11 years, 34% were female, 19% and 79% of recipients were white and African American, respectively. The median and interquartile range (IQR) time between transplant and treatment initiation was 76 (IQR: 68-88) days. All 53 recipients became viremic (genotype: 1a [N = 34], 1b [N = 1], 2 [N = 3], and 3 [N = 15]). The majority (81%) of recipients did not experience clinically significant increases (>3 times higher than upper limit of the normal value) in aminotransferase levels and their HCV RNA levels were in the 5 to 6 log range. One patient developed fibrosing cholestatic hepatitis with complete resolution. All recipients completed antiviral treatment and 100% were HCV RNA-negative and achieved 12-week sustained virologic response. The estimated GFRs at end of treatment and 12-week posttreatment were 67 ± 21 mL/min/1.73 m² and 67 ± 17 mL/min/1.73 m² , respectively. Four recipients developed acute rejection. Kidney transplantation from HCV-infected donors to HCV-negative recipients should be considered in all eligible patients.

Chimney-Patch Arterial Graft in Kidney or Pancreas Transplantation for Recipients with Heavily Calcified Iliac Arteries

Iliac artery calcification is a common phenomenon complicating renal transplantation, particularly in those with diabetes. The potential for vascular clamp injury can threaten the renal allograft, ipsilateral lower extremity, or both. Utilization of internal balloon occlusion can allow for placement of a "Chimney Patch" graft, fashioned from a deceased donor artery, to the calcified vessel, eliminating the risk of clamp injury and minimizing warm ischemic time. We present a series of 6 patients transplanted with internal balloon occlusion with successful renal and pancreatic allograft function and no ipsilateral vascular complications. Internal balloon occlusion is a safe and effective adjunct for renal or pancreas transplant to prevent clamp injury with no adverse effect on allograft function.

No apparent benefit of preemptive sorafenib therapy in liver transplant recipients with advanced hepatocellular carcinoma on explant

BACKGROUND

Sorafenib has shown survival benefits in patients with advanced HCC; however, limited data are available on its role in OLT recipients with advanced HCC in the explant.

AIM

Evaluate the role of preemptive sorafenib therapy on HCC recurrence and survival after OLT with advanced HCC on explant pathology.

METHODS

We retrospectively reviewed the outcome after OLT of all HCC recipients with advanced HCC in the explant pathology from 04/2006 to 12/2012 based on preemptive treatment with sorafenib.

RESULTS

During the observation period, 217 HCC recipients underwent OLT; 50 explants revealed advanced HCC. After exclusion of 5 patients who were lost to follow-up, 45 LT recipients were finally included for analysis. Recipients were grouped as sorafenib Gr (N = 25) and nonsorafenib Gr (N = 20). Both recurrence-free survival (RFS) (P = .67) and overall survival were similar between groups (P = .53) on Kaplan-Meier analysis. Additionally, sorafenib use was neither associated with HCC recurrence-free survival (HR 0.74, 95% CI [0.32-1.70]; P = .48) nor overall survival (HR 0.92, 95% CI [0.39-2.15], P = .84) on multivariate Cox proportional hazard model with sorafenib use as time-varying covariates.

CONCLUSION

Preemptive treatment with sorafenib in OLT recipients with high-risk features in explant does not improve HCC recurrence-free or overall survival.

The importance of antegrade completion angiography in aortobifemoral bypass limb revision

Aortobifemoral bypass is a durable arterial reconstruction with well-defined failure modes. Management of graft limb thrombosis requires restoration of inflow and correction of any causative outflow lesions. Successful, minimally invasive inflow restoration with catheter thrombectomy can become problematic if assessment of technical adequacy is deficient or reveals causal lesions within the graft body. We describe a case illustrating the potential shortfall of retrograde graft limb completion angiography in depicting neointimal flaps, the benefit of antegrade angiography in depicting these flaps, and a novel utilization of a standard endovascular method to correct flaps that involve the graft body.

Imidazole antibiotics inhibit the nitric oxide dioxygenase function of microbial flavohemoglobin

Flavohemoglobins metabolize nitric oxide (NO) to nitrate and protect bacteria and fungi from NO-mediated damage, growth inhibition, and killing by NO-releasing immune cells. Antimicrobial imidazoles were tested for their ability to coordinate flavohemoglobin and inhibit its NO dioxygenase (NOD) function. Miconazole, econazole, clotrimazole, and ketoconazole inhibited the NOD activity of Escherichia coli flavohemoglobin with apparent K(i) values of 80, 550, 1,300, and 5,000 nM, respectively. Saccharomyces cerevisiae, Candida albicans, and Alcaligenes eutrophus enzymes exhibited similar sensitivities to imidazoles. Imidazoles coordinated the heme iron atom, impaired ferric heme reduction, produced uncompetitive inhibition with respect to O(2) and NO, and inhibited NO metabolism by yeasts and bacteria. Nevertheless, these imidazoles were not sufficiently selective to fully mimic the NO-dependent growth stasis seen with NOD-deficient mutants. The results demonstrate a mechanism for NOD inhibition by imidazoles and suggest a target for imidazole engineering.

Flavorubredoxin, an inducible catalyst for nitric oxide reduction and detoxification in Escherichia coli

Nitric oxide (NO) is a poison, and organisms employ diverse systems to protect against its harmful effects. In Escherichia coli, ygaA encodes a transcription regulator (b2709) controlling anaerobic NO reduction and detoxification. Adjacent to ygaA and oppositely transcribed are ygaK (encoding a flavorubredoxin (flavoRb) (b2710) with a NO-binding non-heme diiron center) and ygbD (encoding a NADH:(flavo)Rb oxidoreductase (b2711)), which function in NO reduction and detoxification. Mutation of either ygaA or ygaK eliminated inducible anaerobic NO metabolism, whereas ygbD disruption partly impaired the activity. NO-sensitive [4Fe-4S] (de)hydratases, including the Krebs cycle aconitase and the Entner-Doudoroff pathway 6-phosphogluconate dehydratase, were more susceptible to inactivation in ygaK or ygaA mutants than in the parental strain, and these metabolic poisonings were associated with conditional growth inhibitions. flavoRb (NO reductase) and flavohemoglobin (NO dioxygenase) maximally metabolized and detoxified NO in anaerobic and aerobic E. coli, respectively, whereas both enzymes scavenged NO under microaerobic conditions. We suggest designation of the ygaA-ygaK-ygbD gene cluster as the norRVW modulon for NO reduction and detoxification.