Late-onset acute rejection after living donor liver transplantation

Rejection in Liver Transplantation Recipients

Rejection following liver transplantation continues to impact transplant recipients although rates have decreased over time with advances in immunosuppression management. The diagnosis of rejection remains challenging with liver biopsy remaining the reference standard for diagnosis. Proper classification of rejection type and severity is imperative as this guides management and ultimately graft preservation. Future areas of promise include non-invasive testing for detection of rejection to reduce the morbidity associated with invasive testing and further advances in immunosuppression management to reduce toxicities associated with immunosuppression while minimizing rejection related morbidity.

Current Status of Biomarkers and Molecular Diagnostic Tools for Rejection in Liver Transplantation: Light at the End of the Tunnel?

Strategies to minimize immune-suppressive medications after liver transplantation are limited by allograft rejection. Biopsy of liver is the current standard of care in diagnosing rejection. However, it adds to physical and economic burden to the patient and has diagnostic limitations. In this review, we aim to highlight the different biomarkers to predict and diagnose acute rejection. We also aim to explore recent advances in molecular diagnostics to improve the diagnostic yield of liver biopsies.

LIVER TRANSPLANTATION: TACROLIMUS BLOOD LEVELS VARIATION AND SURVIVAL, REJECTION AND DEATH OUTCOMES

BACKGROUND

Immunosuppressive drugs have important role in transplant of solid grafts, it aim avoid episodes of acute and chronic rejection and improving graft survival and patient survival. In Brazil, in 2016, liver transplantation was the third most frequent, with 1,880 transplants performed, of which 150 in Rio Grande do Sul. Several studies evaluated the association between variability in blood levels of immunosuppressive tacrolimus and late acute cellular graft rejection.

OBJECTIVE

To investigate the association of tacrolimus blood levels with clinical outcomes late acute cellular rejection, death, patient survival and graft survival in patients undergoing liver transplantation.

METHODS

This is a retrospective longitudinal study including patients submitted to adult liver transplantation by the Liver Transplantation Group in the Santa Casa de Misericórdia Hospital of Porto Alegre, from January 2006 to January 2013, and who used tacrolimus as immunosuppressive therapy.

RESULTS

Of the 127 patients included in the study, the majority were male (70.1%), 52-60 years old (33.9%) at the transplant. The most frequent causes of liver transplantation in this series were hepatitis C virus and hepatocellular carcinoma (24.4%) and alcohol (15.7%). Thirteen patients had late acute cellular rejection (10.2%); of these, three had two episodes. Regarding severity classification, seven patients had mild late acute cellular rejection. The mean time of rejection after liver transplantation was 14 months (ranging from 8 to 33 months). Overall survival was 8.98 years. Regarding tacrolimus blood levels, 52 patients with a variation ≥2 standard deviations were identified. Of these patients, eight had rejection; however, the association was not significant (P=0.146). A significant association was found between variation ≥2 standard deviations in tacrolimus blood levels and death (P=0.023) and survival (P=0.019). Regarding 5-year follow-up of graft survival, being two standard deviations above increases by 2.26 times the risk of transplanted graft loss, and for each unit of increase of standard deviation of tacrolimus blood levels there is a two-fold increase in the risk of graft loss in 5 years.

CONCLUSION

Increased risk of graft loss associated with increased standard deviations of tacrolimus blood levels may indicate the need for more rigorous and prospective monitoring of tacrolimus blood levels.

Late T cell-mediated rejection may contribute to poor outcomes in adolescents and young adults with liver transplantation

Although poor long-term graft survival in LT in AYA is recognized, detailed epidemiological data are still lacking. L-TCMR may have poor outcomes. This study aimed to provide a detailed, epidemiological assessment of the association between AYA age and rejection. L-TCMR was defined in this study as TCMR with central vein or perivenular inflammation occurring later than 3 months after LT. A total of 342 patients who survived for at least 3 months after LT between 2005 and 2015 were enrolled. The AYA group (10-24 years) was compared with the C group (less than 10 years), and the incidence and outcomes of L-TCMR were analyzed. In total, 342 patients had LT; 38 of these were AYA with the mean follow-up period of 6.7 years. A total of 304 patients in C group had a mean follow-up period of 6.3 years (P = .28). The incidence of L-TCMR in AYA group was significantly higher than in C group (15.8% vs 4.6%, P = .006). The time to L-TCMR after LT was significantly shorter in AYA group (P = .01). Neither patient survival nor the incidence of non-adherence differed significantly between the groups (P = .18 and P = .89). The number of additional immunosuppressants after L-TCMR was significantly higher in the AYA group (P = .04). A high incidence of L-TCMR was observed in AYA group irrespective of non-adherence. AYA patients with L-TCMR should be followed carefully due to the poor results of post-treatment biopsy and the need for intensive immunosuppressive therapy.

Diagnosis and outcome of resected solitary pulmonary nodules after liver transplantation

OBJECTIVE

Solitary pulmonary nodules after liver transplantation are challenging clinical problems. Herein, we report the causes and clinical courses of resected solitary pulmonary nodules in patients who underwent liver transplantation.

METHODS

We retrospectively obtained medical records of 68 patients who underwent liver transplantation between March 2009 and June 2016. This study mainly focused on patients with solitary pulmonary nodules observed on computed tomography scans during follow-ups that were conducted until their deaths or February 2019.

RESULTS

Computed tomography scans revealed solitary pulmonary nodules in 7 of the 68 patients. Definitive diagnoses were obtained using video-assisted lung resection in all seven patients. None experienced major postoperative complications. The final pathologic diagnoses were primary lung cancer in three patients, pulmonary metastases from hepatocellular carcinoma in one patient, invasive pulmonary aspergillosis in one patient, post-transplant lymphoproliferative disorder in one patient, and hemorrhagic infarction in one patient. The three patients with lung cancer were subsequently treated with standard curative resection.

CONCLUSIONS

Solitary pulmonary nodules present in several serious but potentially curable diseases, such as early-stage lung cancer. Patients who present with solitary pulmonary nodules after liver transplantation should be evaluated by standard diagnostic procedures, including surgical biopsy if necessary.

Mycophenolate mofetil sensor based on molecularly imprinted polymer/multi-walled carbon nanotubes modified carbon paste electrode

Using square wave voltammetry, a carbon paste electrode modified by molecularly imprinted polymer (MIP) as a recognition element of mycophenolate mofetil (MMF) and multi-walled carbon nanotubes was used for MMF monitoring To investigate the electrode during modification, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were utilized. After optimization of the effective parameters, the anodic peak current of MMF was utilized for dynamic range study which was linear in 9.9 nM-87 μM range. The detection limit of the sensor was 7.0 nM. The capture ability of MIP to target was compared with that of non-imprinted polymer (NIP). The practical application of the sensor in biological fluid samples analysis demonstrates its selectivity, sensitivity, and stability.

Acute and Chronic Rejection After Liver Transplantation: What A Clinician Needs to Know

While antibody mediated hyper-acute vasculitic rejection is rare in liver transplant recipients, acute and chronic rejection have clinical significance. The liver allograft behaves differently to other solid organ transplants as acute rejection generally does not impair graft survival and chronic rejection (CR) is uncommon. The incidence of acute and chronic rejection has declined in current era due to improved immunosuppressive regimens. Acute rejection generally improves with steroid boluses and steroid resistant rejection is uncommon. CR may improve with escalation of immunosuppression or may result in irreversible loss of graft function leading to retransplantation or death. The current review discusses diagnosis and management of acute and chronic liver allograft rejection.

Late acute rejection in liver transplant: a systematic review

Introduction:

Late acute rejection leads to worse patient and graft survival after liver transplantation.

Aim:

To analyze the reported results published in recent years by leading transplant centers in evaluating late acute rejection and update the clinical manifestations, diagnosis and treatment of liver transplantation.

Method:

Systematic literature review through Medline-PubMed database with headings related to late acute rejection in articles published until November 2013 was done. Were analyzed demographics, immunosuppression, rejection, infection and graft and patient survival rates.

Results:

Late acute rejection in liver transplantation showed poor results mainly regarding patient and graft survival. Almost all of these cohort studies were retrospective and descriptive. The incidence of late acute rejection varied from 7-40% in these studies. Late acute rejection was one cause for graft loss and resulted in different outcomes with worse patient and graft survival after liver transplant. Late acute rejection has been variably defined and may be a cause of chronic rejection with worse prognosis. Late acute rejection occurs during a period in which the goal is to maintain lower immunosuppression after liver transplantation.

Conclusion:

The current articles show the importance of late acute rejection. The real benefit is based on early diagnosis and adequate treatment at the onset until late follow up after liver transplantation.

Steroid-resistant acute rejection after cadaveric liver transplantation: experience from one single center

BACKGROUND AND OBJECTIVES

Steroid-resistant acute rejection (SRAR) is an infrequent event under current immunosuppressant but still a risk factor leading to graft loss and patients' death after liver transplantation. There are several strategies for managing this complication according to current literatures, but none of the treatment seems convincing and widely accepted. Here we retrospectively analyzed the clinical data of a cohort of patients to gain an insight into this complication.

MATERIALS AND METHODS

A total of 962 adult patients receiving whole liver grafts at a single center between January 2004 and December 2012 were studied. One hundred and forty-two recipients experienced 158 episodes of acute rejection after the operation, 14 recipients had no response to steroid bolus treatment. The clinical data was analyzed retrospectively.

RESULTS

Incidence rate of acute rejection after liver transplant in our single center was 14.7% (142/962), among them 8.8% (14/158) were steroid-resistant. These episodes occurred on 19days (6-72days) after the operation, 3 were controlled by anti-T3-receptor antibody (OKT3) treatment, 4 were reversed by IL-2 receptor inhibitors combining with MMF treatment, 2 were reversed by antithymocyte globulin (ATG) treatment. Five did not recover and 2 received retransplantation. Mortality associated with SRAR was 28.6% (4/14, 1 died from acute liver failure, 1 from chronic liver failure, 1 from renal failure after retransplantation and 1 from pulmonary infection after OKT3 treatment).

CONCLUSION

SRAR is a severe complication with high mortality after liver transplantation; ATG might serve as a potential treatment.

Biliary and vascular anomalies in living liver donors: the role and accuracy of pre-operative radiological mapping

BACKGROUND

The aim of the present study was to determine the utility of computed tomography (CT) and magnetic resonance imaging (MRI) anatomic mapping in the detection of biliary and vascular anomalies prior to a living liver donor (LLD) operation.

METHODS

A retrospective study of all LLD patient charts, operative and radiology reports from 1 January 2002 to 1 January 2012 was conducted. Primary post-operative outcomes assessed included mortality, re-operation, readmission and need for endoscopic or percutaneous intervention. Sensitivity and specificity of MR and CT pre-operative screening was calculated against the gold standard of intra-operative findings.

RESULTS

A total of 34 donors had an average age of 38 years (range: 22-58) with a body mass index (BMI) of 25.6 kg/m(2) (range: 19.8-32.5) and a length of stay (LOS) of 10.1 days (range: 5-41). There were no donor mortalities. Sensitivity and specificity of CT was 70.0% and 91.3%, and of MRI screening 23.1% and 100.0%, respectively. Patients with inaccurate pre-operative CT or MRI did not have an increased risk of complications.

CONCLUSIONS

Even although it was specific, pre-operative MR screening missed up to 77.0% of biliary anomalies. An impeccable surgical technique remains the key in preventing biliary complications of a living donor hepatectomy where pre-operative MRI screening is false.

Late acute liver allograft rejection; a study of its natural history and graft survival in the current era

BACKGROUND

Late acute rejection (LAR) after liver transplantation is often associated with poor clinical outcomes. We reviewed our experience of managing LAR in the current era to determine its natural history.

METHODS

A database of 970 consecutive adult liver transplants was reviewed retrospectively. LAR was defined as histologically proven acute cellular rejection occurring more than 90 days after transplantation.

RESULTS

The incidence of LAR was 11%, with a mean time of 565 days (median, 311 days; range, 90-2922 days) after transplantation. The highest rates for LAR were in seronegative hepatitis (17%), primary biliary cirrhosis (16%), and primary sclerosing cholangitis (13%) with an odds ratio of 2.3, 2.1, and 1.8, respectively. Logistic regression showed that younger recipients, primary biliary cirrhosis, and previous graft loss were independent predictors of LAR (P<0.001). Mean trough whole blood tacrolimus levels were at their lowest levels 1 week before the diagnosis of rejection (5.5 ng/mL; SD, 2.6) compared with levels of 7.7 ng/mL 4 weeks before rejection, showing a clear temporal relation. Graft survival was worse in those with LAR (P<0.01), whereas the best graft survival was among early acute rejection cases (85% 10-year survival; P<0.01). Poor response to treatment correlated with the development of ductopenic rejection (r=0.3; P<0.01). Approximately half with early ductopenic rejection eventually died (n=15).

CONCLUSION

LAR continues to provide a risk to patient and graft survival: understanding risk factors may allow an improvement in monitoring and early intervention and so prevent early graft loss.

Liver Transplant Pathology: Review of Challenging Diagnostic Situations

Histopathologic assessment of allograft liver biopsies has an important role in managing patients who have undergone liver transplantation. In this review, several topics are discussed that create diagnostic problems in transplant pathology, with emphasis on pathologic features and differential diagnosis. The topics discussed are acute cellular rejection, late acute rejection (centrizonal/parenchymal rejection), chronic rejection, plasma cell hepatitis, idiopathic posttransplant chronic hepatitis, fibrosing cholestatic hepatitis, selected viral infections (cytomegalovirus, Epstein-Barr virus, and hepatitis E), and acute antibody-mediated rejection.

Quantitative in situ analysis of FoxP3+ T regulatory cells on transplant tissue using laser scanning cytometry

There is abundant evidence that immune cells infiltrating into a transplanted organ play a critical role for destructive inflammatory or regulatory immune reactions. Quantitative in situ analysis (i.e., in tissue sections) of immune cells remains challenging due to a lack of objective methodology. Laser scanning cytometry (LSC) is an imaging-based methodology that performs quantitative measurements on fluorescently and/ or chromatically stained tissue or cellular specimens at a single-cell level. In this study, we have developed a novel objective method for analysis of immune cells, including Foxp3(+) T regulatory cells (Tregs), on formalin-fixed /paraffin-embedded (FFPE) transplant biopsy sections using iCys® Research Imaging Cytometer. The development of multiple immunofluorescent staining was established using FFPE human tonsil sample. The CD4/CD8 ratio and the population of Tregs among CD4(+) cells were analyzed using iCys and compared with the results from conventional flow cytometry analysis (FCM). Our multiple immunofluorescent staining techniques allow obtaining clear staining on FFPE sections. The CD4/CD8 ratio analyzed by iCys was concordant with those obtained by FCM. This method was also applicable for liver, small intestine, kidney, pancreas, and heart transplant biopsy sections and provide an objective quantification of Tregs within the grafts.