Update and actual trends on bacterial infections following liver transplantation

Microbiome analysis, the immune response and transplantation in the era of next generation sequencing

The human gastrointestinal tract, skin and mucosal surfaces are inhabited by a complex system of bacteria, viruses, fungi, archaea, protists, and eukaryotic parasites with predominance of bacteria and bacterial viruses (bacteriophages). Collectively these microbes form the microbiota of the microecosystem of humans. Recent advancement in technologies for nucleic acid isolation from various environmental samples, feces and body secretions and advancements in shotgun throughput massive parallel DNA and RNA sequencing along with 16S ribosomal gene sequencing have unraveled the identity of otherwise unknown microbial entities constituting the human microecosystem. The improved transcriptome analysis, technological developments in biochemical analytical methods and availability of complex bioinformatics tools have allowed us to begin to understand the metabolome of the microbiome and the biochemical pathways and potential signal transduction pathways in human cells in response to microbial infections and their products. Also, developments in human whole genome sequencing, targeted gene sequencing of histocompatibility genes and other immune response associated genes by Next Generation Sequencing (NGS) have allowed us to have a better conceptualization of immune responses, and alloimmune responses. These modern technologies have enabled us to dive into the intricate relationship between commensal symbiotic and pathogenic microbiome and immune system. For the most part, the commensal symbiotic microbiota helps to maintain normal immune homeostasis besides providing healthy nutrients, facilitating digestion, and protecting the skin, mucosal and intestinal barriers. However, changes in diets, administration of therapeutic agents like antibiotics, chemotherapeutic agents, immunosuppressants etc. along with certain host factors including human histocompatibility antigens may alter the microbial ecosystem balance by causing changes in microbial constituents, hierarchy of microbial species and even dysbiosis. Such alterations may cause immune dysregulation, breach of barrier protection and lead to immunopathogenesis rather than immune homeostasis. The effects of human microbiome on immunity, health and disease are currently under intense research with cutting edge technologies in molecular biology, biochemistry, and bioinformatics along with tremendous ability to characterize immune response at single cell level. This review will discuss the contemporary status on human microbiome immune system interactions and their potential effects on health, immune homeostasis and allograft transplantation.

Care for the organ transplant recipient on the intensive care unit

All transplant recipients receive tacrolimus, mycophenolate and glucocorticoids and these drugs have many side-effects and drug-drug interactions. Common complications include surgical complications, infections, rejection and acute kidney injury. Infections as CMV and PJP can be prevented with prophylactic treatment. Given the complexity of organ transplant recipients a multi-disciplinary team of intensivists, surgeons, pharmacists and transplant specialists is essential. After heart transplantation a temporary pacemaker is required until the conduction system recovers. Stiffening of the heart and increased cardiac markers indicate rejection. An endomyocardial biopsy is performed via the right jugular vein, necessitating its preservation. For lung transplant patients, early intervention for aspiration is warranted to prevent chronic rejection. Risk of any infection is high, requiring active surveillance and intensive treatment, mainly of fungal infections. The liver is immunotolerant requiring lower immunosuppression. Transplantation surgery is often accompanied by massive blood loss and coagulopathy. Other complications include portal vein or hepatic artery thrombosis and biliary leakage or stenosis. Kidney transplant recipients have a high risk of cardiovascular disease and posttransplant anemia should be treated liberally. After postmortal transplantation, delayed graft function is common and dialysis is continued. Ureteral anastomosis complications can be diagnosed with ultrasound.

Liver Transplantation and Early Culture Growth: Risk and Impact?

OBJECTIVE

Despite advances in immunosuppressive drugs, postoperative care, and surgical techniques, bacterial infections remain the most important cause of morbidity and mortality in liver transplant patients. The aim of this study is to evaluate the influence of culture results taken on the first day of admission to intensive care unit on mortality, graft rejection, mechanical ventilation duration, and length of intensive care unit stay. Our study has clinical importance because it is the first study evaluating the cultures obtained on the first day of intensive care unit stays in liver transplant patients.

METHODS

Patients' demographic data, transplant type, rates of deceased and living donors, culture results, amount of blood and blood products used intraoperatively, previous hospital admission, mortality, incidence of graft rejection, mechanical ventilation duration, and length of intensive care unit stay were recorded.

RESULTS

Mortality and graft rejection were 14.8% and 9%, respectively. The mortality was significantly higher in all 3 cultures and/or in only blood culture-positive patients. Graft rejection, mechanical ventilation duration, and length of intensive care unit stay were significantly higher in patients whose 3 cultures were all positive. Only body mass index had a significant effect on mortality, graft rejection, and positive culture results.

CONCLUSIONS

Liver transplant patients' first postoperative day culture results were correlated with mortality, graft rejection, mechanical ventilation duration, and length of intensive care unit stay.

Risk index for early infections following living donor liver transplantation

INTRODUCTION

Post-operative infections in patients undergoing living donor liver transplantation (LDLT) are a major cause of morbidity and mortality. This study aims to develop a practical and efficient prognostic index for early identification and possible prediction of post-transplant infections using risk factors identified by multivariate analysis.

MATERIAL AND METHODS

One hundred patients with post-hepatitic cirrhosis, HCV positive, genotype 4, Child B/C or MELD score 13-25 undergoing LDLT were included. All potential predictors of infection were analyzed by backward logistic regression. Cut-off values were obtained from ROC curve analysis. Significant predictors were combined into a risk index, which was further tested and compared by ROC curve analysis.

RESULTS

Post-operative infection was associated with a significantly higher mortality (50.7% vs. 33.3%). Total leucocyte count, total bilirubin, early biliary complications, fever and C-reactive protein were found to be independent predictors of early infectious complications after LDLT. The risk index predicted infection with the highest sensitivity and specificity as compared with each predictor on its own (AUC = 0.91, 95% CI: 0.830-0.955, p < 0.0001).

CONCLUSIONS

The use of a combined risk index for early diagnosis of post-operative infections can efficiently identify high risk patients.

Immunologic Monitoring to Personalize Immunosuppression After Liver Transplant

Although immunosuppressive drugs have enhanced patient outcomes in transplantation, the liver transplant community has made significant research efforts into the discovery of more accurate and precise methods of posttransplant monitoring and diagnosing. Current research in biomarkers reveals many promising approaches.

Bacterial infections post-living-donor liver transplantation in Egyptian hepatitis C virus-cirrhotic patients: A single-center study

AIM

To determine risk factors, causative organisms and antimicrobial resistance of bacterial infections following living-donor liver transplantation (LDLT) in cirrhotic patients.

METHODS

This prospective study included 45 patients with hepatitis C virus-related end-stage liver disease who underwent LDLT at Ain Shams Center for Organ Transplant, Cairo, Egypt from January 2014 to November 2015. Patients were followed-up for the first 3 mo after LDLT for detection of bacterial infections. All patients were examined for the possible risk factors suggestive of acquiring infection pre-, intra- and post-operatively. Positive cultures based on clinical suspicion and patterns of antimicrobial resistance were identified.

RESULTS

Thirty-three patients (73.3%) suffered from bacterial infections; 21 of them had a single infection episode, and 12 had repeated infection episodes. Bile was the most common site for both single and repeated episodes of infection (28.6% and 27.8%, respectively). The most common isolated organisms were gram-negative bacteria. Acinetobacter baumannii was the most common organism isolated from both single and repeated infection episodes (19% and 33.3%, respectively), followed by Escherichia coli for repeated infections (11.1%), and Pseudomonas aeruginosa for single infections (19%). Levofloxacin showed high sensitivity against repeated infection episodes (P = 0.03). Klebsiella, Acinetobacter and Pseudomonas were multi-drug resistant (MDR). Pre-transplant hepatocellular carcinoma (HCC) and duration of drain insertion (in days) were independent risk factors for the occurrence of repeated infection episodes (P = 0.024).

CONCLUSION

MDR gram-negative bacterial infections are common post-LDLT. Pre-transplant HCC and duration of drain insertion were independent risk factors for the occurrence of repeated infection episodes.

Legionnaire's Disease and Immunosuppressive Drugs

Immunosuppressive agents predispose patients to legionnaire's disease. Patients receiving tumor necrosis factor antagonists are generally not severely immunocompromised by the underlying disease. In patients with malignancy receiving immunosuppressive therapies, it is difficult to balance the underlying disease versus the therapy used. Transplant recipients are often on multiple drugs, including immunosuppressants. It seems that immunosuppressive drugs add to the risk for legionella infection. The index of suspicion should be high for legionella infection early during a compatible clinical syndrome. The control of Legionella species and prevention of transmission should be the foremost goal in protecting susceptible populations from Legionnaire's disease.

Continuous monitoring of the liver graft temperature: relationship between bacterial contamination of the perfusion fluid and early outcome

BACKGROUND

A potential mechanism of the infection would be an infected donor, contamination at the time of the infusion and/or packaging, back-table procedure, and finally during the transplantation, all are potential sources of infection. The aim of our study is to analyze the incidence and significance of infection in the preservation solution according with the graft temperature. The second aim was to analyze the impact graft temperature on the clinical infections and the ischemia reperfusion injury.

METHODS

Sixteen donors were prospectively included in this study, including 9 males and 7 females. The liver graft temperature monitoring shows variation in four different phases: at the harvesting beginning, before the graft packaging, at the beginning of the backtable, at the end of the backtable.

RESULTS

There was no correlation between the functionality of the graft and the temperature of the perfusion fluid.

CONCLUSIONS

In conclusion, we did not found a correlation between graft temperature, culture of the preservation solution and early post-transplant follow up.

Clinical Significance of Contamination of the Preservation Solution in Liver Transplantation

INTRODUCTION

The aim of the present study was to describe the incidence and microbiological profiles of positive cultures obtained from preservation solution (PS) and correlate these findings with infectious complications detected in the liver transplant (LT) recipient.

PATIENTS

We conducted a single-center, retrospective study between December 2010 and August 2014 among 178 LT. In all grafts, a PS culture was carried out. All the infections in the receipt until hospital discharge were collected. In patients with >1, infection was considered the most severe according to Clavien-Dindo classification.

RESULTS

PS culture was positive for bacterial or fungal agents in 79 of 178 LT recipients (44%). The most commonly cultured organisms were coagulase-negative staphylococci (64%), Enterobacteriaceae (17%), and Staphylococcus aureus (4.7%). In the 79 patients with positive PS, 49 blood cultures were requested in the period after LT. Twenty-five postoperative infections (31.7%) were diagnosed. Only 4 of 79 patients (5%) with PS contamination had a postoperative infections related with isolated microorganism.

CONCLUSIONS

Contamination of PS appears in a high percentage of liver grafts before LT, although there is a poor correlation with postoperative infections in LT recipient. In these patients, a standardized process including fungal and bacterial cultures could be useful.

Immunosuppression: trends and tolerance?

Advances in pharmacologic immunosuppression are responsible for the excellent outcomes experienced by recipients of liver transplants. However, long-term follow-up of these patients reveals an increasing burden of morbidity and mortality that is attributable to these drugs. The authors summarize the agents used in contemporary liver transplantation immunosuppression protocols and discuss the emerging trend within the community to minimize or eliminate these agents from use. The authors present recently published data that may provide the foundation for immunosuppression minimization or tolerance induction in the future and review studies that have focused on the utility of biomarkers in guiding immunosuppression management.

Surveillance of bacterial and fungal infections in the postoperative period following liver transplantation: a series from 2005-2011

Orthotopic liver transplantation (OLT) is a life-saving procedure for the treatment of many end-stage diseases, but infectious and acute rejection episodes remain major causes of morbidity and mortality. Bacterial and fungal infections can be due to intra-abdominal, biliary, respiratory, urinary, wound, central venous catheters (CVC) or unknown sources. Using the computerized database of our microbiology laboratory, we analyzed all the bacterial and fungal infections in the first three months following OLT among 151 consecutive adult recipients at single center between January 2005 and December 2011. Samples included blood, bile CVC, urine, and bronchoalveolar lavage (BAL) specimen. Culture and identification of the isolated microorganisms was done in accordance with standard microbiological procedures. Three hundred thirteen samples from the above sites showed positive results for gram-positive cocci (n = 137; 43.8%), gram-negative rods (n = 156; 49.8%), and Candida species (n = 19; 6.1%). One patient (0.3%) experienced a CVC-related infection caused by Fusarium oxysporum. Bacterial and particularly biliary tract infections seem to play major roles in morbidity and mortality in the first three months following OLT. The major contributors to patient morbidity and mortality were candidemia and/or invasive candidiasis mainly from the biliary tract and/or CVC-related infections.

Impact of tobacco and alcohol consumption in patients registered on waiting list on early morbidity following liver transplantation

BACKGROUND

Liver transplantation (LT) is a high-risk surgery associated with postoperative complications. Smoking and drinking are known risk factors of long-term post-LT complications, but their role in early complications is still questioned.

PATIENTS AND METHODS

We retrieved from our medical files the data of all patients registered for LT and who had had a consultation with a physician specialized in substance abuse. Consumption of alcohol, tobacco, and drugs before and after registration for LT was assessed.

RESULTS

One hundred and five patients were included. Pre-registration smoking and drinking rates were 75.3 and 69.5%, respectively. Forty-three patients continued smoking and nine continued drinking until LT. Mortality and early morbidity rates were not impacted by smoking or drinking. Active smokers had significantly increased prevalence of bacterial cholangitis in comparison to patients who stopped smoking when registered for LT.

CONCLUSION

Persistent drinking in patients registered for LT is rare as compared to smoking; however, in our series, smoking until LT was not associated with major risk of early complication, except for cholangitis. This suggests that clinicians should take time to encourage patients to quit smoking and the intervention of a team specialized in substance abuse could be highly beneficial.

Bacterial bloodstream infections in liver transplantation: etiologic agents and antimicrobial susceptibility profiles

Liver transplantation (OLT) is a lifesaving procedure for the treatment of many end-stage liver diseases, but infection and acute rejection episodes still remain the main causes of morbidity and mortality. Bloodstream infections (BSIs), particularly, are the major cause of mortality among these patients. BSIs in OLT, are from intra-abdominal, biliary, respiratory, urinary, wound and/or central venous catheter sources. A certain percentage are of unknown origin. Using the computerized database of our microbiology laboratory, we analyzed all BSIs in 75 consecutive adult liver transplant patients in a single center between January 2008 and July 2011. BSIs occurred in 21/75 (28%) patients. Thirteen subjects had a single; two, two episodes, and the other six patients each >4 episodes. All episodes occurred in the first 60 days following OLT; the majority (74%), in the first month. Among 44 microorganisms recovered, 52.3% were gram-negative, the most frequent being Pseudomonas aeruginosa and Klebsiella pneumoniae; 47.7% were gram-positive, the most frequent being coagulase-negative staphylococci, particularly Staphylococcus epidermidis. Overall 65.9% of the isolates were resistant to several antibiotics: 40.9% displayed the multiding-resistant and 25% the panding-resistant phenotype. There was a high incidence of gram-negative and most importantly, resistant bacteria, which required appropriate therapy. These data showed that it is imperative to promote strategies to prevention and contain antimicrobial resistance.

Confronting the challenge: individualized immune monitoring after organ transplantation using the cellular immune function assay

The survival of a transplanted organ is dependent on avoidance of rejection, achieved through continuous immuno-suppression. Management of the transplant recipient confronts the clinician with a key challenge of post-transplant immune monitoring. Early detection of an activated allo-immune response is a harbinger of incipient rejection. Thus, timely intervention may prevent acute and chronic injury to the transplanted organ. Similarly, over immune-suppression can lead to infections or malignancies, hence the importance of early detection of the precarious suppression. The need for non-invasive systemic immune monitoring of the transplant recipient is therefore imperative. This review describes the cellular immune function assay--a non-invasive diagnostic method for evaluation of the net state of the recipient's cellular immune function. We describe the background that brought about the need for a reliable diagnostic tool for serial immune monitoring, and we overview the main mile-stones in the assimilation of the assay and its implementation in the clinic. The arising conclusion presents a novel non-invasive diagnostic bio-marker for post-transplant immune monitoring which enables the clinician to intervene prior to manifestation of clinical complications. The usefulness of the assay in detecting a state of over-suppression has been consensually described in multiple publications while its contribution in detection and management of under-suppression conditions remains to be determined by means of prospective interventional studies. The cellular immune function assay can be useful and beneficial for patient care only if used for longitudinal monitoring through serial testing.

Invasive fungal infection after liver transplantation: risk factors and significance of immune cell function monitoring

OBJECTIVE

Monitoring immune status in transplant recipients is essential for predicting the risk of infections. The aims of the study were to identify the correlation of a low ImmuKnow adenosine triphosphate (ATP) value with the development of invasive fungal infections (IFIs) and whether this is an independent risk factor for IFIs in liver recipients.

METHODS

We followed up 248 liver recipients who developed 157 infectious episodes. Peripheral CD4(+) T cells were selected freshly for ATP detection. Percentages of T-helper (Th, CD3(+) CD4(+) ) and T-suppressor (Ts, CD3(+) CD8(+) ) lymphocyte subgroups were also examined.

RESULTS

Overall 44 patients (17.7%) were diagnosed as IFIs, of whom 9 (20.5%) died. The average ImmuKnow ATP value in the IFI patients (109 ± 78 ng/mL) was significantly lower than that in common bacterial infections (174 ± 106 ng/mL, P < 0.01) or stable liver recipients (314 ± 132 ng/mL, P < 0.01), while there was no difference in the Th/Ts ratio among each group. Logistic regression analysis showed ImmuKnow ATP value less than 100 ng/mL was an independent risk factor of IFI (OR = 3.44, P = 0.0237). ImmuKnow ATP values had no correlation with lymphocytes or their subgroups, but tended to correlate with the number of neutrophils and total white blood cells.

CONCLUSIONS

ImmuKnow assay monitoring has the potential to identify the patients at risk of developing IFI after liver transplantation (LT), which may provide a feasible measure for optimizing liver recipients' immune cellular function after transplantation.

The occurrence and prevention of foodborne disease in vulnerable people

In developed countries, such as the United Kingdom and the United States, between 15% and 20% of the population show greater susceptibility than the general population to foodborne disease. This proportion includes people with primary immunodeficiency, patients treated with radiation or with immunosuppressive drugs for cancer and diseases of the immune system, those with acquired immune-deficiency syndrome and diabetics, people suffering from liver or kidney disease or with excessive iron in the blood, pregnant women, infants, and the elderly. Malnutrition and use of antacids, particularly proton-pump inhibitors, also increase susceptibility. We review the occurrence of infection by foodborne pathogens in these groups of people and measures to prevent infection. The nature and use of low microbial diets to reduce the risk of foodborne disease in immunocompromised patients are very variable. Diets for vulnerable people in care should exclude higher-risk foods, and vulnerable people in the community should receive clear advice about food safety, in particular avoidance of higher-risk foods and substitution of safer, nutritious foods.

Safety and feasibility of third-party multipotent adult progenitor cells for immunomodulation therapy after liver transplantation--a phase I study (MISOT-I)

BACKGROUND

Liver transplantation is the definitive treatment for many end-stage liver diseases. However, the life-long immunosuppression needed to prevent graft rejection causes clinically significant side effects. Cellular immunomodulatory therapies may allow the dose of immunosuppressive drugs to be reduced. In the current protocol, we propose to complement immunosuppressive pharmacotherapy with third-party multipotent adult progenitor cells (MAPCs), a culture-selected population of adult adherent stem cells derived from bone marrow that has been shown to display potent immunomodulatory and regenerative properties. In animal models, MAPCs reduce the need for pharmacological immunosuppression after experimental solid organ transplantation and regenerate damaged organs.

METHODS

Patients enrolled in this phase I, single-arm, single-center safety and feasibility study (n = 3-24) will receive 2 doses of third-party MAPCs after liver transplantation, on days 1 and 3, in addition to a calcineurin-inhibitor-free "bottom-up" immunosuppressive regimen with basiliximab, mycophenolic acid, and steroids. The study objective is to evaluate the safety and clinical feasibility of MAPC administration in this patient cohort. The primary endpoint of the study is safety, assessed by standardized dose-limiting toxicity events. One secondary endpoint is the time until first biopsy-proven acute rejection, in order to collect first evidence of efficacy. Dose escalation (150, 300, 450, and 600 million MAPCs) will be done according to a 3 + 3 classical escalation design (4 groups of 3-6 patients each).

DISCUSSION

If MAPCs are safe for patients undergoing liver transplantation in this study, a phase II/III trial will be conducted to assess their clinical efficacy.

Infections in liver transplant recipients

Liver transplantation is a standard life-saving procedure for the treatment of many end-stage liver diseases. The success of this procedure may be limited by infectious complications. In this article, we review the contemporary state of infectious complications during the post-operative period, with particular emphasis on those that occur most commonly during the first 6 mo after liver transplantation. Bacteria, and less commonly Candida infections, remain the predominant pathogens during the immediate post-operative period, especially during the first month, and infections caused by drug-resistant strains are emerging. Infections caused by cytomegalovirus and Aspergillus sp. present clinically during the "opportunistic" period characterized by intense immunosuppression. As newer potent immunosuppressive therapies with the major aim of reducing allograft rejection are developed, one potential adverse effect is an increase in certain infections. Hence, it is essential for liver transplant centers to have an effective approach to prevention that is based on predicted infection risk, local antimicrobial resistance patterns, and surveillance. A better understanding of the common and most important infectious complications is anticipated to lead to improvements in quality of life and survival of liver transplant recipients.

Differential effects of plasma and red blood cell transfusions on acute lung injury and infection risk following liver transplantation

Patients with chronic liver disease have an increased risk of developing transfusion-related acute lung injury (TRALI) from plasma-containing blood products. Similarly, red blood cell transfusions have been associated with postoperative and nosocomial infections in surgical and critical care populations. Patients undergoing liver transplantation receive large amounts of cellular and plasma-containing blood components, but it is presently unclear which blood components are associated with these postoperative complications. A retrospective cohort study of 525 consecutive liver transplant patients revealed a perioperative TRALI rate of 1.3% (7/525, 95% confidence interval = 0.6%-2.7%), which was associated with increases in the hospital mortality rate [28.6% (2/7) versus 2.9% (15/518), P = 0.02] and the intensive care unit length of stay [2 (1-11 days) versus 0 days (0-2 days), P = 0.03]. Only high-plasma-containing blood products (plasma and platelets) were associated with the development of TRALI. Seventy-four of 525 patients (14.1%) developed a postoperative infection, and this was also associated with increased in-hospital mortality [10.8% (8/74) versus 2.0% (9/451), P < 0.01] and a prolonged length of stay. Multivariate logistic regression determined that the number of transfused red blood cell units (adjusted odds ratio = 1.08, 95% confidence interval = 1.02-1.14, P < 0.01), the presence of perioperative renal dysfunction, and reoperation were significantly associated with postoperative infection. In conclusion, patients undergoing liver transplantation have a high risk of developing postoperative complications from blood transfusion. Plasma-containing blood products were associated with the development of TRALI, whereas red blood cells were associated with the development of postoperative infections in a dose-dependent manner.

Infectious complications more than 1 year after liver transplantation: a 3-decade nationwide experience

Because few reports have addressed infections late (≥1 year) after liver transplantation (LT), we evaluated the incidence, risk factors and pathogens involved. Infection data were from the Finnish LT registry, with starting date, type and relevant pathogens for 501 Finnish adult LT patients surviving ≥1 year post-transplant. Follow-up end points were end of study, death or retransplantation. Logistic regression to assess risk factors was adjusted for age, gender and follow-up time. With 3923 person-years of follow-up, overall infection incidence was 66/1000 person-years; 155 (31%) suffered 259 infections, and two-thirds experienced only one infection. Cholangitis (20%), pneumonia (19%) and sepsis (14%) were most common. The most frequent bacteria were Enterococcus spp. and Escherichia coli, and the most frequent viruses cytomegalovirus and varicella zoster virus. Fungal infections were rare (n = 7). With 13 fatal infections, 17% of all late deaths involved infection. Primary sclerosing cholangitis (PSC) and Roux-en-Y-type biliary anastomosis were associated with cholangitis; 18% of PSC patients suffered late cholangitis. Late acute rejection was associated with sepsis. Age, gender or cytomegalovirus did not significantly influence late infections. In conclusion, although infection risk under maintenance immunosuppression therapy is relatively low, particular vigilance regarding cholangitis, pneumonia and sepsis seems appropriate.

Clinical outcomes following hematopoietic stem cell transplantation for the treatment of mucopolysaccharidosis VI

Mucopolysaccharidosis VI (MPS VI, Maroteaux-Lamy Syndrome) is one of approximately 50 known lysosomal storage disorders. MPS VI is characterized by an absence or deficiency of N-acetylgalactosamine 4-sulfatase (arylsulfatase B) resulting in accumulation of dermatan sulfate. Prior to the availability of enzyme replacement therapy (ERT), the clinical management of MPS VI was limited to supportive care and allogeneic hematopoietic stem cell transplantation (HSCT); however, due to the rarity of this disease, little is known about the long-term outcomes of HSCT for MPS VI. The following retrospective study was performed using aggregate data gathered by the Center for International Blood and Marrow Transplant Research (CIBMTR) between 1982 and 2007 to determine survival probability for patients with MPS VI following allogeneic HSCT. This analysis identified 45 MPS VI patients with a median age of 5 years (range, 1-22 years) at the time they received an allogeneic HSCT. Cumulative incidence (95% CI) of acute graft-vs.-host disease at 100 days was 36% (21-53%). Probability of survival was 78% (65-89%) at 100 days and 66% (52-79%) at 1 and 3 years. While these data are based upon small numbers of recipients, they represent the largest series to date and may help clinicians assess the relative risks and benefits of currently available therapies.

Study protocol: a pilot study to determine the safety and efficacy of induction-therapy, de novo MPA and delayed mTOR-inhibition in liver transplant recipients with impaired renal function. PATRON-study

BACKGROUND

Patients undergoing liver transplantation with preexisting renal dysfunction are prone to further renal impairment with the early postoperative use of Calcineurin-inhibitors. However, there is only little scientific evidence for the safety and efficacy of de novo CNI free "bottom-up" regimens in patients with impaired renal function undergoing liver transplantation. This is a single-center study pilot-study (PATRON07) investigating safety and efficacy of CNI-free, "bottom-up" immunosuppressive (IS) strategy in patients undergoing liver transplantation (LT) with renal impairment prior to LT.

METHODS/DESIGN

Patients older than 18 years with renal impairment at the time of liver transplantation eGFR < 50 ml/min and/or serum creatinine levels > 1.5 mg/dL will be included. Patients in will receive a CNI-free combination therapy (basiliximab, MMF, steroids and delayed Sirolimus). Primary endpoint is the incidence of steroid resistant acute rejection within the first 30 days after LT. The study is designed as prospective two-step trial requiring a maximum of 29 patients. In the first step, 9 patients will be included. If 8 or more patients show no signs of biopsy proven steroid resistant rejection, additional 20 patients will be included. If in the second step a total of 27 or more patients reach the primary endpoint the regimen is regarded to be safe and efficient.

DISCUSSION

If a CNI-free-"bottom-up" IS strategy is safe and effective, this may be an innovative concept in contrast to classic top-down strategies that could improve the patient short and long-time renal function as well as overall complications and survival after LT. The results of PATRON07 may be the basis for a large multicenter RCT investigating the new "bottom-up" immunosuppressive strategy in patients with poor renal function prior to LT.http://www.clinicaltrials.gov-identifier: NCT00604357.

Immune cell functional assay in monitoring of adult liver transplantation recipients with infection

PURPOSE

To identify the levels of functional immunity measured by the ImmuKnow assay in Chinese liver transplantation recipients and its application in monitoring the risk of posttransplant infection.

METHODS

Forty-five apparent healthy Chinese and 106 adult liver transplant (LT) recipients were under investigation. LTs were grouped in stable status or infection according to their clinical diagnosis. Whole blood samples were collected freshly and cultured within 6 hr, the CD4(+) T cells were selected, and their adenosine triphosphate (ATP) value was assayed the next day. Before stimulation, we also examined the percentage of T-helper (Th; CD3(+) CD4(+)) and T-suppress (Ts; CD3(+) CD8(+)) lymphocyte subpopulations and the ratio of Th/Ts.

RESULTS

The average ImmuKnow assay in infectious LT recipients was 128 + or - 84 ng/mL, significantly lower (P<0.05) than that in stable LTs (305 + or - 149 ng/mL) or in normal adults (301+ or - 101 ng/mL). The ImmuKnow values in LTs had a good negative correlation to infection clinically (r = -0.6217, P<0.001). Infectious risk was high when the ImmuKnow value was less than 130 ng/mL (odds ratio=13, 95% confidence interval 6.0-29.4, P<0.01). The sensitivity of low ImmuKnow values in posttransplant infection was 85.2%, significantly higher than those of Th/Ts ratio and immunosuppressant trough levels (P<0.01); specificity was 76.3%, comparable with that of Th/Ts ratio (75.5%), but greatly higher than immunosuppressant trough levels (P<0.01). ImmuKnow ATP values had no correlation with Th/Ts ratio or immunosuppressant trough levels.

CONCLUSION

ImmuKnow ATP levels are lower in LT recipients with infection, which provides a new tool in monitoring posttransplant infection, and an index of tailoring immunosuppression clinically.

Hepatotrophic factors reduce hepatic fibrosis in rats

CONTEXT: Hepatic fibrosis occurs in response to several aggressive agents and is a predisposing factor in cirrhosis. Hepatotrophic factors were shown to stimulate liver growth and to restore the histological architecture of the liver. They also cause an improvement in liver function and accelerate the reversion of fibrosis before it progresses to cirrhosis. OBJECTIVE: To test the effects of hepatic fibrosis solution composed by amino acids, vitamins, glucose, insulin, glucagon and triiodothyronine on hepatic fibrosis in rats. METHODS: Fibrosis was induced in rats by gastric administration of dimethylnitrosamine (10 mg/kg) for 5 weeks. After liver biopsy, the rats received either hepatotrophic factors solution (40 mg/kg/day) or saline solution for 10 days by intraperitoneal injection. Blood samples and liver fragments were collected for hepatic function analysis, standard histopathology evaluation, and morphometric collagen quantification. RESULTS: Rats in the hepatotrophic factors group showed a decrease of the histopathological components of fibrosis and an increase of their hepatic mass (12.2%). There was no development of neoplasic lesions in both groups. Compared with the saline group, the hepatotrophic factors group also had a decrease of blood levels of hepatic-lesion markers (AST, ALT) and a decrease of collagen content in the portal spaces (31.6%) and perisinusoidal spaces (42.3%), as well as around the hepatic terminal vein (57.7%). Thus, hepatotrophic factors administration in the portal blood promoted a regenerative hepatic response, with an overall reduction of the volumetric density of collagen, improved hepatic function, and a general improvement in the histopathological aspects of fibrosis. CONCLUSION: Taken together, these results suggest the potential therapeutic use of this hepatotrophic factors solution to treat chronic liver diseases.

Incidence and clinical relevance of bacterial contamination in preservation solution for liver transplantation

OBJECTIVE

Postoperative infection is considered one of the most important causes of morbidity and mortality after liver transplantation. We prospectively studied the incidence and significance of infections in preservation solutions for liver transplantation.

MATERIALS AND METHODS

From March 2007 to March 2008, we cultured the University of Wisconsin preservation solution for 60 consecutive liver transplantations. Fluid samples were obtained at the beginning and at the end of the back table procedure. Our posttransplant infection prophylactic protocol consisted of ampicillin and cefotaxime for 48 hours.

RESULTS

Cultures were positive in 59 patients (98.4%). Seventy-five percent of the isolates were superficial saprophytic flora (SSF; Staphylococcus coagulase negative, Streptococcus viridans, and Corynebacterium), nevertheless in 15 cases (25.1%) we isolated high virulence pathogens (Staphylococcus aureus, Klebsiella, Escherichia coli, Enterobacter, and Pseudomonas aeruginosa). There were neither anaerobic nor fungal isolates. Sixteen patients (36%) from the group with SSF developed postoperative fever, including 12 with negative posttransplant cultures, while 4 patients showed positive cultures for various microorganisms distinct from those isolated from the preservation solution. Five patients (30%) with high virulence pathogens in the preservation solution developed posttransplant fever, although no pathogen was isolated.

CONCLUSIONS

Positive cultures of preservation fluids were observed in 98% of patients, although most of them (75%) were SSF. Microorganisms isolated from posttransplant cultures did not match the ones obtained from the preservation solution. Our results did not support routine culturing of the preservation solution provided that one administrator an adequate posttransplant antibiotic prophylactic regimen.

Evaluation of standard liver volume formulae for Chinese adults

AIM: To evaluate different standard liver volume (SLV) formula and verify the applicability of the formulae for Chinese adults.

METHODS: Data from 70 cases of living donor liver transplantation (LDLT) performed at our transplantation centers between January 2008 and April 2009 were analyzed. SLV was estimated using our recently reported formula [the Chengdu formula: SLV (mL) = 11.5 × body weight (kg) + 334] and other reported formulae used for Chinese adults. Actual intraoperative liver volumes were obtained from a review of the patients’ medical records.

RESULTS: The actual right liver volume was not significantly different from the estimated right liver volume determined by the Chengdu formula, but was significantly smaller than estimates using the Heinemann, Urata, Vauthey, and Lee formulae (P < 0.01), and significantly larger than estimates using the Fan formula (P < 0.05).

CONCLUSION: The Chengdu formula was demonstrated to be reliable by its application in LDLT.