DCD liver transplant infection: experience from a single centre in China

Predictive performance of Metagenomic Next Generation Sequencing in early detection of post-liver transplantation infections

Objective

To evaluate the predictive performance of metagenomic next-generation sequencing (mNGS) in identifying and predicting pulmonary infections following liver transplantation and to investigate its association with patient outcomes within the initial four-week post-transplantation period.

Methods

We retrospectively analyzed 41 liver transplant patients with suspected pulmonary infections from August 2022 to May 2023. Bronchoalveolar lavage fluid (BALF) samples were collected on the first postoperative day for metagenomic next generation sequencing (mNGS) and culture. The predictive capability of mNGS for subsequent infections was assessed by monitoring inflammatory biomarkers and comparing the detection rates with culture methods. Real-time Polymerase Chain Reaction (Rt-PCR) was used to monitor Human betaherpesvirus 5 (CMV) and Human parvovirus B19 (B19) weekly during a four-week postoperative period. Inflammatory biomarkers and blood coagulation function were evaluated on specific days throughout the first, third, fifth, and during four weeks following surgery. The study was conducted until August 2023 to evaluate the patients' prognostic survival outcome, classifying them into groups based on the mortality and survival.

Results

The analysis included a total of 41 patients, comprising 32 males and 9 females, with an average age of 52 (47, 63) years. Within one week after liver transplantation, there were 7 cases of bacterial infections, 5 cases of fungal infections, 19 cases of mixed infections, 8 cases without any infection, and 2 cases with unidentified pathogen-associated infections. mNGS successfully predicted 39 (72 %) strains of pathogens, while culture-based methods only detected 28 (52 %) strains. Among the 8 patients diagnosed as non-infected, culture methods identified positive results in 4 cases (50 %), whereas mNGS yielded positive results in 7 cases (87.5 %). The detection rates of CMV and B19 by Rt-PCR within 4 weeks after liver transplantation were 61 % and 17 %, respectively (25/41, 7/41) among the patients. During the study period, a total of 9 patients succumbed while 32 patients survived. The death group and the survival group exhibited significant differences in CRP, HGB, and INR levels at specific monitoring time points. The proportion of CMV detection in blood was significantly higher in the death group compared to the surviving group. Elevated CRP level was identified as a prognostic risk factor.

Conclusions

Despite the presence of false positives, mNGS still presents a potential advantage in predicting pulmonary infection pathogens following liver transplantation. Furthermore, the levels of CRP and CMV carrier status within four weeks post-surgery exhibit significant associations with patient survival and prognosis.

Pharmacokinetic/pharmacodynamic issues for optimizing treatment with beta-lactams of Gram-negative infections in critically ill orthotopic liver transplant recipients: a comprehensive review

Orthotopic liver transplant (OLT) represents the standard of care for managing patients affected by end-stage and life-threatening liver diseases. Although a significant improvement in surgical techniques, immunosuppressant regimens, and prompt identification of early post-transplant complications resulted in better clinical outcome and survival in OLT recipients, the occurrence of early bacterial infections still represents a remarkable cause of morbidity and mortality. In this scenario, beta-lactams are the most frequent antimicrobials used in critical OLT recipients. The aim of this narrative review was to provide a comprehensive overview of the pathophysiological issues potentially affecting the pharmacokinetics of beta-lactams and to identify potential strategies for maximizing the likelihood of attaining adequate pharmacokinetic/pharmacodynamic (PK/PD) targets of beta-lactams in critically ill OLT recipients. A literature search was carried out on PubMed-MEDLINE database (until 31st March 2024) in order to retrieve clinical trials, real-world observational evidence, and/or case series/reports evaluating the PK/PD of traditional and novel beta-lactams in settings potentially involving critically ill OLT recipients. Retrieved evidence were categorized according to the concepts of the so-called "antimicrobial therapy puzzle", specifically assessing a) beta-lactam PK/PD features, with specific regard to aggressive PK/PD target attainment; b) site of infection, with specific regard to beta-lactam penetration in the lung, ascitic fluid, and bile; and c) pathophysiological alterations, focusing mainly on those specifically associated with OLT. Overall, several research gaps still exist in assessing the PK behavior of beta-lactams in critical OLT recipients. The impact of specific OLT-associated pathophysiological alterations on the attainment of optimal PK/PD targets may represent an important field in which further studies are warranted. Assessing the relationship between aggressive beta-lactam PK/PD target attainment and clinical outcome in critical OLT recipients will represent a major challenge in the next future.

Colonization of extended-spectrum β-lactamase-producing Enterobacteriaceae does not affect subsequent infection and liver transplant outcomes: a retrospective observational cohort study

Objective

To investigate the colonization rate of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E), subsequent infections by ESBL-E and ESBL-producing gram-negative bacilli (ESBL-GNB), and the effect of ESBL-E colonization on clinical outcomes in liver transplantation (LT) recipients.

Methods

This is a retrospective cohort study that included patients who underwent LT at Shanghai Renji Hospital between July 2016 and December 2017. Rectal swabs from LT patients at the postoperative ICU enrollment were screened anonymously for ESBL-E carriage. Demographics data, laboratory indexes, operative complications, and clinical course information were also obtained. The extent of ESBL-E colonization, the subsequent infection rates of ESBL-E and ESBL-GNB, and the clinical outcomes were compared between ESBL-E colonized and non-colonized patients.

Results

In total, 496 liver transplant recipients (387 males) were included in this study. ESBL-E colonization was detected in 240 patients (48.4%). There was no significant difference between the rates of ESBL-E infection (5.8 vs. 3.1%, p = 0.143), Ischemia-reperfusion ≥ 3 (27.9 vs. 24.6%, p = 0.403), acute kidney injury (39.6 vs. 38.7%, p = 0.835), acute rejection (2.1 vs. 1.6%, p = 0.664), graft versus host reaction (1.3 vs. 1.2%, p = 0.937), duration of hospitalization (22 vs. 23 days, p = 0.568), 90-day mortality (7.1 vs. 4.7%, p = 0.262) and 1-year mortality (12.9 vs. 9.3%, p = 0.265) in patients with and without ESBL-E colonization. Though the ESBL-GNB infection rate was higher in ESBL-E colonized patients (12.1 vs. 6.6%, p = 0.037), multivariate analysis showed that ESBL-E colonization did not increase the risk of ESBL-GNB infection (Model 1: aOR 1.755, 95% CI: 0.911-3.380, p = 0.093; Model 2: aOR 1.556, 95% CI: 0.761-3.181, p = 0.226). The ESBL-producing bacteria spectrum of colonization was significantly different from that of infections occurring after LT, with only three colonization events leading to infection by the same pathogen identified.

Conclusion

ESBL-E colonization in liver transplant patients is not associated with ESBL-E infection, nor is it a risk factor for post-transplant ESBL-GNB infection. Additionally, ESBL-E colonization does not lead to worse prognoses when compared with non-colonized patients.

Clinical trial registration

Chinese Clinical Trial Registry, Identifier [ChiCTR2100043034].

Risk factors of early bacterial infection and analysis of bacterial composition, distribution and drug susceptibility after cadaveric liver transplantation

BACKGROUND

This study provided a theoretical basis for the clinical diagnosis and treatment of bacterial infection after liver transplantation through analyzing the pathogenic distribution, drug sensitivity and risk factors of bacterial infection after liver transplantation.

METHODS

We collected clinical data from 207 recipients undergoing liver transplantation of graft from donation after citizens' death donors in the Third Xiangya Hospital of Central South University from January 2019 to December 2021 and analyzed the composition and distribution of bacterial pathogens, drug resistance and risk factors of infection.

RESULTS

A total of 90 bacterial infections occurred in 55 recipients within two months after liver transplantation, and the incidence of bacterial infection was 26.6% (55/207). The gram-negative bacteria (46/90, 51.1%) were more prevalent than gram-positive bacteria (44/90, 48.9%). Common sites of infection were the abdominal/biliary tract (26/90, 28.9%), lung (22/90, 22.4%) and urinary tract (22/90, 22.4%). Fourteen cases (6.8%) died after liver transplantation. Klebsiella pneumoniae (17/90, 18.9%) was the most frequent gram-negative bacteria causing infection in liver transplant recipients and 58.7%, 50%, 80.4% and 89.1% of gram-negative bacteria were sensitive to amikacin, minocycline, tigecycline and polymyxin B, respectively. The most common gram-positive bacteria was Enterococcus faecium (30/90, 33.3%) and 97.7%, 100%, 86.4%, 100% and 100% of gram-positive bacteria were sensitive to vancomycin, teicoplanin, daptomycin, tigecycline and linezolid, respectively. Univariate analysis revealed that bacterial infection was associated with female, age (≥ 50 years old), preoperative albumin (≤ 30 g/L), operation duration (≥ 400 min), intraoperative blood loss (≥ 3000 ml) and postoperative ventilator support. Binary Logistic regression analysis showed that female (OR = 3.149, 95% CI: 1.418-6.993, P = 0.005), operation duration (≥ 400 min) (OR = 2.393, 95% CI: 1.202-4.765, P = 0.013) and intraoperative blood loss (≥ 3000 ml) (OR = 2.052, 95% CI: 1.007-4.183, P = 0.048) were independent risk factors for bacterial infection after liver transplantation.

CONCLUSION

The incidence of early bacterial infection after liver transplantation was high, and the infection sites were mainly abdominal/biliary tract, respiratory tract and urinary tract. The most common pathogenic bacterium was gram-negative bacterium. Our study also identified several independent risk factors for bacterial infection after liver transplantation, including female gender, operation duration of 400 min or more, and intraoperative blood loss of 3000 ml or more. By addressing these risk factors, such as implementing strategies to optimize surgical procedures and minimize blood loss, healthcare professionals can work towards reducing the incidence of bacterial infections following liver transplantation.

The clinical effect of early enteral nutrition in liver-transplanted patients: a systematic review and meta-analysis

BACKGROUND

Appropriate nutritional support is critical for patients undergoing liver transplantation (LT). Early enteral nutrition (EEN) has been considered effective in critically ill patients. However, the clinical effect of EEN on liver-transplanted patients is unclear.

AIM

To evaluate the clinical effect of early enteral nutrition in patients receiving a liver transplant.

METHODS

A systematic search was performed on the Cochrane Library, PubMed, CINAHL, EMBASE, Web of Science, WanFang database, Chinese Biomedical Literature Database and China National Knowledge Infrastructure to collect relevant studies up to January, 2020. The results of these studies were pooled to calculate relative risk and mean differences with 95% confidence intervals for dichotomous data and continuous data. All statistical analysis was carried out by Review Manager 5.3.

RESULTS

9 RCTs and 10 cohort studies with 1300 patients were included in this meta-analysis. Compared with TPN, EEN reduced postoperative infection rates, ICU hours, length of hospitalization, and the duration of bowel ventilation as well as strengthening the nutritional status and liver function of LT patients. There is no difference in mortality rates, blood glucose levels or gastrointestinal complications. Compared to TPN, the combined EN + PN method more effectively prevented infection.

CONCLUSION

For patients undergoing liver transplantation, early enteral nutrition with or without combination may considered as a better nutritional therapy than total parenteral nutrition.

Infection within 2 weeks before liver transplantation closely related to prognosis of posttransplant infection: A single-center retrospective observational study in China

BACKGROUND

Infections still represent the main factors influencing morbidity and mortality following liver transplantation. This study aimed to evaluate the incidence and risk factors for infection and survival after liver transplantation.

METHODS

We retrospectively examined medical records in 210 liver recipients who underwent liver transplantation between April 2015 and October 2017 in our hospital. Clinical manifestations and results of pathogen detection test were used to define infection. We analyzed the prevalence, risk factors and prognosis of patients with infection.

RESULTS

The median follow-up was 214 days; the incidence of infection after liver transplantation was 46.7% (n = 98) which included pneumonia (43.4%), biliary tract infection (21.9%), peritonitis (21.4%) and bloodstream infection (7.6%). Among the pathogens in pneumonia, the most frequently isolated was Acinetobacter baumanii (23.5%) and Klebsiella pneumoniae (21.2%). Model for end-stage liver disease (MELD) score (OR = 1.083, 95% CI: 1.045-1.123; P < 0.001), biliary complication (OR = 4.725, 95% CI: 1.119-19.947; P = 0.035) and duration of drainage tube (OR = 1.040, 95% CI: 1.007-1.074; P = 0.017) were independent risk factors for posttransplant infection. All-cause mortality was 11.0% (n = 23). The prognostic factors for postoperative infection in liver recipients were prior-transplant infection, especially pneumonia within 2 weeks before transplantation. Kaplan-Meier curves of survival showed that recipients within 2 weeks prior infection had a significantly lower cumulative survival rate compared with those without infection (65.2% vs. 90.0%; hazard ratio: 4.480; P < 0.001).

CONCLUSIONS

Infection, especially pneumonia within 2 weeks before transplantation, complication with impaired renal function and MELD score after 7 days of transplantation was an independent prognostic factor for postoperative infection in liver transplant recipients.

Bacterial and Fungal Infections After Liver Transplantation: Microbial Epidemiology, Risk Factors for Infection and Death with Infection

Background

Infections, especially bacterial and fungal infections, are the leading cause of high mortality after liver transplantation (LT). This research investigated the pathogenic spectrum, antimicrobial susceptibility results, and risk factors of infection and death with infection to better control such infections.

Material/Methods

A retrospective cohort study was performed, and 433 liver transplant recipients between January 2010 and December 2016 were analyzed.

Results

We found 290 isolates of bacteria and fungi in 170 infected liver transplant patients. Significant independent risk factors for bacterial and fungal infections were prolonged hospital stay (OR 1.034, 95% CI 1.013~1.056, p=0.002), mechanical ventilation (OR 3.806, 95% CI 1.567~9.248, p=0.003), and liver failure (OR 2.659, 95% CI 1.019~6.940, p=0.046). Furthermore, postoperative MELD scores (OR 1.120, 95% CI 1.020~1.230, p=0.017) and septic shock (OR 12.000, 95% CI 1.124~128.066, p=0.003) were independent risk factors for death with infection. CRAB infection is the main pathogenic bacteria of septic shock in LT patients.

Conclusions

We found that 39.3% of recipients had at least 1 bacterial or fungal infection after LT. Shortening the length of hospital stay and early withdrawal of mechanical ventilation will reduce the risk of infection after LT. Patients with liver failure should be more vigilant against postoperative infection. Once an infection occurs, immediate assessment of the postoperative MELD score, early diagnosis of septic shock, and active search for pathogenic evidence for precise treatment will help improve patient prognosis. Routine screening for CRAB colonization before surgery will facilitate empirical use of effective antibiotics.

Liver Transplantation from Voluntary Organ Donor System in China: A Comparison between DBD and DCD Liver Transplants

BACKGROUND

In China, the cases of liver transplantation (LT) from donation after citizens' death have rose year by year since the citizen-based voluntary organ donor system was initiated in 2010. The objective of our research was to investigate the early postoperative and late long-term outcomes of LT from donation after brain death (DBD) and donation after circulatory death (DCD) according to the current organ donation system in China.

METHODS

Sixty-two consecutive cases of LT from donation after citizens' death performed in our hospital between February 2012 and June 2017 were examined retrospectively for short- and long-term outcomes. These included 35 DCD LT and 27 DBD LT.

RESULT

Subsequent median follow-up time of 19 months and 1- and 3-year graft survival rates were comparative between the DBD group and the DCD group (81.5% and 66.7% versus 67.1% and 59.7%; P = 0.550), as were patient survival rates (85.2% and 68.7% versus 72.2% and 63.9%; P = 0.358). The duration of ICU stay of recipients was significantly shorter in the DBD group, in comparison with that of the DCD group (1 versus 3 days, P = 0.001). Severe complication incidence (≥grade III) after transplantation was identical among the DBD and DCD groups (48.1% versus 60%, P = 0.352). There was no significant difference in postoperative mortality between the DBD and DCD groups (3 of 27 cases versus 5 of 35 cases). Twenty-one grafts (33.8%) were lost and 18 recipients (29.0%) were dead till the time of follow-up. Malignancy recurrence was the most prevalent reason for patient death (38.8%). There was no significant difference in incidence of biliary stenosis between the DBD and DCD groups (5 of 27 cases versus 6 of 35 cases, P = 0.846).

CONCLUSION

Although the sample size was small to some extent, this single-center study first reported that LT from DCD donors showed similar short- and long-term outcomes with DBD donors and justified the widespread implementation of voluntary citizen-based deceased organ donation in China. However, the results should be verified with a multicenter larger study.

Safety of Antithymocyte Globulin in Patients Undergoing Liver Transplantation With Livers From Donation After Circulatory Death Donors

Background: Studies suggest that rabbit-antithymocyte globulin (rATG) decreases biliary complications (BCs) after donation-after-circulatory-death-donor liver transplantation (DCD LTx), but safety data are lacking. Objective: Our aim was to assess the safety of rATG for this indication. The secondary end point was efficacy of rATG for this indication. Methods: Adult recipients of DCD LTx were divided into 2 cohorts: protocolized use of rATG in the modern era (July 1, 2013, to December 31, 2016) and a historical control without rATG (January 1, 2005, to June 30, 2013). Incidence of infection, leukopenia, and thrombocytopenia were compared for the safety assessment, incidence of BCs, ischemic cholangiopathy (IC), and transplant outcomes for the efficacy assessment. Results: A total of 83 patients met inclusion criteria: 42 in the historical cohort and 41 in the modern cohort. The modern cohort had significantly fewer bacterial infections at 3 months (historical 54.8% vs modern 23%; P = 0.004) and 1 year (historical 62.1% vs modern 34.2%, P = 0.004). The modern cohort also had fewer fungal infections at these time points (historical 33.3% and 47.9% vs modern 15% and 15%; P = 0.001). There were no significant differences in platelet or white blood cell reduction between groups. There was a nonsignificant, but numerical, trend toward reduced IC/BC in the modern cohort at 1 year (IC: historical 30.1% vs modern 13.2%, P = 0.08; BC: historical 51% vs modern 37.5%, P = 0.13). There was no difference in graft/patient survival. Conclusion and Relevance: Our data suggest no major safety issues with rATG in DCD LTx. Our study should ease clinical apprehension surrounding rATG use for this indication. Future prospective studies are needed to further evaluate the role of rATG and its impact on efficacy end points.

Effects of infection on post-transplant outcomes: living versus deceased donor liver transplants

Introduction

Post-transplant infections have been studied widely but data on comparisons of deceased donor liver transplants (DDLT) and living donor liver transplants (LDLT), type and timings of infections, and their relations to outcomes are not explored.

Material and methods

We analysed data from 612 participants of the Adult-to-Adult Living Donor Liver Transplantation Study (A2ALL), a retrospective data set of LDLT and DDLT. We compared the type and timing of the first post-transplant infection in relation to transplant outcomes between the two groups.

Results

Out of 611 patients, 24.5% experienced the first post-transplant infection, the majority of which were bacterial (35.3%), followed by fungal (11%) and viral infections (4.2%). There was no significant difference in the rate, type or timing of infection between LDLT and DDLT. Patients with late (> 1 year) first infection were 1.8 times more likely to die (95% CI: 1.12-2.98, p = 0.015) and 9 times more likely to have graft failures (95% CI: 3.26-24.8, p < 0.001). DDLT recipients who experienced bacterial infection had a significantly lower survival rate compared to LDLT recipients (p < 0.001).

Conclusions

Late infection is associated with lower survival in both DDLT and LDLT. Bacterial infection might be more detrimental for DDLT than LDLT. Late infection should be managed aggressively to improve outcomes.