Etiologies, risk factors, and outcomes of bacterial cholangitis after living donor liver transplantation

Recipient donor sex combinations in solid organ transplantation and impact on clinical outcome: A scoping review

INTRODUCTION

Solid organ transplantation (SOT) is a lifesaving treatment for end-stage organ failure. Although many factors affect the success of organ transplantation, recipient and donor sex are important biological factors influencing transplant outcome. However, the impact of the four possible recipient and donor sex combinations (RDSC) on transplant outcome remains largely unclear.

METHODS

A scoping review was carried out focusing on studies examining the association between RDSC and outcomes (mortality, graft rejection, and infection) after heart, lung, liver, and kidney transplantation. All studies up to February 2023 were included.

RESULTS

Multiple studies published between 1998 and 2022 show that RDSC is an important factor affecting the outcome after organ transplantation. Male recipients of SOT have a higher risk of mortality and graft failure than female recipients. Differences regarding the causes of death are observed. Female recipients on the other hand are more susceptible to infections after SOT.

CONCLUSION

Differences in underlying illnesses as well as age, immunosuppressive therapy and underlying biological mechanisms among male and female SOT recipients affect the post-transplant outcome. However, the precise mechanisms influencing the interaction between RDSC and post-transplant outcome remain largely unclear. A better understanding of how to identify and modulate these factors may improve outcome, which is particularly important in light of the worldwide organ shortage. An analysis for differences of etiology and causes of graft loss or mortality, respectively, is warranted across the RDSC groups.

PRACTITIONER POINTS

Recipient and donor sex combinations affect outcome after solid organ transplantation. While female recipients are more susceptible to infections after solid organ transplantation, they have higher overall survival following SOT, with causes of death differing from male recipients. Sex-differences should be taken into account in the post-transplant management.

Short-term postoperative bacteriobilia or fungibilia in liver transplantation patients with donation after circulatory death allografts associated with a longer hospital stay: A single-center retrospective observational study in China

BACKGROUND

Normal bile is sterile. Studies have shown that cholangitis after liver transplantation (LT) was associated with a relatively poor prognosis. It remains unclear whether the bacteriobilia or fungibilia impact the patient outcomes in LT recipients, especially with donation after circulatory death (DCD) allografts, which was correlated with a higher risk of allograft failure.

METHODS

This retrospective study included 139 LT recipients of DCD grafts from 2019 to 2021. All patients were divided into two groups according to the presence or absence of bacteriobilia or fungibilia. The prevalence and microbial spectrum of postoperative bacteriobilia or fungibilia and its possible association with outcomes, especially hospital stay were analyzed.

RESULTS

Totally 135 and 171 organisms were isolated at weeks 1 and 2, respectively. Among all patients included in this analysis, 83 (59.7%) developed bacteriobilia or fungibilia within 2 weeks post-transplantation. The occurrence of bacteriobilia or fungibilia (β = 7.43, 95% CI: 0.02 to 14.82, P = 0.049), particularly the detection of Pseudomonas (β = 18.84, 95% CI: 6.51 to 31.07, P = 0.003) within 2 weeks post-transplantation was associated with a longer hospital stay. However, it did not affect the graft and patient survival.

CONCLUSIONS

The occurrence of bacteriobilia or fungibilia, particularly Pseudomonas within 2 weeks post-transplantation, could influence the recovery of liver function and was associated with prolonged hospital stay but not the graft and patient survival.

Bacterial infections in solid organ transplant recipients

PURPOSE OF REVIEW

Bacteria are the leading cause of infections in solid organ transplant (SOT) recipients, significantly impacting patient outcome. Recently detailed and comprehensive epidemiological data have been published.

RECENT FINDING

This literature review aims to provide an overview of bacterial infections affecting different types of SOT recipients, emphasizing underlying risk factors and pathophysiological mechanisms.

SUMMARY

Lung transplantation connects two microbiotas: one derived from the donor's lower respiratory tract with one from the recipient's upper respiratory tract. Similarly, liver transplantation involves a connection to the digestive tract and its microbiota through the bile ducts. For heart transplant recipients, specific factors are related to the management strategies for end-stage heart failure based with different circulatory support tools. Kidney and kidney-pancreas transplant recipients commonly experience asymptomatic bacteriuria, but recent studies have suggested the absence of benefice of routine treatment. Bloodstream infections (BSI) are frequent and affect all SOT recipients. Nonorgan-related risk factors as age, comorbidity index score, and leukopenia contribute to BSI development. Bacterial opportunistic infections have become rare in the presence of efficient prophylaxis. Understanding the epidemiology, risk factors, and pathophysiology of bacterial infections in SOT recipients is crucial for effective management and improved patient outcomes.

Next Generation Sequencing Outperforms Cultivation-Based Methods for Detection of Bacterial Genera in Bile After Liver Transplantation

BACKGROUND AND AIMS

Bacterial cholangitis is a common complication in patients with ischemic type biliary lesions and/or anastomotic strictures after liver transplantation (LTX). Patients frequently need antibiotics and endoscopic retrograde cholangiography (ERC) to improve the bile flow. Antibiotic treatment is based on findings in standard microbiological cultivation (SMC) of bile. However, the cultivation techniques are limited to a subset of bacteria easy-to-cultivate. Therefore, the aim of our study was to evaluate the value of next generation sequencing as an additional diagnostic tool to SMC in ischemic type biliary lesions and/or anastomotic strictures.

METHODS

We sequenced the V1-V2 region of the 16S rRNA gene in 242 stored bile samples in patients after LTX and compared the results with findings of SMC. SMC was performed in n = 135 (56%) fresh bile samples in addition to NGS. SMC was part of the clinical routine in these patients.

RESULTS

NGS detected bacterial genera in bile samples more often than SMC (P = 5.42 × 10-74). SMC showed insufficient discovery of bacterial genera compared to NGS with better performance in patients receiving antibiotics prior to ERC. SMC missed many bacterial genera detected by NGS.

CONCLUSIONS

NGS was more sensitive in detecting bacteria in bile than SMC, no clinical parameters could be used to improve discovery rates in SMC and many genera were missed by SMC. Therefore, NGS should be used in a combined approach with SMC for improved diagnostics to achieve more specific and targeted antibiotic treatments.

Bacteriophage Rescue Therapy of a Vancomycin-Resistant Enterococcus faecium Infection in a One-Year-Old Child following a Third Liver Transplantation

Phage therapy is an experimental therapeutic approach used to target multidrug-resistant bacterial infections. A lack of reliable data with regard to its efficacy and regulatory hurdles hinders a broad application. Here we report, for the first time, a case of vancomycin-resistant Enterococcus faecium abdominal infection in a one-year-old, critically ill, and three times liver transplanted girl, which was successfully treated with intravenous injections (twice per day for 20 days) of a magistral preparation containing two Enterococcus phages. This correlated with a reduction in baseline C-reactive protein (CRP), successful weaning from mechanical ventilation and without associated clinical adverse events. Prior to clinical use, phage genome was sequenced to confirm the absence of genetic determinants conferring lysogeny, virulence or antibiotic resistance, and thus their safety. Using a phage neutralization assay, no neutralizing anti-phage antibodies in the patient's serum could be detected. Vancomycin-susceptible E. faecium isolates were identified in close relation to phage therapy and, by using whole-genome sequencing, it was demonstrated that vancomycin-susceptible E. faecium emerged from vancomycin-resistant progenitors. Covering a one year follow up, we provide further evidence for the feasibility of bacteriophage therapy that can serve as a basis for urgently needed controlled clinical trials.

Modern imaging of cholangitis

Cholangitis refers to inflammation of the bile ducts with or without accompanying infection. When intermittent or persistent inflammation lasts 6 months or more, the condition is classified as chronic cholangitis. Otherwise, it is considered an acute cholangitis. Cholangitis can also be classified according to the inciting agent, e.g. complete mechanical obstruction, which is the leading cause of acute cholangitis, longstanding partial mechanical blockage, or immune-mediated bile duct damage that results in chronic cholangitis.The work-up for cholangitis is based upon medical history, clinical presentation, and initial laboratory tests. Whereas ultrasound is the first-line imaging modality used to identify bile duct dilatation in patients with colicky abdominal pain, cross-sectional imaging is preferable when symptoms cannot be primarily localised to the hepatobiliary system. CT is very useful in oncologic, trauma, or postoperative patients. Otherwise, magnetic resonance cholangiopancreatography is the method of choice to diagnose acute and chronic biliary disorders, providing an excellent anatomic overview and, if gadoxetic acid is injected, simultaneously delivering morphological and functional information about the hepatobiliary system. If brush cytology, biopsy, assessment of the prepapillary common bile duct, stricture dilatation, or stenting is necessary, then endoscopic ultrasound and/or retrograde cholangiography are performed. Finally, when the pathologic duct is inaccessible from the duodenum or stomach, percutaneous transhepatic cholangiography is an option. The pace of the work-up depends upon the severity of cholestasis on presentation. Whereas sepsis, hypotension, and/or Charcot's triad warrant immediate investigation and management, chronic cholestasis can be electively evaluated.This overview article will cover the common cholangitides, emphasising our clinical experience with the chronic cholestatic liver diseases.

The Impact of Biliary Reconstruction Methods on Small Partial Liver Grafts

Supplemental Digital Content is available in the text.

Graft recipient weight ratios are lower in adult-to-adult living-donor liver transplantation than in adult-to-adult deceased-donor liver transplantation. Rapid liver regeneration is essential for increased recipient survival rates in adult-to-adult living-donor liver transplantation. However, the influence of biliary reconstruction methods, including choledocho-choledochostomy and choledocho-jejunostomy, on small partial liver grafts remains unknown. Herein, we investigate the impact of these biliary reconstruction methods on small partial liver grafts.