Infections After Liver Transplantation: A Retrospective, Single-center Study. Transplant Proc. 2015;47:1019-1024. [PMID: 26036509 DOI: 10.1016/j.transproceed.2015.03.009]

Biliary pharmacokinetic/pharmacodynamic analysis of continuous infusion meropenem/vaborbactam in a case series of orthotopic liver transplant recipients

OBJECTIVE

To analyse the biliary pharmacokinetics/pharmacodynamics (PK/PD) of continuous infusion (CI) meropenem-vaborbactam (MEM-VBM) in a case series of orthotopic liver transplant (OLT) recipients being treated for Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) related biliary tract infections (BTIs) or as preemptive therapy of KPC-Kp rectal colonization.

METHODS

Critical OLT recipients receiving CI MEM-VBM (2 g/2 g q8h over 8 h) because of KPC-Kp related BTIs or as preemptive therapy of KPC-Kp rectal colonization, having Kehr's tube positioned and undergoing simultaneous therapeutic drug monitoring of MEM and VBM in plasma and bile were retrospectively assessed. Bile-to-plasma ratio of free steady-state concentrations (fCss) of MEM and VBM was used for assessing biliary penetration. Optimal joint MEM-VBM PK/PD target attainment was defined as MEM fCss/MIC ratio >4 coupled with VBM free area under time-concentration curve (fAUC)/threshold concentration (CT) ratio >24.

RESULTS

Overall, four critical OLT recipients were included. Median bile-to-plasma ratio was 0.32 for MEM (range 0.21-0.79) and 0.40 for VBM (range 0.20-0.77). Biliary MEM-VBM joint PK/PD target attainment was optimal in 3/4 OLT recipients and quasi-optimal in the other one.

CONCLUSIONS

The 1:1 proportion between MEM and VBM concentrations was maintained unchanged in the bile, allowing us to assume that the efficacy of MEM-VBM may be appropriate even in the treatment of BTIs. CI administration was an effective strategy for attaining aggressive biliary joint PK/PD targets against pathogens with an MIC up to 2 mg/L.

Safety of Biologic and Small Molecule Therapy for Inflammatory Bowel Disease Among Solid Organ Transplant Recipients: Systematic Review and Meta-Analysis

BACKGROUND

Patients undergoing organ transplantation are often on immunosuppressing medications to prevent rejection of the transplant. The data on use of concomitant immunosuppression for inflammatory bowel disease (IBD) and organ transplant management are limited. This study sought to evaluate the safety of biologic and small molecule therapy for the treatment of IBD among solid organ transplant recipients.

METHODS

Medline, Embase, and Web of Science databases were systematically searched for studies reporting on safety outcomes associated with the use of biologic and small molecule therapy (infliximab, adalimumab, certolizumab, golimumab, vedolizumab, ustekinumab, and tofacitinib) in patients with IBD postsolid organ transplant (eg, liver, kidney, heart, lung, pancreas). The primary outcome was infectious complications. Secondary outcomes included serious infections, colectomy, and discontinuation of biologic therapy.

RESULTS

Seven hundred ninety-seven articles were identified for screening, yielding 16 articles for the meta-analyses with information on 163 patients. Antitumor necrosis factor α (Anti-TNFs; infliximab and adalimumab) were used in 8 studies, vedolizumab in 6 studies, and a combination of ustekinumab or vedolizumab and anti-TNFs in 2 studies. Two studies reported outcomes after kidney and cardiac transplant respectively, whereas the rest of the studies included patients with liver transplants. The rates of all infections and serious infections were 20.09 per 100 person-years (100-PY; 95% CI, 12.23-32.99 per 100-PY, I2 = 54%) and 17.39 per 100-PY (95% CI, 11.73-25.78 per 100-PY, I2 = 21%), respectively. The rates of colectomy and biologic medication discontinuation were 12.62 per 100-PY (95% CI, 6.34-25.11 per 100-PY, I2 = 34%) and 19.68 per 100-PY (95% CI, 9.97-38.84 per 100-PY, I2 = 74%), respectively. No cases of venous thromboembolism or death attributable to biologic use were reported.

CONCLUSION

Biologic therapy is overall well tolerated in patients with solid organ transplant. Long-term studies are needed to better define the role of specific agents in this patient population.

Role of a Real-Time TDM-Based Expert Clinical Pharmacological Advice Program in Optimizing the Early Pharmacokinetic/Pharmacodynamic Target Attainment of Continuous Infusion Beta-Lactams among Orthotopic Liver Transplant Recipients with Documented or Suspected Gram-Negative Infections

(1) Objectives: To describe the attainment of optimal pharmacokinetic/pharmacodynamic (PK/PD) targets in orthotopic liver transplant (OLT) recipients treated with continuous infusion (CI) beta-lactams optimized using a real-time therapeutic drug monitoring (TDM)-guided expert clinical pharmacological advice (ECPA) program during the early post-surgical period. (2) Methods: OLT recipients admitted to the post-transplant intensive care unit over the period of July 2021-September 2023, receiving empirical or targeted therapy with CI meropenem, piperacillin-tazobactam, meropenem-vaborbactam, or ceftazidime-avibactam optimized using a real-time TDM-guided ECPA program, were retrospectively retrieved. Steady-state beta-lactam (BL) and/or beta-lactamase inhibitor (BLI) plasma concentrations (Css) were measured, and the Css/MIC ratio was selected as the best PK/PD target for beta-lactam efficacy. The PK/PD target of meropenem was defined as being optimal when attaining a fCss/MIC ratio > 4. The joint PK/PD target of the BL/BLI combinations (namely piperacillin-tazobactam, ceftazidime-avibactam, and meropenem-vaborbactam) was defined as being optimal when the fCss/MIC ratio > 4 of the BL and the fCss/target concentration (CT) ratio > 1 of tazobactam or avibactam, or the fAUC/CT ratio > 24 of vaborbactam were simultaneously attained. Multivariate logistic regression analysis was performed for testing potential variables that were associated with a failure in attaining early (i.e., at first TDM assessment) optimal PK/PD targets. (3) Results: Overall, 77 critically ill OLT recipients (median age, 57 years; male, 63.6%; median MELD score at transplantation, 17 points) receiving a total of 100 beta-lactam treatment courses, were included. Beta-lactam therapy was targeted in 43% of cases. Beta-lactam dosing adjustments were provided in 76 out of 100 first TDM assessments (76.0%; 69.0% decreases and 7.0% increases), and overall, in 134 out of 245 total ECPAs (54.7%). Optimal PK/PD target was attained early in 88% of treatment courses, and throughout beta-lactam therapy in 89% of cases. Augmented renal clearance (ARC; OR 7.64; 95%CI 1.32-44.13) and MIC values above the EUCAST clinical breakpoint (OR 91.55; 95%CI 7.12-1177.12) emerged as independent predictors of failure in attaining early optimal beta-lactam PK/PD targets. (4) Conclusion: A real-time TDM-guided ECPA program allowed for the attainment of optimal beta-lactam PK/PD targets in approximately 90% of critically ill OLT recipients treated with CI beta-lactams during the early post-transplant period. OLT recipients having ARC or being affected by pathogens with MIC values above the EUCAST clinical breakpoint were at high risk for failure in attaining early optimal beta-lactam PK/PD targets. Larger prospective studies are warranted for confirming our findings.

West Nile Virus Infection in Liver Transplant Recipient With Neither De Novo Infection nor Donor-Derived Infection: A Case Report

West Nile virus was first described in 1937 and has sinceperiodically appearedin variousparts oftheworld by infecting people and horses. Reported infection symptoms and signs may be highly variable, ranging from fever and myalgias to meningoencephalitis. A 59-year-old patient was admitted to the University Clinical Centre of Serbia, Belgrade, in September 2018, where livertransplantwasperformedtotreat cirrhosisof ethyl etiology. Immunosuppressive therapy was started immediately after successful transplant, with the patientreceiving methylprednisolone, tacrolimus, and mycophenolate mofetil. Mycophenolate mofetil was excluded from therapy on postoperative day 3 because of progressively worse white blood cell count. The patient became febrile on postoperative day 11 (39.6 °C), and arm tremor, nausea, vomiting, and frequent fluid stools occurred. He complained of pain in the muscles and joints of the lower extremities. The next day he experienced occasional disorientation. Neurological findings revealed no signs of acute focal neurological deficit. We performed culture tests to isolate pathological microorganisms, and results were negative in cultures of the blood, urine, feces, ascites, and a smear of the wound and tip of the central venous catheter. Lumbar puncture resulted in a clear cerebrospinal fluid that was sent for analysis that showed significant increases in white blood cell count (94 × 106 cells/L), total proteins (1.61 g/L), and microalbumin (504.5 mg/L), with a reduction of immunoglobulin G. On postoperative day 15, positive serology of West Nile virus immunoglobulin M in cerebrospinal fluid was verified. Intensive monitoring and symptomatic and supportive therapy resulted in clinical and laboratory improvement, and the patient was discharged in good general condition on postoperative day 22. Considering the high risk of posttransplant complications, there remains the question of whether all donors and recipients should be tested forWest Nile virus atthe onset oftransplant.

Duration of operation and diagnosis of hepatitis B (HBV) is an independent risk factor for surgical site infections after liver transplantation

Objectives

Surgical site infections (SSI) are the most common complications after liver transplantation (LT). Although there are some risk factors known in the literature after LT, the available data is insufficient for routine use. In the present study, it was aimed to define the parameters that may be used to clearly determine the risk of SSI after LT in our clinic.

Material and Methods

In the present study, we evaluated 329 patients who underwent liver transplantation with regard to risk factors for surgical site infections. The relation between demographic data and SSI was evaluated using SPSS, Graphpad, and Medcalc statistical programs.

Results

In a total of 329 patients, SSIs were determined in 37 (11.24%). Among the 37 patients, 24 were classified as organ space (64.9%) and 13 as deep SSI (35.1%). None of these patients developed superficial incisional infection. SSI showed statistically significant relation with operation time (p= 0.008), diabetes (p= 0.004), and cirrhosis due to hepatitis B (p <0.001).

Conclusion

As a result, deep and organ space infections are much more observed in patients undergoing liver transplantation with hepatitis B, diabetes mellitus and prolonged surgery. This is thought to have developed because of chronic irritation and increased inflammation. Since data on hepatitis B and duration of surgery are limited in the literature, this study is considered to be a contribution to the literature.

Laparoscopic repeat liver resection for hepatic epithelioid hemangioendothelioma

BACKGROUND

Optimal treatment for patients with hepatic epithelioid hemangioendothelioma (HEHE) remains unclear. Laparoscopic repeat liver resection (LR) is a minimally invasive and potentially effective surgical option for multiple HEHEs.

CASE PRESENTATION

A 42-year-old woman with no relevant history was admitted for multiple liver tumors. Six tumors were observed on T2-weighted magnetic resonance imaging (MRI) including one in S2, two in S3, two in S7, and one in S8. Pathological evaluation of percutaneous tumor biopsy tissue suggested a diagnosis of HEHE and laparoscopic LR was planned. The procedure began with partial resection of S7 and partial resection of S8 and left lateral sectionectomy were performed. Another tumor was found intraoperatively on the surface of S6, necessitating removal by partial resection. Pathological evaluation of the resected tumor tissue from all seven tumors concurred with that of the preoperative biopsy. The patient was discharged on postoperative day 6 without any complications. A follow-up MRI 15 months after the primary surgery revealed one tumor each in S4, S6, and S8. Laparoscopic repeat LR was performed. The patient was discharged on postoperative day 5 without any complications. All three recurrent tumors were pathologically confirmed as HEHEs.

CONCLUSIONS

We successfully treated primary and recurrent HEHEs with laparoscopic LR, which is a reasonable minimally invasive procedure considering the possibility of multiple courses of liver surgery in patients with HEHE.

Management of bacterial and fungal infections in end stage liver disease and liver transplantation: Current options and future directions

Patients with liver cirrhosis are susceptible to infections due to various mechanisms, including abnormalities of humoral and cell-mediated immunity and occurrence of bacterial translocation from the intestine. Bacterial infections are common and represent a reason for progression to liver failure and increased mortality. Fungal infections, mainly caused by Candida spp., are often associated to delayed diagnosis and high mortality rates. High level of suspicion along with prompt diagnosis and treatment of infections are warranted. Bacterial and fungal infections negatively affect the outcomes of liver transplant candidates and recipients, causing disease progression among patients on the waiting list and increasing mortality, especially in the early post-transplant period. Abdominal, biliary tract, and bloodstream infections caused by Gram-negative bacteria [e.g., Enterobacteriaceae and Pseudomonas aeruginosa (P. aeruginosa)] and Staphylococcus spp. are commonly encountered in liver transplant recipients. Due to frequent exposure to broad-spectrum antibiotics, invasive procedures, and prolonged hospitalizations, these patients are especially at risk of developing infections caused by multidrug resistant bacteria. The increase in antimicrobial resistance hampers the choice of an adequate empiric therapy and warrants the knowledge of the local microbial epidemiology and the implementation of infection control measures. The main characteristics and the management of bacterial and fungal infections in patients with liver cirrhosis and liver transplant recipients are presented.

INFECÇÕES RELACIONADAS À ASSISTÊNCIA À SAÚDE E FATORES ASSOCIADOS NO PÓS-OPERATÓRIO DE TRANSPLANTE HEPÁTICO

RESUMO Objetivo: identificar a incidência das infecções relacionadas à assistência à saúde e seus fatores associados, durante o primeiro mês do pós-operatório de pacientes adultos submetidos ao transplante hepático em um hospital público de Fortaleza. Método: estudo retrospectivo, descritivo com abordagem quantitativa, realizado com 53 receptores de fígado no primeiro semestre do ano de 2015. Os dados foram coletados através dos prontuários, fichas ambulatoriais e de notificação de infecções. Resultados: dos pacientes avaliados, 15 (28,3%) apresentaram infecção durante o primeiro mês, em que o mais prevalente foi a sepse clínica (n=6; 37,4%), seguida de infecção do trato respiratório (n=3; 18,8%), trato urinário (n=3;18,8%), sítio cirúrgico (n=3; 18,8%) e por último, infecção de corrente sanguínea (n=1; 6,2%). Os que apresentaram associação estatística em relação a não ocorrência de infecções foram o grupo dos pacientes casados e a indicação de cirrose por hepatite C. A média dos dias de internação no pós-operatório, o uso do imunossupressor micofenolato de mofetil e a média do uso de alguns dispositivos invasivos, foram identificados como os fatores associados à ocorrência de infecções, sendo estatisticamente significativos para p=<0,05. Conclusão: a identificação da incidência das infecções relacionadas à assistência à saúde e seus fatores associados em pacientes submetidos ao transplante hepático, poderá subsidiar o direcionamento das ações de saúde, com a finalidade de diminuir a morbimortalidade associada às infecções e otimizando a recuperação desses pacientes.

Infections in live donor liver transplant recipients: A study of timeline, aetiology and antimicrobial resistance of bacterial and fungal infections from the developing world

Infections are the leading cause of morbidity and mortality in liver transplant (LT) recipients. We studied timeline, spectrum of infection, system involved, and antimicrobial resistance in 64 patients undergoing live donor LT with 6-month follow-up. Of 64 patients, 38 (59.5%) patients had 103 infectious episodes, 10 patients had single infectious episode and 28 patients had two or more infectious episodes. 96 (93.2%) were bacterial and Candida infections were in 7 (6.8%). Early phase had 30 (29.1%) episodes; intermediate phase 25 (24.2%) and late phase 48 (46.6%). Mortality was 11/64 (17.1%). Knowledge of timeline, aetiological agent and antimicrobial resistance is useful to guide empirical therapy and infection prevention.

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.

Looking inward: The impact of operative time on graft survival after liver transplantation

BACKGROUND

Operative time often has been cited as an important factor for postoperative outcomes. Despite this belief, most efforts to improve liver transplant outcomes have largely focused on only patient and donor factors, and little attention has been paid on operative time. The primary objective of this project was to determine the impact of operative time on graft survival after liver transplant.

METHODS

A retrospective review of 2,877 consecutive liver transplants performed at a single institution was studied. Data regarding recipient, donor, and operative characteristics, including detailed granular operative times were collected prospectively and retrospectively reviewed. Using an instrument variable approach, Cox multivariate modeling was performed to assess the impact of operative time without the confounding of known and unknown variables.

RESULTS

Of the 2,396 patients who met the criteria for review, the most important factors determining liver transplant graft survival included recipient history of Hepatitis C (hazard ratio 1.45, P = .02), donor age (hazard ratio 1.23, P = .03), use of liver graft from donation after cardiac death donor (hazard ratio 1.50, P < .01), and operative time (hazard ratio 1.26, P = .01). In detailed analysis of stages of the liver transplant operation, the time interval from incision to anhepatic phase was associated with graft survival (hazard ratio 1.33; P = .02).

CONCLUSION

Using a novel instrument variable approach, we demonstrate that operative time (in particular, the time interval from incision to anhepatic time) has a significant impact on graft survival. It also seems that some of this efficiency is under the influence of the transplant surgeon.

Microbial epidemiology and risk factors of infections in recipients after DCD liver transplantation

AIM

Infection is a major cause of increased mortality after a liver transplant (LT). This study sought to identify the incidence, prevalence and risk factors of microbial infection for recipients who underwent LT using grafts from donors after cardiac death (DCD).

METHODS

We retrospectively analysed the frequency and characteristics of post-transplantation infections in 236 recipients who underwent DCD LT between 1 January 2010 and 31 December 2014 in our centre and evaluated the risk factors of post-transplantation infection.

RESULTS

Overall, 162 recipients acquired at least one type of infection during hospitalisation after LT, and the morbidity rate was 68.6%. Moreover, 19 of the 236 recipients died, with an overall mortality rate of 8.1%. In total, 752 pathogens were isolated. Gram-positive bacteria, Gram-negative bacteria and fungi accounted for 26.1% (196), 58.2% (438) and 15.7% (118) of the pathogens, respectively. Kaplan-Meier curves of 1-year survival showed that recipients with infection had a significantly lower cumulative survival rate compared with those without infection (83.2% vs. 90.6%, p < 0.05). Multivariate analysis revealed that age > 60 years (p = 0.010) and severe hepatitis (p = 0.036) were independent risk factors for infection during hospitalisation after LT.

CONCLUSION

Infection is a common complication after a DCD-LT that could impair 1-year survival. We suggest physicians pay more attention to the infection of recipients post-LT, especially those recipients greater than 60 years of age and those who suffered from severe hepatitis.

Management of the Liver Transplant Recipient: Approach to Allograft Dysfunction

Liver transplant (LT) recipients are living longer than ever today and many will experience some form of allograft dysfunction. The common causes of allograft dysfunction vary significantly depending on the timing since LT. Most allograft abnormalities are manageable with minimally invasive procedures, medications, and lifestyle modification. The most common differential diagnoses by time period after LT, and diagnostic and management considerations, are highlighted. Collaboration and comanagement of LT recipients between primary care and the transplant hepatologist is essential for optimizing recipient and allograft outcomes.