Update in infectious diseases in liver transplant recipients

Ceftazidime-Avibactam as Salvage Treatment for Infections Due to Carbapenem-Resistant Klebsiella pneumoniae in Liver Transplantation Recipients

Background

Ceftazidime-avibactam (CZA) has been approved in vitro activity against carbapenem-resistant K. pneumoniae (CRKP), but the experience for the treatment of CRKP in liver transplantation (LT) recipients was limited, and previous data on its efficacy in this setting are lacking.

Methods

LT recipients with CRKP infection who received CZA treatment were reviewed retrospectively, microbiological and clinical response, adverse events were also assessed. The primary outcome was 30-day mortality after CZA administration.

Results

CZA was used in 21 LT recipients (including 4 pediatric patients) with CRKP infections after failure with other antimicrobials. CZA was administered as monotherapy in 4 patients. Median time from the onset of CRKP infection until the initiation of CZA treatment was 2 days (IQR, 1–6.5), and the median treatment duration was 12 days (IQR, 8.5–18.5). The mortality at 14 days, 30 days and all-cause was 28.6%, 38.1% and 42.9%, respectively. In adult patients, clinical response of 14 days and 30 days was 70.6% (12/17) and 58.8% (10/17), respectively, while in pediatric patients the 14-day and 30-day clinical response were both 75%, respectively. The relapse rate during the treatment developed in 3 patients after 30 days with the cessation of CZA monotherapy. CZA resistance was not detected in any case and 3 (3/21, 14.3%) patients developed acute kidney injury related to uncontrolled infection.

Conclusion

CZA shows promising results, even in monotherapy, for the treatment of patients with severe infections due to carbapenem-resistant K. pneumoniae among LT recipients. The emergence of resistance to CZA was not observed.

Evaluation of Cytomegalovirus Infections in Liver Transplant Recipients Under Universal Prophylaxis: A Single Centre Experience

Background: Cytomegalovirus (CMV) is one of the leading viral agents that can pave the way for serious complications and organ damage in solid organ transplant (SOT) recipients after transplantation. Strategies have been developed to protect at-risk patients from CMV infection following transplantation. Since more than 90% of adults in Turkey were positive for CMV IgG, universal CMV prophylaxis was applied, and the results were evaluated. Objectives: This study aimed to evaluate the results of universal CMV prophylaxis after liver transplantation in the long term. Methods: A total of 1,090 liver transplant patients were evaluated in terms of CMV infection in the Organ Transplantation Institute of Inonu University, Malatya, Turkey, from October 2014 to December 2019. In order to identify the CMV infections, quantitative nucleic acid amplification (QNAT) was used to detect potential CMV DNA. The cut-off value of CMV DNA was determined to be 1000 copies/mL after transplantation. Results: According to the clinical and laboratory assessments, 33 (3%) patients were diagnosed with CMV infection, and 25 (2.3%) patients were evaluated as possibly having CMV syndrome. Also, eight of the 33 patients were assessed as having end-organ CMV disease and 25 as probable CMV syndrome. In the late period following prophylaxis, CMV infection was observed in 10 (0.9%) cases. The infection rate after prophylaxis (0.9%) was lower than the infection rate (2.1%) seen during prophylaxis. Conclusions: Close clinical follow-up with CMV prophylaxis and strict monitoring of CMV DNA by determining a specific cut-off point are important in the follow-up of liver transplant patients.

High mortality associated with gram-negative bacterial bloodstream infection in liver transplant recipients undergoing immunosuppression reduction

BACKGROUND

Immunosuppression is an important factor in the incidence of infections in transplant recipient. Few studies are available on the management of immunosuppression (IS) treatment in the liver transplant (LT) recipients complicated with infection. The aim of this study is to describe our experience in the management of IS treatment during bacterial bloodstream infection (BSI) in LT recipients and assess the effect of temporary IS withdrawal on 30 d mortality of recipients presenting with severe infection.

AIM

To assess the effect of temporary IS withdrawal on 30 d mortality of LT recipients presenting with severe infection.

METHODS

A retrospective study was conducted with patients diagnosed with BSI after LT in the Department of Liver Surgery, Renji Hospital from January 1, 2016 through December 31, 2017. All recipients diagnosed with BSI after LT were included. Univariate and multivariate Cox regression analysis of risk factors for 30 d mortality was conducted in the LT recipients with Gram-negative bacterial (GNB) infection.

RESULTS

Seventy-four episodes of BSI were identified in 70 LT recipients, including 45 episodes of Gram-positive bacterial (GPB) infections in 42 patients and 29 episodes of GNB infections in 28 patients. Overall, IS reduction (at least 50% dose reduction or cessation of one or more immunosuppressive agent) was made in 28 (41.2%) cases, specifically, in 5 (11.9%) cases with GPB infections and 23 (82.1%) cases with GNB infections. The 180 d all-cause mortality rate was 18.5% (13/70). The mortality rate in GNB group (39.3%, 11/28) was significantly higher than that in GPB group (4.8%, 2/42) (P = 0.001). All the deaths in GNB group were attributed to worsening infection secondary to IS withdrawal, but the deaths in GPB group were all due to graft-versus-host disease. GNB group was associated with significantly higher incidence of intra-abdominal infection, IS reduction, and complete IS withdrawal than GPB group (P < 0.05). Cox regression showed that rejection (adjusted hazard ratio 7.021, P = 0.001) and complete IS withdrawal (adjusted hazard ratio 12.65, P = 0.019) were independent risk factors for 30 d mortality in patients with GNB infections after LT.

CONCLUSION

IS reduction is more frequently associated with GNB infection than GPB infection in LT recipients. Complete IS withdrawal should be cautious due to increased risk of mortality in LT recipients complicated with BSI.

IS

The Utilization and Diagnostic Yield of Upper Endoscopy for Evaluation of Gastrointestinal Symptoms Within the First Year After Liver Transplantation

Background Gastrointestinal (GI) symptoms impact quality of life and increase health care utilization after liver transplantation (LTx). Esophagogastroduodenoscopy (EGD) is commonly used to investigate these symptoms. Aims The aim of this study was to investigate the diagnostic yield and utilization of EGD after LTx for common GI symptoms. Methods This single-center retrospective cohort study was conducted at a large liver transplant center and included all adults who underwent EGD within the first year after receiving LTx between January 1, 2015, and December 31, 2016. Biliary procedures were excluded. Results Of 437 patients who underwent LTx during the study period, 64 (15%) underwent EGD for the evaluation of GI symptoms within the first year of transplantation. After applying exclusion criteria, 57 (13%) cases were analyzed. GI hemorrhage (hematemesis/melena) was the most common reason (4%; n=18) for evaluation with EGD followed by nausea/anorexia (3%; n=12). Symptoms were investigated with EGD, including epigastric/abdominal pain (2%; n=9), dysphagia/odynophagia (2%; n=8), anemia (1%; n=5), diarrhea (1%; n=4), and heartburn (0.2%; n=1). The diagnostic yield of EGD was highest with GI hemorrhage (83%) followed by dysphagia/odynophagia (75%). EGD diagnostic yield was lower for the other symptoms, ranging from 0% to 25%. Conclusions EGD was commonly utilized within the first year of LTx, with the highest diagnostic yields for GI hemorrhage and dysphagia/odynophagia. Because of the low diagnostic yield of EGD for other symptoms, we recommend a careful selection of patients for EGD following LTx.

Clinical Manifestation, Distribution, and Drug Resistance of Pathogens Among Abdominal Solid Organ Transplant Recipients With Klebsiella pneumoniae Infections

BACKGROUND

A Klebsiella pneumoniae infection is a life-threatening disease among abdominal solid organ transplant (ASOT) recipients. The objectives of our present work are to investigate the distribution and drug resistance of pathogens, and clinical manifestation among ASOT recipients suffering from K pneumoniae infections.

METHODS

The medical records of 53 ASOT recipients with 63 episodes of K pneumoniae infections from October 1, 2013 to June 1, 2019 were reviewed according to the Declaration of Helsinki and the Declaration of Istanbul. There were no grafts from prisoners used in these 53 patients and the donors were not coerced or paid. The distribution and drug resistance of each pathogen and clinical manifestation among ASOT recipients with K pneumoniae infections were retrospectively reviewed and summarized.

RESULTS

Prevalence and mortality of K pneumoniae infections among ASOT recipients were 4.5% and 32.1%, respectively. The origins of K pneumoniae infections were the blood (n = 21), deep wound and skin (n = 10), urinary tract (n = 9), abdomen (n = 6), and lung (n = 7). The numbers of organs from donors after cardiac death and living-related donors were 52 and 1, respectively. Twenty-nine patients had a serum creatinine level >1.5 mg/dL at the onset of K pneumoniae infections. Fifty-eight percent of K pneumoniae strains were carbapenem resistant. The resistance rate of K pneumoniae to 5 of 12 antibiotics investigated was more than 60%. The strains were relatively susceptible to meropenem, tigecycline, sulfamethoxazole, and amikacin; while there were distinctly increasing trends of resistance to meropenem and amikacin as time went on.

CONCLUSIONS

The clinical manifestation of K pneumoniae infections included elevated serum creatinine level, high carbapenem-resistant rate, and mortality. The drug-resistance rates of K pneumoniae to the most commonly used antibiotics were high with an increasing trend of resistance in recent years. Tigecycline, meropenem, sulfamethoxazole, and amikacin are recommended to treat K pneumoniae infections among ASOT recipients.

Multidrug-resistant Combined Infections in a Liver Transplanted Patient: Case Report

We report a case of successfully treated multiple liver abscesses in a liver-transplanted patient, sustained by combined multidrug-resistant infections. Two months after a liver transplant, a computed tomography scan revealed the presence of multiple abscesses in the liver graft. Blood cultures and abscessual liver fluid were both positive for acquired colistin- and carbapenem- resistant Klebsiella pneumoniae and an extended-spectrum of beta-lactamases-producing Enterobacter aerogenes. The treatment strategy consisted of different prolonged antimicrobial combinations and draining of the abscesses with complete recovery of the liver lesions.

Risk factors and outcomes of carbapenem-resistant Klebsiella pneumoniae infections in liver transplant recipients

Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection is increasing in incidence and is associated with increased mortality in liver transplantation (LT) recipients. We performed a retrospective cohort study of all patients transplanted between January 2010 and January 2013 to identify the incidence and risk factors for post-LT CRKP infection and evaluate the impact of this infection on outcomes in a CRKP-endemic area. We studied 304 recipients, of whom 20 (6.6%) developed CRKP and 36 (11.8%) carbapenem-susceptible Klebsiella pneumoniae (CSKP) infections in the year following LT. Among the 20 recipients with post-LT CRKP infection, 8 (40%) were infected in ≥ 2 sites; 13 (65%) had surgical site-intra-abdominal infections; 12 (60%) had pneumonia; and 3 (15%) had a urinary tract infection. There were 6 patients with a CRKP infection before LT, 5 of whom developed a CRKP infection after LT. Significant risk factors for post-LT CRKP infection in multivariate analysis included laboratory Model for End-Stage Liver Disease at LT (odds ratio [OR], 1.07; P = 0.001), hepatocellular carcinoma (OR, 3.19; P = 0.02), Roux-en-Y biliary choledochojejunostomy (OR, 3.15; P = 0.04), and bile leak (OR, 5.89; P = 0.001). One-year estimated patient survival was 55% (95% confidence interval, 31%-73%), 72% (55%-84%), and 93% (89%-96%), for patients with CRKP, CSKP, and no Klebsiella pneumoniae infection, respectively. In multivariate analysis, CRKP (hazard ratio [HR], 6.92; P < 0.001) and CSKP infections (CSKP, HR, 3.84; P < 0.001), as well as bile leak (HR, 2.10; P = 0.03) were the strongest predictors of post-LT mortality. In an endemic area, post-LT CRKP infection is common, occurring in 6.6% of recipients, and is strongly associated with post-LT mortality. Improved strategies for screening and prevention of CRKP infection are urgently needed.

Incidence and Risk Factors for Tuberculosis After Liver Transplantation in an Endemic Area: A Nationwide Population-Based Matched Cohort Study

Morbidity and mortality from tuberculosis (TB) are high in Taiwan. We conducted a nationwide population-based matched cohort study using data retrieved from the Taiwan's National Health Insurance Research Database to determine the impact of TB after liver transplantation (LT). During 2000-2011, we identified 3202 liver transplant recipients and selected subjects from the general population matched for age, sex, and comorbidities on the same index date of recognition of LT with a 1:10 ratio. The data were analyzed using Cox proportional hazards models. Compared to the matched cohort, liver transplant patients had a higher risk for TB (adjusted HR 2.25, 95% CI 1.65-3.05, p < 0.001), and those with TB showed higher mortality (HR 2.27, 95% CI 1.30-3.97, p = 0.004). Old age (HR 2.64, 95% CI 1.25-5.54, p = 0.011) and mammalian target of rapamycin inhibitors (mTORis) (HR 3.09, 95% CI 1.68-5.69, p < 0.001) were significant risk factors for TB in LT; mTORis were also associated with mortality after adjusting for confounders (HR 2.13, 95% CI 1.73-2.62, p < 0.001). Therefore, regular surveillance of TB and treatment of latent TB infection in high-risk patients after LT are important, especially in TB-endemic areas.

Management of infections pre- and post-liver transplantation: report of an AISF consensus conference

The burden of infectious diseases both before and after liver transplantation is clearly attributable to the dysfunction of defensive mechanisms of the host, both as a result of cirrhosis, as well as the use of immunosuppressive agents. The present document represents the recommendations of an expert panel commended by the Italian Association for the Study of the Liver (AISF), on the prevention and management of infectious complications excluding hepatitis B, D, C, and HIV in the setting of liver transplantation. Due to a decreased response to vaccinations in cirrhosis as well as within the first six months after transplantation, the best timing for immunization is likely before transplant and early in the course of disease. Before transplantation, a vaccination panel including inactivated as well as live attenuated vaccines is recommended, while oral polio vaccine, Calmette-Guerin's bacillus, and Smallpox are contraindicated, whereas after transplantation, live attenuated vaccines are contraindicated. Before transplant, screening protocols should be divided into different levels according to the likelihood of infection, in order to reduce costs for the National Health Service. Recommended preoperative and postoperative prophylaxis varies according to the pathologic agent to which it is directed (bacterial vs. viral vs. fungal). Timing after transplantation greatly determines the most likely agent involved in post-transplant infections, and specific high-risk categories of patients have been identified that warrant closer surveillance. Clearly, specifically targeted treatment protocols are needed upon diagnosis of infections in both the pre- as well as the post-transplant scenarios, not without considering local microbiology and resistance patterns.

Impacts of pretransplant infections on clinical outcomes of patients with acute-on-chronic liver failure who received living-donor liver transplantation

Background

Liver transplantation is the only therapeutic modality for patients with acute-on chronic liver failure (ACLF). These patients are at high risk for bacterial infections while awaiting transplantation. The aim of this study was to elucidate whether an adequately treated bacterial infection influences the outcomes after transplantation in this patient population.

Methodology/Principal Findings

54 recipients (median age, 49.5 years [range, 22–60]) of adult-to-adult living donor liver transplant (LDLT) for ACLF were categorized as those with pretransplant infection (Group 1, n = 34) or without pretransplant infection (Group 2, n = 20) for retrospective analyses. With the exception of a higher male-female ratio (P = 0.046) and longer length of pretransplant hospital stay (P = 0.026) in Group 1, similar demographic, laboratory and clinical features were found in both groups. Patients in Group 1 (totally 42 pretransplant infection episodes) were adequately treated with effective antibiotic(s) before receiving LDLT. All included patients were followed up until one year after transplantation or death. Sixty-one posttransplant infection episodes were found in an overall of 44 ACLF patients (27 in Group 1 vs. 15 in Group 2; P = 0.352). Frequently encountered posttransplant infections were intraabdominal infection, pneumonia, bloodstream infection and urinary tract infection. Two patients died in each group (P = 0.622). No significant difference was found in the length of posttransplant ICU stay, and in one-year survival, graft rejection, and posttransplant infection rate between both groups. The longer overall hospital stay (mean day, 89.0 vs. 65.5, P = 0.024) found in Group 1 resulted from a longer pretransplant hospital stay receiving treatment for pretransplant infection(s) and/or awaiting transplantation.

Conclusions

These data suggested that an adequately treated pretransplant infection do not pose a significant risk for clinical outcomes including posttransplant fatality in recipients in adult-to-adult LDLT for ACLF.

Cytomegalovirus infection: its incidence and management in cytomegalovirus-seropositive living related liver transplant recipients: a single-center experience

It is believed that antiviral prophylaxis decreases the incidence of cytomegalovirus (CMV) reactivation and disease. There are few data regarding weekly assays for CMV DNA after transplantation and the subsequent management of CMV. Here we report a cohort of living related liver transplantation (LRLT) patients who were treated for invasive CMV disease or for CMV infections if they were receiving steroids for rejection. Patients who underwent liver transplantation at our center between September 2006 and August 2010 and were recipient-positive/donor-positive (R(+) /D(+) ) were prospectively included. Patients were tested for CMV DNA 3 weeks after transplantation. CMV DNA-positive patients underwent weekly DNA monitoring until there were 2 consecutive negative reports. Those who developed CMV disease or had rising DNA titers while they were on treatment for rejection were treated. A Cox regression analysis was performed for factors predicting survival. Two hundred sixty-six of the 306 R(+) /D(+) patients were CMV DNA-negative 3 weeks after transplantation, and 40 had detectable DNA. One of the DNA-negative patients developed CMV disease after treatment for rejection with methylprednisolone. Thirty patients had <500 copies/mL, and 10 had ≥500 copies/mL. Two of the 30 patients with DNA levels < 500 copies/mL developed CMV disease. Six of the 10 patients with DNA levels ≥500 copies/mL developed disease. CMV disease occurred in 9 of the 306 patients (2.9%). One patient received treatment for a rise in DNA titers while he was receiving steroids. There was a significant correlation between steroid administration for acute cellular rejection (ACR) and CMV reactivation (P = 0.003) and disease (P = 0.002). A multivariate analysis showed that CMV reactivation/disease did not predict survival. There was no difference in survival between CMV DNA-positive patients and CMV DNA-negative patients (P = 0.68). In conclusion, CMV reactivation is common after LRLT (13%), but the disease is rare (2.9%) without prophylaxis in CMV immunoglobulin G-positive recipients. The administration of steroids for ACR strongly correlates with CMV reactivation and disease. CMV reactivation and disease did not affect survival in our patient cohort.

Mortality associated with carbapenem-resistant Klebsiella pneumoniae infections in liver transplant recipients

Resistant bacterial infections are important causes of morbidity and mortality after liver transplantation (LT). This was a retrospective cohort study evaluating the outcomes associated with carbapenem-resistant Klebsiella pneumoniae (CRKP) infections after LT. In a 2005-2006 cohort of 175 consecutive LT recipients, 91 infection episodes were observed in 61 patients (35%). The mortality rate 1 year after LT was 18% (32/175). Enterococcus (43%) and Klebsiella species (37%) were the most frequently isolated bacteria. CRKP infections occurred in 14 patients, and 10 of these patients (71%) died. Seven of these deaths occurred within 30 days of the CRKP infection. The median time to the onset of CRKP infections was 12 days (range = 1-126 days) after LT. The survival rate was significantly lower for patients with a CRKP infection versus patients without a CRKP infection (29% versus 86%, log-rank P < 0.001). In a multivariate analysis, the only pre-LT and post-LT clinical variables significantly associated with death were a Model for End-Stage Liver Disease score ≥ 30 (hazard ratio = 3.4, P = 0.04) and a post-LT CRKP infection (hazard ratio = 4.9, P = 0.007). In conclusion, the outcomes associated with CRKP infections in LT recipients are poor. Because the optimal treatment strategies for CRKP infections remain undefined, improved preventive strategies are needed to curtail the devastating impact of CRKP in LT recipients.