Fungal infections after liver transplantation: outcomes and risk factors revisited in the MELD era

Single-center experience of antifungal prophylaxis for coccidioidomycosis in heart transplant recipients within an endemic area

In endemic regions, coccidioidomycosis causes substantial morbidity and mortality for patients receiving solid organ transplants. We aimed to demonstrate the effect of antifungal coccidioidal prophylaxis in heart transplant (HT) recipients. We retrospectively reviewed the electronic health records of all patients who received HTs between October 19, 2005, and December 13, 2014. We collected information regarding antifungal regimens and determined whether patients subsequently developed infections. Our 174-person cohort all received antifungal prophylaxis for at least 6 months (mean follow-up, 53.8 months). One proven and one probable coccidioidal infection (each, 0.6%) occurred during the study period. The incidence of coccidioidomycosis was 0.6% at 1 year and 2.3% at 5 years. No cases of proven coccidioidomycosis occurred within 2 years after transplantation. No patients developed disseminated disease, and no sentinel events were attributed to coccidioidomycosis. Both fluconazole and voriconazole were well tolerated. In the absence of intolerance or contraindication, we suggest continuing a universal antifungal prophylactic regimen with fluconazole for at least 6-12 months in HT recipients residing in a coccidioidomycosis-endemic area.

Detection of (1,3)-β-d-Glucan for the Diagnosis of Invasive Fungal Infection in Liver Transplant Recipients

Invasive fungal infections (IFI) are complications after liver transplantation involving high morbidity and mortality. (1,3)-β-d-glucan (BG) is a biomarker for IFI, but its utility remains uncertain. This study was designed to evaluate the impact of BG following their diagnosis. Between January 2013 and May 2016, 271 liver transplants were performed in our institution. Serum samples were tested for BG (Fungitell^®, Associates Cape Code Inc., Falmouth, MA, USA) at least weekly between liver transplantation and the discharge of patients. Nineteen patients (7%) were diagnosed with IFI, including 13 cases of invasive candidiasis (IC), eight cases of invasive pulmonary aspergillosis, and one case of septic arthritis due to Scedosporium apiospernum. Using a single BG sample for the primary analysis of IFI, 95% (21/22) of the subjects had positive BG (>80 pg/mL) at the time of IFI diagnosis. The area under the ROC curves to predict IFI was 0.78 (95% CI: 0.73–0.83). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of BG for IFI were 75% (95% CI: 65–83), 65% (62–68), 17% (13–21), and 96% (94–97), respectively. Based on their high NPV, the BG test appears to constitute a good biomarker to rule out a diagnosis of IFI.

Complications of invasive mycoses in organ transplant recipients

INTRODUCTION

Opportunistic mycoses remain a significant complication in organ recipients. Areas covered: This review is an evidence-based presentation of current state-of-knowledge and our perspective on recent developments in the field Expert commentary: Invasive fungal infections are associated with reduced allograft and patient survival, increase in healthcare resource utilization, and newly appreciated but largely unrecognized immunologic sequelae, such as immune reconstitution syndrome. Given adverse outcomes associated with established infections, prophylaxis is a widely used strategy for the prevention of these infections. Currently available biomarkers that detect circulating fungal cell wall constituents i.e., galactomannan and 1, 3-β-D-glucan have not proven to be beneficial as screening tools for employing targeted prophylaxis or as diagnostic assays in this patient population. However, subsets of patients at risk for opportunistic fungal infections can be identified based on clinically identifiable characteristics or events. Preventive strategies targeted towards these patients are a rational approach for optimizing outcomes.

Effect of Prophylactic Antifungal Protocols on the Prognosis of Liver Transplantation: A Propensity Score Matching and Multistate Model Approach

Background. Whether routine antifungal prophylaxis decreases posttransplantation fungal infections in patients receiving orthotopic liver transplantation (OLT) remains unclear. This study aimed to determine the effectiveness of antifungal prophylaxis for patients receiving OLT. Patients and Methods. This is a retrospective analysis of a database at Chang Gung Memorial Hospital. We have been administering routine antibiotic and prophylactic antifungal regimens to recipients with high model for end-stage liver disease scores (>20) since 2009. After propensity score matching, 402 patients were enrolled. We conducted a multistate model to analyze the cumulative hazards, probability of fungal infections, and risk factors. Results. The cumulative hazards and transition probability of “transplantation to fungal infection” were lower in the prophylaxis group. The incidence rate of fungal infection after OLT decreased from 18.9% to 11.4% (p = 0.052); overall mortality improved from 40.8% to 23.4% (p < 0.001). In the “transplantation to fungal infection” transition, prophylaxis was significantly associated with reduced hazards for fungal infection (hazard ratio: 0.57, 95% confidence interval: 0.34–0.96, p = 0.033). Massive ascites, cadaver transplantation, and older age were significantly associated with higher risks for mortality. Conclusion. Prophylactic antifungal regimens in high-risk recipients might decrease the incidence of posttransplant fungal infections.

Antifungal prophylaxis in liver transplant recipients: one size does not fit all

BACKGROUND

Targeted antifungal prophylaxis against Candida species or against Candida species and Aspergillus species, according to individual patient risk factors (RFs), is recommended by experts. However, recent studies have reported fluconazole is as effective as broader spectrum antifungals for preventing invasive fungal infection (IFI) after liver transplantation (LT).

METHODS

We performed a retrospective cohort study of all adult patients who underwent LT at our 1420-bed tertiary teaching hospital, from June 2010 to December 2014, to assess the rate and etiology of IFI within 100 days after LT, to investigate the compliance with targeted prophylaxis, and to analyze risk factors for developing IFI.

RESULTS

In total, 303 patients underwent LT. Patients were classified as having low (no RFs), intermediate (1 RF for invasive candidiasis [IC]), and high risk (1 RF for invasive aspergillosis [IA] or ≥2 RFs for IC) for IFI in 20%, 30%, and 50% of cases, respectively. A total of 139 patients received antifungal prophylaxis: 98 with a mold-active drug and 41 with fluconazole. Overall adherence to targeted prophylaxis was 53%. Nineteen patients (6.3%) developed IFI: 7 IC and 12 IA. Multivariate Cox regression analysis, adjusted for median model for end-stage liver disease score at LT, stratification risk group, and adherence to targeted prophylaxis, showed that graft dysfunction, renal replacement therapy, and prophylaxis with fluconazole were independent risk factors for IFI. Seven of the 9 patients who received fluconazole prophylaxis and developed IFI were classified as having high risk for IFI, and 6 developed IA.

CONCLUSION

Recommended stratification is accurate for predicting patients at very high risk for IFI, who should receive prophylaxis with a mold-active drug.

Efficacy and cost-effectiveness of voriconazole prophylaxis for prevention of invasive aspergillosis in high-risk liver transplant recipients

Aspergillus infection remains a significant and deadly complication after liver transplantation (LT). We sought to determine whether the antifungal prophylactic use of voriconazole reduces the incidence of invasive aspergillosis (IA) in high-risk LT recipients without prohibitively increasing cost. During the study era (April 2008 to April 2014), 339 deceased donor LTs were performed. Of those patients, 174 high-risk recipients were administered antifungal prophylaxis with voriconazole. The median biological Model for End-Stage Liver Disease score at the time of LT was 33 (range, 18-49) with 56% requiring continuous renal replacement therapy and 50% requiring ventilatory support immediately before transplantation. Diagnosis of IA was stratified as proven, probable, or possible according to previously published definitions. No IA was documented in patients receiving voriconazole prophylaxis. At 90 days after LT, the institutional cost of prophylaxis was $5324 or 5.6% of the predicted cost associated with post-LT aspergillosis. There was no documentation of resistant strains isolated from any recipient who received voriconazole. In conclusion, these data suggest that voriconazole prophylaxis is safe, clinically effective, and cost-effective in high-risk LT recipients.

Fungal infections after liver transplantation: incidence and outcome

BACKGROUND

Fungal infections, although less frequent than bacterial infections, represent a severe comorbidity with an exponential increase in mortality rate in liver transplantation patients. The incidence of invasive fungal infections (IFIs) after solid organ transplantation ranges from 7% to 42%, with Candida spp. and Aspergillus spp. as the most common pathogens. Fungal infections in liver transplant recipients have been associated with poor outcome and mortality rates ranging from 65% to 90% for invasive aspergillosis and 30% to 50% for invasive candidiasis. The results largely depend on early diagnosis and early initiation of specific treatment for IFIs. Therefore, the diagnosis must be prompt, preferably based on microbiological data, both cultures and biomarkers, and/or based on clinical features and known risk factors.

MATERIALS AND METHODS

This study evaluated the incidence of fungal infections in patients after liver transplantation in our center between January 2003 and December 2012. The retrospective analysis of 215 consecutive liver transplantation patients was undertaken to estimate incidence, risk factors, and clinical courses of IFIs in the first 3 months after liver transplantation.

RESULTS

Candidemia and invasive candidiasis microbiologically proven were found in 26 patients (12%), whereas in 6 patients (2.8%) invasive fungal infections from other non-Candida fungi developed: Aspergillus (4 cases: 2 A fumigatus, 2 A terreus), Fusarium oxysporum (1 case), and Rhodotorula rubra (1 case). Two patients with Aspergillus and the patient with Fusarium died. The patient with Rhodotorula as well as 22 of the patients with candidemia (85%) survived. All of the episodes developed during the first 3 months posttransplantation. All cases have followed a previous polymicrobial bacterial infection (especially in the biliary tract) with large use of combined antibiotic therapies.

CONCLUSIONS

The rate of fungal infection was found to increase in parallel with the number of risk factors. Prophylactic strategies can decrease the risk of fungal infections. Early detection and treatment with adequate early empiric therapy is the key to obtaining a better outcome in liver transplantation patients.

Prophylactic use of liposomal amphotericin B in preventing fungal infections early after liver transplantation: a retrospective, single-center study

In this study the authors evaluated the efficacy of prophylaxis with liposomal amphotericin B (L-AmB) in the incidence of fungal infections (FI) during the first 3 months after liver transplant (LT). The study was retrospective and accessed a 4-year period from 2008 to 2011. All patients who died in the first 48 hours after LT were excluded. Patients were divided by the risk groups for FI: Group 1, high-risk (at least 1 of the following conditions: urgent LT; serum creatinine >2 mg/dL; early acute kidney injury [AKI] after LT; retransplantation; surgical exploration early post-LT; transfused cellular blood components [>40 U]); and Group 2, low-risk patients. Group 1 patients were further separated into those who received antifungal prophylaxis with L-AmB and those who did not. Prophylaxis with L-AmB consisted of intravenous administration of L-AmB, 100 mg daily for 14 days. Four hundred ninety-two patients underwent LT; 31 died in the first 48 hours after LT. From the remaining 461 patients, 104 presented with high-risk factors for FI (Group 1); of these, 66 patients received antifungal prophylaxis and 38 did not. In this group 8 FI were observed, 5 in patients without antifungal prophylaxis (P = .011). Three more FI were identified in Group 2. By logistic regression analysis, the categorical variable high-risk group was independently related to the occurrence of invasive FI (P = .006). We conclude that prophylaxis with L-AmB after LT was effective in reducing the incidence of FI. No influence on mortality was detected.

Targeted versus universal antifungal prophylaxis among liver transplant recipients

Guidelines recommend targeted antifungal prophylaxis for liver transplant (LT) recipients based on tiers of risk, rather than universal prophylaxis. The feasibility and efficacy of tiered, targeted prophylaxis is not well established. We performed a retrospective study of LT recipients who received targeted prophylaxis (n = 145; voriconazole [VORI; 54%], fluconazole [8%], no antifungal [38%]) versus universal VORI prophylaxis (n = 237). Median durations of targeted and universal prophylaxis were 11 and 6 days, respectively (p < 0.0001). The incidence of invasive fungal infections (IFIs) in targeted and universal groups was 6.9% and 4.2% (p = 0.34). Overall, intra-abdominal candidiasis (73%) was the most common IFI. Posttransplant bile leaks (p = 0.001) and living donor transplants (p = 0.04) were independent risk factors for IFI. IFIs occurred in 6% of high-risk transplants who received prophylaxis and 4% of low-risk transplants who did not receive prophylaxis (p = 1.0). Mortality rates (100 days) were 10% (targeted) and 7% (universal) (p = 0.26); attributable mortality due to IFI was 10%. Compliance with prophylaxis recommendations was 97%. Prophylaxis was discontinued for toxicity in 2% of patients. Targeted antifungal prophylaxis in LT recipients was feasible and safe, effectively prevented IFIs and reduced the number of patients exposed to antifungals. Bile leaks and living donor transplants should be considered high-risk indications for prophylaxis.

Contribution of (1,3)-beta-D-glucan to diagnosis of invasive candidiasis after liver transplantation

Invasive candidiasis (IC) causes high morbidity and mortality rates after liver transplantation, in part due to delayed diagnosis. The fungal cell wall component (1,3)-beta-d-glucan (BG) could be an early biomarker of IC. This preliminary prospective study was designed to evaluate the contribution of BG measurements to the diagnosis of IC after liver transplantation. All consecutive patients who underwent liver transplantation at Henri Mondor Hospital in France between January and June 2013 were enrolled prospectively in the study. They were monitored weekly for colonization by Candida, and colonization index values were calculated. Serum samples were tested for BG (Fungitell; Cape Cod Inc.) at least weekly between liver transplantation and discharge from the hospital. A total of 52 patients (including 39 male patients) were enrolled, with a median age of 55 years (range, 31 to 69 years). The median Model for End-Stage Liver Disease (MELD) score was 27 (range, 6 to 40). Cultures from 42 patients (81%) yielded Candida spp., with the most common Candida species isolated being Candida glabrata (47%). Six cases of documented IC were found for four of the 52 patients. On the day the clinical diagnosis of IC was made, analysis based on combining two sequential BG-positive samples (>146 pg/ml) and a colonization index of ≥0.5 revealed sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) results of 83%, 89%, 50%, and 97.6%, respectively. The detection of BG associated with Candida colonization may be a promising tool based on a high NPV that can rule out IC among high-risk patients.

Randomized trial of micafungin for the prevention of invasive fungal infection in high-risk liver transplant recipients

In this randomized clinical trial comparing micafungin 100 mg with standard-care antifungal prophylaxis (fluconazole, liposomal amphotericin B, or caspofungin) in high-risk liver transplant patients, micafungin 100 mg was noninferior and had a better kidney safety profile.

Background. Invasive fungal infection (IFI) following liver transplant is associated with significant morbidity and mortality. Antifungal prophylaxis is rational for liver transplant patients at high IFI risk.

Methods. In this open-label, noninferiority study, patients were randomized 1:1 to receive intravenous micafungin 100 mg or center-specific standard care (fluconazole, liposomal amphotericin B, or caspofungin) posttransplant. The primary endpoint was clinical success (absence of a proven/probable IFI and no need for additional antifungals) at end of prophylaxis (EOP). Noninferiority (10% margin) of micafungin vs standard care was assessed in the per protocol and full analysis sets. Safety assessments included adverse events and liver and kidney function tests.

Results. The full analysis set comprised 344 patients (172 micafungin; 172 standard care). Mean age was 51.2 years; 48.0% had a Model for End-Stage Liver Disease score ≥20. At EOP (mean treatment duration, 17 days), clinical success was 98.6% for micafungin and 99.3% for standard care (Δ standard care – micafungin [95% confidence interval], 0.7% [−2.7% to 4.4%]) in the per protocol set and 96.5% and 93.6%, respectively (−2.9% [−8.0% to 1.9%]), in the full analysis set. Incidences of drug-related adverse events for micafungin and standard care were 11.6% and 16.3%, leading to discontinuation in 6.4% and 11.6% of cases, respectively. At EOP, liver function tests were similar but creatinine clearance was higher in micafungin- vs standard care–treated patients.

Conclusions. Micafungin was noninferior to standard care as antifungal prophylaxis in liver transplant patients at high risk for IFI. Adverse event profiles and liver function at EOP were similar, although kidney function was better with micafungin.

Clinical Trials Registration. NCT01058174.

Randomized, double-blind trial of anidulafungin versus fluconazole for prophylaxis of invasive fungal infections in high-risk liver transplant recipients

Invasive fungal infections (IFIs) are a common complication in liver transplant recipients. There are no previous randomized trials of an echinocandin for the prevention of IFIs in solid organ transplant recipients. In a randomized, double-blind trial conducted at University-affiliated transplant centers, 200 high-risk liver transplant recipients (100 patients per group) received either anidulafungin or fluconazole for antifungal prophylaxis. Randomization was stratified by Model for End-Stage Liver Disease score ≥30 and receipt of a pretransplant antifungal agent. The primary end point was IFI in a modified intent-to-treat analysis. The overall incidence of IFI was similar for the anidulafungin (5.1%) and the fluconazole groups (8.0%) (OR 0.61, 95% CI 0.19-1.94, p = 0.40). However, anidulafungin prophylaxis was associated with less Aspergillus colonization or infection (3% vs. 9%, p = 0.08), lower breakthrough IFIs among patients who had received pretransplant fluconazole (0% vs. 27%, p = 0.07), and fewer cases of antifungal resistance (no cases vs. 5 cases). Both drugs were well-tolerated. Graft rejection, fungal-free survival, and mortality were similar for both groups. Thus, anidulafungin and fluconazole have similar efficacy for antifungal prophylaxis in most liver transplant recipients. Anidulafungin may be beneficial if the patient has an increased risk for Aspergillus infection or received fluconazole before transplantation.

Infections after orthotopic liver transplantation

Opportunistic infections are a leading cause of morbidity and mortality after orthotopic liver transplantation. Systemic immunosuppression renders the liver recipient susceptible to de novo infection with bacteria, viruses and fungi post-transplantation as well to reactivation of pre-existing, latent disease. Pathogens are also transmissible via the donor organ. The time from transplantation and degree of immunosuppression may guide the differential diagnosis of potential infectious agents. However, typical systemic signs and symptoms of infection are often absent or blunted after transplant and a high index of suspicion is needed. Invasive procedures are often required to procure tissue for culture and guide antimicrobial therapy. Antimicrobial prophylaxis reduces the incidence of opportunistic infections and is routinely employed in the care of patients after liver transplant. In this review, we survey common bacterial, fungal, and viral infections after orthotopic liver transplantation and highlight recent developments in their diagnosis and management.

Impact of anti-thymocyte globulin during immunosuppression induction in patients with hepatitis C after liver transplantation

BACKGROUND

Induction immunosuppression with anti-thymocyte globulin (ATG) provides potential benefits after liver transplantation (LT). However, its use in patients with LT and hepatitis C (HCV) is controversial.

AIM

To evaluate the 1- and 2-year patient survival and HCV recurrence rate in patients receiving ATG during the induction phase of immunosuppression (IPI) after LT.

METHODS

A total of 49 patients undergoing their first LT for HCV were randomized to receive ATG during IPI. Patient survival and HCV recurrence were determined at 1 and 2 years. The frequency of acute cellular rejection (ACR), infections, and neoplasms was also evaluated.

RESULTS

Twenty-six patients were randomized to receive ATG (Arm-1) and 23 to standard induction therapy (Arm-2). Those given ATG had lower HCV recurrence (26.9 vs 73.9 %, p = 0.001). The 1- and 2-year patient survival rates were similar for both arms (p = 0.33). Infections occurred in 46.1 % subjects in Arm-1 and 34.7 % in Arm-2 (p = 0.562). There was a greater proportion of fungal infections in Arm-1 (19.2 vs 0 %, p = 0.032).

CONCLUSIONS

ATG during the IPI was associated with lower frequency of recurrence of HCV in patients undergoing LT. This, however, did not affect the 1- and 2-year survival and the frequency of ACR, infections, or neoplasms.

Genetic variants of innate immune receptors and infections after liver transplantation

Infection is the leading cause of complication after liver transplantation, causing morbidity and mortality in the first months after surgery. Allograft rejection is mediated through adaptive immunological responses, and thus immunosuppressive therapy is necessary after transplantation. In this setting, the presence of genetic variants of innate immunity receptors may increase the risk of post-transplant infection, in comparison with patients carrying wild-type alleles. Numerous studies have investigated the role of genetic variants of innate immune receptors and the risk of complication after liver transplantation, but their results are discordant. Toll-like receptors and mannose-binding lectin are arguably the most important studied molecules; however, many other receptors could increase the risk of infection after transplantation. In this article, we review the published studies analyzing the impact of genetic variants in the innate immune system on the development of infectious complications after liver transplantation.