Safety of Inhaled Amphotericin B Lipid Complex as Antifungal Prophylaxis in Lung Transplant Recipients

Clinical Significance and Therapeutic Challenges of Scedosporium spp. and Lomentospora prolificans Isolates in a Single-Center Cohort of Lung Transplant Recipients

(1) Background: Emerging fungal infections associated with Scedosporium spp. and Lomentospora prolificans (S/L) are becoming more frequent and are very difficult to treat. Our objective was to analyze the frequency and management of S/L isolates in lung transplant (LTx) recipients, the patient outcomes and in vitro antifungal sensitivity. (2) Methods: We included all patients with S/L isolation during post-transplant follow-up. Data were collected from electronic medical records. All samples were cultivated on Sabouraud Chloramphenicol agar. Isolations of S/L were submitted to in vitro susceptibility tests. (3) Results: A total of 11 (2%) of the 576 LTx recipients included had at least one isolation of S/L. Classification for the 11 cases were colonization (4; 36%) and infection (7; 65%). Five infections were pulmonary (71%) and two were disseminated (29%). S. apiospermum complex was the most frequently occurring isolation in patients with pulmonary disease while L. prolificans was the most frequent in patients with disseminated disease. Ten patients were treated. The most frequent antifungal drugs used were voriconazole (n = 8) and terbinafine (n = 6). Seven patients (70%) received more than one drug. The mortality rate associated with L. prolificans isolation was 50% for colonization and 100% for disseminated disease. (4) Conclusions: Scedosporium spp. and L. prolificans infections are associated with high morbidity and mortality rates. New diagnostic and therapeutic tools are required to reduce the impact of these infections.

New and emerging roles for inhalational and direct antifungal drug delivery approaches for treatment of invasive fungal infections

INTRODUCTION

The rising prevalence of difficult-to-treat, deep-seated invasive fungal diseases (IFD) has led to high mortality. Currently available antifungal treatments, administered predominantly orally or intravenously, may not sufficiently penetrate certain body sites, and/or are associated with systemic toxicity. Little is known about how to position alternative administration approaches such as inhalational and direct drug delivery routes.

AREAS COVERED

This review provides an updated overview of unconventional drug delivery strategies for managing IFD, focusing on inhalational (to target the lungs) and direct delivery methods to the central nervous system, bone/joint, and eyes. Novel compounds (e.g. opelconazole) and existing antifungals with innovative drug delivery systems currently undergoing clinical trials and/or used off-label in the clinical setting are discussed.

EXPERT OPINION

For both inhalational agents and direct delivery approaches, there are similar challenges that include the absence of: approved formulations for specific administration routes, delivery vehicles that are simple and safe to use whilst maintaining potency and efficiency of delivery, animal models suitable for investigating pharmacokinetic/pharmacodynamic profiles of inhaled antifungals, and consensus on the composite endpoints and intervals for of follow-up in clinical trials. To meet these challenges, cooperation of all stakeholders in drug development and regulation is required.

Pneumonia in Transplant Recipients: A Comprehensive Review of Diagnosis and Management

Transplant recipients have an increased risk of complications, including graft dysfunction and infections, which can be life-threatening if not recognized early. Pneumonia ranks as one of the most frequent complications in both solid organ and hematopoietic stem cell transplants. Clinical symptoms manifest late during infections in immunocompromised patients. An aggressive approach centered on early confirmatory diagnosis and a low threshold for empiric therapy is often the most effective strategy. The isolation of a pathogen in an upper airway sample does not necessarily mean the same organism is responsible for pneumonia. Viruses such as CMV (cytomegalovirus virus) may function as co-pathogens for opportunistic infections in transplant recipients in addition to causing their own primary infectious syndrome. Furthermore, some viruses exhibit immunomodulatory effects that can affect the graft function. Given the exhaustive list of causative pathogens responsible for pneumonia, the best approach to the diagnosis is to have a conceptual framework that includes a detailed history, such as the type of transplant, degree of immunosuppression, antimicrobial prophylaxis, risk factors, time of presentation since transplantation and the radiographic pattern on the CT chest (computer tomography of the chest). Management depends predominantly on the degree of antimicrobial resistance, drug-to-drug interaction, and adjustments to the immunosuppression.

Risk Factors for Invasive Fungal Infection in Lung Transplant Recipients on Universal Antifungal Prophylaxis

Background

Many centers use universal antifungal prophylaxis after lung transplant, but risk factors for invasive fungal infection (IFI) in this setting are poorly described.

Methods

This retrospective, single-center cohort study including 603 lung transplant recipients assessed risk factors for early (within 90 days of transplant) invasive candidiasis (IC) and invasive mold infection (IMI) and late (90-365 days after transplant) IMI using Cox proportional hazard regression.

Results

In this cohort, 159 (26.4%) patients had 182 IFIs. Growth of yeast on donor culture (hazard ratio [HR], 3.30; 95% CI, 1.89-5.75) and prolonged length of stay (HR, 1.02; 95% CI, 1.01-1.03) were associated with early IC risk, whereas transplantation in 2016 or 2017 (HR, 0.21; 95% CI, 0.06-0.70; HR, 0.25; 95% CI, 0.08-0.80, respectively) and female recipient sex (HR, 0.53; 95% CI, 0.30-0.93) were associated with reduced risk. Antimold therapy (HR, 0.21; 95% CI, 0.06-0.78) was associated with lower early IMI risk, and female donor sex (HR, 0.40; 95% CI, 0.22-0.72) was associated with lower late IMI risk. Recent rejection was a risk factor for late IMI (HR, 1.73; 95% CI, 1.02-2.95), and renal replacement therapy predisposed to early IC, early IMI, and late IMI (HR, 5.67; 95% CI, 3.01-10.67; HR, 7.54; 95% CI, 1.93-29.45; HR, 5.33; 95% CI, 1.46-19.49, respectively).

Conclusions

In lung transplant recipients receiving universal antifungal prophylaxis, risk factors for early IC, early IMI, and late IMI differ.

Fungal Infections and Colonization after Bilateral Lung Transplant: A Six-Year Single-Center Experience

Fungal infections (FIs) are one of the leading causes of morbidity and mortality within the first year of lung transplant (LT) in LT recipients (LTRs). Their prompt identification and treatment are crucial for a favorable LTR outcome. The objectives of our study were to assess (i) the FI incidence and colonization during the first year after a bilateral LT, (ii) the risk factors associated with FI and colonization, and (iii) the differences in fungal incidence according to the different prophylactic strategies. All bilateral LTRs admitted to the intensive care unit of Padua University Hospital were retrospectively screened, excluding patients <18 years of age, those who had been re-transplanted, and those who had received ventilation and/or extracorporeal membrane oxygenation before LT. Overall, 157 patients were included. A total of 13 (8%) patients developed FI, and 36 (23%) developed colonization, which was mostly due to Aspergillus spp. We did not identify independent risk factors for FI. Groups of patients receiving different prophylactic strategies reported a similar incidence of both FI and colonization. The incidence of FI and fungal colonization was 8% and 23%, respectively, with no differences between different antifungal prophylaxes or identified predisposing factors. Further studies with larger numbers are needed to confirm our results.

Antifungal prophylaxis with nebulized amphotericin-B in solid-organ transplant recipients with severe COVID-19: a retrospective observational study

COVID-19-associated pulmonary aspergillosis (CAPA) has emerged as a frequent complication in the intensive care unit (ICU). However, little is known about this life-threatening fungal superinfection in solid organ transplant recipients (SOTRs), including whether targeted anti-mold prophylaxis might be justified in this immunosuppressed population. We performed a multicentric observational retrospective study of all consecutive ICU-admitted COVID-19 SOTRs between August 1, 2020 and December 31, 2021. SOTRs receiving antifungal prophylaxis with nebulized amphotericin-B were compared with those without prophylaxis. CAPA was defined according the ECMM/ISHAM criteria. Sixty-four SOTRs were admitted to ICU for COVID-19 during the study period. One patient received antifungal prophylaxis with isavuconazole and was excluded from the analysis. Of the remaining 63 SOTRs, nineteen (30.2%) received anti-mold prophylaxis with nebulized amphotericin-B. Ten SOTRs who did not receive prophylaxis developed pulmonary mold infections (nine CAPA and one mucormycosis) compared with one who received nebulized amphotericin-B (22.7% vs 5.3%; risk ratio 0.23; 95%CI 0.032-1.68), but with no differences in survival. No severe adverse events related to nebulized amphotericin-B were recorded. SOTRs admitted to ICU with COVID-19 are at high risk for CAPA. However, nebulized amphotericin-B is safe and might reduce the incidence of CAPA in this high-risk population. A randomized clinical trial to confirm these findings is warranted.

Diagnosis and Antifungal Prophylaxis for COVID-19 Associated Pulmonary Aspergillosis

The COVID-19 pandemic has redemonstrated the importance of the fungal-after-viral phenomenon, and the question of whether prophylaxis should be used to prevent COVID-19-associated pulmonary aspergillosis (CAPA). A distinct pathophysiology from invasive pulmonary aspergillosis (IPA), CAPA has an incidence that ranges from 5% to 30%, with significant mortality. The aim of this work was to describe the current diagnostic landscape of CAPA and review the existing literature on antifungal prophylaxis. A variety of definitions for CAPA have been described in the literature and the performance of the diagnostic tests for CAPA is limited, making diagnosis a challenge. There are only six studies that have investigated antifungal prophylaxis for CAPA. The two studied drugs have been posaconazole, either a liquid formulation via an oral gastric tube or an intravenous formulation, and inhaled amphotericin. While some studies have revealed promising results, they are limited by small sample sizes and bias inherent to retrospective studies. Additionally, as the COVID-19 pandemic changes and we see fewer intubated and critically ill patients, it will be more important to recognize these fungal-after-viral complications among non-critically ill, immunocompromised patients. Randomized controlled trials are needed to better understand the role of antifungal prophylaxis.