Aspergillus fumigatus and aspergillosis: From basics to clinics

The current state of laboratory mycology and access to antifungal treatment in Europe: a European Confederation of Medical Mycology survey

Access to the appropriate tools is crucial for early diagnosis and clinical management of invasive fungal infections. This Review aims to describe the invasive fungal infection diagnostic capacity of Europe to better understand the status and the most pressing aspects that need improvement. To our knowledge, this is the first time that the mycological diagnostic capability and access to antifungal treatments of institutions has been evaluated at a pan-European level. Between Nov 1, 2021, and Jan 31, 2022, 388 institutions in Europe self-assessed their invasive fungal infection management capability. Of the 388 participating institutions from 45 countries, 383 (99%) had access to cultures, 375 (97%) to microscopy, 363 (94%) to antigen-detection assays, 329 (85%) to molecular tests (mostly PCR), and 324 (84%) to antibody tests for diagnosis and management. With the exception of microscopy, there were considerable differences in access to techniques among countries according to their gross domestic product. At least one triazole was available in 363 (94%) of the institutions, one echinocandin in 346 (89%), and liposomal amphotericin B in 301 (78%), with country gross domestic product-based differences. Differences were also observed in the access to therapeutic drug monitoring. Although Europe is well prepared to manage invasive fungal infections, some institutions do not have access to certain diagnostic tools and antifungal drugs, despite most being considered essential by WHO. These limitations need to be overcome to ensure that all patients receive the best diagnostic and therapeutic management.

A Laboratory-Based Study on Multiple Biomarker Testing in the Diagnosis of COVID-19-Associated Pulmonary Aspergillosis (CAPA): Real-Life Data

(1) Background: Coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) raises concerns to contribute to an increased mortality. The incidence of CAPA varies widely within hospitals and countries, partly because of difficulties in obtaining a reliable diagnosis. (2) Methods: Here, we assessed Aspergillus culture-positive and culture-negative respiratory tract specimens via direct fungal microscopy (gold standard) and compared the results with galactomannan enzyme immunoassay (GM-EIA) and Aspergillus PCR. (3) Results: 241 respiratory samples from patients suffering from SARS-CoV-2 pneumonia were evaluated. Results showed both diagnostic tools, Aspergillus PCR and GM-EIA, to be positive or negative displaying a sensitivity of 0.90, a specificity of 0.77, a negative predictive value (NPV) of 0.95, and a positive predictive value (PPV) of 0.58 in Aspergillus sp. culture and microscopic-positive specimens. Non-bronchoalveolar lavage (BAL) samples, obtained within a few days from the same patient, showed a high frequency of intermittent positive or negative GM-EIA or Aspergillus PCR results. Positivity of a single biomarker is insufficient for a proper diagnosis. A broad spectrum of Aspergillus species was detected. (4) Conclusions: Our study highlights the challenges of combined biomarker testing as part of diagnosing CAPA. From the results presented, we highly recommend the additional performance of direct microscopy in respiratory specimens to avoid overestimation of fungal infections by applying biomarkers.

Genomic and Phenotypic Trait Variation of the Opportunistic Human Pathogen Aspergillus flavus and Its Close Relatives

Fungal diseases affect millions of humans annually, yet fungal pathogens remain understudied. The mold Aspergillus flavus can cause both aspergillosis and fungal keratitis infections, but closely related species are not considered clinically relevant. To study the evolution of A. flavus pathogenicity, we examined genomic and phenotypic traits of two strains of A. flavus and three closely related species, Aspergillus arachidicola (two strains), Aspergillus parasiticus (two strains), and Aspergillus nomiae (one strain). We identified >3,000 orthologous proteins unique to A. flavus, including seven biosynthetic gene clusters present in A. flavus strains and absent in the three nonpathogens. We characterized secondary metabolite production for all seven strains under two clinically relevant conditions, temperature and salt concentration. Temperature impacted metabolite production in all species, whereas salinity did not affect production of any species. Strains of the same species produced different metabolites. Growth under stress conditions revealed additional heterogeneity within species. Using the invertebrate fungal disease model Galleria mellonella, we found virulence of strains of the same species varied widely; A. flavus strains were not more virulent than strains of the nonpathogens. In a murine model of fungal keratitis, we observed significantly lower disease severity and corneal thickness for A. arachidicola compared to other species at 48 h postinfection, but not at 72 h. Our work identifies variations in key phenotypic, chemical, and genomic attributes between A. flavus and its nonpathogenic relatives and reveals extensive strain heterogeneity in virulence that does not correspond to the currently established clinical relevance of these species. IMPORTANCE Aspergillus flavus is a filamentous fungus that causes opportunistic human infections, such as aspergillosis and fungal keratitis, but its close relatives are considered nonpathogenic. To begin understanding how this difference in pathogenicity evolved, we characterized variation in infection-relevant genomic, chemical, and phenotypic traits between strains of A. flavus and its relatives. We found extensive variation (or strain heterogeneity) within the pathogenic A. flavus as well as within its close relatives, suggesting that strain-level differences may play a major role in the ability of these fungi to cause disease. Surprisingly, we also found that the virulence of strains from species not considered to be pathogens was similar to that of A. flavus in both invertebrate and murine models of disease. These results contrast with previous studies on Aspergillus fumigatus, another major pathogen in the genus, for which significant differences in infection-relevant chemical and phenotypic traits are observed between closely related pathogenic and nonpathogenic species.

Triazole-resistant Aspergillus luchuensis, an industrially important black Aspergillus spp. used in fermentation in East Asia, isolated from the patient with invasive pulmonary aspergillosis in China

Aspergillus luchuensis, an industrially important member of Aspergillus species belonging to section Nigri used in fermentation in East Asia, was isolated from an immunocompromised patient with probable invasive pulmonary aspergillosis who failed voriconazole therapy in China. This isolate showed non-wild-type susceptibility to itraconazole, voriconazole, isavuconazole, and posaconazole. A G1378A mutation in cyp51A, resulting in the G441S amino acid substitution, which is the homolog to G448S conferring triazole-resistance in A. fumigatus, was detected in the A. luchuensis isolate.

Liposomal amphotericin B—the future

Advances in medicine have led to a growing number of people with compromised or suppressed immune systems who are susceptible to invasive fungal infections. In particular, severe fungal infections are becoming increasingly common in ICUs, affecting people within and outside of traditional risk groups alike. This is exemplified by the emergence of severe viral pneumonia as a significant risk factor for invasive pulmonary aspergillosis, and the recognition of influenza-associated pulmonary aspergillosis and, more recently, COVID-19-associated pulmonary aspergillosis.

The treatment landscape for haematological malignancies has changed considerably in recent years, and some recently introduced targeted agents, such as ibrutinib, are increasing the risk of invasive fungal infections. Consideration must also be given to the risk of drug–drug interactions between mould-active azoles and small-molecule kinase inhibitors.

At the same time, infections caused by rare moulds and yeasts are increasing, and diagnosis continues to be challenging. There is growing concern about azole resistance among both moulds and yeasts, mandating continuous surveillance and personalized treatment strategies.

It is anticipated that the epidemiology of fungal infections will continue to change and that new populations will be at risk. Early diagnosis and appropriate treatment remain the most important predictors of survival, and broad-spectrum antifungal agents will become increasingly important. Liposomal amphotericin B will remain an essential therapeutic agent in the armamentarium needed to manage future challenges, given its broad antifungal spectrum, low level of acquired resistance and limited potential for drug–drug interactions.

Mnt1, an α-(1 → 2)-mannosyltransferase responsible for the elongation of N-glycans and O-glycans in Aspergillus fumigatus

The fungal cell wall is necessary for survival as it serves a barrier for physical protection. Therefore, glycosyltransferases responsible for the synthesis of cell wall polysaccharides may be suitable targets for drug development. Mannose is a monosaccharide that is commonly found in sugar chains in the walls of fungi. Mannose residues are present in fungal-type galactomannan, O-glycans, N-glycans, glycosylphosphatidylinositol anchors, and glycosyl inositol phosphorylceramides in Aspergillus fumigatus. Three genes that are homologous to α-(1 → 2)-mannosyltransferase genes and belong to the glycosyltransferase family 15 were found in the A. fumigatus strain, Af293/A1163, genome: cmsA/ktr4, cmsB/ktr7, and mnt1. It is reported that the mutant ∆mnt1 strain exhibited a wide range of properties that included high temperature and drug sensitivity, reduced conidia formation, leakage at the hyphal tips, and attenuation of virulence. However, it is unclear whether Mnt1 is a bona fide α-(1 → 2)-mannosyltransferase and which mannose residues are synthesized by Mnt1 in vivo. In this study, we elucidated the structure of the Mnt1 reaction product, the structure of O-glycan in the Δmnt1 strain. In addition, the length of N-glycans attached to invertase was evaluated in the Δmnt1 strain. The results indicated that Mnt1 functioned as an α-(1 → 2)-mannosyltransferase involved in the elongation of N-glycans and synthesis of the second mannose residue of O-glycans. The widespread abnormal phenotype caused by the disruption of the mnt1 gene is the combined result of the loss of mannose residues from O-glycans and N-glycans. We also clarified the enzymatic properties and substrate specificity of Mnt1 based on its predicted protein structure.

Uptake of the Siderophore Triacetylfusarinine C, but Not Fusarinine C, Is Crucial for Virulence of Aspergillus fumigatus

Siderophores play an important role in fungal virulence, serving as trackers for in vivo imaging and as biomarkers of fungal infections. However, siderophore uptake is only partially characterized. As the major cause of aspergillosis, Aspergillus fumigatus is one of the most common airborne fungal pathogens of humans. Here, we demonstrate that this mold species mediates the uptake of iron chelated by the secreted siderophores triacetylfusarinine C (TAFC) and fusarinine C by the major facilitator-type transporters MirB and MirD, respectively. In a murine aspergillosis model, MirB but not MirD was found to be crucial for virulence, indicating that TAFC-mediated uptake plays a dominant role during infection. In the absence of MirB, TAFC becomes inhibitory by decreasing iron availability because the mutant is not able to recognize iron that is chelated by TAFC. MirB-mediated transport was found to tolerate the conjugation of fluorescein isothiocyanate to triacetylfusarinine C, which might aid in the development of siderophore-based antifungals in a Trojan horse approach, particularly as the role of MirB in pathogenicity restrains its mutational inactivation. Taken together, this study identified the first eukaryotic siderophore transporter that is crucial for virulence and elucidated its translational potential as well as its evolutionary conservation. IMPORTANCE Aspergillus fumigatus is responsible for thousands of cases of invasive fungal disease annually. For iron uptake, A. fumigatus secretes so-called siderophores, which are taken up after the binding of environmental iron. Moreover, A. fumigatus can utilize siderophore types that are produced by other fungi or bacteria. Fungal siderophores raised considerable interest due to their role in virulence and their potential for the diagnosis and treatment of fungal infections. Here, we demonstrate that the siderophore transporter MirB is crucial for the virulence of A. fumigatus, which reveals that its substrate, triacetylfusarinine C, is the most important siderophore during infection. We found that in the absence of MirB, TAFC becomes inhibitory by decreasing the availability of environmental iron and that MirB-mediated transport tolerates the derivatization of its substrate, which might aid in the development of siderophore-based antifungals. This study significantly improved the understanding of fungal iron homeostasis and the role of siderophores in interactions with the host.

Quantitative PCR Effectively Quantifies Triazole-Susceptible and Triazole-Resistant Aspergillus fumigatus in Mixed Infections

Increasing resistance to triazole antifungals in Aspergillus fumigatus is worrisome because of the associated high mortality of triazole-resistant A. fumigatus (TRAF) infections. While most studies have focused on single triazole-susceptible (WT) or TRAF infections, reports of TRAF cases developing mixed WT and TRAF infections have been described in several studies. However, the prevalence of mixed infections and their responses to current recommended therapies are unknown and could be inappropriate, leading to poor clinical outcomes. To address the urgent need for tools to diagnose, monitor disease development and therapy efficacies in mixed infection settings where quantification of WT versus TRAF is key, this study developed a novel qPCR assay to differentiate WT and TRAF harboring the cyp51A-TR34/L98H mutation. The proposed assay successfully quantified A. fumigatus and discriminated TRAF-TR34 in vitro and in vivo, which was achieved by increasing the yield of extracted DNA through improved homogenization and specific primers targeting the WT-sequence or TR34-insertion and a TaqMan-probe directed to A. fumigatus. The here-developed qPCR assay overcomes sensitivity issues of methodologies such as CFU counts, providing specific, reproducible, and reliable quantitative information to study and follow up the (interplay and individual) effects of mixed A. fumigatus infections on disease development and treatment responses.

Hypoxia inducible-factor 1 alpha regulates neutrophil recruitment during fungal-elicited granulomatous inflammation

Chronic pulmonary aspergillosis (CPA) is a devastating disease with increasing prevalence worldwide. The characteristic granulomatous-like inflammation poses as the major setback to effective antifungal therapies by limiting drug access to fungi. These inflammatory lung structures are reported to be severely hypoxic; nevertheless, the underlying mechanisms whereby these processes contribute to fungal persistence remain largely unknown. Hypoxia-inducible factor 1 alpha (HIF-1α), besides being the major cellular response regulator to hypoxia, is a known central immune modulator. Here, we used a model of Aspergillus fumigatus airway infection in myeloid-restricted HIF-1α knock-out (mHif1α^-/-) mice to replicate the complex structures resembling fungal granulomas and evaluate the contribution of HIF-1α to antifungal immunity and disease development. We found that fungal-elicited granulomas in mHif1α^-/- mice had significantly smaller areas, along with extensive hyphal growth and increased lung fungal burden. This phenotype was associated with defective neutrophil recruitment and an increased neutrophil death, therefore highlighting a central role for HIF-1α-mediated regulation of neutrophil function in the pathogenesis of chronic fungal infection. These results hold the promise of an improved capacity to manage the progression of chronic fungal disease and open new avenues for additional therapeutic targets and niches of intervention.

CAR T cells targeting Aspergillus fumigatus are effective at treating invasive pulmonary aspergillosis in preclinical models

Aspergillus fumigatus is a ubiquitous mold that can cause severe infections in immunocompromised patients, typically manifesting as invasive pulmonary aspergillosis (IPA). Adaptive and innate immune cells that respond to A. fumigatus are present in the endogenous repertoire of patients with IPA but are infrequent and cannot be consistently isolated and expanded for adoptive immunotherapy. Therefore, we gene-engineered A. fumigatus-specific chimeric antigen receptor (Af-CAR) T cells and demonstrate their ability to confer antifungal reactivity in preclinical models in vitro and in vivo. We generated a CAR targeting domain AB90-E8 that recognizes a conserved protein antigen in the cell wall of A. fumigatus hyphae. T cells expressing the Af-CAR recognized A. fumigatus strains and clinical isolates and exerted a direct antifungal effect against A. fumigatus hyphae. In particular, CD8⁺ Af-CAR T cells released perforin and granzyme B and damaged A. fumigatus hyphae. CD8⁺ and CD4⁺ Af-CAR T cells produced cytokines that activated macrophages to potentiate the antifungal effect. In an in vivo model of IPA in immunodeficient mice, CD8⁺ Af-CAR T cells localized to the site of infection, engaged innate immune cells, and reduced fungal burden in the lung. Adoptive transfer of CD8⁺ Af-CAR T cells conferred greater antifungal efficacy compared to CD4⁺ Af-CAR T cells and an improvement in overall survival. Together, our study illustrates the potential of gene-engineered T cells to treat aggressive infectious diseases that are difficult to control with conventional antimicrobial therapy and support the clinical development of Af-CAR T cell therapy to treat IPA.

Central Sugar Metabolism and the Cell Wall

The human opportunistic pathogen Aspergillus fumigatus is recognized for its versatile cell wall when it comes to remodeling its components in adaptation to external threats, and this remodeling renders it refractory to antifungals targeting cell wall biosynthesis. A specific role for general sugar metabolism in the regulation of the synthesis of cell wall polymers has been previously demonstrated. Delving deeper into central sugar metabolism may reveal unexpected fundamental aspects in cell wall construction, as shown by the work of Zhou and coworkers (Y. Zhou, K. Yan, Q. Qin, O.G. Raimi, et al., mBio 13:e01426-22, 2022, https://doi.org/10.1128/mbio.01426-22) on the roles of the phosphoglucose isomerase of A. fumigatus in cell wall biosynthesis.

Treatment of a descending thoracic mycotic aneurysm secondary to disseminated aspergillosis infection with thoracic endovascular aortic repair

Mycotic aortic aneurysms are a rare and potentially fatal aortic pathology. Advancements in vascular technology have allowed endovascular repair to be a durable and less invasive option for the treatment of mycotic aortic aneurysms. We have presented the case of a 51-year-old man with a mycotic aneurysm of the descending thoracic aorta secondary to chronic, disseminated aspergillosis infection after liver transplantation. The aneurysm was successfully treated with thoracic aortic stent graft deployment. No perioperative complications occurred, and follow-up computed tomography angiography showed no signs of an endoleak. The patient will continue with lifelong antifungal therapy and close follow-up with vascular surgery.

Lung and gut microbiomes in pulmonary aspergillosis: Exploring adjunctive therapies to combat the disease

Species within the Aspergillus spp. cause a wide range of infections in humans, including invasive pulmonary aspergillosis, chronic pulmonary aspergillosis, and allergic bronchopulmonary aspergillosis, and are associated with high mortality rates. The incidence of pulmonary aspergillosis (PA) is on the rise, and the emergence of triazole-resistant Aspergillus spp. isolates, especially Aspergillus fumigatus, limits the efficacy of mold-active triazoles. Therefore, host-directed and novel adjunctive therapies are required to more effectively combat PA. In this review, we focus on PA from a microbiome perspective. We provide a general overview of the effects of the lung and gut microbiomes on the growth of Aspergillus spp. and host immunity. We highlight the potential of the microbiome as a therapeutic target for PA.

Prediction and validation of host-pathogen interactions by a versatile inference approach using Aspergillus fumigatus as a case study

Biological networks are characterized by diverse interactions and dynamics in time and space. Many regulatory modules operate in parallel and are interconnected with each other. Some pathways are functionally known and annotated accordingly, e.g., endocytosis, migration, or cytoskeletal rearrangement. However, many interactions are not so well characterized. For reconstructing the biological complexity in cellular networks, we combine here existing experimentally confirmed and analyzed interactions with a protein-interaction inference framework using as basis experimentally confirmed interactions from other organisms. Prediction scoring includes sequence similarity, evolutionary conservation of interactions, the coexistence of interactions in the same pathway, orthology as well as structure similarity to rank and compare inferred interactions. We exemplify our inference method by studying host-pathogen interactions during infection of Mus musculus (phagolysosomes in alveolar macrophages) with Aspergillus fumigatus (conidia, airborne, asexual spores). Three of nine predicted critical host-pathogen interactions could even be confirmed by direct experiments. Moreover, we suggest drugs that manipulate the host-pathogen interaction.

Aspergillus spp. osteoarticular infections: an updated systematic review on the diagnosis, treatment and outcomes of 186 confirmed cases

Aspergillus spp. osteoarticular infections are destructive opportunistic infections, while there is no clear consensus on their management. The purpose of this review is to investigate the current literature regarding Aspergillus spp. osteoarticular infections. An electronic search of the PubMed and Scopus databases was conducted considering studies that assessed osteoarticular infections from Aspergillus spp. We included only studies with biopsy proven documentation of positive cultures or histological findings for Aspergillus spp., and those with essential information for each case such as the anatomical location of the infection, the type of treatment (conservative, surgical, combination), the antifungal therapy, and the outcome. Overall, 148 studies from 1965 to 2021 including 186 patients were included in the review. One hundred and seven (57.5%) patients underwent surgical debridement in addition to antifungal therapy, while 79 (42.7%) patients were treated only conservatively. Complete infection resolution was reported in 107 (57.5%) patients, while partial resolution in 29 (15.5%) patients. Surgical debridement resulted in higher complete infection resolution rate compared to only antifungal therapy (70.0% vs. 40.5%, P < 0.001), while complete resolution rate was similar for antifungal monotherapy and combination/sequential therapy (58.3% vs. 54.5%; P = 0.76). Last, complete resolution rate was also similar for monotherapy with amphotericin B (58.1%) and voriconazole (58.6%; P = 0.95). The results of this study indicate that antifungal monotherapy has similar efficacy with combination/sequential therapy, while voriconazole has similar efficacy with amphotericin B. Moreover, surgical debridement of the infected focus results in better outcomes in terms of infection eradication compared to conservative treatment.

LAY SUMMARY

Antifungal monotherapy has similar efficacy with combination/sequential therapy, and voriconazole has similar efficacy with amphotericin B for the treatment of Aspergillus spp. osteoarticular infections, while surgical debridement of the infected focus improves the infection eradication rate.

COVID-19-associated fungal infections

Coronavirus disease 2019 (COVID-19)-associated invasive fungal infections are an important complication in a substantial number of critically ill, hospitalized patients with COVID-19. Three groups of fungal pathogens cause co-infections in COVID-19: Aspergillus, Mucorales and Candida species, including Candida auris. Here we review the incidence of COVID-19-associated invasive fungal infections caused by these fungi in low-, middle- and high-income countries. By evaluating the epidemiology, clinical risk factors, predisposing features of the host environment and immunological mechanisms that underlie the pathogenesis of these co-infections, we set the scene for future research and development of clinical guidance.

Hoenigl and colleagues review the epidemiology, immunology and clinical risk factors contributing to COVID-19-associated fungal infections.

Novel Treatment Approach for Aspergilloses by Targeting Germination

Germination of conidia is an essential process within the Aspergillus life cycle and plays a major role during the infection of hosts. Conidia are able to avoid detection by the majority of leukocytes when dormant. Germination can cause severe health problems, specifically in immunocompromised people. Aspergillosis is most often caused by Aspergillus fumigatus (A. fumigatus) and affects neutropenic patients, as well as people with cystic fibrosis (CF). These patients are often unable to effectively detect and clear the conidia or hyphae and can develop chronic non-invasive and/or invasive infections or allergic inflammatory responses. Current treatments with (tri)azoles can be very effective to combat a variety of fungal infections. However, resistance against current azoles has emerged and has been increasing since 1998. As a consequence, patients infected with resistant A. fumigatus have a reported mortality rate of 88% to 100%. Especially with the growing number of patients that harbor azole-resistant Aspergilli, novel antifungals could provide an alternative. Aspergilloses differ in defining characteristics, but germination of conidia is one of the few common denominators. By specifically targeting conidial germination with novel antifungals, early intervention might be possible. In this review, we propose several morphotypes to disrupt conidial germination, as well as potential targets. Hopefully, new antifungals against such targets could contribute to disturbing the ability of Aspergilli to germinate and grow, resulting in a decreased fungal burden on patients.

Molecular identification and antifungal susceptibility of clinically relevant and cryptic species of Aspergillus sections Flavi and Nigri

Introduction. Aspergillus sections Flavi and Nigri comprise clinically relevant and cryptic species that differ significantly in drug susceptibility, meaning that effective treatment depends on correct species identification.Hypothesis/Gap Statement. There are no comprehensive data for molecular identification and antifungal susceptibility testing (AFST) of clinically relevant and cryptic species of Aspergillus sections Flavi and Nigri as the main agents of invasive and non-invasive aspergillosis in Iran. We aimed to perform molecular identification and AFST of 213 clinical Aspergillus isolates belonging to sections Flavi and Nigri. Molecular identification of isolates was performed using sequencing of the β-tubulin gene and in vitro AFST was conducted according to the Clinical and Laboratory Standards Institute (CLSI) M38-A3 guidelines.Results. The most common isolates in sections Flavi and Nigri were Aspergillus flavus (110/113, 97.3 %) and Aspergillus tubingensis (49/100, 49.0 %), respectively. A total of 62/213 (29.1 %) isolates belonging to cryptic species were identified; among them, A. tubingensis was the most prevalent (49/62, 79.0%). Aspergillus flavus and A. niger isolates that responded to the minimum inhibitory concentrations (MICs) of itraconazole above the epidemiological cutoff values were the most frequently detected: 8/110 (7.3 %) and 3/41 (7.3 %), respectively. In section Flavi, Aspergillus alliaceus responded to amphotericin B at a high MIC (>16 µg mL^-1) and in section Nigri, one of the three Aspergillus luchuensis/awamori isolates responded to itraconazole at an MIC >16 µg ml^-1. Interestingly, for all Aspergillus welwitschiae isolates, the MIC₅₀ and MIC₉₀ of itraconazole were both 16 µg ml^-1.Conclusion. A considerable presence of A. flavus and A. niger isolates showing non-wild-type responses to azoles in clinical cases of aspergillosis indicates the importance of classifying clinical Aspergillus isolates at the species level and performing antifungal susceptibility testing on the isolates, which would ensure appropriate treatment.

Performance of the Euroimmun Aspergillus Antigen ELISA for the Diagnosis of Invasive Pulmonary Aspergillosis in Bronchoalveolar Lavage Fluid

Invasive pulmonary aspergillosis (IPA) is a life-threatening disease that affects mainly immunocompromised hosts. Galactomannan testing from serum and bronchoalveolar lavage fluid (BALF) represents a cornerstone in diagnosing the disease. Here, we evaluated the diagnostic performance of the novel Aspergillus-specific galactomannoprotein (GP) enzyme-linked immunosorbent assay (ELISA; Euroimmun Medizinische Labordiagnostika) compared with the established Platelia Aspergillus GM ELISA (GM; Bio-Rad Laboratories) for the detection of Aspergillus antigen in BALF. Using the GP ELISA, we retrospectively tested 115 BALF samples from 115 patients with clinical suspicion of IPA and GM analysis ordered in clinical routine. Spearman's correlation statistics and receiver operating characteristics (ROC) curve analysis were performed. Optimal cutoff values were determined using Youden's index. Of 115 patients, 1 patient fulfilled criteria for proven IPA, 42 for probable IPA, 15 for putative IPA, 10 for possible IPA, and 47 did not meet criteria for IPA. Sensitivities and specificities for differentiating proven/probable/putative versus no IPA (possible excluded) were 74% and 96% for BALF GP and 90% and 96% for BALF GM at the manufacturer-recommended cutoffs. Using the calculated optimal cutoff value of 12 pg/mL, sensitivity and specificity of the BALF GP were 90% and 96%, respectively. ROC curve analysis showed an area under the curve (AUC) of 0.959 (95% confidence interval [CI] of 0.923 to 0.995) for the GP ELISA and an AUC of 0.960 (95% CI of 0.921 to 0.999) for the GM ELISA for differentiating proven/probable/putative IPA versus no IPA. Spearman's correlation analysis showed a strong correlation between the ELISAs (rho = 0.809, P < 0.0001). The GP ELISA demonstrated strong correlation and test performance similar to that of the GM ELISA and could serve as an alternative test for BALF from patients at risk for IPA.

Synergy Between Pseudomonas aeruginosa Filtrates And Voriconazole Against Aspergillus fumigatus Biofilm Is Less for Mucoid Isolates From Persons With Cystic Fibrosis

Persons with cystic fibrosis (CF) frequently suffer from Pseudomonas aeruginosa and Aspergillus fumigatus co-infections. There is evidence that co-infections with these interacting pathogens cause airway inflammation and aggravate deterioration of lung function. We recently showed that P. aeruginosa laboratory isolates synergistically interact with the anti-fungal azole voriconazole (VCZ), inhibiting biofilm metabolism of several A. fumigatus laboratory strains. Interaction was usually mediated via pyoverdine, but also via pyocyanin or pyochelin. Here we used planktonic filtrates of 7 mucoid and 9 non-mucoid P. aeruginosa isolates from CF patients, as well as 8 isolates without CF origin, and found that all of these isolates interacted with VCZ synergistically at their IC50 as well as higher dilutions. CF mucoid isolates showed the weakest interactive effects. Four non-mucoid P. aeruginosa CF isolates produced no or very low levels of pyoverdine and did not reach an IC50 against forming A. fumigatus biofilm; interaction with VCZ still was synergistic. A VCZ-resistant A. fumigatus strain showed the same level of susceptibility for P. aeruginosa anti-fungal activity as a VCZ-susceptible reference strain. Filtrates of most Pseudomonas isolates were able to increase anti-fungal activity of VCZ on a susceptible A. fumigatus strain. This was also possible for the VCZ-resistant strain. In summary these data show that clinical P. aeruginosa isolates, at varying degrees, synergistically interact with VCZ, and that pyoverdine is not the only molecule responsible. These data also strengthen the idea that during co-infections of A. fumigatus and P. aeruginosa lower concentrations of VCZ might be sufficient to control fungal growth.

Prevalence of COVID-19-Associated Pulmonary Aspergillosis: Critical Review and Conclusions

First reports of cases and case series of COVID-19-associated pulmonary aspergillosis (CAPA) emerged during the first months of the pandemic. Prevalence rates varied widely due to the fact that CAPA was, and still remains, challenging to diagnose in patients with COVID-19-associated acute respiratory failure (ARF). The clinical picture and radiological findings of CAPA are unspecific and can resemble those of severe COVID-19. Hence, mycological evidence became a key component in establishing a diagnosis. However, blood tests lack sensitivity in early treatable phases of CAPA and once positive, mortality has been shown to exceed 80% despite systemic antifungal therapy. The primarily airway invasive growth in non-neutropenic patients and the late occurrence of angioinvasion in the course of disease may mainly account for these diagnostic obstacles. Testing of bronchoalveolar lavage (BAL) is therefore crucial in the diagnostic process, but was rarely performed during the early phase of the pandemic, which potentially interfered with the accuracy of reported prevalence. Current guidelines recommend treatment of CAPA during its early airway invasive phase, which may result in some overtreatment (i.e., treatment in patients that may not develop angioinvasive infection) and adverse drug events, yet there is no viable alternative approach. Timely treatment of cases needs to be ensured for patients with mycological evidence of CAPA in the lower respiratory tract given the independent contribution of CAPA to devastating mortality rates of around 50% that have been shown in multiple studies. Here, we review the evolution of reported CAPA prevalence and the role of CAPA as an important opportunistic infection affecting COVID-19 patients in intensive care units (ICUs).

Species Distribution and Antifungal Susceptibilities of Aspergillus Section Fumigati Isolates in Clinical Samples from the United States

Aspergillus species are capable of causing both invasive disease and chronic infections in immunocompromised patients or those with preexisting lung conditions. Aspergillus fumigatus is the most commonly cultured species, and there is increasing concern regarding resistance to the azoles, which are the mainstays of antifungal therapy against aspergillosis. We evaluated the species distribution and susceptibility profiles of isolates within Aspergillus section Fumigati in the United States over a 52-month period.

Understanding the genetic basis of immune responses to fungal infection

INTRODUCTION

Fungal infections represent a global public health problem that affect millions of people. Despite remarkable advances achieved over the last decades, available diagnostic and therapeutic tools remain insufficient for the optimal management of these diseases. The clinical course of fungal infection is highly variable, and evidence accumulated from patients with rare mutations and cohort-based studies suggests that the trajectory of disease is largely defined by patient genetics and its impact on immune responses. Therefore, there is an urgent need to elucidate the precise mechanisms by which which genetic variants influence the risk, progression, and outcome of fungal infection.

AREAS COVERED

In this review, we highlight recent advances in our understanding of the genetic factors that influence antifungal immune responses based on candidate gene studies and genome-wide approaches performed in different experimental and clinical models.

EXPERT OPINION

Research on genetics of susceptibility to infection is expected to lead to a detailed knowledge framework for the pathogenesis of human fungal infections and unveil novel targets and pathways amenable to clinical intervention.

NLRP3, NLRC4 and NLRC5 Gene Polymorphisms Associate with Susceptibility of Pulmonary Aspergillosis in Non-Neutropenic Patients

Background: Non-neutropenic pulmonary aspergillosis is one of the most common and serious fungal infections. Previous studies have shown that single nucleotide polymorphisms (SNPs) of pattern recognition receptors genes are associated with susceptibility to aspergillosis. NOD-like receptors (NLRs) play an important role in the immunological response against fungal infection. In this study, we investigated the relationship between polymorphisms of three NLRs and susceptibility to pulmonary aspergillosis disease in non-neutropenic patients. Methods: We included 73 patients with proven pulmonary aspergillosis and 103 healthy controls. A total of sixteen SNPs in the NLRP3, NLRC4, and NLRC5 genes were detected by PCR-direct sequencing. Then, we evaluated the association between these polymorphisms and susceptibility to aspergillosis. Results: Fifteen SNPs were consistent with Hardy–Weinberg equilibrium except for NLRP3 rs7525979. A total of eight SNPs (NLRP3 rs3806265, NLRC4 rs212704 and NLRC5 rs1684579, rs12598522, rs3995817, rs3995818, rs34531240, rs28438857) were observed an association with susceptibility of pulmonary aspergillosis. The CC homozygote of NLRP3 rs3806265, TT homozygote of NLRC5 rs1684579 and T allele of NLRC5 rs12598522 were associated with a higher risk of aspergillosis while TT homozygote of NLRC4 rs212704 was associated with a lower risk of aspergillosis. Especially in the invasive pulmonary aspergillosis subgroup, the TT homozygote of NLRC5 rs1684579 and rs3995817, the CC homozygote of NLRC5 rs34531240 and rs28438857, GG homozygote of NLRC5 rs3995818, the C allele and CC homozygote of NLRP3 rs3806265 were associated with higher susceptibility. Conclusions: This study showed an association between polymorphisms of NLRP3, NLRC4, and NLRC5 and susceptibility to pulmonary aspergillosis for the first time. Further investigations in larger populations are needed, and functional studies are also required to investigate the function of these NLRs in aspergillosis, as well as other fungal infection diseases.

Recent Advances in Fungal Infections: From Lung Ecology to Therapeutic Strategies With a Focus on Aspergillus spp

Fungal infections are estimated to be the main cause of death for more than 1.5 million people worldwide annually. However, fungal pathogenicity has been largely neglected. This is notably the case for pulmonary fungal infections, which are difficult to diagnose and to treat. We are currently facing a global emergence of antifungal resistance, which decreases the chances of survival for affected patients. New therapeutic approaches are therefore needed to face these life-threatening fungal infections. In this review, we will provide a general overview on respiratory fungal infections, with a focus on fungi of the genus Aspergillus. Next, the immunological and microbiological mechanisms of fungal pathogenesis will be discussed. The role of the respiratory mycobiota and its interactions with the bacterial microbiota on lung fungal infections will be presented from an ecological perspective. Finally, we will focus on existing and future innovative approaches for the treatment of respiratory fungal infections.

Immune Privilege Furnishes a Niche for Latent Infection

The microenvironment of the CNS (eye and brain) is fertile ground for infection if the barriers are breached. The result of pathogen invasion is often devastating destruction of tissues. In the eye, inflammation is broadly classified either as "infectious" (i.e. caused by infection) or "non-infectious". However, increasingly, forms of intraocular inflammation (IOI), which clinically appear to be "non-infectious" turn out to be initiated by infectious agents, suggesting that pathogens have been retained in latent or persistent form within ocular tissues and have reactivated to cause overt disease. A similar pathogenesis applies to latent infections in the brain. Not all CNS tissues provide an equally protective niche while different pathogens escape detection using different strategies. This review summarises how immune privilege (IP) in the CNS may be permissive for latent infection and allow the eye and the brain to act as a reservoir of pathogens which often remain undetected for the lifetime of the host but in states of immune deficiency may be activated to cause sight- and life-threatening inflammation.

Case Report: Chronic Pulmonary Aspergillosis-An Unusual Long-Term Complication of Lung Cancer Treatment

Background: Chronic pulmonary aspergillosis (CPA) is a rare complication of radiochemotherapy for lung cancer. It may develop months or years after radical treatment. The diagnosis of CPA is challenging and complex. Not only fungal infection but also cancer relapse always have to be taken under consideration. Antifungal therapy is the base treatment, especially in the case when a surgical procedure is not possible. Standard treatment for at least 6 months is recommended but the optimal duration of the antifungal therapy is unknown. We present the clinical case of CPA, in which we had to perform multidirectional diagnostic tests to confirm the diagnosis and modified treatment due to the recurrence of the disease.

Case Presentation: We report a patient who developed CPA three and a half years after concurrent radiochemotherapy for locally advanced non-small-cell lung cancer. Non-specific symptoms were the cause of delayed diagnosis of fungal infection. Samples collected during bronchoscopy allowed to exclude the recurrence of lung cancer and establish the diagnosis of CPA. The patient was treated with itraconazole for 6 months. A few months later, controlled chest CT scans revealed the progression of CPA. Initially, retreatment with itraconazole was implemented. Due to the progression of fungal infection, voriconazole was used in the second line of treatment. Unfortunately, this therapy was complicated by the side effects and deterioration of the patient's condition. The reintroduction of itraconazole resulted in clinical and radiological improvement. Treatment is scheduled for at least 12 months.

Conclusion: Chronic pulmonary aspergillosis (CPA) was the cause of clinical deterioration and radiological progression in a patient after the radical treatment of lung cancer. In the described case, the diagnosis of CPA was delayed because of the suspicion of the recurrence of lung cancer. As the surgery was not possible, antifungal therapy with itraconazole was implemented and the proper dosage and duration led to significant clinical improvement.

Grading of Anatomopathological Disparity in the Cases of Invasive Pulmonary Aspergillosis in wild avian species as recorded in Pigeons (Columba livia), Peafowls (Pavo cristatus), and Griffon Vultures (Gyps fulvus)

Aspergillosis which is caused by Aspergillus fumigatus, a fungal pathogen, can vary from a localized infection to severe life-threatening invasive or disseminated systemic diseases in birds. The present study aimed to evaluate and grade the anatomopathological disparity in the cases of invasive pulmonary aspergillosis (IPA) in Columba livia (pigeons), Pavo cristatus (peafowls), and Gyps fulvus (Griffon vultures). Necropsy gross lesions varied from mere congestion of lungs in P. cristatus, congestion and large necrotizing masses surrounded by a zone of hyperemia (10 mm dia) in lungs of C. livia, and typically disseminated granuloma in the lungs, air sacs, and organs of other serous membranes in G. fulvus. Histopathology varied from extensive parenchymal necrosis amidst exuberant fungal invasion in P. cristatus, multifocal to focally extensive tissue necrosis with colonies of fungal hyphae surrounded by heterophils and lymphocytes in C. livia, as well as typical mycotic granuloma embedded in the lungs, air sacs, and thoracoabdominal serous membranes with angio-invasion in G. fulvus. Based on gross and histopathological findings, we diagnosed the cases as Acute Invasive Pulmonary Aspergillosis (AIPA) in peafowls and pigeons, as well as Chronic Invasive Pulmonary Aspergillosis (CIPA) in Griffon vultures. There is a paucity of case reports on aspergillosis in wild avian species, and this report strived to document the cases of IPA in peafowls, pigeons, and vultures. This is the first report of its kind which evaluated anatomopathological disparity of IPA in pigeons, peafowls, and vultures with a proposed anatomopathological grading system which would help to understand and investigate the nature of aspergillosis in different avian hosts.

Novel Clinical and Laboratorial Challenges in Aspergillosis

In recent years, research in the areas of Aspergillus and aspergillosis has continued to advance rapidly, including advancements in genomics, immunological studies, clinical areas, and diagnostic areas. Recently, new risk groups for the development of aspergillosis have emerged—patients with influenza- or COVID-19-ssociated pulmonary aspergillosis. The rise and spread of antifungal resistances have also become a clinical concern in some geographic areas and have drawn the attention of clinicians due to difficulties in treating these infections. In this paper, a snapshot of these issues is presented, emphasizing these novel clinical and laboratorial challenges in the aspergillosis field and focusing on their actual relevance.

Itraconazole loaded nano-structured lipid carrier for topical ocular delivery: Optimization and evaluation

BACKGROUND & OBJECTIVES

Low penetration efficiency and retention time are the main therapeutic concerns that make it difficult for most of the drugs to be delivered to the intraocular tissues. These challenging issues are often related to those drugs, which have low or poor solubility and low permeability. The goal of this study was designed to develop nanostructured lipid carriers (NLCs) loaded with itraconazole (ITZ) with the objective of enhancing topical ocular permeation and thereby improving clinical efficacy.

MATERIALS AND METHODS

ITZ-loaded NLCs were fabricated by a high-speed homogenization technique using surfactant (Poloxamer 407), and lipids (stearic acid and oleic acid). Optimization of formulations was performed by 3 level factorial design and the selected formulation (F6) was evaluated by differential scanning calorimetry and transmission electron microscopy. Antifungal activity was assessed by measuring the zone of inhibition and irritation potential using the HET-CAM test.

RESULTS

The independent variables (lipid ratio-X1 and percentage of emulsifier-X2) have a positive impact on percentage entrapment efficiency (Y2) and percentage release (Y3) but have a negative impact on particle size (Y1). Based on the better entrapment efficiency (94.65%), optimum particle size (150.67 nm), and percentage cumulative drug release (68.67%), batch F6 was selected for further evaluation. Electron microscopic images revealed that the prepared particles are spherical and have nano size. Antifungal studies demonstrated enhancement in the zone of inhibition by formulation F6 as compared to a commercial eye drop. The non-irritancy of optimized formulation (F6) was confirmed with a zero score.

INTERPRETATION & CONCLUSION

In summary, the optimized NLCs seem to be a potent carrier for the effective delivery of itraconazole in ocular therapy.

The high osmolarity glycerol (HOG) pathway in fungi†

While fungi are widely occupying nature, many species are responsible for devastating mycosis in humans. Such niche diversity explains how quick fungal adaptation is necessary to endow the capacity of withstanding fluctuating environments and to cope with host-imposed conditions. Among all the molecular mechanisms evolved by fungi, the most studied one is the activation of the phosphorelay signalling pathways, of which the high osmolarity glycerol (HOG) pathway constitutes one of the key molecular apparatus underpinning fungal adaptation and virulence. In this review, we summarize the seminal knowledge of the HOG pathway with its more recent developments. We specifically described the HOG-mediated stress adaptation, with a particular focus on osmotic and oxidative stress, and point out some lags in our understanding of its involvement in the virulence of pathogenic species including, the medically important fungi Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus, compared to the model yeast Saccharomyces cerevisiae. Finally, we also highlighted some possible applications of the HOG pathway modifications to improve the fungal-based production of natural products in the industry.

Selection and Amplification of Fungicide Resistance in Aspergillus fumigatus in Relation to DMI Fungicide Use in Agronomic Settings: Hotspots versus Coldspots

Aspergillus fumigatus is a ubiquitous saprophytic fungus. Inhalation of A. fumigatus spores can lead to Invasive Aspergillosis (IA) in people with weakened immune systems. The use of triazole antifungals with the demethylation inhibitor (DMI) mode of action to treat IA is being hampered by the spread of DMI-resistant "ARAf" (azole-resistant Aspergillus fumigatus) genotypes. DMIs are also used in the environment, for example, as fungicides to protect yield and quality in agronomic settings, which may lead to exposure of A. fumigatus to DMI residues. An agronomic setting can be a "hotspot" for ARAf if it provides a suitable substrate and favourable conditions for the growth of A. fumigatus in the presence of DMI fungicides at concentrations capable of selecting ARAf genotypes at the expense of the susceptible wild-type, followed by the release of predominantly resistant spores. Agronomic settings that do not provide these conditions are considered "coldspots". Identifying and mitigating hotspots will be key to securing the agronomic use of DMIs without compromising their use in medicine. We provide a review of studies of the prevalence of ARAf in various agronomic settings and discuss the mitigation options for confirmed hotspots, particularly those relating to the management of crop waste.

Genetic Analyses of Amphotericin B Susceptibility in Aspergillus fumigatus

Aspergillus fumigatus is a ubiquitous saprophytic mold that can cause a range of clinical syndromes, from allergic reactions to invasive infections. Amphotericin B (AMB) is a polyene antifungal drug that has been used to treat a broad range of systemic mycoses since 1958, including as a primary treatment option against invasive aspergillosis in regions with high rates (≥10%) of environmental triazole resistance. However, cases of AMB-resistant A. fumigatus strains have been increasingly documented over the years, and high resistance rates were recently reported in Brazil and Canada. The objective of this study is to identify candidate mutations associated with AMB susceptibility using a genome-wide association analysis of natural strains, and to further investigate a subset of the mutations in their putative associations with differences in AMB minimum inhibitory concentration (MIC) and in growths at different AMB concentrations through the analysis of progeny from a laboratory genetic cross. Together, our results identified a total of 34 candidate single-nucleotide polymorphisms (SNPs) associated with AMB MIC differences-comprising 18 intergenic variants, 14 missense variants, one synonymous variant, and one non-coding transcript variant. Importantly, progeny from the genetic cross allowed us to identify putative SNP-SNP interactions impacting progeny growth at different AMB concentrations.

The Antifungal Pipeline: Fosmanogepix, Ibrexafungerp, Olorofim, Opelconazole, and Rezafungin

The epidemiology of invasive fungal infections is changing, with new populations at risk and the emergence of resistance caused by the selective pressure from increased usage of antifungal agents in prophylaxis, empiric therapy, and agriculture. Limited antifungal therapeutic options are further challenged by drug-drug interactions, toxicity, and constraints in administration routes. Despite the need for more antifungal drug options, no new classes of antifungal drugs have become available over the last 2 decades, and only one single new agent from a known antifungal class has been approved in the last decade. Nevertheless, there is hope on the horizon, with a number of new antifungal classes in late-stage clinical development. In this review, we describe the mechanisms of drug resistance employed by fungi and extensively discuss the most promising drugs in development, including fosmanogepix (a novel Gwt1 enzyme inhibitor), ibrexafungerp (a first-in-class triterpenoid), olorofim (a novel dihyroorotate dehydrogenase enzyme inhibitor), opelconazole (a novel triazole optimized for inhalation), and rezafungin (an echinocandin designed to be dosed once weekly). We focus on the mechanism of action and pharmacokinetics, as well as the spectrum of activity and stages of clinical development. We also highlight the potential future role of these drugs and unmet needs.

Antifungal prophylaxis for prevention of COVID-19-associated pulmonary aspergillosis in critically ill patients: an observational study

BACKGROUND

Coronavirus disease 19 (COVID-19)-associated pulmonary aspergillosis (CAPA) emerged as important fungal complications in patients with COVID-19-associated severe acute respiratory failure (ARF). Whether mould active antifungal prophylaxis (MAFP) can prevent CAPA remains elusive so far.

METHODS

In this observational study, we included all consecutive patients admitted to intensive care units with COVID-19-associated ARF between September 1, 2020, and May 1, 2021. We compared patients with versus without antifungal prophylaxis with respect to CAPA incidence (primary outcome) and mortality (secondary outcome). Propensity score adjustment was performed to account for any imbalances in baseline characteristics. CAPA cases were classified according to European Confederation of Medical Mycology (ECMM)/International Society of Human and Animal Mycoses (ISHAM) consensus criteria.

RESULTS

We included 132 patients, of whom 75 (57%) received antifungal prophylaxis (98% posaconazole). Ten CAPA cases were diagnosed, after a median of 6 days following ICU admission. Of those, 9 CAPA cases were recorded in the non-prophylaxis group and one in the prophylaxis group, respectively. However, no difference in 30-day ICU mortality could be observed. Thirty-day CAPA incidence estimates were 1.4% (95% CI 0.2-9.7) in the MAFP group and 17.5% (95% CI 9.6-31.4) in the group without MAFP (p = 0.002). The respective subdistributional hazard ratio (sHR) for CAPA incidence comparing the MAFP versus no MAFP group was of 0.08 (95% CI 0.01-0.63; p = 0.017).

CONCLUSION

In ICU patients with COVID-19 ARF, antifungal prophylaxis was associated with significantly reduced CAPA incidence, but this did not translate into improved survival. Randomized controlled trials are warranted to evaluate the efficacy and safety of MAFP with respect to CAPA incidence and clinical outcomes.

Desferrioxamine B-Mediated Pre-Clinical In Vivo Imaging of Infection by the Mold Fungus Aspergillus fumigatus

Fungal infections are a serious threat, especially for immunocompromised patients. Early and reliable diagnosis is crucial to treat such infections. The bacterially produced siderophore desferrioxamine B (DFO-B) is utilized by a variety of microorganisms for iron acquisition, while mammalian cells lack the uptake of DFO-B chelates. DFO-B is clinically approved for a variety of long-term chelation therapies. Recently, DFO-B-complexed gallium-68 ([68Ga]Ga-DFO-B) was shown to enable molecular imaging of bacterial infections by positron emission tomography (PET). Here, we demonstrate that [68Ga]Ga-DFO-B can also be used for the preclinical molecular imaging of pulmonary infection caused by the fungal pathogen Aspergillus fumigatus in a rat aspergillosis model. Moreover, by combining in vitro uptake studies and the chemical modification of DFO-B, we show that the cellular transport efficacy of ferrioxamine-type siderophores is impacted by the charge of the molecule and, consequently, the environmental pH. The chemical derivatization has potential implications for its diagnostic use and characterizes transport features of ferrioxamine-type siderophores.

Risk factors and outcome of pulmonary aspergillosis in critically ill coronavirus disease 2019 patients-a multinational observational study by the European Confederation of Medical Mycology

Objectives

Coronavirus disease 2019 (COVID-19) -associated pulmonary aspergillosis (CAPA) has emerged as a complication in critically ill COVID-19 patients. The objectives of this multinational study were to determine the prevalence of CAPA in patients with COVID-19 in intensive care units (ICU) and to investigate risk factors for CAPA as well as outcome.

Methods

The European Confederation of Medical Mycology (ECMM) conducted a multinational study including 20 centres from nine countries to assess epidemiology, risk factors and outcome of CAPA. CAPA was defined according to the 2020 ECMM/ISHAM consensus definitions.

Results

A total of 592 patients were included in this study, including 11 (1.9%) patients with histologically proven CAPA, 80 (13.5%) with probable CAPA, 18 (3%) with possible CAPA and 483 (81.6%) without CAPA. CAPA was diagnosed a median of 8 days (range 0–31 days) after ICU admission predominantly in older patients (adjusted hazard ratio (aHR) 1.04 per year; 95% CI 1.02–1.06) with any form of invasive respiratory support (HR 3.4; 95% CI 1.84–6.25) and receiving tocilizumab (HR 2.45; 95% CI 1.41–4.25). Median prevalence of CAPA per centre was 10.7% (range 1.7%–26.8%). CAPA was associated with significantly lower 90-day ICU survival rate (29% in patients with CAPA versus 57% in patients without CAPA; Mantel–Byar p < 0.001) and remained an independent negative prognostic variable after adjusting for other predictors of survival (HR 2.14; 95% CI 1.59–2.87, p ≤ 0.001).

Conclusion

Prevalence of CAPA varied between centres. CAPA was significantly more prevalent among older patients, patients receiving invasive ventilation and patients receiving tocilizumab, and was an independent strong predictor of ICU mortality.