Clinical features of invasive pulmonary aspergillosis vs. colonization in COPD patients distributed by gold stage

Global incidence and mortality of severe fungal disease

Current estimates of fungal disease incidence and mortality are imprecise. Population at risk denominators were used to estimate annual incidence for 2019-21. Extensive literature searches from 2010 to 2023 were combined with over 85 papers on individual country and global disease burden. Crude and attributable mortality were estimated using a combination of untreated mortality, the proportion of patients who are treated, and percentage survival in treated patients. Awareness, guidelines, and accessibility of diagnostics and therapies informed the ratio of treated to untreated cases. Estimates do not include influenza or COVID-19 outbreaks. Data from more than 120 countries were included. Annually, over 2 113 000 people develop invasive aspergillosis in the context of chronic obstructive pulmonary disease, intensive care, lung cancer, or haematological malignancy, with a crude annual mortality of 1 801 000 (85·2%). The annual incidence of chronic pulmonary aspergillosis is 1 837 272, with 340 000 (18·5%) deaths. About 1 565 000 people have a Candida bloodstream infection or invasive candidiasis each year, with 995 000 deaths (63·6%). Pneumocystis pneumonia affects 505 000 people, with 214 000 deaths (42·4%). Cryptococcal meningitis affects 194 000 people, with 147 000 deaths (75·8%). Other major life-threatening fungal infections affect about 300 000 people, causing 161 000 deaths (53·7%). Fungal asthma affects approximately 11·5 million people and might contribute to 46 000 asthma deaths annually. These updated estimates suggest an annual incidence of 6·5 million invasive fungal infections and 3·8 million deaths, of which about 2·5 million (68%; range 35-90) were directly attributable.

Improved diagnostic markers for invasive pulmonary aspergillosis in COPD patients

Background

The prevalence of invasive pulmonary aspergillosis (IPA) among patients with chronic obstructive pulmonary disease (COPD) is steadily increasing, leading to high mortality. Although early diagnosis can significantly reduce mortality, the efficacy of current diagnostic methods is limited. Consequently, there is a need for novel approaches for early IPA detection.

Methods

This retrospective study involved 383 hospitalized COPD patients with GOLD stages III and IV. The IPA group (67 patients) and non-IPA group (316 patients) were identified at the First Affiliated Hospital of Guangzhou Medical University between January 2016 and February 2022. We analyzed common serological indicators in our hospital to identify predictive indicators for the early diagnosis of IPA in COPD patients.

Results

The sensitivity and specificity of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin (PCT), lactate dehydrogenase (LDH), and ceruloplasmin (CER) for diagnosing IPA in COPD patients were as follows: CRP (91.2%, 57.7%), ESR (77.5%, 73.0%), PCT (60.5%, 71.4%), LDH (50.0%, 88.8%), and CER (60.7%, 74.3%). Combinations of biomarkers, such as CRP-ESR, CRP-LDH, ESR-LDH, ESR-CER, and LDH-CER, showed promising diagnostic potential, with larger area under the curve (AUC) values for IPA diagnosis in COPD patients. However, no statistically significant difference was observed between the diagnostic efficacy of single biomarkers and combined biomarkers. Notably, compared to those in the unassisted ventilation group, the patients in the assisted ventilation group (including noninvasive ventilation and tracheal intubation/incision-assisted ventilation group) exhibited significantly greater PCT and LDH levels, while the CER significantly decreased (p=0.021). There were no significant differences in biomarker levels between the ICU group and the non-ICU group. CRP (p<0.01), ESR (p=0.028), PCT (p<0.01), and CER (p<0.01) were positively correlated with hospitalization duration, whereas LDH was not correlated with hospitalization duration.

Conclusion

Our study highlights the diagnostic potential of CRP, ESR, PCT, LDH, and CER for IPA in COPD patients. CRP and LDH can also initially predict the need for assisted ventilation, while CRP can initially estimate the length of hospitalization. This study represents the first report of the potential of CER for diagnosing IPA, suggesting its significance for further research.

Prognostic factors and outcomes of invasive pulmonary aspergillosis, a retrospective hospital-based study

Objective

Invasive pulmonary aspergillosis (IPA) affects immunocompromised hosts and is associated with higher risks of respiratory failure and mortality. However, the clinical outcomes of different IPA types have not been identified.

Methods

Between September 2002 and May 2021, we retrospectively enrolled patients with IPA in Taichung Veterans General Hospital, Taiwan. Cases were classified as possible IPA, probable IPA, proven IPA, and putative IPA according to EORTC/MSGERC criteria and the AspICU algorithm. Risk factors of respiratory failure, kidney failure, and mortality were analyzed by logistic regression. A total of 3-year survival was assessed by the Kaplan-Meier method with log-rank test for post-hoc comparisons.

Results

We included 125 IPA patients (50: possible IPA, 47: probable IPA, 11: proven IPA, and 17: putative IPA). Comorbidities of liver cirrhosis and solid organ malignancy were risk factors for respiratory failure; diabetes mellitus and post-liver or kidney transplantation were related to kidney failure. Higher galactomannan (GM) test optical density index (ODI) in either serum or bronchoalveolar lavage fluid was associated with dismal outcomes. Probable IPA and putative IPA had lower 3-year respiratory failure-free survival compared to possible IPA. Probable IPA and putative IPA exhibited lower 3-year renal failure-free survival in comparison to possible IPA and proven IPA. Putative IPA had the lowest 3-year overall survival rates among the four IPA groups.

Conclusion

Patients with putative IPA had higher mortality rates than the possible, probable, or proven IPA groups. Therefore, a prompt diagnosis and timely treatment are warranted for patients with putative IPA.

Acute Invasive Pulmonary Aspergillosis: Clinical Presentation and Treatment

Among all clinical manifestations of pulmonary aspergillosis, invasive pulmonary aspergillosis (IPA) is the most acute presentation. IPA is caused by Aspergillus hyphae invading the pulmonary tissue, causing either tracheobronchitis and/or bronchopneumonia. The degree of fungal invasion into the respiratory tissue can be seen as a spectrum, going from colonization to deep tissue penetration with angio-invasion, and largely depends on the host's immune status. Patients with prolonged, severe neutropenia and patients with graft-versus-host disease are at particularly high risk. However, IPA also occurs in other groups of immunocompromised and nonimmunocompromised patients, like solid organ transplant recipients or critically ill patients with severe viral disease. While a diagnosis of proven IPA is challenging and often warranted by safety and feasibility, physicians must rely on a combination of clinical, radiological, and mycological features to assess the likelihood for the presence of IPA. Triazoles are the first-choice regimen, and the choice of the drug should be made on an individual basis. Adjunctive therapy such as immunomodulatory treatment should also be taken into account. Despite an improving and evolving diagnostic and therapeutic armamentarium, the burden and mortality of IPA still remains high. This review aims to give a comprehensive and didactic overview of the current knowledge and best practices regarding the epidemiology, clinical presentation, diagnosis, and treatment of acute IPA.

Prognostic Scores and Azole-Resistant Aspergillus fumigatus in Invasive Aspergillosis from an Indian Respiratory Medicine ICU (ICU Patients with IA Suspicion)

Objective: To assess the effectiveness of three general prognostic models (APACHE II, SAPS II, and SOFA) with serum galactomannan antigen in a clinically suspected invasive aspergillosis (IA) subpopulation admitted to a respiratory medicine ICU and to identify azole-resistant Aspergillus fumigatus (ARAF) cases. Methodology and Results: A total of 235 clinically suspected IA patients were prospectively enrolled and observed 30-day mortality was 29.7%. The three general models showed poor discrimination assessed by area under receiver operating characteristic (ROC) curves (AUCs, <0.7) and good calibration (p = 0.92, 0.14, and 0.13 for APACHE II, SAPS II, and SOFA, respectively), evaluated using Hosmer–Lemeshow goodness-of-fit tests. However, discrimination was significantly better with galactomannan values (AUC, 0.924). In-vitro antifungal testing revealed higher minimum inhibitory concentration (MIC) for 12/34 isolates (35.3%) whereas azole resistance was noted in 40% of Aspergillus fumigatus isolates (6/15) with two hotspot cyp51A mutations, G54R and P216L. Conclusions: Patients diagnosed with putative and probable IA (71.4% and 34.6%, respectively), had high mortality. The general prognostic model APACHE II seemed fairly accurate for this subpopulation. However, the use of local GM cut-offs calculated for mortality, may help the intensivists in prompt initiation or change of therapy for better outcome of patients. In addition, the high MICs highlight the need of antifungal surveillance to know the local resistance rate which might aid in patient treatment.

Respiratory Mycoses in COPD and Bronchiectasis

Chronic obstructive pulmonary disease (COPD) and bronchiectasis represent chronic airway diseases associated with significant morbidity and mortality. Bacteria and viruses are commonly implicated in acute exacerbations; however the significance of fungi in these airways remains poorly defined. While COPD and bronchiectasis remain recognized risk factors for the occurrence of Aspergillus-associated disease including chronic and invasive aspergillosis, underlying mechanisms that lead to the progression from colonization to invasive disease remain uncertain. Nonetheless, advances in molecular technologies have improved our detection, identification and understanding of resident fungi characterizing these airways. Mycobiome sequencing has revealed the complex varied and myriad profile of airway fungi in COPD and bronchiectasis, including their association with disease presentation, progression, and mortality. In this review, we outline the emerging evidence for the clinical importance of fungi in COPD and bronchiectasis, available diagnostic modalities, mycobiome sequencing approaches and association with clinical outcomes.

Prospective observational study of respiratory Aspergillus colonization or disease in patients with various stages of chronic obstructive pulmonary disease utilizing culture versus nonculture techniques

Chronic obstructive pulmonary disease (COPD) patients have been recognized to be at increased risk of Aspergillus spp. colonization, which may progress to invasive pulmonary aspergillosis (IPA). The objective of this study was to determine the frequency of Aspergillus colonization, or disease, in a cohort of COPD patients. A prospective observational study was undertaken to determine Aspergillus colonization, or disease, in consecutive COPD patients undergoing bronchoscopy. Fungal culture as well as galactomannan antigen (GM) and Aspergillus nucleic acid detection (PCR) were performed on bronchoalveolar lavage fluid (BAL) samples. One hundred and fifty patients were recruited. One hundred and twelve (74.7%) were outpatients, 38 (25.33%) were inpatients, of whom 6 (4%) were in the intensive care unit. Most patients (N = 122, 81.3%) were either COPD GOLD (Global Initiative for Chronic Obstructive Lung Disease) stages 1 or 2. Nine (6%) patients were on systemic steroids, 64 (42.7%) on inhaled steroids, and 9 (6%) on both. Seventeen patients (11.3%) had at least one positive test for Aspergillus detection (culture ± galactomannan ± polymerase chain reaction [PCR]), 13 (76.4%) of whom were COPD GOLD stages 1 or 2.  Five patients had probable or putative IPA. Aspergillus sp. was detected in five patients (3.3%) by culture, but detection increased to 17 (11.3%) by the additional testing for GM or Aspergillus DNA. The frequency of Aspergillus detection in this cohort of COPD patients may reflect the predominance of early GOLD stages among the study population but deserves further investigation to determine its relevance as a predictive risk factor for IPA.

LAY SUMMARY

COPD is a risk factor for Aspergillus spp. colonization. Bronchoalveolar lavage samples of 150 COPD patients were tested for presence of Aspergillus fumigatus, which was detected in five patients (3.3%) by culture, but detection of Aspergillus increased to 17 (11.3%) by additional GM and PCR testing.

Is bronchoscopic view a reliable method in diagnosis of tracheobronchial aspergillosis in critically ill non-neutropenic patients?

INTRODUCTION

Pulmonary aspergillosis is the main respiratory fungal infection however; its diagnosis is missed or delayed in critically ill non-neutropenic patients. Despite the utility of fiberoptic bronchoscopy for the evaluation of tracheobronchial aspergillosis (TBA) in immunocompromised patients has been extensively studied, however its utility in critically ill non-neutropenic patients is underestimated.

OBJECTIVES

To assess the bronchoscopic changes suspected TBA relative to the microbiological and histopathological aspects in critically ill non-neutropenic patients admitted to respiratory intensive care unit (RICU).

METHODS

We prospectively studied 139 critically ill non-neutropenic patients admitted to RICU and had a clinical suspicion of broncho-pulmonary Aspergillus infection. Those patients were subjected to clinical and bronchoscopic assessment for the evaluation of suspected TBA. Microbiological culture of bronchoalveolar lavage (BAL) and histopathological examination of tracheobronchial biopsies were done.

RESULTS

Bronchoscopic changes suspected TBA were found in 48.2% of patients (67/139), where Aspergillus infection was confirmed microbiologically in 59.7% (40/67) and histopathologically in 56.7% (38/67). Of these changes, whitish plaques ± ulcers, pseudomembrane and/or sticky secretion with hyperemic mucosa were detected in 68.7%, 26.9% and 16.4% respectively. These changes were mostly seen in the main bronchi (54/67; 80.6%). The sensitivity, specificity, positive, negative predictive values and overall accuracy of these bronchoscopic changes as compared with BAL fluid results were 83.3%, 70.3%, 53.2%, 91.2% and 74.1% respectively.

CONCLUSIONS

Bronchoscopy could be a reliable procedure for TBA diagnosis in critically ill non-neutropenic patients. Whitish plaques ± ulcers were the prominent bronchoscopic changes with reasonable diagnostic accuracy for prediction of TBA.

Invasive Pulmonary Aspergillosis in Chronic Obstructive Pulmonary Disease Exacerbations

Nowadays, reports in the literature support that patients with severe chronic obstructive pulmonary disease (COPD) are at higher risk to develop invasive pulmonary aspergillosis (IPA). However, the interpretation of Aspergillus-positive cultures from the airways in critically ill COPD is still a challenge. Indeed, as the patient could be merely colonized, tissue samples are required to ascertain IPA diagnosis but they are rarely obtained before death. Consequently, diagnosis is often only suspected on the basis of a combination of three elements: clinical characteristics, radiological images (mostly thoracic CT scan), and microbiological, and occasionally serological, results. To facilitate the analysis of these data, several algorithms have been developed, and the best effectiveness has been demonstrated by the Clinical algorithm. This is of importance as IPA prognosis in these patients remains presently very poor and using such an algorithm could promote prompter diagnosis, early initiation of treatment, and subsequently improved outcome.While the most classical presentation of IPA in critically ill COPD patients features a combination of obstructive respiratory failure, antibiotic-resistant pneumonia, recent or chronic corticosteroid therapy, and positive Aspergillus cultures from the lower respiratory tract, the present article will also address less typical presentations and discuss the most appropriate treatments which could alter prognosis.

Role of Common γ-Chain Cytokines in Lung Interleukin-22 Regulation after Acute Exposure to Aspergillus fumigatus

Humans are constantly exposed to the opportunistic mold Aspergillus fumigatus, and disease caused by this pathogen is often determined by the magnitude of local and systemic immune responses. We have previously shown a protective role for interleukin-22 (IL-22) after acute A. fumigatus exposure. Here, employing IL-22^Cre R26R^eYFP reporter mice, we identified iNKT cells, γδ T cells, and type 3 innate lymphoid cells (ILC3s) as lung cell sources of IL-22 in response to acute A. fumigatus exposure. As these cells often utilize common γ-chain cytokines for their development or maintenance, we determined the role of IL-7, IL-21, and IL-15 in lung IL-22 induction and A. fumigatus lung clearance. We observed that IL-7, IL-21, and IL-15 were essential for, partially required for, or negatively regulated the production of IL-22, respectively. Deficiency in IL-7 and IL-21, but not IL-15R, resulted in impaired fungal clearance. Surprisingly, however, the absence of IL-7, IL-21, or IL-15R signaling had no effect on neutrophil recruitment. The levels of IL-1α, an essential anti-A. fumigatus proinflammatory cytokine, were increased in the absence of IL-7 and IL-15R but decreased in the absence of IL-21. IL-7 was responsible for maintaining lung iNKT cells and γδ T cells, whereas IL-21 was responsible for maintaining lung iNKT cells and ILC3s. In contrast, IL-15R deficiency had no effect on the absolute numbers of any IL-22 cell source, rather resulting in enhanced per cell production of IL-22 by iNKT cells and γδ T cells. Collectively, these results provide insight into how the IL-22 response in the lung is shaped after acute A. fumigatus exposure.

Utility of serum Aspergillus-galactomannan antigen to evaluate the risk of severe acute exacerbation in chronic obstructive pulmonary disease

Background

Recent studies have shown that the microbiome, namely Aspergillus species, play a previously unrecognized role in both stable and exacerbated chronic obstructive pulmonary disease (COPD). Galactomannan is a major component of the Aspergillus cell wall that has been widely used as a diagnostic marker.

Objectives

To explore whether serum levels of Aspergillus-galactomannan antigen could be used to evaluate the risk of severe acute exacerbation of COPD (AE-COPD).

Methods

We measured the Aspergillus-galactomannan antigen levels of 191 patients with stable COPD, and examined its clinical relevance including AE-COPD.

Results

There were 77 (40.3%) patients who were positive for serum Aspergillus-galactomannan antigen (≥0.5). High Aspergillus-galactomannan antigen level (≥0.7) was associated with older age and presence of bronchiectasis and cysts on computed tomography images. Compared to patients with low Aspergillus-galactomannan antigen level (<0.7), patients with high Aspergillus-galactomannan antigen level had significantly higher incidence of severe AE-COPD (P = 0.0039, Gray’s test) and respiratory-related mortality (P = 0.0176, log-rank test). Multivariate analysis showed that high Aspergillus-galactomannan antigen level was independently associated with severe AE-COPD (hazard ratio, 2.162; 95% confidence interval, 1.267−3.692; P = 0.005).

Conclusion

Serum Aspergillus-galactomannan antigen was detected in patients with COPD, and elevated serum Aspergillus-galactomannan antigen was associated with severe AE-COPD.

Invasive mould infections in the ICU setting: complexities and solutions

Infections caused by filamentous fungi represent a major burden in the ICU. Invasive aspergillosis is emerging in non-neutropenic individuals with predisposing conditions, e.g. corticosteroid treatment, chronic obstructive pulmonary disease, liver cirrhosis, solid organ cancer, HIV infection and transplantation. Diagnosis is challenging because the signs and symptoms are non-specific, and initiation of additional diagnostic examinations is often delayed because clinical suspicion is low. Isolation of an Aspergillus species from the respiratory tract in critically ill patients, and tests such as serum galactomannan, bronchoalveolar lavage 1-3-β-d-glucan and specific PCR should be interpreted with caution. ICU patients should start adequate antifungal therapy upon suspicion of invasive aspergillosis, without awaiting definitive proof. Voriconazole, and now isavuconazole, are the drugs of choice. Mucormycosis is a rare, but increasingly prevalent disease that occurs mainly in patients with uncontrolled diabetes mellitus, immunocompromised individuals or previously healthy patients with open wounds contaminated with Mucorales. A high proportion of cases are diagnosed in the ICU. Rapidly progressing necrotizing lesions in the rhino-sinusal area, the lungs or skin and soft tissues are the characteristic presentation. Confirmation of diagnosis is based on demonstration of tissue invasion by non-septate hyphae, and by new promising molecular techniques. Control of underlying predisposing conditions, rapid surgical resection and administration of liposomal amphotericin B are the main therapeutic actions, but new agents such as isavuconazole are a promising alternative. Patients with mucormycosis receive a substantial part of their care in ICUs and, despite advances in diagnosis and treatment, mortality remains very high.

Multiple cavities with halo sign in a case of invasive pulmonary aspergillosis during therapy for drug-induced hypersensitivity syndrome

A 67-year-old female with rheumatoid arthritis and asthma-chronic obstructive pulmonary disease overlap syndrome was admitted for drug-induced hypersensitivity syndrome (DIHS) caused by salazosulfapyridine. Human herpes virus 6 (HHV-6) variant B was strongly positive on peripheral blood. Multiple cavities with ground grass opacities rapidly emerged predominantly in the upper and middle lobes. She was diagnosed with invasive pulmonary aspergillosis (IPA), and was treated successfully with antifungal agents. Therapeutic systemic corticosteroids, emphysematous change in the lungs, and the worsening of the patient's general condition due to DIHS were considered major contributing factor leading to IPA. HHV-6 reactivation could have an effect on clinical course of IPA. Cavities with halo sign would provide an early clue to IPA in non-neutropenic and immunosuppressive patients.

Development of Aspergillosis in a cohort of non-neutropenic, non-transplant patients colonised by Aspergillus spp

BACKGROUND

A previous study explored factors discriminating colonization and true infection among non-transplant, non-neutropenic patients with repeated Aspergillus spp. isolation from lower respiratory samples. The present study explored the evolution of patients with Aspergillus colonization in that study to determine the percentage of cases progressing to aspergillosis and time to development.

METHODS

Clinical records were retrospectively reviewed (for each patient from his end date in the past study) and data from all respiratory processes suffered by patients up to April 2015 were recorded. Comparisons of variables were performed between colonized patients that developed aspergillosis and those that did not. A Kaplan-Meier curve was used to describe time to development of aspergillosis in chronic obstructive pulmonary disease (COPD) patients for II-IV stages of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification.

RESULTS

Sixty seven colonized patients were followed, 12 of them (17.9%) developed aspergillosis. Diagnoses included six tracheobronchitis (4 invasive, 2 simple tracheobronchitis), four pulmonary disease (2 invasive pulmonary aspergillosis, 2 chronic pulmonary aspergillosis), one allergic bronchopulmonary aspergillosis and one pulmonary aspergilloma. Up to 47 (70.4%) of the study patients presented COPD. Among patients developing aspergillosis COPD was more frequent (100%) than among those that did not develop aspergillosis (35 out of 55; 63.6%) (p = 0.012), as well as GOLD IV patients were more frequent among COPD patients developing aspergillosis than among COPD patients that did not (50.0 vs. 26.1%, p = 0.046). Mean time to development of aspergillosis was 18.4 months (median: 8.5) with a wide range (1-58). Overtime, the percentage of patients developing aspergillosis was significantly higher among GOLD IV patients than among GOLD II-III patients (p = 0.032).

CONCLUSIONS

The high percentage of cases progressing to aspergillosis among colonized patients, especially among those with COPD (25.5%), stresses the importance of colonization as risk factor, and creates awareness of the possible change from colonization to invasive disease in GOLD IV patients.

Putative invasive pulmonary aspergillosis in critically ill patients with chronic obstructive pulmonary disease: a matched cohort study

Introduction

Patients with advanced chronic obstructive pulmonary disease (COPD) are at risk for developing invasive pulmonary aspergillosis. A clinical algorithm has been validated to discriminate colonization from putative invasive pulmonary aspergillosis (PIPA) in Aspergillus-positive respiratory tract cultures of critically ill patients. We focused on critically ill patients with COPD who met the criteria for PIPA.

Methods

This matched cohort study included critically ill patients with COPD from two university hospital intensive care units (ICUs). We studied the risk factors for PIPA as well as the impact of PIPA on short- and long-term outcomes. Whether PIPA was associated with a pattern of bacterial colonization and/or infection 6 months before and/or during ICU stay was assessed. In addition, antifungal strategies were reviewed.

Results

Fifty cases of PIPA in critically ill patients with COPD in the ICU were matched with one hundred control patients with COPD. The ICU short- and the long-term (at 1 year) mortality were significantly increased in the PIPA group (p < 0.001 for all variables). PIPA was a strong independent risk factor for mortality in the ICU (odds ratio 7.44, 95 % confidence interval 2.93–18.93, p < 0.001) before vasopressor therapy, renal replacement therapy, and duration of mechanical ventilation. Before ICU admission, the use of corticosteroids and antibiotics significantly increased the risk of PIPA (p = 0.004 and p < 0.001, respectively). No significant difference in bacterial etiologic agents responsible for colonization and/or infection was found between the groups. Antifungal treatment was started in 64 % of PIPA cases, with a poor impact on the overall outcome.

Conclusions

PIPA was a strong death predictor in critically ill patients with COPD. The use of corticosteroids and antibiotics before ICU admission was a risk factor for PIPA. PIPA was not associated with a specific bacterial pattern of colonization or infection. Prompting antifungal treatment in critically ill patients with COPD who have PIPA may not be the only factor involved in prognosis reversal.

How to treat fungal infections in ICU patients

Fungal infections represent a major burden in the critical care setting with increasing morbidity and mortality. Candidiasis is the leading cause of such infections, with C. albicans being the most common causative agent, followed by Aspergillosis and Mucormycosis. The diagnosis of such infections is cumbersome requiring increased clinical vigilance and extensive laboratory testing, including radiology, cultures, biopsies and other indirect methods. However, it is not uncommon for definitive evidence to be unavailable. Risk and host factors indicating the probability of infections may greatly help in the diagnostic approach. Timely and adequate intervention is important for their successful treatment. The available therapeutic armamentarium, although not very extensive, is effective with low resistance rates for the newer antifungal agents. However, timely and prudent use is necessary to maximize favorable outcomes.

Role of therapeutic drug monitoring in pulmonary infections: use and potential for expanded use of dried blood spot samples

Respiratory tract infections are among the most common infections in men. We reviewed literature to document their pharmacological treatments, and the extent to which therapeutic drug monitoring (TDM) is needed during treatment. We subsequently examined potential use of dried blood spots as sample procedure for TDM. TDM was found to be an important component of clinical care for many (but not all) pulmonary infections. For gentamicin, linezolid, voriconazole and posaconazole dried blood spot methods and their use in TDM were already evident in literature. For glycopeptides, β-lactam antibiotics and fluoroquinolones it was determined that development of a dried blood spot (DBS) method could be useful. This review identifies specific antibiotics for which development of DBS methods could support the optimization of treatment of pulmonary infections.

Epidemiology of invasive aspergillosis in critically ill patients: clinical presentation, underlying conditions, and outcomes

Introduction

Invasive aspergillosis (IA) is a fungal infection that particularly affects immunocompromised hosts. Recently, several studies have indicated a high incidence of IA in intensive care unit (ICU) patients. However, few data are available on the epidemiology and outcome of patients with IA in this setting.

Methods

An observational study including all patients with a positive Aspergillus culture during ICU stay was performed in 30 ICUs in 8 countries. Cases were classified as proven IA, putative IA or Aspergillus colonization according to recently validated criteria. Demographic, microbiologic and diagnostic data were collected. Outcome was recorded 12 weeks after Aspergillus isolation.

Results

A total of 563 patients were included, of whom 266 were colonized (47%), 203 had putative IA (36%) and 94 had proven IA (17%). The lung was the most frequent site of infection (94%), and Aspergillus fumigatus the most commonly isolated species (92%). Patients with IA had higher incidences of cancer and organ transplantation than those with colonization. Compared with other patients, they were more frequently diagnosed with sepsis on ICU admission and more frequently received vasopressors and renal replacement therapy (RRT) during the ICU stay. Mortality was 38% among colonized patients, 67% in those with putative IA and 79% in those with proven IA (P < 0.001). Independent risk factors for death among patients with IA included older age, history of bone marrow transplantation, and mechanical ventilation, RRT and higher Sequential Organ Failure Assessment score at diagnosis.

Conclusions

IA among critically ill patients is associated with high mortality. Patients diagnosed with proven or putative IA had greater severity of illness and more frequently needed organ support than those with Aspergillus spp colonization.

The potential impact of the pulmonary microbiome on immunopathogenesis of Aspergillus-related lung disease

Aspergillosis is an infection or allergic response caused by fungi of the genus Aspergillus. The most common forms of aspergillosis are allergic bronchopulmonary aspergillosis, chronic pulmonary aspergillosis, and invasive pulmonary aspergillosis. Aspergillus also plays an important role in fungal sensitized asthma. Humans inhale Aspergillus spores every day and when the host is immunocompromised, Aspergillus spp. may cause severe pulmonary disease. There is increasing evidence that the microbiome plays a significant role in immune regulation, chronic inflammatory diseases, metabolism, and other physiological processes, including recovery from the effects of antibiotic treatment. Bacterial microbiome mediated resistance mechanisms probably play a major role in limiting fungal colonization of the lungs, and may therefore prevent humans from contracting Aspergillus-related diseases. In this perspective, we review this emerging area of research and discuss the role of the microbiome in aspergillosis, role of Aspergillus in the microbiome, and the influence of the microbiome on anti-Aspergillus host defense and its role in preventing aspergillosis.

[Invasive pulmonary aspergillosis in patients with chronic obstructive pulmonary disease]

Invasive pulmonary aspergillosis (IPA) is a common infection in immunocompromised patients with hematological malignancies or allogenic stem cell transplantation, and is less frequent in the context of chronic obstructive pulmonary disease (COPD). Mucociliary activity impairment, immunosuppression due to the inhibition of alveolar macrophages and neutrophils by steroids, and receiving broad-spectrum antibiotics, play a role in the development of IPA in COPD patients. Colonized patients or those with IPA are older, with severe CODP stage (GOLD≥III), and have a higher number of comorbidities. The mortality rate is high due to the fact that having a definitive diagnosis of IPA in COPD patients is often difficult. The main clinical and radiological signs of IPA in these types of patients are non-specific, and tissue samples for definitive diagnosis are often difficult to obtain. The poor prognosis of IPA in COPD patients could perhaps be improved by faster diagnosis and prompt initiation of antifungal treatment. Some tools, such as scales and algorithms based on risk factors of IPA, may be useful for its early diagnosis in these patients.

How to manage aspergillosis in non-neutropenic intensive care unit patients

Invasive aspergillosis has been mainly reported among immunocompromised patients during prolonged periods of neutropenia. Recently, however, non-neutropenic patients in the ICU population have shown an increasing risk profile for aspergillosis. Associations with chronic obstructive pulmonary disease and corticosteroid therapy have been frequently documented in this cohort. Difficulties in achieving a timely diagnosis of aspergillosis in non-neutropenic patients is related to the non-specificity of symptoms and to lower yields with microbiological tests compared to neutropenic patients. Since high mortality rates are typical of invasive aspergillosis in critically ill patients, a high level of suspicion and prompt initiation of adequate antifungal treatment are mandatory. Epidemiology, risk factors, diagnostic algorithms, and different approaches in antifungal therapy for invasive aspergillosis in non-neutropenic patients are reviewed.

Current and future therapies for invasive aspergillosis

Invasive fungal infections have increase worldwide and represent a threat for immunocompromised patients including HIV-infected, recipients of solid organ and stem cell transplants, and patients receiving immunosuppressive therapies. High mortality rates and difficulties in early diagnosis characterize pulmonary fungal infections. Invasive pulmonary aspergillosis has been reviewed focussing on therapeutic management. Although new compounds have become available in the past years (i.e., amphotericin B lipid formulations, last-generation azoles, and echinocandines), new diagnostic tools and careful therapeutic management are mandatory to assure an early appropriate targeted treatment that represents the key factor for a successful conservative approach in respiratory fungal infections.

Eosinophil deficiency compromises lung defense against Aspergillus fumigatus

Exposure to the mold Aspergillus fumigatus may result in allergic bronchopulmonary aspergillosis, chronic necrotizing pulmonary aspergillosis, or invasive aspergillosis (IA), depending on the host's immune status. Neutrophil deficiency is the predominant risk factor for the development of IA, the most life-threatening condition associated with A. fumigatus exposure. Here we demonstrate that in addition to neutrophils, eosinophils are an important contributor to the clearance of A. fumigatus from the lung. Acute A. fumigatus challenge in normal mice induced the recruitment of CD11b+ Siglec F+ Ly-6G(lo) Ly-6C(neg) CCR3+ eosinophils to the lungs, which was accompanied by an increase in lung Epx (eosinophil peroxidase) mRNA levels. Mice deficient in the transcription factor dblGATA1, which exhibit a selective deficiency in eosinophils, demonstrated impaired A. fumigatus clearance and evidence of germinating organisms in the lung. Higher burden correlated with lower mRNA expression of Epx (eosinophil peroxidase) and Prg2 (major basic protein) as well as lower interleukin 1β (IL-1β), IL-6, IL-17A, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and CXCL1 levels. However, examination of lung inflammatory cell populations failed to demonstrate defects in monocyte/macrophage, dendritic cell, or neutrophil recruitment in dblGATA1-deficient mice, suggesting that the absence of eosinophils in dlbGATA1-deficient mice was the sole cause of impaired lung clearance. We show that eosinophils generated from bone marrow have potent killing activity against A. fumigtaus in vitro, which does not require cell contact and can be recapitulated by eosinophil whole-cell lysates. Collectively, our data support a role for eosinophils in the lung response after A. fumigatus exposure.