Allergic Bronchopulmonary Aspergillosis

Serum Cytokine Changes in a Patient with Chronic Pulmonary Aspergillosis Overlapping with Allergic Bronchopulmonary Aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) and chronic pulmonary aspergillosis (CPA) are diseases caused by Aspergillus infection, and CPA can develop from ABPA in some cases. We herein report a patient with CPA overlapping with ABPA. Serum cytokine levels were evaluated at 4 time points: the ABPA diagnosis, CPA diagnosis, 6 months after the start of voriconazole (VRCZ), and 12 months after re-administration of VRCZ. Interleukin (IL)-13 levels decreased upon glucocorticoid treatment, whereas IL-25 and IL-33 levels decreased rapidly with the initiation of antifungals. Early antifungal therapy may be important to control disease progression and prevent CPA overlap.

Clinical Manifestation and Treatment of Allergic Bronchopulmonary Aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is a complex hypersensitivity reaction to airway colonization by Aspergillus fumigatus in patients with asthma and cystic fibrosis. The pathophysiology of ABPA involves a complex interplay between the fungus and the host immune response, which causes persistent inflammation and tissue damage. Patients present with chronic cough, wheezing, and dyspnea due to uncontrolled asthma. Characteristic symptoms include the expectoration of brownish mucus plugs. Radiographic findings often reveal fleeting pulmonary infiltrates, bronchiectasis, and mucus impaction. However, the definitive diagnosis of ABPA requires a combination of clinical, radiological, and immunological findings. The management of ABPA aims to reduce symptoms, prevent disease progression, and minimize the future risk of exacerbations. The treatment approach involves systemic glucocorticoids or antifungal agents to suppress the inflammatory response or fungal growth and prevent exacerbations. Biological agents may be used in patients with severe disease or glucocorticoid dependence. This review provides an overview of the clinical manifestations and current treatment options for ABPA.

Pathogenicity and virulence of Aspergillus fumigatus

Pulmonary infections caused by the mould pathogen Aspergillus fumigatus are a major cause of morbidity and mortality globally. Compromised lung defences arising from immunosuppression, chronic respiratory conditions or more recently, concomitant viral or bacterial pulmonary infections are recognised risks factors for the development of pulmonary aspergillosis. In this review, we will summarise our current knowledge of the mechanistic basis of pulmonary aspergillosis with a focus on emerging at-risk populations.

Prevalence of Aspergillus sensitization and Allergic Bronchopulmonary Aspergillosis in bronchial asthma: A systematic review of Indian studies

Background

The prevalence of allergic bronchopulmonary aspergillosis (ABPA) in Indian asthmatic patients remains unknown. We systematically reviewed the literature for estimating the prevalence of Aspergillus sensitization (AS) and ABPA in Indian subjects with bronchial asthma.

Methods

We searched the PubMed and Embase databases for studies from India reporting the prevalence of AS or ABPA in at least 50 asthmatics. The primary outcome of our study was to assess the prevalence of ABPA. The secondary outcomes were to evaluate the prevalence of AS in asthma and ABPA in Aspergillus-sensitized asthma. We pooled the prevalence estimates using a random effects model and examined the factors influencing the prevalence using multivariate meta-regression.

Results

Of the 8,383 records retrieved, 34 studies with 14,580 asthmatics met the inclusion criteria. All the studies were from tertiary centers. The pooled prevalence of ABPA in asthmatics (26 studies; 5,554 asthmatics) was 16.2% [95% confidence interval (CI), 12.5-20.4]. The pooled prevalence of AS in asthma (29 studies; 13,405 asthmatics) was 30.9% (95% CI, 25.3-36.6), while the prevalence of ABPA in AS (20 studies; 1,493 asthmatics) was 48.2% (95% CI, 39.6-56.8). Meta-regression identified studies published after 2009 (OR 1.14; 95% CI, 1.02-1.28) and studies with severe asthmatics (OR 1.12; 95% CI, 1.00-1.26) as the only factors associated with higher ABPA prevalence.

Conclusions

There is a high prevalence of ABPA in Indian asthmatic subjects at tertiary centers, underscoring the need for screening all asthmatic subjects in special asthma and chest clinics for ABPA.

Severe Fungal Asthma: A Role for Biologics and Inhaled Antifungals

Allergic asthma has traditionally been treated with inhaled and systemic glucocorticosteroids. A continuum of allergic fungal airways disease associated with Aspergillus fumigatus colonization and/or atopic immune responses that encompasses fungal asthma, severe asthma with fungal sensitization and allergic bronchopulmonary aspergillosis is now recognized along a phenotypic severity spectrum of T2-high immune deviation lung disease. Oral triazoles have shown clinical, anti-inflammatory and microbiologic efficacy in this setting; in the future inhaled antifungals may improve the therapeutic index. Humanized monoclonal antibody biologic agents targeting T2-high disease also show efficacy and promise of improved control in difficult cases. Developments in these areas are highlighted in this overview.

Laboratory biomarkers in the diagnosis and follow-up of treatment of allergic bronchopulmonary aspergillosis in cystic fibrosis

Allergic bronchopulmonary aspergillosis (ABPA), a severe inflammatory respiratory disease, is caused by a hypersensitivity reaction to the colonization of the airways with Aspergillus fumigatus. It is most often described in patients with asthma or cystic fibrosis. The diagnosis of ABPA is based on a combination of clinical, radiological, and immunological findings that have been included in different diagnostic criteria over the years. In this paper, we review the biomarkers included in these diagnostic criteria and novel research biomarkers that may be used in the diagnosis and treatment follow-up of ABPA in cystic fibrosis.

Pulmonary aspergillosis: diagnosis and treatment

Aspergillusspecies are the most frequent cause of fungal infections of the lungs with a broad spectrum of clinical presentations including invasive pulmonary aspergillosis (IPA) and chronic pulmonary aspergillosis (CPA). IPA affects immunocompromised populations, which are increasing in number and diversity with the advent of novel anti-cancer therapies. Moreover, IPA has emerged as a complication of severe influenza and coronavirus disease 2019 in apparently immunocompetent hosts. CPA mainly affects patients with pre-existing lung lesions and is recognised increasingly frequently among patients with long-term survival following cure of tuberculosis or lung cancer. The diagnosis of pulmonary aspergillosis is complex as it relies on the presence of clinical, radiological and microbiological criteria, which differ according to the type of pulmonary aspergillosis (IPA or CPA) and the type of patient population. The management of pulmonary aspergillosis is complicated by the limited number of treatment options, drug interactions, adverse events and the emergence of antifungal resistance.

Higher risk for influenza-associated pulmonary aspergillosis (IAPA) in asthmatic patients: A Swiss multicenter cohort study on IAPA in critically ill influenza patients

BACKGROUND

Influenza-associated pulmonary aspergillosis (IAPA) is an important complication of severe influenza with high morbidity and mortality.

METHODS

We conducted a retrospective multicenter study in tertiary hospitals in Switzerland during 2017/2018 and 2019/2020 influenza seasons. All adults with PCR-confirmed influenza infection and treatment on intensive-care unit (ICU) for >24 h were included. IAPA was diagnosed according to previously published clinical, radiological, and microbiological criteria. We assessed risk factors for IAPA and predictors for poor outcome, which was a composite of in-hospital mortality, ICU length of stay ≥7 days, mechanical ventilation ≥7 days, or extracorporeal membrane oxygenation.

RESULTS

One hundred fifty-eight patients (median age 64 years, 45% females) with influenza were included, of which 17 (10.8%) had IAPA. Asthma was more common in IAPA patients (17% vs. 4% in non-IAPA, P = 0.05). Asthma (OR 12.0 [95% CI 2.1-67.2]) and days of mechanical ventilation (OR 1.1 [1.1-1.2]) were associated with IAPA. IAPA patients frequently required organ supportive therapies including mechanical ventilation (88% in IAPA vs. 53% in non-IAPA, P = 0.001) and vasoactive support (75% vs. 45%, P = 0.03) and had more complications including ARDS (53% vs. 26%, P = 0.04), respiratory bacterial infections (65% vs. 37%, P = 0.04), and higher ICU-mortality (35% vs. 16.4%, P = 0.05). IAPA (OR 28.8 [3.3-253.4]), influenza A (OR 3.3 [1.4-7.8]), and higher SAPS II score (OR 1.07 [1.05-1.10]) were independent predictors of poor outcome.

INTERPRETATION

High clinical suspicion, early diagnostics, and therapy are indicated in IAPA because of high morbidity and mortality. Asthma is likely an underappreciated risk factor for IAPA.

Progress and challenges in fungal lung disease in cystic fibrosis

PURPOSE OF REVIEW

This review is an overview of the recent progress made for the diagnosis and understanding of fungal lung disease in people with cystic fibrosis (CF), with a focus on Aspergillus fumigatus , the most common filamentous fungus in the CF airway. Currently, the longstanding question of the clinical significance of Aspergillus fumigatus and other fungi in CF respiratory cultures, in the absence of allergy, remains. Clinical criteria and biomarkers are needed to classify fungal lung disease and determine who may warrant therapy.

RECENT FINDINGS

Several retrospective and prospective studies have described the prevalence of A. fumigatus and other fungi in the CF lung and factors contributing to the changes in fungal epidemiology. Selective fungus culture testing for the detection of fungi in CF sputa has been well studied, yet a standardized fungus culture protocol has yet to be defined. Culture-independent molecular studies and other fungal diagnostic testing have been conducted in the CF population, leading to efforts to better understand the clinical role of these tests. Recent works have aimed to determine whether chronic A. fumigatus colonization is associated with lung disease progression measured by FEV 1 percentage predicted, structural lung disease, lung clearance index and respiratory quality-of-life. However, the existing knowledge gaps remain: definition of a fungal respiratory infection, the association between fungal infection and clinical outcomes, and indications for antifungal therapy.

SUMMARY

Significant progress has been made for the detection and diagnosis of fungal lung disease. Yet, the role and impact of A. fumigatus and other fungal infections on respiratory health in people with CF remains to be determined.

Biologic drugs in treating allergic bronchopulmonary aspergillosis in patients with cystic fibrosis: a systematic review

BACKGROUND

Aspergillus fumigatus is a common saprophytic fungus causing allergic bronchopulmonary aspergillosis (ABPA) in patients with cystic fibrosis (CF). The recommended first-line treatment for ABPA is oral steroids, followed by antifungal therapy. However, both treatments are not free from adverse effects; thus, efforts are being made to identify new drugs showing the same effectiveness but with fewer or no side-effects. Therein, biologic drugs have been significantly implemented in clinical practice in treating ABPA in patients with CF.

OBJECTIVE

To systematically review the available literature, providing evidence for the administration of biologic drugs as a new potential treatment of ABPA in both the paediatric and adult populations with CF.

METHODS

A systematic review of the literature published between January 2007 and July 2021 was performed, using a protocol registered with the International Prospective Register of Systematic Reviews (PROSPERO CRD42021270932).

RESULTS

A total of 21 studies focusing on the use of biologics in treating ABPA in CF patients was included. We highlighted a paucity of data providing evidence for biologic drug use in ABPA.

CONCLUSION

Scientific evidence is insufficient to support firm conclusions and randomised clinical trials are urgently required to investigate the efficacy and safety of biologics for ABPA in CF patients.

Clinical and immunological characteristics of Aspergillus fumigatus-sensitized asthma and allergic bronchopulmonary aspergillosis

Background

Aspergillus fumigatus (A.f) is a common airborne allergen that contributes to allergic asthma. In some patients, A.f can colonize in the airway and lead to allergic bronchopulmonary aspergillosis (ABPA). However, our understanding of the pathogenesis of A.f-sensitized asthma and ABPA remains inadequate.

Objective

We aimed to investigate the clinical and immunological characteristics of A.f-sensitized asthma and ABPA.

Methods

A total of 64 ABPA and 57 A.f-sensitized asthma patients were enrolled in the study, and 33 non-A.f-sensitized asthma patients served as the control group. The clinical and immunological parameters included lung function, fractional exhaled nitric oxide (FeNO), induced sputum and blood cell analysis, specific IgE/IgG/IgA of A.f and its components, cytokines (IL-33, IL-25, and TSLP) and CD4⁺T cell subsets.

Results

The eosinophils in blood, induced sputum, and FeNO were significantly higher in ABPA patients compared to that in A.f-sensitized patients. The combination of FeNO and eosinophils (EO) parameters presented good diagnostic efficiency in differentiating A.f (+) asthma from ABPA, with a sensitivity of 80% and a specificity of 100%. Specific IgE, IgG, and IgA against A.f also increased in ABPA patients. However, serum IL-25, IL-33, and TSLP showed no significant differences between the two groups. Cell analysis showed an increase in IFN-γ⁺Th1 cells in the ABPA patients. FlowSOM analysis further confirmed that the frequency of CD3⁺CD4⁺PD-1⁺CD127⁺IFN-γ⁺T cells was higher in ABPA patients.

Conclusion

Our findings suggest the distinct humoral and cell immunological responses in A.f-sensitized asthma and ABPA patients. ABPA patients have more severe eosinophilic inflammation and enhanced Th1 responses compared with A.f-sensitized asthma patients.

Serum Cytokines Usefulness for Understanding the Pathology in Allergic Bronchopulmonary Aspergillosis and Chronic Pulmonary Aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) and chronic pulmonary aspergillosis (CPA) are important fungal infections caused by Aspergillus species. An overlap of ABPA and CPA has been reported; therefore, it is critical to determine whether the main pathology is ABPA or CPA and whether antifungals are required. In this study, we investigated whether the serum cytokine profile is useful for understanding the pathology and for differentiating between these diseases. We compared the various serum cytokine levels among healthy subjects and patients diagnosed with asthma, ABPA, or CPA at Nagasaki University Hospital between January 2003 and December 2018. In total, 14 healthy subjects, 19 patients with asthma, 11 with ABPA, and 10 with CPA were enrolled. Interleukin (IL) -5 levels were significantly higher in patients with ABPA than in those with CPA, and IL-33 and tumor necrosis factor (TNF) levels were significantly higher in patients with CPA than in those with asthma (p < 0.05, Dunn’s multiple comparison test). The sensitivity and specificity of the IL-10/IL-5 ratio (cutoff index 2.47) for diagnosing CPA were 70% and 100%, respectively. The serum cytokine profile is useful in understanding the pathology of ABPA and CPA, and the IL-10/IL-5 ratio may be a novel supplemental biomarker for indicating the pathology of CPA.

Characterising the allergic profile of children with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) is a genetic condition that affects multiple organ systems. Allergic bronchopulmonary aspergillosis (ABPA) is a well-recognised problem but other allergic conditions are less well documented in CF.

OBJECTIVE

To characterise the allergic profile of a cohort of children with CF, with a focus on those with ABPA.

METHODS

A cohort of children with CF were interviewed and retrospective data were collected regarding their allergic histories and other relevant clinical features.

RESULTS

The cohort included 37 children with median age of 9 years (interquartile range: 6-12). There was a history of ≥1 allergic condition(s) in 28/37 children (76%). The most common allergic condition was allergic rhinitis (AR) in 21/37 (57%) and 16 of these 21 children (76%) had another allergic condition. All children with ABPA (8) had another allergic condition. In some children ABPA exacerbations appeared to be seasonal, suggesting possible cross-sensitisation between Aspergillus fumigatus and aeroallergens associated with seasonal AR. Allergic conditions were also common in children with Pseudomonas aeruginosa infection.

The Use of Targeted Monoclonal Antibodies in the Treatment of ABPA—A Case Series

Allergic bronchopulmonary aspergillosis (ABPA) is a pulmonary disorder occurring in response to Aspergillus fumigatus that can complicate the course of asthma and cystic fibrosis. Here we present a case of acute ABPA without central bronchiectasis, a case of chronic active ABPA with central bronchiectasis, and a case of severe relapsing ABPA with central bronchiectasis. All three were initially treated with corticosteroids and antifungal agents but had an incomplete response. These patients were then treated with anti-IgE therapy with omalizumab before being switched to the anti-IL5R agent benralizumab. They responded well to both agents. These case reports highlight the potential role of omalizumab and benralizumab in the treatment of ABPA, but further studies are required to evaluate the effectiveness of these medications. Longer follow-up periods and objective measurements of the impact of treatment are necessary.

Epidemiology and outcomes of allergic bronchopulmonary aspergillosis in the elderly

BACKGROUND

The prevalence and outcomes of allergic bronchopulmonary aspergillosis (ABPA) in the elderly remain unknown.

METHODS

We reviewed our database to identify the proportion of subjects diagnosed with ABPA at ≥60 years of age (ABPA-elderly). We compared the clinical features, treatment and outcomes of ABPA-elderly versus the non-elderly (ABPA diagnosed at <60 years of age).

RESULTS

Between 2007 and 2019, we encountered 810 ABPA subjects with a mean age of 34.9 years (49.4% women). Of these, 43 (5.3%) were aged ≥60 years (ABPA-elderly). There was a trend towards lower median (interquartile range [IQR]) serum total IgE (4900 [2659-10000] vs. 7156 [23360-11963] IU/mL; P = .06) and Aspergillus fumigatus-specific IgE (12.3 [4.8-29.6] vs. 22.4 [7.7-41.5] kUA/L; P = .06) in the elderly than the non-elderly. Eosinophil counts were similar in the two groups. The median [IQR] number of segments involved by bronchiectasis (5 [2-9] vs. 7 [4-11]) was significantly lower in the ABPA-elderly (P = .001). The proportion of subjects experiencing ABPA exacerbations was significantly (P = .047) lower in the elderly (25.6%) vs. the non-elderly (40.8%). There was also a tendency towards a lower mean number of exacerbations in the elderly (155 vs. 208 exacerbation per 1000 person-years) than the non-elderly (P = .09). There was also a trend towards longer mean time to first exacerbation in the ABPA-elderly than the non-elderly (1612 vs. 1159 days).

CONCLUSION

ABPA was uncommon in the elderly. The bronchiectasis is less extensive with a trend towards lower immunological severity and fewer exacerbations in the elderly than the non-elderly subjects with ABPA.

Review of current and future therapeutics in ABPA

Allergic bronchopulmonary aspergillosis is an allergic pulmonary condition caused by hypersensitivity to antigens of Aspergillus sp. found most commonly in patients with underlying asthma or cystic fibrosis. Host factors which alter the innate and adaptive immune responses to this abundant airborne fungus contribute to the development of chronic airway inflammation, bronchiectasis, and fibrosis. Traditionally, treatment has focussed on reducing fungal burden and immune response to fungal antigens. However, a significant proportion of patients continue to suffer recurrent exacerbations with progressive lung damage, and the side effect burden of existing treatments is high. New treatments including novel antifungal agents, monoclonal antibodies against aspects of the adaptive immune response as well as targeted immunotherapies may be better tolerated and achieve improved outcomes but have not yet been studied in large-scale randomised control trials.

A randomised trial of prednisolone versus prednisolone and itraconazole in acute-stage allergic bronchopulmonary aspergillosis complicating asthma

Whether a combination of glucocorticoid and antifungal triazole is superior to glucocorticoid alone, in reducing exacerbations, in patients with allergic bronchopulmonary aspergillosis (ABPA) remains unknown. We aimed to compare the efficacy and safety of prednisolone-itraconazole combination versus prednisolone monotherapy in ABPA.We randomised subjects with treatment-naïve acute-stage ABPA complicating asthma to receive either prednisolone alone (four months) or a combination of prednisolone and itraconazole (four and six months, respectively). The primary outcomes were exacerbation rates at 12 months and glucocorticoid-dependent ABPA within 24 months of initiating treatment. The key secondary outcomes were response rates and percentage decline in serum total IgE at six weeks, time to first ABPA exacerbation, and treatment-emergent adverse effects (AE).We randomised 191 subjects to receive either prednisolone (n=94) or prednisolone-itraconazole combination (n=97). The one-year exacerbation rate was 33% and 20.6% in the prednisolone and the prednisolone-itraconazole arms, respectively (p=0.054). None of the participants progressed to glucocorticoid-dependent ABPA. All the subjects experienced a composite response at 6-weeks, along with a decline in serum total IgE (mean decline, 47.6% versus 45.5%). The mean time to first ABPA exacerbation (417 days) was not different between the groups. None of the participants required modification of therapy due to AE.There was a trend towards a decline in ABPA exacerbations at 1-year with the prednisolone-itraconazole combination than prednisolone monotherapy. A three-arm trial comparing itraconazole and prednisolone monotherapies with their combination, preferably in a multicentric design, is required to define the best treatment strategy for acute-stage ABPA.

Successful Treatment of Allergic Bronchopulmonary Aspergillosis Using a Combination of Inhaled Fluticasone Furoate/Vilanterol and Oral Voriconazole

Systemic corticosteroids are considered to be the standard treatment for allergic bronchopulmonary aspergillosis (ABPA). However, there is controversy regarding use of inhaled corticosteroid (ICS) therapy for ABPA. Here we report a case of ABPA that was successfully treated with inhaled fluticasone furoate/vilanterol (FF/VI) and oral voriconazole (VRCZ). The patient was a 62-year-old Japanese man with bronchiectasis and diabetes mellitus who presented with fever, cough, and purulent sputum. Computed tomography scans of the chest showed consolidation in the left upper and lower lobes. Laboratory investigations revealed an abnormal increase in the number of eosinophils (3,340/mm³) and elevated levels of C-reactive protein (3.04 mg/dL) and serum immunoglobulin E (IgE) (763 U/mL). Eight days after admission, he experienced a sudden attack of asthma. Aspergillus-precipitating antibodies were positive and Aspergillus fumigatus was detected in sputum culture. These results were consistent with a diagnosis of ABPA, and he was started on inhaled FF/VI and oral VRCZ. Systemic corticosteroids were not used because of the patient’s history of diabetes mellitus and left atrial thrombus. His symptoms and consolidation improved significantly after treatment. He has not experienced an exacerbation for more than 3 years. In mild cases of ABPA in which total IgE is relatively low, inhaled FF/VI in combination with oral VRCZ can be considered as an alternative treatment to systemic corticosteroids in patients with ABPA.

Misdiagnosis of persistent asthma of a patient suffering from acute bronchopulmonary aspergillosis (ABPA)

Background

Allergic bronchopulmonary aspergillosis (ABPA) is a condition characterized by an exaggerated immune response (a hypersensitivity response) to the fungus Aspergillus (most commonly Aspergillus fumigatus).ABPA causes airway inflammation that if left untreated can lead to bronchiectasis (an abnormal dilation of the airways) due to the immune system and fungal spores damaging sensitive lung tissues and ultimately leading to scarring.

Case presentation

We present a case of a 32-year-old female patient who was misdiagnosed with persistent asthma and treated accordingly for several months until a reexamination was done and a diagnosis of ABPA was concluded. Treatment was altered which led to the successful recovery of the patient.

Conclusion

A reevaluation of the patients' condition was needed to arrive to the correct diagnosis and to put her on the correct treatment as an ABPA patient instead of persistent asthma, concluding that the medical history and physical examination are both of vital significance to stipulate a correct diagnosis.

Peroxiredoxin Asp f3 Is Essential for Aspergillus fumigatus To Overcome Iron Limitation during Infection

Aspergillus fumigatus is an important fungal pathogen that causes allergic reactions but also life-threatening infections. One of the most abundant A. fumigatus proteins is Asp f3. This peroxiredoxin is a major fungal allergen and known for its role as a virulence factor, vaccine candidate, and scavenger of reactive oxygen species. Based on the hypothesis that Asp f3 protects A. fumigatus against killing by immune cells, we investigated the susceptibility of a conditional aspf3 mutant by employing a novel assay. Surprisingly, Asp f3-depleted hyphae were killed as efficiently as the wild type by human granulocytes. However, we identified an unexpected growth defect of mutants that lack Asp f3 under low-iron conditions, which explains the avirulence of the Δaspf3 deletion mutant in a murine infection model. A. fumigatus encodes two Asp f3 homologues which we named Af3l (Asp f3-like) 1 and Af3l2. Inactivation of Af3l1, but not of Af3l2, exacerbated the growth defect of the conditional aspf3 mutant under iron limitation, which ultimately led to death of the double mutant. Inactivation of the iron acquisition repressor SreA partially compensated for loss of Asp f3 and Af3l1. However, Asp f3 was not required for maintaining iron homeostasis or siderophore biosynthesis. Instead, we show that it compensates for a loss of iron-dependent antioxidant enzymes. Iron supplementation restored the virulence of the Δaspf3 deletion mutant in a murine infection model. Our results unveil the crucial importance of Asp f3 to overcome nutritional immunity and reveal a new biological role of peroxiredoxins in adaptation to iron limitation.

Allergic Diseases Caused by Aspergillus Species in Patients with Cystic Fibrosis

Aspergillus spp. are spore forming molds; a subset of which are clinically relevant to humans and can cause significant morbidity and mortality. A. fumigatus causes chronic infection in patients with chronic lung disease such as asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF). In patients with CF, A. fumigatus infection can lead to allergic disease, such as allergic bronchopulmonary aspergillosis (ABPA) which is associated with high rates of hospitalizations for acute exacerbations and lower lung function. ABPA results from T_H2 immune response to Aspergillus antigens produced during hyphal growth, marked by high levels of IgE and eosinophil activation. Clinically, patients with ABPA experience difficulty breathing; exacerbations of disease and are at high risk for bronchiectasis and lung fibrosis. Oral corticosteroids are used to manage aspects of the inflammatory response and antifungal agents are used to reduce fungal burden and lower the exposure to fungal antigens. As the appreciation for the severity of fungal infections has grown, new therapies have emerged that aim to improve treatment and outcomes for patients with CF.

Allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is an inflammatory disease caused by immunologic reactions initiated against Aspergillus fumigatus colonizing the airways of patients with asthma and cystic fibrosis. The common manifestations include treatment-resistant asthma, transient and fleeting pulmonary opacities and bronchiectasis. It is believed that globally there are about five million cases of ABPA, with India alone accounting for about 1.4 million cases. The occurrence of ABPA among asthmatic patients in special clinics may be as high as 13 per cent. Thus, a high degree of suspicion for ABPA should be entertained while treating a patient with bronchial asthma, particularly in specialized clinics. Early diagnosis and appropriate treatment can delay (or even prevent) the onset of bronchiectasis, which suggests that all patients of bronchial asthma should be screened for ABPA, especially in chest clinics. The current review summarizes the recent advances in the pathogenesis, diagnosis and management of ABPA.

Role of circulating microRNA-132 in allergic bronchopulmonary aspergillosis: A case-control study

Allergic bronchopulmonary aspergillosis (ABPA) is an allergic respiratory disease. In the current study, we aimed to evaluate the roles of miRNA-21 and miRNA132 as biomarkers in the diagnosis of ABPA. A total of 30 controls, 30 allergic asthmatic patients, 30 severe asthma with fungal sensitization (SAFS) patients, and 30 ABPA patients were included. Real-time polymerase chain reaction was used to quantify the level of miRNAs expression. The expression level of miRNA-21 was significantly higher in allergic asthmatic, SAFS, and ABPA patients in comparison with controls (p < 0.001). However, no significant difference was detected in the expression level of miRNA-21 among the different patient groups (p > 0.05). The ABPA patients had significantly higher levels of miRNA-132 expression compared to controls, allergic asthmatic patients, and SAFS patients (p < 0.001), but there was a non-significant difference between controls and allergic asthmatic patients (p = 0.09). At a cut-off of 1.52, the sensitivity of miRNA-132 expression was 93.3% and the specificity was 100% different ABPA from healthy controls. At a cut-off of 6.5, miRNA-132 expression was found to reliably differentiate between ABPA and SAFS, with a sensitivity of 86.7% and a specificity of 80%. In ABPA patients, miRNA-132 expression positively correlation with the levels of serum IL-5 (r = 0.91, p < 0.001). miRNA-132 has a role in ABPA detection and distinguishing ABPA from allergic asthma and SAFS. These preliminary data from case-control study need further studies to confirm its finding.

Frequent Pet Contact as Risk Factor for Allergic Bronchopulmonary Aspergillosis in Cystic Fibrosis

Aspergillus fumigatus (Af) frequently colonizes the respiratory tract of patients with cystic fibrosis (CF). Af is associated with loss of pulmonary function and allergic bronchopulmonary aspergillosis (ABPA), a hypersensitivity fungal lung disease. Environmental factors have impact on CF patients’ lung function variation. The aim of this nationwide questionnaire survey was to investigate the amount of CF patients with frequent pet contact including pet species and to examine the potential impact of frequent pet contact on the occurrence of Af colonization and ABPA diagnosis in these patients. The survey was carried out in 31 German CF centers in 2018. A total of 1232 who completed the surveys were included, and statistical analysis was performed by chi-squared test. Within the study cohort 49.8% of subjects (n = 614; CF patients < 18years: 49.4%, n = 234; ≥ 18years: 50.1%, n = 380) reported frequent contact to pets, of which 60.7% reported frequent contact to dogs, 42.3% to cats and other animals. Of those with frequent pet contact, 71.8% (n = 441) had contact to one pet or more pets from the same family. Af colonization was not significantly associated with frequent pet contact. ABPA diagnosis was documented in 16.7% (n = 206) of all included CF patients and was significantly associated with frequent pet contact (18.9%, n = 116, p = 0.042), confirming previous single center examinations. Particularly, patients with frequent contact to dogs showed an increased ABPA prevalence of 21.3%. Frequent pet contact might be a risk factor for ABPA. CF patients who are sensitized to Af should be informed about the increased risk to develop an ABPA by frequent pet contact. Patients with recurrent onset of ABPA should be evaluated in terms of frequent pet contact.

The infectious propagules of Aspergillus fumigatus are coated with antimicrobial peptides

Fungal spores are unique cells that mediate dispersal and survival in the environment. For pathogenic fungi encountering a susceptible host, these specialised structures may serve as infectious particles. The main causative agent of the opportunistic disease aspergillosis, Aspergillus fumigatus, produces asexual spores, the conidia, that become dissipated by air flows or water currents but also serve as propagules to infect a susceptible host. We demonstrate that the defX gene of this mould encodes putative antimicrobial peptides resembling cysteine-stabilised (CS)αβ defensins that are expressed in a specific spatial and temporal manner in the course of asexual spore formation. Localisation studies on strains expressing a fluorescent proxy or tagged defX alleles expose that these antimicrobial peptides are secreted to coat the conidial surface. Deletion mutants reveal that the spore-associated defX gene products delay the growth of Gram-positive Staphylococcus aureus and demonstrate that the defX gene and presumably its encoded spore-associated defensins confer a growth advantage to the fungal opponent over bacterial competitors. These findings have implications with respect to the ecological niche of A. fumigatus that serves as a 'virulence school' for this human pathogenic mould; further relevance is given for the infectious process resulting in aspergillosis, considering competition with the host microbiome or co-infecting microorganisms to break colonisation resistance at host surfaces.

Obstructive lung diseases and allergic bronchopulmonary aspergillosis

PURPOSE OF REVIEW

Allergic bronchopulmonary aspergillosis (ABPA) is a disease frequently complicating asthma and cystic fibrosis. ABPA is increasingly recognized in other obstructive lung diseases (OLDs), including chronic obstructive pulmonary disease (COPD) and noncystic fibrosis bronchiectasis. Herein, we summarize the recent developments in ABPA complicating OLDs.

RECENT FINDINGS

Recent research has described the clinical features and natural history of ABPA complicating asthma in children and the elderly. We have gained insights into the pathophysiology of ABPA, especially the role of eosinophil extracellular trap cell death and mucus plugs. The utility of recombinant fungal antigens in the diagnosis of ABPA has been established. Newer, more sensitive criteria for the diagnosis of ABPA have been proposed. Although ABPA is uncommon in COPD and noncystic fibrosis bronchiectasis, aspergillus sensitization is more common and is associated with a higher exacerbation rate.

SUMMARY

Several advances have occurred in the diagnosis and treatment of ABPA in recent years. However, there is an unmet need for research into the genetic predisposition, pathophysiology, and treatment of ABPA. Apart from asthma and cystic fibrosis, patients with other OLDs also require evaluation for Aspergillus sensitization and ABPA.

The perils of a persistent cough

Always consider an underlying diagnosis of Aspergillus-related disease when faced with persistent symptoms in an individual with predisposing risk factors (e.g. asthma) http://bit.ly/3aBTQip.

Genome Wide Analysis Reveals the Role of VadA in Stress Response, Germination, and Sterigmatocystin Production in Aspergillus nidulans Conidia

In the Aspergillus species, conidia are asexual spores that are infectious particles responsible for propagation. Conidia contain various mycotoxins that can have detrimental effects in humans. Previous study demonstrated that VadA is required for fungal development and spore viability in the model fungus Aspergillus nidulans. In the present study, vadA transcriptomic analysis revealed that VadA affects the mRNA expression of a variety of genes in A. nidulans conidia. The genes that were primarily affected in conidia were associated with trehalose biosynthesis, cell-wall integrity, stress response, and secondary metabolism. Genetic changes caused by deletion of vadA were related to phenotypes of the vadA deletion mutant conidia. The deletion of vadA resulted in increased conidial sensitivity against ultraviolet stress and induced germ tube formation in the presence and absence of glucose. In addition, most genes in the secondary metabolism gene clusters of sterigmatocystin, asperfuranone, monodictyphenone, and asperthecin were upregulated in the mutant conidia with vadA deletion. The deletion of vadA led to an increase in the amount of sterigmatocystin in the conidia, suggesting that VadA is essential for the repression of sterigmatocystin production in conidia. These results suggest that VadA coordinates conidia maturation, stress response, and secondary metabolism in A. nidulans conidia.

Diagnostic cut-off value for Aspergillus fumigatus- and flavus-specific IgG with clinical relevance in chronic pulmonary Aspergillus infection: A pilot study in Taiwan

BACKGROUND

The diagnostic cut-off value for chronic pulmonary Aspergillosis (CPA) by Aspergillus fumigatus-specific IgG has never been evaluated In Taiwan. The cut-off value for Aspergillus flavus-specific IgG has not been evaluated worldwide.

OBJECTIVES

Evaluate diagnostic cut-off value of Aspergillus IgG and its application characteristics.

PATIENTS/METHODS

Blood from control groups and treatment-naïve patients with CPA infections was collected for Aspergillus-specific IgG measurements. Controls were patients who had chest radiographic abnormalities and signs of respiratory tract infection, but were negative for Aspergillus and resolved without anti-mould therapy. Confirmation and probability of CPA were defined according to radiological features and positivity for an Aspergillus or galactomannan index. Chest computer tomography patterns were recorded for the presence of aspergilloma or nodules, subacute invasive aspergillosis, chronic cavitary pulmonary aspergillosis and chronic fibrotic pulmonary aspergillosis.

RESULTS

A total of 35 cases and 50 disease controls were included. The levels of A. fumigatus- and A. flavus-specific IgG correlated with CPA progression (P < .05) but not with the presence of Aspergillus species from clinical specimens (P > .05). The best cut-off value for A. fumigatus IgG was 21.7 mg/L with area under curve (AUC) for receiver operating characteristic curve (ROC) 0.934 and had 85.7% sensitivity and 92.0% specificity. For A. flavus IgG, the best cut-off value was 22.1 mgA/L and the AUC was 0.928 with 88.2% sensitivity and 94.1% specificity.

CONCLUSION

The level of Aspergillus-specific IgG correlated with radiographic characteristics in patients with CPA and the best cut-off values compared to controls were 21.7 mgA/L for A. fumigatus-specific IgG and 22.1 mgA/L for A. flavus-specific IgG.

Analysis of serum polyunsaturated fatty acid metabolites in allergic bronchopulmonary aspergillosis

BACKGROUND

The importance of lipid mediators in allergic diseases has been long recognized, whereas little is known about their role in allergic bronchopulmonary aspergillosis (ABPA). We investigated whether lipid mediators are associated with ABPA.

METHODS

We recruited 12 ABPA patients, 23 asthma patients and 12 healthy control in our study. Serum of 11 ABPA patients were collected before and following treatment. 36 polyunsaturated fatty acid metabolites were measured in serum samples by using liquid chromatography-mass spectrometry. This study was approved by the Ethics Committee of the First Affiliated Hospital of Guangzhou Medical University, with ethics number GYFYY-2016-73.

RESULTS

Levels of arachidonic acid (AA), 15(S)-hydroxyeicosatetraenoic acid (HETE), 12(S)-HETE, 8(S)-HETE, 5(S)-HETE, LTB₄, PGB₂, 12(S)-hydroxyeicosapentaenoic acid (HEPE), 12-hydro-xyheptadecatrienoic acid (HHTrE) were significantly higher in ABPA patients than that in HC groups. Compared with asthma group, ABPA group expressed lower levels of 15(S)-hy-droperoxyeicosatetraenoic acid (HPETE), 5(S)-HPETE, 13(S)-hydroperoxyoctadecadienoic acid (HPODE) and 9(S)-HPODE. In APBA patients, AA level was positively correlated with serumtotal IgE (tIgE). The levels of 12(S)-HPETE, 15(S)-HEPE and 12(S)-HEPE correlated with Asp-ergillus fumigatus specific IgE(A. fumigatus sIgE) positively. Peripheral blood eosinophilia correlated with high levels of 12(S)-HETE and 15(S)-HETE. In addition, the serum levels of15(S)-HETE and 12(S)-HETE in ABPA subjects both declined with the decrease of tIgE, A. fumigatus sIgE and sIgG concentrations after treatment.

CONCLUSIONS

We present data regarding the role of polyunsaturated fatty acid metabolites in APBA for the first time. Most of the tested metabolites increased in ABPA when co-mpared with healthy controls and 15(S)-HETE and 12(S)-HETE may play a role in the pat-hogenesis of ABPA. These findings can provide new ideas for diagnosis, therapy and mon-itor of ABPA.

Clinical characteristics of allergic bronchopulmonary aspergillosis

BACKGROUND

Allergic bronchopulmonary aspergillosis (ABPA) is an allergic pulmonary disease caused by a hypersensitivity reaction to Aspergillus colony in the airways. Due to the diversity of disease manifestations and physicians' incomplete knowledge of ABPA, patients with ABPA are often misdiagnosed and given poor prognosis.

OBJECTIVES

To investigate the clinical characteristics, treatment and prognosis status among patients with ABPA.

METHODS

We retrospectively analyzed 75 patients diagnosed as ABPA in Zhongshan Hospital, Fudan University between October 2008 and June 2018.

RESULTS

Among 75 patients, 28% had asthma as the predisposing condition and 69% suffered from misdiagnosis before ABPA diagnosis was made, among which 21% were misdiagnosed as tuberculosis. About 34% of patients had eosinophil count below 500 cells/μL and 25% had total serum IgE level <1000 IU/mL. Nearly half of patients did not meet the diagnostic criteria of ABPA and all the patients who overlapped with invasive pulmonary aspergillosis (IPA) did not meet the diagnostic criteria of standard ABPA. Patients who did not fully meet the diagnostic criteria were more likely treated with inhaled corticosteroids (ICS) and antibiotics, but more difficult to attain response and remission and easier to develop advanced ABPA.

CONCLUSIONS

This study demonstrates an unsatisfactory situation of diagnosis, treatment and prognosis of ABPA, including a high misdiagnosis rate, uncertainty in the diagnosis of ABPA, lack of standardization in treatment and relatively poor prognosis.

Use of monoclonal antibodies for allergic bronchopulmonary aspergillosis in patients with asthma and cystic fibrosis: literature review

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity reaction (HR) mediated by antigens to Aspergillus fumigatus. It is estimated that 2-15% of patients with cystic fibrosis (CF) and between 1% and 5% of asthmatics develop ABPA, affecting approximately 4.8 million people worldwide. The goals of treatment are controlling inflammation, reducing the number of exacerbations and limiting the progression of lung damage. Systemic steroids are therefore used as the mainstay therapy, along with antifungal medications. However, many patients do not respond or develop side effects to treatment. In this scenario, biological drugs such as Omalizumab, Mepolizumab, Benralizumab and Dupilumab have been implemented in clinical practice, even though there is a lack of scientific evidence to support their use. We performed a literature review of the studies carried out which analyzed biologics for the management of ABPA in adult populations with asthma and CF. To our knowledge this is the first literature review that included all biologics. We included a total of 32 studies, all but one were descriptive studies, and the vast majority evaluated the use of Omalizumab. Biologics appeared to have more benefit for patients with ABPA and asthma than CF, specifically at decreasing the frequency of acute exacerbations and by having a steroid-sparing effect. Although a decrease in serum IgE level is considered a measure of therapy success, values may not decline as expected in the context of a significant clinical improvement, highlighting the importance of measuring patient-oriented outcomes. As evidence comes mainly from case series and case reports, randomized controlled trials are needed to evaluate further the safety and efficacy of biologics in ABPA.The reviews of this paper are available via the supplemental material section.

Novel Hit Compounds as Putative Antifungals: The Case of Aspergillus fumigatus

The prevalence of invasive fungal infections has been dramatically increased as the size of the immunocompromised population worldwide has grown. Aspergillus fumigatus is characterized as one of the most widespread and ubiquitous fungal pathogens. Among antifungal drugs, azoles have been the most widely used category for the treatment of fungal infections. However, increasingly, azole-resistant strains constitute a major problem to be faced. Towards this direction, our study focused on the identification of compounds bearing novel structural motifs which may evolve as a new class of antifungals. To fulfil this scope, a combination of in silico techniques and in vitro assays were implemented. Specifically, a ligand-based pharmacophore model was created and served as a 3D search query to screen the ZINC chemical database. Additionally, molecular docking and molecular dynamics simulations were used to improve the reliability and accuracy of virtual screening results. In total, eight compounds, bearing completely different chemical scaffolds from the commercially available azoles, were proposed and their antifungal activity was evaluated using in vitro assays. Results indicated that all tested compounds exhibit antifungal activity, especially compounds 1, 2, and 4, which presented the most promising minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values and, therefore, could be subjected to further hit to lead optimization.

Elevated serum levels of periostin in patients with allergic bronchopulmonary aspergillosis

BACKGROUND

Serum periostin levels have been reported to be an indicator of Th2 inflammation in asthmatic patients.

OBJECTIVE

This study aimed to investigate serum levels of periostin in patients with allergic bronchopulmonary aspergillosis (ABPA) and to evaluate its diagnostic and monitoring value in the disease.

METHODS

Patients with ABPA (n = 19) and asthma (n = 24), including severe asthma with fungal sensitisation (SAFS, n = 11) and severe asthma without fungal sensitization (SAwFS, n = 13), were enrolled. Serum levels of periostin were analysed by enzyme-linked immunosorbent assay. Serum total IgE and Aspergillus fumigatus specific IgE, IgG were measured by ImmunoCAP. Levels of cytokines (IFN-γ, IL-4, IL-5, IL-8, IL-10, IL-13 and IL-17A) were measured by Meso Scale Discovery (MSD).

RESULTS

Serum levels of periostin in ABPA patients (85.55 ng/mL, [68.28-166] ng/mL) were higher than those in SAFS (50.99 ng/mL, [32.02-71.80] ng/mL; P < 0.01). Among the analysed cytokines, IL-5 levels in ABPA (1.55 pg/mL, [0.96-3.33] pg/mL) were higher than those in SAFS (0.31 pg/mL, [0.26-0.56] pg/mL; P < 0.05) or SAwFS (0.34 pg/mL, [0.21-0.56] pg/mL; P < 0.01). Serum periostin levels was positively associated with total IgE levels (r = 0.319, P < 0.05), serum IL-5 levels (r = 0.484, P < 0.01) and blood eosinophil counts (r = 0.428, P < 0.05). In ROC analysis, the clinical reference value of periostin was 68.8 ng/mL for differential diagnosis of ABPA and SAFS, with the area under the curve (AUC) of 0.81. Longitudinally, serum periostin levels did not change significantly after treatment in ABPA.

CONCLUSIONS

These findings suggested that serum levels of periostin were up-regulated in ABPA patients, which may be associated with eosinophilic inflammation.

Pathophysiological aspects of Aspergillus colonization in disease

Aspergillus colonization of the lower respiratory airways is common in normal people, and of little clinical significance. However, in some patients, colonization is associated with severe disease including poorly controlled asthma, allergic bronchopulmonary aspergillosis (ABPA) with sputum plugs, worse lung function in chronic obstructive pulmonary aspergillosis (COPD), invasive aspergillosis, and active infection in patients with chronic pulmonary aspergillosis (CPA). Therefore, understanding the pathophysiological mechanisms of fungal colonization in disease is essential to develop strategies to avert or minimise disease. Aspergillus cell components promoting fungal adherence to the host surface, extracellular matrix, or basal lamina are indispensable for pathogen persistence. However, our understanding of individual differences in clearance of A. fumigatus from the lung in susceptible patients is close to zero.

Allergic bronchopulmonary aspergillosis presumably unmasked by PD-1 inhibition

Programmed cell death-1 (PD-1) inhibitors stimulate immune recognition of tumour cells in cancer patients, but have significant autoimmune side effects including pneumonitis. We report the case of a patient with asthma and mild eosinophilia who developed unusual pulmonary side effect of bronchiectasis, severe eosinophilia (absolute eosinophil count: 3200 c/mm³) and elevated IgE levels (7050 IU/mL; normal: <164 IU/mL) 4 months into therapy with the PD-1 inhibitor pembrolizumab. Aspergillus fumigatus IgG was elevated at 15.60 U/mL (normal: <12.01 U/mL). He responded to therapy with corticosteroids and voriconazole and was able to resume pembrolizumab thereafter with good clinical response.

CYP51 as drug targets for fungi and protozoan parasites: past, present and future

The efficiency of treatment of human infections with the unicellular eukaryotic pathogens such as fungi and protozoa remains deeply unsatisfactory. For example, the mortality rates from nosocomial fungemia in critically ill, immunosuppressed or post-cancer patients often exceed 50%. A set of six systemic clinical azoles [sterol 14α-demethylase (CYP51) inhibitors] represents the first-line antifungal treatment. All these drugs were discovered empirically, by monitoring their effects on fungal cell growth, though it had been proven that they kill fungal cells by blocking the biosynthesis of ergosterol in fungi at the stage of 14α-demethylation of the sterol nucleus. This review briefs the history of antifungal azoles, outlines the situation with the current clinical azole-based drugs, describes the attempts of their repurposing for treatment of human infections with the protozoan parasites that, similar to fungi, also produce endogenous sterols, and discusses the most recently acquired knowledge on the CYP51 structure/function and inhibition. It is our belief that this information should be helpful in shifting from the traditional phenotypic screening to the actual target-driven drug discovery paradigm, which will rationalize and substantially accelerate the development of new, more efficient and pathogen-oriented CYP51 inhibitors.

Asthma and Fungus: Role in Allergic Bronchopulmonary Aspergillosis (ABPA) and Other Conditions

Asthma is an allergic, respiratory disorder characterized by hyper responsiveness of the airway to external stimuli. Considerable research is currently being directed towards understanding the role of environmental and genetic factors contributing to the development of asthma and its severity. Recent years have seen a substantial rise in evidence linking fungi to asthma. Few major clinical conditions associated with fungal sensitization and hypersensitive immune response are Allergic bronchopulmonary aspergillosis (ABPA), Allergic fungal rhinosinusitis (AFRS) and Severe asthma with fungal sensitization (SAFS). The most common fungi implicated in these conditions belong to genus Aspergillus, although an association with several other fungi has been described. In this review authors discuss the varying clinical characteristics of fungus induced respiratory complications in individuals with asthma. They also highlight the epidemiology of these conditions including their prevalence in children and their fungal etiological profile. Laboratory diagnostic methods and clinical case definitions have also been discussed. Future studies evaluating the role of fungal exposure and susceptibility to asthma are required. Till date there are no guidelines for the diagnosis and treatment of ABPA in pediatric population, thus it is also imperative to establish validated clinical definitions of fungal allergic manifestations in pediatric patients with asthma to fully understand this complex interaction.

Role of Serological Tests in the Diagnosis of Mold Infections

Purpose of Review

To understand the role of antibody detection in the diagnosis of infections caused by filamentous fungi (molds). Rapid and accurate profiling of infection-causing fungal pathogens remains a significant challenge in modern health care. Classical fungal culture and serology continue to be relevant even though over the past few decades, antigen (biomarker) assays such as ELISA and lateral flow devices have been developed and validated.

Recent Findings

This article reviews the current antibody detection systems (serological tests) for the diagnosis of mold infections associated with pulmonary disease and introduces new developments. Classic and more recently developed serological techniques and their performance characteristics, including immunodiffusion, complement fixation, and ELISA.

Summary

The diseases covered are allergic bronchopulmonary aspergillosis, chronic pulmonary aspergillosis, invasive aspergillosis, mucormycosis, diseases caused by filamentous basidiomycetes, infection caused by Talaromyces marneffei and pythiosis. Serology remains a cornerstone for fungal diagnostic testing.

The pathogenicity ofAspergillus fumigatus, drug resistance, and nanoparticle delivery

The genus Aspergillus includes fungal species that cause major health issues of significant economic importance. These microorganisms are also the culprit for production of carcinogenic aflatoxins in grain storages, contaminating crops, and economically straining the production process. Aspergillus fumigatus is a very important pathogenic species, being responsible for high human morbidity and mortality on a global basis. The prevalence of these infections in immunosuppressed individuals is on the rise, and physicians struggle with the diagnosis of these deadly pathogens. Several virulence determinants facilitate fungal invasion and evasion of the host immune response. Metabolic functions are also important for virulence and drug resistance, since they allow fungi to obtain nutrients for their own survival and growth. Following a positive diagnostic identification, mortality rates remain high due, in part, to emerging resistance to frequently used antifungal drugs. In this review, we discuss the role of the main virulence, drug target, and drug resistance determinants. We conclude with the review of new technologies being developed to treat aspergillosis. In particular, microsphere and nanoparticle delivery systems are discussed in the context of improving drug bioavailability. Aspergillus will likely continue to cause problematic infections in immunocompromised patients, so it is imperative to improve treatment options.

Vitamin D levels in asthmatic patients with and without allergic bronchopulmonary aspergillosis

Vitamin D deficiency is believed to be a pathogenetic factor in patients with allergic bronchopulmonary aspergillosis (ABPA) and cystic fibrosis. Whether vitamin D deficiency is also prevalent in ABPA complicating asthma, remains unknown. Herein, we evaluated vitamin D levels in asthmatic patients with and without ABPA. In a prospective study, plasma vitamin D (25[OH]D) levels were measured in consecutive subjects with asthma (n = 75), ABPA (n = 158) and healthy volunteers (n = 50). Vitamin D levels <20 ng/mL were considered as vitamin D deficiency. There was no difference in mean (95% CI) vitamin D levels between healthy controls (15.3 [12.7-17.9]), asthmatics (19.2 [16.3-22.1]) and subjects with ABPA (18.9 [16.9-20.8]) (P = .22). Vitamin D deficiency was encountered in 70%, 64% and 65% of the healthy controls, asthmatics and ABPA subjects, respectively, and was not different between the groups (P = .79). There was no difference in the asthma control, pulmonary function, immunological findings and the severity of bronchiectasis, in patients with ABPA, with and without vitamin D deficiency. Vitamin D deficiency is equally prevalent in asthmatic patients with or without ABPA in the Indian subcontinent, and does not appear to play a major role in the pathogenesis of ABPA complicating asthma.

Developments in the diagnosis and treatment of allergic bronchopulmonary aspergillosis

INTRODUCTION

Allergic bronchopulmonary aspergillosis (ABPA) is a complex pulmonary disorder characterized by recurrent episodes of wheezing, fleeting pulmonary opacities and bronchiectasis. It is the most prevalent of the Aspergillus disorders with an estimated five million cases worldwide. Despite six decades of research, the pathogenesis, diagnosis and treatment of this condition remains controversial. The International Society for Human and Animal Mycology has formed a working group to resolve the controversies around this entity. In the year 2013, this group had proposed new criteria for diagnosis and staging, and suggested a treatment protocol for the management of this disorder. Since then, several pieces of new evidence have been published in the investigation and therapeutics of this condition. Areas covered: A non-systematic review of the available literature was performed. We summarize the current evidence in the evaluation and treatment of this enigmatic disorder. We suggest modifications to the existing criteria and propose a new scoring system for the diagnosis of ABPA. Expert commentary: All patients with asthma and cystic fibrosis should routinely be screened for ABPA using A. fumigatus-specific IgE levels. Glucocorticoids should be used as the first-line of therapy in ABPA, and itraconazole reserved in those with recurrent exacerbations and glucocorticoid-dependent disease.

Are allergic fungal rhinosinusitis and allergic bronchopulmonary aspergillosis lifelong conditions?

Aspergillus fumigatus can cause several allergic disorders including Aspergillus-sensitized asthma, allergic bronchopulmonary aspergillosis (ABPA), and allergic fungal rhinosinusitis (AFRS). ABPA is an immunological pulmonary disorder caused by allergic reactions mounted against antigens of A. fumigatus colonizing the airways of patients with asthma (and cystic fibrosis). Allergic bronchopulmonary mycosis is an allergic fungal airway disease caused by thermotolerant fungi other than A. fumigatus On the other hand, AFRS is a type of chronic rhinosinusitis that is also a result of hypersensitivity reactions to the presence of fungi that become resident in the sinuses. The pathogenesis of ABPA and AFRS share several common features, and in fact, AFRS can be considered as the upper airway counterpart of ABPA. Despite sharing similar immunopathogenetic features, the simultaneous occurrence of the two disorders is uncommon. Due to the lacuna in understanding of the causative mechanisms, and deficiencies in the diagnosis and treatment, these disorders unfortunately are lifelong illnesses. This review provides an overview of the pathogenesis, diagnosis, and long-term outcomes of both these disorders.