Allergic bronchopulmonary aspergillosis

High-Frequency Direct Detection of Triazole Resistance in Aspergillus fumigatus from Patients with Chronic Pulmonary Fungal Diseases in India

Aspergillosis due to azole-resistant Aspergillus fumigatus is a worldwide problem with major therapeutic implications. In patients with invasive aspergillosis, a low yield of fungal cultures results in underestimation of azole resistance. To detect azole resistance in A. fumigatus, we applied the AsperGenius^® Resistance multiplex real-time polymerase chain reaction (PCR) assay to detect TR₃₄/L98H, and TR₄₆/T289A/Y121F mutations and the AsperGenius^® G54/M220 RUO PCR assay to detect G54/M220 mutations directly in bronchoalveolar lavage (BAL) samples of 160 patients with chronic respiratory diseases in Delhi, India. Only 23% of samples were culture-positive compared to 83% positivity by A. fumigatus species PCR highlighting concerns about the low yield of cultures. Notably, 25% of BAL samples (33/160 patients) had azole resistance-associated mutation by direct detection using PCR assay. Detection of resistance-associated mutations was found mainly in 59% and 43% patients with chronic pulmonary aspergillosis (CPA) and allergic bronchopulmonary aspergillosis (ABPA), respectively. Overall, a G54 mutation, conferring itraconazole resistance, was the predominant finding in 87.5% and 67% of patients with CPA and ABPA, respectively. In culture-negative, PCR-positive samples, we detected azole-resistant mutations in 34% of BAL samples. Azole resistance in chronic Aspergillus diseases remains undiagnosed, warranting standardization of respiratory culture and inclusion of rapid techniques to detect resistance markers directly in respiratory samples.

Diagnosis of allergic bronchopulmonary aspergillosis: a case-based approach

Allergic bronchopulmonary aspergillosis is a pulmonary disease occurring in patients with asthma or cystic fibrosis, consequent to a dysregulated immune response to inhaled Aspergillus conidia. The usual presentation is with poorly controlled asthma. Patients may also present with expectoration of mucus plugs, hemoptysis, constitutional symptoms and radiological opacities. Patients may experience smoldering lung destruction despite well-controlled asthma. With emerging data, the diagnostic criteria transcribed by an International Expert Committee in 2013 are the latest evidence-based guidelines. Herein, we utilize a case-based approach to elaborate on the diagnosis of this disease. The review intends to provide a lucid understanding of the diagnostic process for the expert as well as the primary physician, involved in management of this enigmatic disorder.

Efficacy and safety of nebulised amphotericin B (NAB) in severe asthma with fungal sensitisation (SAFS) and allergic bronchopulmonary aspergillosis (ABPA)

BACKGROUND AND RATIONALE

Antifungal therapy for severe asthma with fungal sensitisation (SAFS) and allergic bronchopulmonary aspergillosis (ABPA) remains poorly studied. We assessed the efficacy and safety of NAB as second and third line therapy in SAFS and ABPA.

METHODS

21 adult asthmatics with SAFS (n = 11) and ABPA (n = 10) who had either failed itraconazole (n = 8), voriconazole proceeded by itraconazole (n = 5) or developed adverse events (AEs) to either agent (n = 7) were treated with 10mg of NAB (Fungizone) twice daily. We audited clinical and immunological response, using the Asthma Quality of Life Questionnaire (AQLQ-J) scores, asthma control, FEV1, healthcare utilisation and IgE. Patients were followed up for 12 months.

RESULTS

Twenty-one patients were treated (SAFS, n = 11) and (ABPA, n = 10), M: F = 8:12, median age 65 years (range, 24-78). The median duration of therapy was 30 days (0-1825). Clinical benefit was observed in three (14.3 %) in which overall mean AQLQ-J score improved by + 2.9, mean FEV1 improved by 0.5 L and there was improvement in overall asthma control. Seven (33%) failed initial dose (bronchospasm). Eleven (52.4%) discontinued within 12 months of therapy due to delayed bronchospasm (n = 3, within 4 weeks), equipment problems (n = 2, within 4 weeks) and lack of clinical benefit (n = 4, within 16 weeks).

CONCLUSION

Our data suggest that the overall efficacy of NAB in this group of patients is poor and associated with bronchospasm. However, the excellent response in 3 patients, suggest it may be considered when other alternatives have been exhausted. Overcoming the initial bronchospasm may improve tolerability.

Fungal allergy in asthma-state of the art and research needs

Sensitization to fungi and long term or uncontrolled fungal infection are associated with poor control of asthma, the likelihood of more severe disease and complications such as bronchiectasis and chronic pulmonary aspergillosis. Modelling suggests that >6.5 million people have severe asthma with fungal sensitizations (SAFS), up to 50% of adult asthmatics attending secondary care have fungal sensitization, and an estimated 4.8 million adults have allergic bronchopulmonary aspergillosis (ABPA). There is much uncertainty about which fungi and fungal allergens are relevant to asthma, the natural history of sensitisation to fungi, if there is an exposure response relationship for fungal allergy, and the pathogenesis and frequency of exacerbations and complications. Genetic associations have been described but only weakly linked to phenotypes. The evidence base for most management strategies in ABPA, SAFS and related conditions is weak. Yet straightforward clinical practice guidelines for management are required. The role of environmental monitoring and optimal means of controlling disease to prevent disability and complications are not yet clear. In this paper we set out the key evidence supporting the role of fungal exposure, sensitisation and infection in asthmatics, what is understood about pathogenesis and natural history and identify the numerous areas for research studies.

Global burden of allergic bronchopulmonary aspergillosis with asthma and its complication chronic pulmonary aspergillosis in adults

Allergic bronchopulmonary aspergillosis (ABPA) complicates asthma and may lead to chronic pulmonary aspergillosis (CPA) yet global burdens of each have never been estimated. Antifungal therapy has a place in the management of ABPA and is the cornerstone of treatment in CPA, reducing morbidity and probably mortality. We used the country-specific prevalence of asthma from the Global Initiative for Asthma (GINA) report applied to population estimates to calculate adult asthma cases. From five referral cohorts (China, Ireland, New Zealand, Saudi Arabia and South Africa), we estimated the prevalence of ABPA in adults with asthma at 2.5% (range 0.72-3.5%) (scoping review). From ABPA case series, pulmonary cavitation occurred in 10% (range 7-20%), allowing an estimate of CPA prevalence worldwide using a deterministic scenario-based model. Of 193 million adults with active asthma worldwide, we estimate that 4,837,000 patients (range 1,354,000-6,772,000) develop ABPA. By WHO region, the ABPA burden estimates are: Europe, 1,062,000; Americas, 1,461,000; Eastern Mediterranean, 351,000; Africa, 389,900; Western Pacific, 823,200; South East Asia, 720,400. We calculate a global case burden of CPA complicating ABPA of 411,100 (range 206,300-589,400) at a 10% rate with a 15% annual attrition. The global burden of ABPA potentially exceeds 4.8 million people and of CPA complicating ABPA ˜ 400,000, which is more common than previously appreciated. Both conditions respond to antifungal therapy justifying improved case detection. Prospective population and clinical cohort studies are warranted to more precisely ascertain the frequency of ABPA and CPA in different locations and ethnic groups and validate the model inputs.

Voriconazole and posaconazole improve asthma severity in allergic bronchopulmonary aspergillosis and severe asthma with fungal sensitization

Rationale and objectives. Severe asthma with fungal sensitization (SAFS) and allergic bronchopulmonary aspergillosis (ABPA) are progressive allergic fungal lung diseases whose effective treatment remains to be established. Current treatment with itraconazole is associated with a 40% failure rate and adverse events (AEs). We assessed the effect of voriconazole or posaconazole as second- and third-line therapies. Methods. We conducted a retrospective review of adult asthmatic patients with either ABPA or SAFS receiving voriconazole or posaconazole. Clinical, radiological, and immunological evaluation was used to assess response. Results. There were 25 patients, ABPA (n = 20) or SAFS (n = 5), 10 males, median age = 58 years. All patients had failed itraconazole (n = 14) or developed AEs (n = 11). There were 33 courses of therapy analyzed, 24 with voriconazole and 9 with posaconazole. Clinical response to voriconazole was observed in 17/24 (70%) patients at 3 months, 15/20 (75%) at 6 months, and 12/16 (75%) at 12 months compared with 7/9 (78%) at 3, 6, and 12 months for posaconazole. Eighteen of 24 (75%) patients discontinued oral corticosteroids (OCS), 12 of them within 3 months of therapy. Asthma severity was downgraded from severe to moderate (n = 8) and moderate to mild (n = 1) asthma in 9 of 24 (38%) asthmatic patients. There was a marked reduction in OCS and short-acting beta-2 agonist use, health-care utilization due to asthma, and improvement in overall health status. Furthermore, there was a statistically significant reduction in immunological markers appearing at 9 months (p = .008) for total IgE and at 12 months for radioallergosorbent test IgE for Aspergillus fumigatus (p = .0056). Six of 23 (26%) patients on voriconazole had AEs requiring discontinuation before 6 months compared with none on posaconazole (p = .15). Four relapsed (57%), one at 3 months and three at 12 months after discontinuation. Conclusion. Both voriconazole and posaconazole are potentially effective alternative treatment options for SAFS and ABPA and may improve asthma control and reduce severity, though larger prospective studies are required to support these retrospective study findings.

Mannose-binding lectin genotype and serum levels in patients with chronic and allergic pulmonary aspergillosis

Several studies suggest mannose-binding lectin (MBL) deficiency is associated with various manifestations of aspergillosis. MBL serum levels and function are genetically determined, but levels rise during inflammation. We address the relative frequency of deficient genotypes, the relationship between serum level and genotype and both age and disease manifestations in patients with chronic pulmonary (CPA) and allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS). DNA was extracted from blood samples, and MBL2 genotyping was performed using the INNO-LiPA MBL2 kit. Serum MBL concentrations were determined using ELISA. One hundred and eight patients were evaluated, 70 (65%) with CPA, 38 (35%) with allergic disease (ABPA, SAFS or undefined) and 13 (12%) had both CPA and ABPA. The mean MBL serum level was 1849 μg L(-1) and did not differ between groups. Forty subjects (37%) had exon 1 genotypes producing nonfunctional MBL (A/B, A/C, A/D and O/O), a frequency not different from published normal controls. A/A subjects with CPA had higher levels (2981 μg L(-1)) compared with allergic A/A subjects (2202 μg L(-1)) (pc0.012). No single haplotype, genotype or allele was significantly related to any aspergillosis phenotype. Worse breathlessness was associated with higher MBL levels among A/A subjects (P = 0.009) and conversely nonfunctional genotypes. Mean MBL values were higher in those with an Medical Research Council (MRC) breathlessness score of 5 compared with those with and MRC score of 1 (P = 0.023). A/A allergic subjects (n = 27) in this study were ≈ 11 years younger than allergic A/O subjects (n = 11, P = 0.02). Subjects with worse respiratory status or more severe CPA had higher MBL serum levels (P = 0.023; P = 0.034). Bronchiectasis was not associated with MBL levels in CPA or allergic aspergillosis. MBL genotype and serum level modulate progression of aspergillosis.

High-frequency triazole resistance found In nonculturable Aspergillus fumigatus from lungs of patients with chronic fungal disease

BACKGROUND

Oral triazole therapy is well established for the treatment of invasive (IPA), allergic (ABPA), and chronic pulmonary (CPA) aspergillosis, and is often long-term. Triazole resistance rates are rising internationally. Microbiological diagnosis of aspergillosis is limited by poor culture yield, leading to uncertainty about the frequency of triazole resistance.

METHODS

Using an ultrasensitive real-time polymerase chain reaction (PCR) assay for Aspergillus spp., we assessed respiratory fungal load in bronchoalveolar lavage (BAL) and sputum specimens. In a subset of PCR-positive, culture negative samples, we further amplified the CYP51A gene to detect key single-nucleotide polymorphisms (SNPs) associated with triazole resistance.

RESULTS

Aspergillus DNA was detected in BAL from normal volunteers (4/11, 36.4%) and patients with culture or microscopy confirmed IPA (21/22, 95%). Aspergillus DNA was detected in sputum in 15 of 19 (78.9%) and 30 of 42 (71.4%) patients with ABPA and CPA, compared with 0% and 16.7% by culture, respectively. In culture-negative, PCR-positive samples, we detected triazole-resistance mutations (L98H with tandem repeat [TR] and M220) within the drug target CYP51A in 55.1% of samples. Six of 8 (75%) of those with ABPA and 12 of 24 (50%) with CPA had resistance markers present, some without prior triazole treatment, and in most despite adequate plasma drug concentrations around the time of sampling.

CONCLUSIONS

The very low organism burdens of fungi causing infection have previously prevented direct culture and detection of antifungal resistance in clinical samples. These findings have major implications for the sustainability of triazoles for human antifungal therapy.

Aspergillus sensitization is associated with airflow limitation and bronchiectasis in severe asthma

BACKGROUND

Abnormalities, including bronchiectasis, that are detectable on high-resolution computed tomography (HRCT) have been associated with severe asthma. Bronchiectasis is associated with the diagnosis of allergic bronchopulmonary aspergillosis (ABPA), which also occurs in patients with severe asthma. We sought to determine the frequency and pattern of HRCT abnormality and the relationship with Aspergillus fumigatus sensitization in one severe asthma population.

METHODS

We examined our database of patients attending a supraregional severe asthma service (Manchester, UK). Clinical, physiological and immunological characteristics were compared between those with HRCT evidence of airway disease (specifically bronchiectasis) and those with no radiological abnormality.

RESULTS

Of 133 patients analysed, 111 (83.4%) had an abnormal HRCT with bronchial wall thickening (41.3%), bronchiectasis (35.3%), air trapping (20.3%) and bronchial dilatation (16.5%) occurring most frequently. Radiological evidence of airway disease was associated with more obstructive spirometry (postbronchodilator FEV₁/FVC ratio 73.2%vs 64.8% [difference -8.5%, 95% CI -16.9 to -0.1, P = 0.048]). A. fumigatus sensitization was associated with a 2.01 increased hazard ratio of bronchiectasis (95% CI 1.26 to 3.22, P = 0.005), and more obstructive spirometry (postbronchodilator FEV₁/FVC ratio 57.6 vs 70.3 [difference -12.8, 95% CI -19.8 to -5.7, P = 0.001]). Patients with A. fumigatus sensitization had variable clinical and radiological characteristics that frequently did not conform to the conventional diagnostic criteria for ABPA.

CONCLUSION

Patients with severe asthma frequently have radiological abnormalities on HRCT. Sensitization to A. fumigatus is associated with bronchiectasis and greater airflow obstruction, even when diagnostic criteria for ABPA are not met.

Prevalence of allergic bronchopulmonary aspergillosis in patients with cystic fibrosis in the state of Bahia, Brazil

OBJECTIVE

To determine the prevalence of allergic bronchopulmonary aspergillosis (ABPA) in patients with cystic fibrosis treated at a referral center in the state of Bahia, Brazil.

METHODS

A cross-sectional study, with prospective data collection, carried out at the Cystic Fibrosis Referral Center of Bahia of the Octavio Mangabeira Specialized Hospital. We evaluated 74 patients diagnosed with cystic fibrosis, older than six years of age, treated between December 9, 2003 and March 7, 2005. We analyzed the following variables: gender, age, forced vital capacity, forced expiratory volume in one second, pharmacodynamic response, chest X-ray findings, facial sinus X-ray findings, wheezing, cultures for Aspergillus spp., total immunoglobulin E (IgE), specific IgE for Aspergillus fumigatus and immediate skin test reactivity to A.fumigatus antigen.

RESULTS

Of the 74 patients, 2 were diagnosed with ABPA. We found total IgE levels > 1,000 IU/mL in 17 (23%), positive immediate skin reactivity to A. fumigatus antigen in 19 (25.7%) and wheezing in 60 (81.1%).

CONCLUSIONS

The prevalence of ABPA was 2.7%. The high levels of total IgE, high incidence of wheezing and high rate of immediate skin test reactivity to A. fumigatus antigen suggest that these patients should be carefully monitored due to their propensity to develop ABPA.

Aspergilose broncopulmonar alérgica com imagem radiológica em "dedo de luva"

A aspergilose broncopulmonar alérgica é uma doença pulmonar que ocorre em pacientes com asma ou fibrose cística, desencadeada pela reação de hipersensibilidade à presença do fungo Aspergilus fumigatus nas vias aéreas. Relatamos aqui um caso em que uma paciente com quadro clínico sugestivo de asma apresentou critérios clínicos, laboratoriais e radiológicos compatíveis com o diagnóstico de aspergilose broncopulmonar alérgica. A importância de tais achados deve-se ao fato de que quanto mais precocemente for feito o diagnóstico, menores serão os riscos de agravamento do quadro respiratório e de aparecimento de fibrose.

Aspergillus in the lung: diverse and coincident forms

Pulmonary disease caused by the fungus Aspergillus has traditionally been regarded as belonging to one of the following, apparently distinct, entities: saprophytic aspergilloma; allergic bronchopulmonary aspergillosis (ABPA); and invasive aspergillosis (IPA); which may be further categorised as angioinvasive, acute or chronic airway invasive) [1]. It is not always obvious that there is overlap between these entities, and that in any given patient more than one Aspergillus-related pathological process can co-exist [2]. The aim of this article is to review the clinical and imaging features of the main categories of Aspergillus-related pulmonary disease and, in particular, to highlight the overlap between them.

Allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) complicates asthma and cystic fibrosis. The survival factors in Aspergillus fumigatus that support saprophytic growth in bronchial mucus are not understood. Prednisone remains the most definitive treatment but need not be administered indefinitely. MHC II -restricted CD4(+) T( H)2 clones have been derived from patients with ABPA. The total serum IgE concentration is elevated sharply but is "nonspecific. " IgE serum isotypic antibodies to A fumigatus are useful in diagnosis; this is in contrast to the situation for patients with asthma without ABPA. High-resolution computed tomography of the chest demonstrates multiple areas of bronchiectasis in most patients with ABPA and is a useful radiologic tool. Some asthma control patients might have a few bronchiectatic airways, but not to the extent seen in or of the same character as those in ABPA. This review discusses clinical, radiologic, investigational, pathogenetic, and treatment issues of ABPA.

Allergic bronchopulmonary aspergillosis: a review of a disease with a worldwide distribution

Allergic bronchopulmonary aspergillosis (ABPA), an immunologically mediated lung disease, occurs predominantly in patients with asthma. This chronic relapsing disorder ranges clinically from mild asthma to fatal destructive lung disease and is caused by hypersensitivity to colonized Aspergillus fumigatus (Af). The immunopathogenesis of the disease is yet to be understood clearly. Specific IgE-Af and IgG-Af, the serological markers, contribute to the diagnosis. Radiologically, ABPA is characterized by fleeting pulmonary infiltrates often confused with pulmonary tuberculosis. However, central bronchiectasis on computed tomography is considered to be the hallmark of the disease. Early diagnosis and therapy with prednisolone, the cornerstone of management, could alter the course of the disease and prevent the development of end-stage lung fibrosis.

Current pharmacotherapy of allergic bronchopulmonary aspergillosis

Although no well-designed studies have been carried out, the available data support the use of corticosteroids for acute exacerbations of allergic bronchopulmonary aspergillosis (ABPA). Neither the optimal steroid dose nor the duration of therapy has been standardised but limited data suggest the starting dose should be prednisone (approximately 0.5 mg/kg/day). The decision to taper steroids should be made on an individual basis, depending on clinical course. The available data suggest that clinical symptoms alone are inadequate to make such decisions, since significant lung damage may occur in asymptomatic patients. Increasing serum IgE levels, new or worsening infiltrate on chest radiograph and worsening spirometry suggest that steroids should be used. Multiple asthmatic exacerbations in a patient with ABPA suggest that chronic steroid therapy should be used. Itraconazole appears useful as a steroid sparing agent.