Usefulness of Two Aspergillus PCR Assays and Aspergillus Galactomannan and β-d-Glucan Testing of Bronchoalveolar Lavage Fluid for Diagnosis of Chronic Pulmonary Aspergillosis

The Utility of Real-Time PCR, Metagenomic Next-Generation Sequencing, and Culture in Bronchoalveolar Lavage Fluid for Diagnosis of Pulmonary Aspergillosis

Timely detection of Aspergillus infection is crucial given the high mortality rate of pulmonary aspergillosis (PA). Here, the diagnostic performances for PA of mycological culture, Aspergillus real-time PCR, and metagenomic next-generation sequencing (mNGS) assay from bronchoalveolar lavage fluid, were evaluated. In total, 139 patients with suspected fungal pneumonia were enrolled between December 2021 and July 2023, collecting 139 bronchoalveolar lavage fluid samples for real-time PCR and culture, with 87 undergoing mNGS assay. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve with 95% CIs of these assays for PA were as follows: 35.3% (14.2%-61.7%), 100.0% (94.0%-100.0%), 100.0% (54.1%-100.0%), 84.5% (79.3%-88.6%), and 0.676 (0.560-0.779), respectively, for culture; 82.4% (56.6%-96.2%), 98.3% (91.1%-100.0%), 93.3% (66.4%-99.0%), 95.2% (87.6%-98.2%), and 0.903 (0.815-0.959), respectively, for same diagnostic performance of real-time PCR and mNGS; and 94.1% (71.3%-99.9%), 96.7% (88.5%-99.6%), 88.9% (67.1%-96.9%), 98.3% (89.6%-99.7%), and 0.954 (0.880-0.989), respectively, for real-time PCR combining mNGS; real-time PCR, mNGS, and their combination significantly improved in area under the curve values over culture (P < 0.001), but real-time PCR testing and mNGS had no significant difference with each other and their combination. Overall, the performance of culture was limited by low sensitivity; both real-time PCR and mNGS assays as single diagnostic tests are promising compared with culture and combined tests.

Clinical Features, Treatment Outcome and Potential risk Factors for Recurrence Among Patients with Chronic Pulmonary Aspergillosis in a Resource-limited Setting: A Retrospective Observational Study

OBJECTIVE

To evaluate the clinical characteristics and treatment outcomes of patients with chronic pulmonary aspergillosis (CPA) and to determine risk factors for disease recurrence.

METHODS

A total of 43 patients with CPA (mean ± SD age: 61.4 ± 10.5 years, 83.7% were males) were included in this retrospective study. Data on demographic, clinical and disease-related characteristics, galactomannan (GM) test positivity in bronchoalveolar lavage (BAL) samples, histopathological diagnosis, imaging (CT) findings and CPA forms, antifungal therapy, recurrence rate and time to recurrence were recorded.

RESULTS

Chronic obstructive pulmonary disease (COPD;76.7%) was the leading predisposing factor, and the aspergillus nodule (37.2%) was the most prevalent CPA form.GM test positivity was noted in 89.7% (35/39) of BAL samples. Median duration of voriconazole treatment was 180 days. CPA recurrence was noted in 14.0% of patients, while the comorbid tuberculosis sequela (66.7% vs. 16.2%, p = 0.02) and mild immunosuppressive disorder (100.0% vs. 51.4%, p = 0.032) were significantly more common in patients with recurrence vs. those without recurrence. Recurrence rate was 50.0% (3 of 6 patients) in patients with simple aspergilloma, and ranged from 0.0% to 25.0% in those with other CPA forms. Treatment duration and time to recurrence ranged 70-270 days and 1.1-37 months, respectively in simple aspergilloma, while they were ranged 150-180 days and 30-43.3 months, respectively in other CPA forms.

CONCLUSIONS

Our findings indicate the importance of considering CPA in differential diagnosis in patients with predisposing conditions, and emphasize the tuberculosis sequela, immunosuppressive disorder and the certain CPA forms managed with shorter duration of antifungal therapy (i.e., simple aspergilloma) as the potential risk factors of CPA recurrence.

Diagnostic performance of serum galactomannan and β-D-glucan for invasive aspergillosis in suspected patients: A meta-analysis

BACKGROUND

Serum galactomannan (GM) and β-D-glucan (BG) are known markers of invasive aspergillosis (IA). The aim of this meta-analysis was to evaluate the efficiency of serum GM and BG as diagnostic markers of symptomatic IA infection and compare the performance of the combined tests with that of either test individually.

METHODS

A literature search was carried out using PubMed, Web of Science, and EMBASE databases to include relevant studies published in English up to May 2023. The quality assessment was performed using Review Manager 5.3 software. A bivariate model was applied to pool diagnostic parameters using Stata 14.0 software. We used Cochrane I2 index to assess heterogeneity and identify the potential source of heterogeneity by meta-regression. Paired t tests were used to compare the value of GM and BG for IA diagnosis when used in combination or alone.

RESULTS

Sixteen studies were eligible for inclusion in the meta-analysis. For proven or probable IA, serum GM and BG yielded a pooled sensitivity of 0.53 (95% CI 0.40-0.66) vs 0.72 (95% CI 0.61-0.81) and a pooled specificity of 0.94 (95% CI 0.91-0.97) vs 0.82 (95% CI 0.73-0.88). The area under the curve (AUC) of ROC was 0.90 (95% CI 0.87-0.92) vs 0.83 (95% CI 0.80-0.86) for all studies. The pooled sensitivity and specificity for IA diagnosis by combined GM and BG assays (GM/BG) were 0.84 (95% CI 0.69-0.86) and 0.76 (95% CI 0.69-0.81), respectively. The sensitivity of the combined GM/BG test to diagnose IA was higher than of the GM or BG test alone.

CONCLUSION

Serum GM and BG tests had a relatively high accuracy for IA diagnosis in suspected patients. The diagnostic accuracy of both assays is comparable, and the diagnostic sensitivity is further improved by the combined detection of the 2 markers.

Chronic pulmonary aspergillosis: comprehensive insights into epidemiology, treatment, and unresolved challenges

Chronic pulmonary aspergillosis (CPA) is a challenging respiratory infection caused by the environmental fungus Aspergillus. CPA has a poor prognosis, with reported 1-year mortality rates ranging from 7% to 32% and 5-year mortality rates ranging from 38% to 52%. A comprehensive understanding of the pathogen, pathophysiology, risk factors, diagnosis, surgery, hemoptysis treatment, pharmacological therapy, and prognosis is essential to manage CPA effectively. In particular, Aspergillus drug resistance and cryptic species pose significant challenges. CPA lacks tissue invasion and has specific features such as aspergilloma. The most critical risk factor for the development of CPA is pulmonary cavitation. Diagnostic approaches vary by CPA subtype, with computed tomography (CT) imaging and Aspergillus IgG antibodies being key. Treatment strategies include surgery, hemoptysis management, and antifungal therapy. Surgery is the curative option. However, reported postoperative mortality rates range from 0% to 5% and complications range from 11% to 63%. Simple aspergilloma generally has a low postoperative mortality rate, making surgery the first choice. Hemoptysis, observed in 50% of CPA patients, is a significant symptom and can be life-threatening. Bronchial artery embolization achieves hemostasis in 64% to 100% of cases, but 50% experience recurrent hemoptysis. The efficacy of antifungal therapy for CPA varies, with itraconazole reported to be 43-76%, voriconazole 32-80%, posaconazole 44-61%, isavuconazole 82.7%, echinocandins 42-77%, and liposomal amphotericin B 52-73%. Combinatorial treatments such as bronchoscopic triazole administration, inhalation, or direct injection of amphotericin B at the site of infection also show efficacy. A treatment duration of more than 6 months is recommended, with better efficacy reported for periods of more than 1 year. In anticipation of improvements in CPA management, ongoing advances in basic and clinical research are expected to contribute to the future of CPA management.

Effect of volume of instillate on the diagnostic utility of bronchoalveolar lavage galactomannan in patients with suspected chronic pulmonary aspergillosis-A pilot study

BACKGROUND

Bronchoalveolar lavage (BAL) galactomannan (GM) is commonly used to diagnose Aspergillus-related lung diseases. However, unlike serum GM, which is measured in undiluted blood, BAL-GM is estimated using variable aliquots and cumulative volume of instillates during bronchoscopy.

OBJECTIVE

Since different studies have reported varying diagnostic accuracy and cut-offs for BAL-GM in CPA, we hypothesized that the total volume of instillate and 'order/label' of aliquots significantly affects the BAL-GM values, which was evaluated as part of this study.

PATIENTS & METHODS

We obtained 250 BAL samples from 50 patients (five from each) with suspected chronic pulmonary aspergillosis. BAL fluid was collected after instilling sequential volumes of 40 mL of normal saline each for the first four labels and a fifth label was prepared by mixing 1 mL from each of the previous labels. The GM level of each label was measured by PLATELIA™ ASPERGILLUS Ag enzyme immunoassay. This study measured the discordance, level of agreement, diagnostic characteristics (sensitivity, specificity and AUROC) and best cut-offs for BAL-GM in the different aliquots of lavage fluid.

RESULTS

The study population, classified into CPA (28%) and non-CPA (72%) groups, based on ERS/ESCMID criteria (excluding BAL-GM) were not different with respect to clinico-radiological characteristics. The discordance of BAL-GM positivity (using a cut-off of >1) between the serial labels for the same patient ranged between 10% and 22%, while the discordance between classification using BAL-GM positivity (using a cut-off of ≥1) and clinic-radio-microbiological classification ranged between 18% and 30%. The level of agreement for serial labels was at best fair (<0.6 for all except one 'label'). The AUROC for the serial samples ranged between 0.595 and 0.702, with the '40 mL and the 'mix' samples performing the best. The best BAL-GM cut-off also showed significant variation between serial labels of varying dilutions (Range:1.01 - 4.26).

INTERPRETATION

This study highlights the variation in BAL-GM measured and the 'positivity' between different 'labels' of aliquots of BAL, with the first aliquot and the mixed sample showing the best performances for diagnosis of CPA. Future studies should attempt to 'standardise' the instilled volume for BAL-GM estimation to standardise the diagnostic yield.

Utility of a loop-mediated isothermal amplification detection kit to diagnose chronic pulmonary aspergillosis

BACKGROUND

Diagnosing chronic pulmonary aspergillosis (CPA) is still challenging, and infection with Aspergillus spp. must be detected early. The aim of this study was to evaluate, for the first time, the usefulness of a new loop-mediated isothermal amplification (LAMP) test kit in diagnosing CPA.

METHODS

This cross-sectional study was performed at the National Hospital Organization Kinki-Chuo Chest Medical Center. We prospectively enrolled patients with and without CPA. The primary outcomes of this study were the sensitivity and specificity of LAMP for the diagnosis of CPA.

RESULTS

In total, 34 patients with CPA and 21 without CPA (the control group) were enrolled between October 2019 and December 2021. Among the 34 patients with CPA, cultures were positive for CPA in 16 and negative for 18. The majority of fungi isolated in sputum were A. fumigatus in 15 specimens; Aspergillus flavus was isolated in 1) LAMP demonstrated 55.9% sensitivity (95% confidence interval [CI] 37.9-72.8) and 100.0% specificity (95% CI 77.2-100.0).

CONCLUSION

LAMP is an acceptable tool for diagnosing CPA, and its application in clinical practice necessitates more studies.

Analytical and clinical validation of multiplex droplet digital PCR assay for detecting pathogenic fungal infection in lungs

Pulmonary invasive fungal infection in immunocompromised hosts is difficult to diagnose, and current tools for diagnosis or monitoring of response to antifungal treatments have inherent limitations. Droplet digital PCR (ddPCR) has emerged as a promising tool for pulmonary pathogen detection with high sensitivity. This study presents a novel ddPCR panel for rapid and sensitive identification of pulmonary fungal pathogens. First, a ddPCR method for detecting three fungal genera, including Pneumocystis, Aspergillus, and Cryptococcus, was established and evaluated. Then, the clinical validation performance of ddPCR was compared with that of qPCR using 170 specimens, and the 6 specimens with inconsistent results were further verified by metagenomics next-generation sequencing, which yielded results consistent with the ddPCR findings. Finally, the area under the ROC curve (AUC) was used to evaluate the efficiency of ddPCR. While the qPCR identified 16 (9.41%) cases of Aspergillus and 6 (3.53%) cases of Pneumocystis, ddPCR detected 20 (11.76%) Aspergillus cases and 8 (4.71%) Pneumocystis cases. The AUC for Aspergillus, Cryptococcus, and Pneumocystis was 0.974, 0.998, and 0.975, respectively. These findings demonstrated that the ddPCR assay is a highly sensitive method for identifying pathogens responsible for invasive fungal pulmonary infections, and is a promising tool for early diagnosis.      .

The Utility of Galactomannan and Polymerase Chain Reaction Assays in Bronchoalveolar Lavage for Diagnosis of Chronic Pulmonary Aspergillosis

The diagnosis of chronic pulmonary aspergillosis (CPA) is established by combined clinic-radio-microbiological criteria. Out of the different microbiological criteria, a positive serology for Aspergillus-specific IgG levels is the cornerstone of diagnosis. Alternatively, other microbiological evidence are sometimes sought viz., positive Aspergillus antigen (broncho-alveolar lavage fluid, i.e., BALF galactomannan ≥ 1.0), histopathological demonstration of the fungi following lung biopsy or resection, demonstration of hyaline septate hyphae in direct microscopy resembling Aspergillus spp. or its growth on a respiratory specimen. However, the exact roles of BALF- GM and the newer BALF-PCR have not been confirmed by studies till date. This study enrolled 210 patients with suspected CPA. Of the participants, 88 patients met the criteria for CPA, whereas 122 patients had an alternative diagnosis. The sensitivity-specificity of AsperGenius® PCR and "in-house" PCR were 52.27(36.69-67.54) %-33.78 (23.19-45.72) % and 36.36 (22.41-52.23) %-39.19 (28.04-51.23) % respectively. The sensitivity/specificity of BALF (> 1.0) and serum galactomannan (> 1.0) were 46.55% (33.34-60.13)/64.08% (54.03-73.3) and 29.82% (22.05-37.6)/86.84% (81.1-92.59) respectively. The optimal cut-off values for BALF-Galactomannan and serum galactomannan in diagnosing CPA were found to be 0.69 (sensitivity: 64%; specificity: 53%) and 0.458 (sensitivity: 67%; specificity: 64%) respectively. This results of this study suggests that Aspergillus PCR from BAL may not be a good "rule-in" test for diagnosing CPA. While the performances of GM in BAL and serum may be better than PCR, it should be best used in conjunction with other clinical, radiological, and other microbiological characteristics.

Diagnosis of Chronic Pulmonary Aspergillosis: Clinical, Radiological or Laboratory?

Chronic pulmonary aspergillosis (CPA) is a chronic progressive lung disease associated with a poor prognosis and a 5-year mortality rate of approximately 40-50%. The disease is characterized by slowly progressive destruction of the lung parenchyma, in the form of multiple cavities, nodules, infiltrates or fibrosis. CPA can be challenging to diagnose due to its non-specific symptoms and similarities with other respiratory conditions combined with the poor awareness of the medical community about the disease. This can result in delayed treatment even for years and worsening of the patient's condition. Serological tests certainly play a significant role in diagnosing CPA but cannot be interpreted without radiological confirmation of CPA. Although many data are published on this hot topic, there is yet no single definitive test for diagnosing CPA, and a multidisciplinary approach which involves a combination of clinical picture, radiological findings, microbiological results and exclusion of other mimicking diseases, is essential for the accurate diagnosis of CPA.

Systematic review and meta-analysis of galactomannan antigen testing in serum and bronchoalveolar lavage for the diagnosis of chronic pulmonary aspergillosis: defining a cutoff

BACKGROUND

A clear cutoff value of galactomannan (GM) has not been established for chronic pulmonary aspergillosis (CPA) and is frequently extrapolated from invasive pulmonary aspergillosis. We performed a systematic review and meta-analysis to evaluate the diagnostic performance of serum and bronchoalveolar lavage (BAL) GM, and to propose a cutoff.

METHODS

We extracted from the studies the cutoff of serum or/and BAL GM associated with true positives, false positives, true negatives, and false negatives. We performed a multi-cutoff model and a non-parametric random effect model. We estimated the optimal cutoff and the area under the curve (AUC) for GM in serum and BAL samples.

RESULTS

Nine studies from 1999 to 2021 were included. Overall, the optimal cutoff of serum GM was 0.96 with a sensitivity of 0.29 (95%CI: 0.14-0.51); specificity of 0.88 (95%CI: 0.73-0.95); and AUC of 0.529 (with a CI: [0.415-0.682] [0.307-0.713]). The AUC for the non-parametric ROC model was 0.631. For BAL GM the cutoff was 0.67 with a sensitivity of 0.68 (95%CI: 0.51-0.82), specificity of 0.84 (95%CI: 0.70-0.92), and AUC of 0.814 (with a CI: [0.696-0.895] [0.733-0.881]). The AUC for the non-parametric model was 0.789.

CONCLUSION

The diagnosis of CPA requires the assessment of a combination of mycological and serological factors, as no single serum and/or BAL GM antigen test is adequate. BAL GM performed better than serum, with better sensitivity and excellent accuracy.

Current and Future Pathways in Aspergillus Diagnosis

Aspergillus fumigatus has been designated by the World Health Organization as a critical priority fungal pathogen. Some commercially available diagnostics for many forms of aspergillosis rely on fungal metabolites. These encompass intracellular molecules, cell wall components, and extracellular secretomes. This review summarizes the shortcomings of antibody tests compared to tests of fungal products in body fluids and highlights the application of β-d-glucan, galactomannan, and pentraxin 3 in bronchoalveolar lavage fluids. We also discuss the detection of nucleic acids and next-generation sequencing, along with newer studies on Aspergillus metallophores.

False-positive Elevation of Beta-D-glucan and Aspergillus Galactomannan Levels Due to Mendelson's Syndrome after Rice Aspiration

Both 1,3-beta-D-glucan (BDG) and galactomannan (GM) are polysaccharide components of the fungal cell wall. Although elevated levels of serum BDG and Aspergillus GM suggest invasive fungal infection or Pneumocystis pneumonia and aspergillosis, respectively, it is also necessary to consider the possibility of false-positives. We herein report a 68-year-old man with marked elevation in serum BDG and GM levels accompanied by Mendelson's syndrome after rice aspiration. With the improvement of Mendelson's syndrome, his serum BDG and GM levels decreased. The false-positive serum BDG and GM findings may have been due to his aspiration of food containing them. It is important to take a detailed history of aspiration in addition to making a conventional differential diagnosis in patients with pneumonia with elevated serum BDG and GM levels.

Clinical manifestations, associated risk factors and treatment outcomes of Chronic Pulmonary Aspergillosis (CPA): Experiences from a tertiary care hospital in Lahore, Pakistan

Background

Chronic pulmonary aspergillosis (CPA) has a wide spectrum of illnesses depending on the progression of the disease and comorbid conditions. However, there is an inadequacy of investigations regarding clinical, laboratory, risk factor and prognostic data on CPA. The current study is aimed to consider the clinical manifestations, risk factors and outcomes of CPA.

Methodology

Retrospective records of all patients with a confirmed diagnosis of CPA who sought treatment at Gulab Devi Chest Hospital Lahore, Pakistan from January 2017 to December 2019 were evaluated. Data regarding demographics, clinical manifestations, comorbidities, radiographic and microbiological findings, length of hospital stay (LOS) and intensive care unit (ICU) admission was collected and analyzed to identify the factors associated with mortality. The independent factors associated with mortality were also identified by appropriate analyses.

Results

A total of 218 CPA patients were included in this study. The mean age was 45.75 ± 6.26 years. Of these, 160 (73.4%) were male, and 65 (29.8%) had diabetes. The mean LOS was 18.5 ± 10.9 days. The most common type of CPA was simple aspergilloma (56%) followed by chronic cavitary pulmonary aspergillosis (CCPA) (31.2%). About one half of the patients had a history of pulmonary tuberculosis (TB) and treatment response rates were low in patients with active TB. The overall mortality rate was 27.1%. ICU admission was required for 78 (35.8%) patients. Diabetes mellitus (DM), hematological malignancies and chronic kidney disease (CKD) were the common underlying conditions predicting a poor outcome. Mean LOS, hematological malignancies, consolidation and ICU admission were identified as the independent factors leading to mortality.

Conclusions

CPA had a significant association with TB in the majority of cases. Treatment response rates in cases with active TB were comparatively low. Cases with high mean LOS, hematological malignancies, consolidation, ICU admission, CKD and DM experienced poor outcomes. High mean LOS, hematological malignancies, consolidation and ICU stay were identified as independent risk factors for mortality. Future large prospective studies, involving aspergillus specific immunoglobulin G (IgG) antibody testing, are required for a better understanding of CPA in Pakistan.

Specificity Influences in (1→3)-β-d-Glucan-Supported Diagnosis of Invasive Fungal Disease

(1→3)-β-glucan (BDG) testing as an adjunct in the diagnosis of invasive fungal disease (IFD) has been in use for nearly three decades. While BDG has a very high negative predictive value in this setting, diagnostic false positives may occur, limiting specificity and positive predictive value. Although results may be diagnostically false positive, they are analytically correct, due to the presence of BDG in the circulation. This review surveys the non-IFD causes of elevated circulating BDG. These are in the main, iatrogenic patient contamination through the use of BDG-containing medical devices and parenterally-delivered materials as well as translocation of intestinal luminal BDG due to mucosal barrier injury. Additionally, infection with Nocardia sp. may also contribute to elevated circulating BDG. Knowledge of the factors which may contribute to such non-IFD-related test results can improve the planning and interpretation of BDG assays and permit investigational strategies, such as serial sampling and BDG clearance evaluation, to assess the likelihood of contamination and improve patient care.

Clinical evaluation of two different (1,3)-ß-d-glucan assays for diagnosis of invasive fungal diseases: A retrospective cohort study

BACKGROUND

Early diagnosis of invasive fungal diseases (IFDs) remains a major challenge in routine clinical practice.

OBJECTIVES

The aim of this retrospective cohort study was to evaluate the diagnostic performance of the fungal biomarker (1,3)-ß-d-glucan (BDG) using the β-Glucan test (GT) and the well-established Fungitell assay® (FA) in real-life clinical practice.

PATIENTS/METHODS

We included 109 patients with clinical suspicion of IFD who were treated at Jena University Hospital, Germany, between November 2018 and March 2019. The patients were classified according to the latest update of the EORTC/MSG consensus definitions of IFD. The first serum sample of every patient was analysed for BDG using the FA and the GT, respectively.

RESULTS

Fifty-six patients (51.4%) had at least one host factor for IFD. In patients with proven (n = 11) or probable IFDs (n = 20), median BDG concentrations were 145.0 pg/ml for the FA and 5.1 pg/ml for the GT, respectively. A positive test result of both BDG assays at manufacturer's cut-offs predicted 89.5%-98.3% of proven or probable IFD, but the sensitivity of both assays was limited: The FA identified 60.7% of IFDs (cut-off: 80 pg/ml). Reducing the GT cut-off value from 11.0 to 4.1 pg/ml increased the detection rate of IFDs from 35.5% to 54.8%.

CONCLUSIONS

A positive test result of both BDG assays at manufacturer's cut-off was highly predictive for IFD, but except for Pneumocystis jirovecii pneumonia sensitivities were limited. Adjustment of the GT cut-off value equalised sensitivities of GT and FA.

ATS Core Curriculum 2020. Adult Pulmonary Medicine

The American Thoracic Society Core Curriculum updates clinicians annually in adult and pediatric pulmonary disease, medical critical care, and sleep medicine in a 3- to 4-year recurring cycle of topics. The topics of the 2020 Pulmonary Core Curriculum include pulmonary vascular disease (submassive pulmonary embolism, chronic thromboembolic pulmonary hypertension, and pulmonary hypertension) and pulmonary infections (community-acquired pneumonia, pulmonary nontuberculous mycobacteria, opportunistic infections in immunocompromised hosts, and coronavirus disease [COVID-19]).

A Collaborative Tale of Diagnosing and Treating Chronic Pulmonary Aspergillosis, from the Perspectives of Clinical Microbiologists, Surgical Pathologists, and Infectious Disease Clinicians

Chronic pulmonary aspergillosis (CPA) refers to a spectrum of Aspergillus-mediated disease that is associated with high morbidity and mortality, with its true prevalence vastly underestimated. The diagnosis of CPA includes characteristic radiographical findings in conjunction with persistent and systemic symptoms present for at least three months, and evidence of Aspergillus infection. Traditionally, Aspergillus infection has been confirmed through histopathology and microbiological studies, including fungal culture and serology, but these methodologies have limitations that are discussed in this review. The treatment of CPA requires an individualized approach and consideration of both medical and surgical options. Most Aspergillus species are considered susceptible to mold-active triazoles, echinocandins, and amphotericin B; however, antifungal resistance is emerging and well documented, demonstrating the need for novel therapies and antifungal susceptibility testing that correlates with clinical response. Here, we describe the clinical presentation, diagnosis, and treatment of CPA, with an emphasis on the strengths and pitfalls of diagnostic and treatment approaches, as well as future directions, including whole genome sequencing and metagenomic sequencing. The advancement of molecular technology enables rapid and precise species level identification, and the determination of molecular mechanisms of resistance, bridging the clinical infectious disease, anatomical pathology, microbiology, and molecular biology disciplines.

Chronic Pulmonary Aspergillosis: Notes for a Clinician in a Resource-Limited Setting Where There Is No Mycologist

Chronic pulmonary aspergillosis (CPA) is a spectrum of several progressive disease manifestations caused by Aspergillus species in patients with underlying structural lung diseases. Duration of symptoms longer than three months distinguishes CPA from acute and subacute invasive pulmonary aspergillosis. CPA affects over 3 million individuals worldwide. Its diagnostic approach requires a thorough Clinical, Radiological, Immunological and Mycological (CRIM) assessment. The diagnosis of CPA requires (1) demonstration of one or more cavities with or without a fungal ball present or nodules on chest imaging, (2) direct evidence of Aspergillus infection or an immunological response to Aspergillus species and (3) exclusion of alternative diagnoses, although CPA and mycobacterial disease can be synchronous. Aspergillus antibody is elevated in over 90% of patients and is the cornerstone for CPA diagnosis. Long-term oral antifungal therapy improves quality of life, arrests haemoptysis and prevents disease progression. Itraconazole and voriconazole are alternative first-line agents; voriconazole is preferred for patients with contra-indications to itraconazole and in those with severe disease (including large aspergilloma). In patients co-infected with tuberculosis (TB), it is not possible to treat TB with rifampicin and concurrently administer azoles, because of profound drug interactions. In those with pan-azole resistance or intolerance or progressive disease while on oral triazoles, short-term courses of intravenous liposomal amphotericin B or micafungin is used. Surgery benefits patients with well-circumscribed simple aspergillomas and should be offered earlier in low-resource settings.

Galactomannan detection in bronchoalveolar lavage fluids: A diagnostic approach for fungus ball in patients with pulmonary tuberculosis?

BACKGROUND

Several previous studies have shown cavitary lung lesions in old pulmonary tuberculosis (PTB) increase the risk of fungus ball. Detection of galactomannan (GM) in bronchoalveolar lavage (BAL) is also proposed as a diagnostic approach for the fungus ball.

OBJECTIVES

We evaluated the diagnosis of fungus balls and GM levels in BAL samples in PTB patients.

METHODS

A total of 110 PTB patients were evaluated for fungus ball during 2017-2019. The patients were evaluated for radiological, histopathological results and mycological findings of BAL including GM detection and culture. The sensitivity, specificity and positive and negative predictive value for GM test were calculated. The optimal cut-off for BAL GM testing was determined by receiver operating characteristic (ROC).

RESULTS

Of 110 PTB patients, nine (8.18%) showed fungus ball, all with old PTB. The molecularly confirmed Aspergillus species were A. flavus, A. fumigatus and A. ochraceus. The sensitivity and specificity of BAL GM ≥ 0.5 in old PTB patients with fungus ball were 100%, 41.5%, respectively. The statistical analysis of the mean ± SEM of BAL GM levels was demonstrated a higher levels of GM in patients with fungus ball/aspergilloma compared to old PTB patients without fungus ball/aspergilloma. The optimal cut-off value for BAL GM was determined as 0.50 by ROC curve analysis.

CONCLUSION

According to our results, we can recommend the detection of GM in BAL samples as a diagnostic approach for fungus ball in PTB patients.

High-volume culture and quantitative real-time PCR for the detection of Aspergillus in sputum

OBJECTIVES

Sputum culture is an insensitive method for the diagnosis of pulmonary aspergillosis. Growth of the organism allows identification of the causative species and susceptibility testing, both of which can inform treatment choices. The current practice is to culture an aliquot of diluted sputum. We assessed the value of culturing large volumes of unprocessed sputum, a method that we have termed high-volume culture (HVC).

METHODS

Specimens were processed by conventional culture (using an aliquot of homogenized, diluted sputum on Sabouraud agar at 37°C and 45°C for up to 5 days) and HVC (using undiluted sputum on Sabouraud agar at 30°C for up to 14 days). A separate specimen was tested by quantitative real-time PCR. Antifungal susceptibility testing was performed by the EUCAST standard.

RESULTS

We obtained sputum specimens from 229 individuals with the following conditions: chronic pulmonary aspergillosis (66.8%, 153/229), allergic bronchopulmonary aspergillosis (25.3%, 58/229) and Aspergillus bronchitis (7.9%, 18/229). Individuals with invasive pulmonary aspergillosis were not included. The positivity rate of conventional culture was 15.7% (36/229, 95% CI 11.6%-21.0%) and that of HVC was 54.2% (124/229, 95% CI 47.7%-60.5%) (p < 0.001). The higher positivity rate of HVC was demonstrated regardless of administration of antifungal treatment. Quantitive real-time PCR had an overall positivity rate of 49.2% (65/132, 95% CI 40.9%-57.7%), comparable to that of HVC.

CONCLUSION

Detection of Aspergillus spp. in sputum is greatly enhanced by HVC. HVC allows for detection of azole-resistant isolates that would have been missed by conventional culture. This method can be performed in any microbiology laboratory without the need for additional equipment.

Diagnostic Aspects of Chronic Pulmonary Aspergillosis: Present and New Directions

Purpose of Review

Diagnosis of chronic pulmonary aspergillosis (CPA) is important since many diseases have a similar appearance, but require different treatment. This review presents the well-established diagnostic criteria and new laboratory diagnostic approaches that have been evaluated for the diagnosis of this condition.

Recent Findings

Respiratory fungal culture is insensitive for CPA diagnosis. There are many new tests available, especially new platforms to detectAspergillusIgG. The most recent innovation is a lateral flow device, a point-of-care test that can be used in resource-constrained settings. Chest radiographs without cavitation or pleural thickening have a 100% negative predictive value for chronic cavitary pulmonary aspergillosis in the African setting.

Summary

Early diagnosis of CPA is important to avoid inappropriate treatment. It is our contention that these new diagnostics will transform the diagnosis of CPA and reduce the number of undiagnosed cases or cases with a late diagnosis.

Efficiency of A fumigatus-specific IgG and galactomannan testing in the diagnosis of simple aspergilloma

BACKGROUND

An early diagnosis of chronic pulmonary aspergillosis (CPA) at the stage of simple aspergilloma (SA) remains a challenge in low- and middle-income countries, where imaging may not be routinely available.

OBJECTIVE

We investigate the role of Aspergillus fumigatus-specific IgG in serum, and galactomannan (GM) in bronchoalveolar lavage fluid (BALF) and serum for the diagnosis of SA.

METHODS

We included 46 consecutive treatment-naïve subjects with SA. The 81 controls were subjects of treated pulmonary tuberculosis with residual radiological abnormality and minimal symptoms; and subjects with pulmonary disorders other than CPA who underwent bronchoscopy. The diagnosis of SA was based on consistent clinical features along with radiological manifestations (cavity with fungal ball).

RESULTS

Using receiver operating characteristic (ROC) curve analysis, the best cut-off value for A fumigatus-specific IgG was 27.3 mgA/L (AUROC, 0.839; sensitivity, 63.5%; specificity, 98.3%). The best cut-off value for serum and BALF-GM was 0.7 (AUROC, 0.636; sensitivity, 32%; specificity, 96.2%) and 2.5 (AUROC, 0.833; sensitivity, 63.7%; specificity, 97.1%), respectively. A combination of A fumigatus-specific IgG (>27 mgA/L) or serum GM (≥0.7) or BALF-GM (≥2.5) had a sensitivity and specificity of 82.6% and 96%, respectively.

CONCLUSIONS

A combination of serological tests has the best sensitivity in diagnosing SA. More studies are needed to confirm our findings.

Evaluation of LDBio Aspergillus ICT Lateral Flow Assay for IgG and IgM Antibody Detection in Chronic Pulmonary Aspergillosis

Detecting Aspergillus-specific IgG is critical to diagnosing chronic pulmonary aspergillosis (CPA). Existing assays are often cost- and resource-intensive and not compatible with resource-constrained laboratory settings. LDBio Diagnostics has recently commercialized a lateral flow assay based on immunochromatographic technology (ICT) that detects Aspergillus antibodies (IgG and IgM) in less than 30 min, requiring minimal laboratory equipment. A total of 154 CPA patient sera collected at the National Aspergillosis Centre (Manchester, United Kingdom) and control patient sera from the Peninsula Research Bank (Exeter, United Kingdom) were evaluated. Samples were applied to the LDBio Aspergillus ICT lateral flow assay, and results were read both visually and digitally. Results were compared with Aspergillus IgG titers in CPA patients, measured by ImmunoCAP-specific IgG assays. For proven CPA patients versus controls, sensitivity and specificity for the LDBio Aspergillus ICT were 91.6% and 98.0%, respectively. In contrast, the routinely used ImmunoCAP assay exhibited 80.5% sensitivity for the same cohort (cutoff value, 40 mg of antigen-specific antibodies [mgA]/liter). The assay is easy to perform but challenging to read when only a very faint band is present (5/154 samples tested). The ImmunoCAP Aspergillus IgG titer was also compared with the Aspergillus ICT test line intensity or rate of development, with weak to moderate correlations. The Aspergillus ICT lateral flow assay exhibits excellent sensitivity for serological diagnosis of CPA. Quantifying IgG from test line intensity measurements is not reliable. Given the short run time, simplicity, and limited resources needed, the LDBio Aspergillus ICT is a suitable diagnostic tool for CPA in resource-constrained settings.

Prospective study of the serum Aspergillus-specific IgG, IgA and IgM assays for chronic pulmonary aspergillosis diagnosis

Background

Chronic pulmonary aspergillosis (CPA) is an underdiagnosed and misdiagnosed disease and now increasingly recognised. However, the diagnosis of CPA remains challenging. In this study, we aimed to investigate the diagnostic values of serum Aspergillus-specific IgG, IgA and IgM antibodies in patients with CPA.

Methods

The prospective study was performed at Chinese People’s Liberation Army General Hospital in Beijing, from January 2017 to December 2017. Adult patients with lung lesions presented as cavity, nodule, mass, bronchiectasis or severe fibrotic destruction with at least two lobes in CT imaging were enrolled. One hundred healthy persons were also enrolled as additional controls. The serum levels of Aspergillus-specific IgG, IgA and IgM antibodies and galactomannan (GM) levels were measured simultaneously by plate ELISA kit.

Results

A total of 202 patients were enrolled in this study, including 42 CPA patients, 60 non-CPA patients and 100 healthy persons. The most common underlying lung diseases in CPA patients were bronchiectasis (28.6%) and COPD (19.0%). The most common symptoms in the CPA patients were cough (76.2%), sputum (71.4%), and fever (45.2%); chest pain (4.8%) was infrequent. Receiver operating characteristic (ROC) curve analysis revealed that the optimal CPA diagnostic cut-off of Aspergillus-specific IgG, IgA and IgM assays and GM test were 89.3 AU/mL, 8.2 U/mL, 73.3 AU/mL and 0.5μg/L, respectively. The serum levels of Aspergillus-specific IgG and IgA in CPA patients were higher than these in non-CPA patients or healthy persons. The sensitivities and specificities of Aspergillus-specific IgG, IgA, IgM tests and GM test were 78.6 and 94.4%, 64.3 and 89.4%, 50.0 and 53.7% and 71.4 and 58.1%, respectively.

Conclusions

The sensitivity and specificity of serum Aspergillus-specific IgG assay are satisfactory for diagnosing CPA, while the performance of Aspergillus-specific IgA assay is moderate. Aspergillus-specific IgM assay and serum GM test have limited value for CPA diagnosis.

Trial registration

NCT03027089. Registered 20 January 2017.

Evaluation of Aspergillus-Specific Lateral-Flow Device Test Using Serum and Bronchoalveolar Lavage Fluid for Diagnosis of Chronic Pulmonary Aspergillosis

The Aspergillus-specific lateral-flow device (AspLFD) test is a newly developed point-of-care diagnostic method for invasive pulmonary aspergillosis. However, evidence of the diagnostic performance of the AspLFD for chronic pulmonary aspergillosis (CPA) is limited. Therefore, we conducted a retrospective study to investigate this in comparison with the galactomannan (GM) β-d-glucan (BDG) test. Fifty patients with chronic pulmonary aspergillosis and 65 patients with respiratory disease, as a control, were enrolled in this study. The majority of the CPA disease entities were chronic pulmonary aspergillosis (64.0%, n = 32), followed by subacute invasive pulmonary aspergillosis (IPA) (20.0%, n = 10) and simple pulmonary aspergilloma (SPA) (16.0%, n = 8). The sensitivity and specificity of the AspLFD test in serum samples were 62.0% and 67.7%, respectively. The GM test (cutoff index, 1.54) showed a sensitivity of 22% and a specificity of 92.3%, while the sensitivity and specificity of the BDG test (cutoff, 19.3 pg/ml) were 48% and 90.8%, respectively. In bronchoalveolar lavage fluid samples, the AspLFD test showed a sensitivity of 66.7% and a specificity of 69.2%, while those of the GM test (cutoff index, 0.6) were 72.7% and 83.1%, respectively. The Aspergillus precipitating antibody test had 70% sensitivity. Unlike the Aspergillus precipitating antibody test, the AspLFD on serum samples showed similar sensitivity to non-fumigatus Aspergillus species. Patients with false-positive results for the AspLFD on serum samples were of a significantly higher age and had a higher prevalence of cavitary lesions in chest computed tomography than patients with negative results in the control group. Given the results in this study, the performance of the AspLFD using serum was acceptable as a point-of-care test for the diagnosis of CPA.

Diagnostic role of polymerase chain reaction in bronchoalveolar lavage fluid for invasive pulmonary aspergillosis in immunocompromised patients - A retrospective cohort study

BACKGROUND

This study aimed to evaluate the diagnostic role of PCR detection of Aspergillus DNA in the broncho-alveolar lavage (BAL) fluid in a large cohort of patients suspected to have invasive pulmonary aspergillosis (IPA).

METHODS

Consecutive immunocompromised patients who underwent bronchoscopy with BAL sampling and PCR detection of Aspergillus DNA for the diagnosis of pulmonary infiltrates were included in the study. Galactomannan (GM) antigen testing in BAL and serum and BAL fungal culture were also performed. Patients were classified as having IPA (proven/probable/possible) or no-IPA according to the EORTC/MSG diagnostic criteria.

RESULTS

During 12 years (2005-2016), 1248 bronchoscopies were performed for 1072 patients. 77% had hematological malignancy, of them 40% had AML and 35.6% underwent HSCT. IPA was diagnosed in 531 patients (42.5%), 7-proven, 280-probable and 244-possible. PCR was positive in 266 cases, of them 213 had IPA, indicating a true positive rate of 80% (213/266) and a false positive rate of 20% (53/266). These results establish the diagnostic performance of PCR to have sensitivity of 40%, specificity of 93%, PPV- 80% and NPV-68%. Of 244 patients with possible IPA, 80 had positive PCR. Including PCR in the diagnostic criteria would move 80 cases from the possible group to the probable one. A combination of positive PCR and/or BAL-GM increases sensitivity to 74%, while positivity of both tests elevates PPV to 99.4%.

CONCLUSIONS

Inclusion PCR for the detection of Aspergillus-DNA in BAL in the mycological criteria of the EORTC/MSG definitions increases the rate and the certainty of IPA diagnosis.

Utility of Serum and Bronchoalveolar Lavage Fluid Galactomannan in Diagnosis of Chronic Pulmonary Aspergillosis

The value of serum and bronchoalveolar lavage fluid galactomannan (BALF-GM) in diagnosing chronic pulmonary aspergillosis (CPA) remains unclear. Here, we study the diagnostic efficacy of GM in the diagnosis of CPA. We included consecutive treatment-naive subjects with CPA. For calculating the specificity of serum GM, we enrolled diseased controls (minimally symptomatic subjects previously treated for pulmonary tuberculosis, not meeting the criteria for CPA). To calculate the specificity of BALF-GM, subjects with pulmonary disorders other than CPA who underwent bronchoscopy were included. We determined the cutoff of serum and BALF-GM levels using receiver operating characteristic (ROC) curve analysis. We enrolled 243 consecutive treatment-naive subjects (53.5% males) of CPA with a mean (standard deviation) age of 43.6 (14.7) years. Forty-five (60% males; age, 46.7 [15.7] years) and 27 (59.3% males; age, 52.6 [12.8] years) subjects served as controls for serum and BALF-GM, respectively. The best cutoff value for serum and BALF-GM was 0.55 (area under the ROC curve [AUROC], 0.605; sensitivity, 38%; specificity, 87%) and 1.375 (AUROC, 0.836; sensitivity, 68%; specificity, 93%), respectively. At a cutoff value of 2.5, BALF-GM had a sensitivity and specificity of 50% and 100%, respectively. BALF-GM performs better than serum GM and may be helpful in the diagnosis of CPA in selected patients. More studies are required to confirm our findings.

A CPAnet consensus statement on research priorities for chronic pulmonary aspergillosis: a neglected fungal infection that requires attention

Chronic pulmonary aspergillosis (CPA) is a severe fungal infection with a high morbidity and mortality, and is usually seen in immunocompetent patients with respiratory disorders. Clinical presentation is nonspecific and often overlaps with the symptoms and the radiological pattern caused by the underlying disease. Clinical management of CPA is further hampered by limited information about the epidemiology, disease dynamics, sensitivity and specificity of different mycological tests, mechanisms of antifungal resistance, efficient treatment and management strategies. In order to contribute to a better understanding and to improve CPA patient management and outcome, we established the Chronic Pulmonary Aspergillosis Network (CPAnet), a self-organized multinational research collaboration. Key research priorities, defined by using a modified Delphi process, include the establishment of a multinational web-based registry, the validation of different diagnostic tests, the establishment of a culture collection from samples of patients with proven CPA and the establishment of a consensus on a treatment outcome definition.

Improving the rates of Aspergillus detection: an update on current diagnostic strategies

INTRODUCTION

The spectrum of disease caused by Aspergillus spp. is dependent on the immune system of the host, and ranges from invasive aspergillosis (IA) to chronic pulmonary aspergillosis (CPA). Early and reliable diagnosis of Aspergillus disease is important to decrease associated morbidity and mortality. Areas covered: The following review will give an update on current diagnostic strategies for the diagnosis of IA and CPA. Expert commentary: Several new diagnostics for IA (including point-of-care tests) are now available to complement galactomannan testing. In particular, immunoPET/MRI imaging may be a promising approach for diagnosing IA in the near future. Notably, nearly all new biomarkers and tests for IA have been evaluated in the hematology setting only. Validation of biomarkers and tests is therefore needed for the increasing proportion of patients who develop IA outside the hematology setting. As an important first step, reliable definitions of IA are needed for non-hematology settings as clinical presentation and radiologic findings differ in these settings. CPA diagnosis is based on a combination of radiological findings in chest CT, mycological evidence (e.g. by the Aspergillus-specific IgG assay), exclusion of alternative diagnosis and chronicity. ([18F]FDG) PET/CT and immuno PET/MRI imaging are promising new imaging approaches.

[Aspergillus in airway material : Ignore or treat?]

Fungi of the genus Aspergillus are ubiquitously present. Even though humans inhale Aspergillus spores daily under natural conditions, Aspergillus-associated pulmonary diseases only occur under special circumstances. Whether an Aspergillus-associated disease develops and which type of Aspergillus-associated disease develops depends on the constitution of the host. The spectrum of Aspergillus-associated pulmonary diseases ranges from allergic diseases, such as hypersensitivity pneumonitis to allergic infectious diseases, such as allergic bronchopulmonary aspergillosis (ABPA) and bronchocentric granulomatosis (BG) to infectious diseases, such as invasive (IA) or semi-invasive aspergillosis (SIA) and chronic pulmonary aspergillosis (CPA). Identification of Aspergillus spp. from sputum or bronchopulmonary secretions is not sufficient for a definitive diagnosis of Aspergillus-associated infections. The gold standard is the identification of Aspergillus spp. from lung tissue by culture or by histopathological methods; however, in clinical practice the decision to initiate antifungal therapy is more often based on immunological methods, such as the detection of Aspergillus-specific IgG antibodies from peripheral blood or galactomannan antigens from bronchoalveolar lavages. Acute IA or SIA infections have a high mortality and require immediate antifungal therapy. With rare exceptions CPA cannot be cured by medicinal therapy alone; however, active CPA can be brought into remission with antifungal therapy. Eradication of Aspergillus in CPA can as a rule only be successful using a combined antimycotic and surgical intervention.

Evaluation of Galactomannan Testing, the Aspergillus-Specific Lateral-Flow Device Test and Levels of Cytokines in Bronchoalveolar Lavage Fluid for Diagnosis of Chronic Pulmonary Aspergillosis

Background: Diagnosis of chronic pulmonary aspergillosis (CPA) is challenging. Symptoms are unspecific or missing, radiological findings are variable and proof of mycological evidence is limited by the accuracy of diagnostic tests. The goal of this study was to investigate diagnostic performance of galactomannan (GM), the newly formatted Aspergillus-specific lateral-flow-device test (LFD), and a number of cytokines in bronchoalveolar lavage fluid (BALF) samples obtained from patients with CPA, patients with respiratory disorders without CPA and healthy individuals.

Methods: Patients with CPA (n = 27) and controls (n = 27 with underlying respiratory diseases but without CPA, and n = 27 healthy volunteers) were recruited at the Medical University of Graz, Austria and the Research Center Borstel, Germany between 2010 and 2018. GM, LFD and cytokine testing was performed retrospectively at the Research Center Borstel.

Results: Sensitivity and specificity of GM testing from BALF with a cut off level of ≥0.5 optical density index (ODI) was 41 and 100% and 30 and 100% with a cut off level of ≥1.0 ODI. ROC curve analysis showed an AUC 0.718 (95% CI 0.581–0.855) for GM for differentiating CPA patients to patients with other respiratory diseases without CPA. The LFD resulted positive in only three patients with CPA (7%) and was highly specific. CPA patients did not differ significantly in the BALF cytokine profile compared to patients with respiratory disorders without CPA, but showed significant higher values for IFN-γ, IL-1b, IL-6, IL-8, and TNF-α compared to healthy individuals.

Conclusion: Both GM and LFD showed insufficient performance for diagnosing CPA, with sensitivities of BALF GM below 50%, and sensitivity of the LFD below 10%. The high specificities may, however, result in a high positive predictive value and thereby help to identify semi-invasive or invasive disease.

Recent Advances in Diagnosing Chronic Pulmonary Aspergillosis

Purpose: The diagnosis of chronic pulmonary aspergillosis (CPA) is occasionally complicated due to poor sensitivity of mycological culture and colonization of Aspergillus species in the airway. Several diagnostic methods have been developed for the diagnosis of invasive pulmonary aspergillosis; however, their interpretation and significance are different in CPA. This study aimed to review the recent advances in diagnostic methods and their characteristics in the diagnosis of CPA.

Recent findings: Radiological findings of lung, histopathology, and culture are the gold standard of CPA diagnosis. Serodiagnosis methods involving the use of galactomannan and β-D-glucan have low sensitivity and specificity. An Aspergillus-specific IgG antibody assay showed good performance and had better sensitivity and reproducibility than conventional precipitant antibody assays. Currently, it is the most reliable method for diagnosing CPA caused by Aspergillus fumigatus, but evidence on its effectiveness in diagnosing CPA caused by non-fumigatus Aspergillus is lacking. Newly developed lateral flow device Aspergillus and detection of volatile organic compounds in breath have potential, but evidence on its effectiveness in diagnosing CPA is lacking. The increasing prevalence of azole-resistant A. fumigatus strains has become a threat to public health. Some of the azole-resistant-related genes can be detected directly from clinical samples using a commercially available kit. However, its clinical efficacy for routine use remains unclear, since resistance-related genes greatly differ among regions and countries.

Conclusion: Several issues surrounding the diagnosis of CPA remain unclear. Hence, further investigations and clinical studies are needed to improve the accuracy and efficiency of CPA diagnosis.