Aspergillus-specific Antibodies Research Articles

Chronic pulmonary aspergillosis in tea population of Assam.

Chronic pulmonary aspergillosis (CPA) is a disease commonly caused by Aspergillus fumigatus and other Aspergillus speciescharacterizedby cavitary lung lesions. Tea garden population is an agrarian population of Assam, mostly associated with tea plantations. Assam is a major tea-producing state with 803 tea gardens producing approximately 50% of the total tea in India, of which 177 are present in the Dibrugarh district alone. Tuberculosis is common in tea garden workers. This community-based cross-sectional study in the tea garden community of Dibrugarh was done to find the prevalence of Aspergillus IgG antibodies and CPA cases in individuals with chronic respiratory symptoms. Patients visiting 3 tea garden hospitals and 2 referral hospitals with chronic cough and/or haemoptysis, weight loss/fatigue, and other respiratory symptoms for a duration of 3 months or more were included in this one-year study. Serum samples were tested by Immunocap Phadia 200 for Aspergillus fumigatus-specific IgG antibodies. CPA cases were diagnosed based on clinical, radiological, and serological criteria. Out of 128 samples, seropositivity was seen in 41 (32.0%) patients (cutoff value: 27 mgA/l). Male preponderance (1.6:1) with a mean age of 41.9 (±15.69) was observed. Haemoptysis and fatigue were significant symptoms seen (p-values: 0.0086 and 0.0098, respectively). Aspergillus fumigatus-specific IgG antibody was found to be significantly high in 29 out of 76 patients (38.1%) with a history of tuberculosis. Amongst them, seropositivity with active TB was 5 out of 27 patients (18.5%), and seropositivity with post-TB was 24 out of 49 patients (48.9%). Chronic cavitary pulmonary aspergillosis was the predominant type (38.1%). Proven CPA (clinically, radiologically, and serologically positive) were 22 (17.1%, 95% CI 10.7%-26.0%), and possible CPA (clinically and serologically positive but without radiological data) were 19 (14.8%, 95% CI 8.9%-23.1%). A high prevalence of CPA (60 per 100 000) was detected. High Aspergillus seropositivity of 48.9% was seen in the post-TB population. Aspergillus-specific IgG antibody testing is the only confirmatory method for diagnosing CPA, which is available in limited centres in India. Aspergillus seropositivity should be detected in post-TB patients presenting with chronic respiratory symptoms.

Retrospective Comparison of Two Aspergillus IgG Enzyme Immunoassays for Diagnosing Pulmonary Aspergillosis

Aspergillus-specific antibodies are diagnostic indicators of allergic bronchopulmonary aspergillosis (ABPA) and chronic pulmonary aspergillosis (CPA). Tests for detecting Aspergillus-specific antibodies were not used clinically in Japan, and the production of the Aspergillus precipitin test was discontinued. Thus, alternative tests for diagnosing aspergillosis are urgently needed. We retrospectively evaluated 64 patients with suspected ABPA and CPA who underwent precipitin antibody testing. Serum Aspergillus IgG levels were measured and compared using the Bordier Aspergillus fumigatus ELISA and the Platelia Aspergillus IgG (Bio-Rad) kits. Of the participants, 18 were diagnosed with CPA, and 8 were diagnosed with ABPA. Both the Bordier and Bio-Rad kits showed high sensitivity and specificity for CPA and ABPA. The area under the receiver operating characteristic curves for the Bordier and Bio-Rad kits were 0.97 and 0.95, respectively, for CPA, and 0.89 and 0.91, respectively, for ABPA. In contrast to the Bordier kit, the Bio-Rad kit showed relatively low anti-Aspergillus IgG levels and lower sensitivity to non-fumigatus Aspergillus infections. The Aspergillus-specific IgG ELISA tests showed sufficient diagnostic accuracy. Therefore, these assays are recommended as alternatives to the precipitin kit for diagnosing aspergillosis in clinical settings in Japan.

Value Evaluation of Quantitative Aspergillus fumigatus-Specific IgG Antibody Test in the Diagnosis of Non-neutropenic Invasive Pulmonary Aspergillosis.

The role of Aspergillus-specific IgG antibody test in the diagnosis of non-neutropenic invasive pulmonary aspergillosis (IPA) is still uncertain, and related studies are also limited. This study aims to evaluate the quantitative test value of Aspergillus fumigatus-specific IgG antibody in non-neutropenic IPA, which could provide additional evidence for related clinical diagnosis. This prospective study collected clinical data of suspected IPA patients from January, 2020 to December, 2022, and patients were divided into two groups, IPA and non-IPA. The study analyzed clinical characteristics and diagnostic value of Aspergillus-specific IgG antibody test, using the receiver operating characteristic (ROC) curve to evaluate diagnostic efficacy. The study enrolled 59 IPA cases and 68 non-IPA cases, the average admission age of IPA group was 63.2±9.6 (33-79), and the gender ratio (male:female) of IPA group was 42:17. The proportion of patients with history of smoking and COPD were higher in IPA group (59.3% vs 39.7%, P=0.027; 33.9% vs 14.7%, P =0.011, respectively). The level of Aspergillus fumigatus-specific IgG antibody in IPA group was significantly higher than non-IPA group (202.1±167.0 vs 62.6±58.0, P<0.001). The area under the ROC curve was 0.799 (95%CI: 0.718, 0.865 P<0.001), and the cut-off with best diagnostic efficacy was 91 AU/mL. Immunological test plays an important role in the diagnosis of pulmonary aspergillosis, and Aspergillus-specific IgG antibody test has the good diagnostic value in non-neutropenic IPA.

Point-of-Care Diagnosis of Chronic Pulmonary Aspergillosis in Respiratory Disease Patients: Hope in a Resource-Limited Setting

Introduction: Chronic pulmonary aspergillosis (CPA) is a global health burden, however the diagnosis is still challenging due to non-specific clinical and radiological features. To overcome this problem, the lateral flow assay to detect Aspergillus-specific antibodies has the potential for rapid CPA diagnosis (point-of-care test/POCT). The aim of this study is to describe the profile of POCT Aspergillus-specific antibody detection in various populations as part of CPA diagnosis in Indonesia.Methods: This study is a part of previous CPA studies conducted in Jakarta between 2018-2021. The tests were carried out at the Laboratory of Parasitology Department, Faculty of Medicine Universitas Indonesia. All sera were tested using Aspergillus-specific immunochromatography lateral flow assay (LDBio, Diagnostics, Lyon, France) according to the manufacturer's instructions.Results: There were 314 patients' sera derived from four groups: post-TB (n=82), active TB (n=105), uncontrolled-asthma (n=50), and lung cancer (n=77). The positive results of LDBio Aspergillus ICT were 43% in post TB, 11% in active TB, 16% in uncontrolled asthma, and 14% in lung cancer patients. Further analysis revealed that the prevalence of CPA was 6-22% in those populations.Conclusion: The LDBio Aspergillus ICT has the potential as a POCT for early diagnosis of CPA. The risk of CPA was found highest in the post-TB group compared to others.

Aspergillus-specific IgG antibodies for diagnosing chronic pulmonary aspergillosis compared to the reference standard

To evaluate the performance of Aspergillus-specific IgG antibodies for diagnosing chronic pulmonary aspergillosis (CPA) by using a cohort of patients with histologically proven CPA as a reference standard. We collected Aspergillus-specific IgG antibody titres from patients with histologically proven CPA in collaboration with CPAnet study sites in Denmark, Germany, Belgium, India, Moldova, and Pakistan (N=47). Additionally, sera from diseased and healthy controls were prospectively collected at the Medical Clinic of the Research Center, Borstel, Germany (n=303). Aspergillus-specific IgG antibody titres were measured by the ImmunoCAP® assay (Phadia 100, Thermo Fisher Scientific, Uppsala, Sweden). An Aspergillus-specific IgG antibody titre ≥50 mgA/L was considered positive. Using patients with histologically proven CPA as the reference standard, the ImmunoCAP® Aspergillus-specific IgG antibody test had a sensitivity and specificity of 85.1% (95% CI: 71.7-93.8%) and 83.6% (95% CI: 78.0-88.3%), respectively. Patients with histologically proven CPA had significantly higher Aspergillus-specific IgG antibody titre with a median of 83.45 mgA/L (interquartile range 38.9-115.5) than all other cohorts (p<0.001). False-positive test results occurred in one-third of 79 healthy controls. Our study results confirm a high sensitivity of the Aspergillus-specific IgG antibody test for the diagnosis of CPA when using patients with histologically proven CPA as a reference standard. However, positive test results should always match radiological findings as false-positive test results limit the interpretation of the test.

Clinical, Microbiological, Serological and Radiological Profile of Patients With Mild-Moderate and Severe Allergic Bronchopulmonary Aspergillosis (ABPA).

Objective Allergic bronchopulmonary aspergillosis (ABPA) is a complex hypersensitivity reaction to Aspergillus antigen mostly Aspergillus fumigatus that occurs almost exclusively in patients with asthma and cystic fibrosis. ABPA is an underdiagnosed and undertreated disease because of its presentation with various grades of severity in asthma patients. Data available regarding the clinical, serological, and radiological profile of ABPA patients is limited due to lack of consensus on diagnostic criteria and treatment guidelines. Thus ABPA is a significant disease, especially in the Indian population where the incidence of allergic diseases like asthma is on the rise. Methods This prospective study was conducted in the Department of Pulmonary Medicine at one of the tertiary centers of north India. All consecutive patients diagnosed withallergic bronchopulmonary aspergillosis (ABPA) from 1st January 2017to 30th September 2017 were included in the study. A total of 67 consecutive patients diagnosedwithbronchial asthma were included in the study. The diagnosis of ABPA was based upon either criterion given by Rosenberg and Patersonor the International Society of Human and Animal Mycology (ISHAM) criteria. Patients diagnosed with ABPAwere finally divided into mild, moderate, and severe. Results The majority of patients showed an obstructive pattern on spirometry and moderate to severe obstruction was the most common pattern observed among patients who had an obstructive pattern on spirometry. Also, all three patients with the mixed pattern on spirometry had severe disease. Serological analysis revealed that patients in the moderate category had a higher level of absolute eosinophil count (AEC), total IgE, and Aspergillus-specific IgE antibodies, especially in patients who hadeither high attenuation mucus (HAM) or centrilobular nodules on their high-resolution computed tomography (HRCT) scan. Conclusion ABPA is a disease of divergent presentation. We concluded to have alternate or add-on criteria for the classification of ABPA which was not based on the sequelae of chronic inflammatory changes in the lungs.

Detection of serum Aspergillus-specific IgM and IgG antibody levels for the diagnosis of chronic pulmonary aspergillosis developed in patients with tuberculosis.

Chronic pulmonary aspergillosis (CPA) is common among individuals with underlying lung diseases. The clinical manifestations of CPA include systemic symptoms (e.g., weight loss, fatigue, fever), chronic productive cough, chest discomfort, and occasional haemoptysis, which are similar to the manifestations of pulmonary tuberculosis (PTB) and are often misdiagnosed as PTB. Considering the striking similarities between CPA and PTB in clinical manifestations and imaging features, more specific microbiological and serological detections are needed for a definitive diagnosis. This study aimed to explore the clinical characteristics of CPA in TB as well as the diagnostic significance of Aspergillus-specific IgG and Aspergillus-specific IgM.A total of 140 patients diagnosed with TB by culture between December 2017 and February 2019 were included. Enrolled patients were categorized into two groups (CPA group and non-CPA group) according to CPA diagnostic criteria. All collected specimens were subjected to Aspergillus-specific IgG and IgM detection testing.The median concentration of Aspergillus-specific IgG in the CPA group (211.04 AU/ml) was significantly higher than that in the non-CPA group (77.88 AU/ml) (Z value - 6.397, P < 0.001). The sensitivity and specificity of Aspergillus-specific IgG for CPA diagnosis were 81.82% and 72.97%, respectively. In the chronic cavitary pulmonary aspergillosis (CCPA) group, the IgG positivity rate (≥ 120 AU/ml) was 96.2%, which was 21.4% in the non-CCPA patients (P < 0.001).The detection of Aspergillus-specific IgG serological changes is feasible and facilitates reliable differentiation between Aspergillus and Mycobacterium tuberculosis infection. However, Aspergillus-specific IgM has limited diagnostic value, with unsatisfactory sensitivity results.

Aspergillus-Specific IgG Antibodies are Associated With Fungal-Related Complications and Chronic Lung Allograft Dysfunction After Lung Transplantation.

Fungal exposure and sensitization negatively affect outcomes in various respiratory diseases, however, the effect of fungal sensitization in lung transplant (LTx) recipients is still unknown. We performed a retrospective cohort study of prospectively collected data on circulating fungal specific IgG/IgE antibodies, and their correlation with fungal isolation, chronic lung allograft dysfunction (CLAD) and overall survival after LTx. 311 patients transplanted between 2014 and 2019 were included. Patients with elevated Aspergillus fumigatus or Aspergillus flavus IgG (10%) had more mold and Aspergillus species isolation (p = 0.0068 and p = 0.0047). Aspergillus fumigatus IgG was specifically associated with Aspergillus fumigatus isolation in the previous or consecutive year (AUC 0.60, p = 0.004 and AUC 0.63, p = 0.022, respectively). Elevated Aspergillus fumigatus or Aspergillus flavus IgG was associated with CLAD (p = 0.0355), but not with death. Aspergillus fumigatus, Aspergillus flavus or Aspergillus niger IgE was elevated in 19.3% of patients, but not associated with fungal isolation, CLAD or death. Mold isolation and Aspergillus species isolation from respiratory cultures were associated with CLAD occurrence (p = 0.0011 and p = 0.0005, respectively), and Aspergillus species isolation was also associated with impaired survival (p = 0.0424). Fungus-specific IgG could be useful in long-term follow-up post-LTx, as a non-invasive marker for fungal exposure, and thus a diagnostic tool for identifying patients at risk for fungal-related complications and CLAD.

The clinical value of Aspergillus-specific IgG antibody test in the diagnosis of nonneutropenic invasive pulmonary aspergillosis

Aspergillus-specific IgG antibody (Asp IgG) has been successfully applied in the diagnosis of chronic pulmonary aspergillosis. We explored its value in nonneutropenic invasive pulmonary aspergillosis (IPA) by a multicenter, prospective, and controlled study. We enrolled 372 clinically suspected nonneutropenic patients with IPA from February 2015 to August 2022. After excluding 4 cases with Aspergillus colonization, the remaining 368 cases were finally confirmed as patients with IPA (n=99), or non-IPA patients (n=269) consisting of community-acquired pneumonia (n=206), tuberculosis (n=22), nontuberculous mycobacteria (n=5), lung abscess (n=6), or noninfectious diseases (n=30). Asp IgG in plasma samples was tested by enzyme-linked immunosorbent assay. At cut-off value of ≥80 AU/mL, Asp IgG had much higher sensitivity (59.6% vs. 19.2%, p<0.0001), but lower specificity (77.0% vs. 96.3%, p<0.0001) than serum galactomannan (GM) (cut-off value of ≥1.0), and similar sensitivity (59.6% vs. 55.6%, p=0.611) but lower specificity (77.0% vs. 91.2%, p=0.001) than bronchoalveolar lavage fluid (BALF) GM (cut-off value of ≥1.0), respectively. Combination diagnosis of either positive for Asp IgG or BALF GM had higher sensitivity (81.0% vs. 55.6%, p=0.002), but lower specificity (75.2% vs. 91.2%, p=0.001) than BALF GM alone. The receiver operating characteristic curve showed that Asp IgG had an optimal diagnostic value when the cut-off value was 56.6 AU/ml, and the sensitivity and specificity were 77.8% and 63.9%, respectively. The diagnostic value of Asp IgG for IPA is superior to serum GM, and a little inferior to BALF GM in nonneutropenic patients with IPA. Considering the convenience of taking blood samples, it is a good screening and diagnostic method for nonneutropenic patients with IPA, especially for those who cannot bear invasive procedures.

Importance of Aspergillus-Specific Antibody Screening for Diagnosis of Chronic Pulmonary Aspergillosis after Tuberculosis Treatment: A Prospective Follow-Up Study in Ghana.

Chronic pulmonary aspergillosis (CPA) often occurs in patients that have been previously treated for pulmonary tuberculosis (PTB). A limited number of studies have looked at the development of CPA at different times following the completion of a PTB treatment course. This prospective longitudinal study aimed to determine the incidence of CPA at two timepoints, at the end of the PTB treatment (T1) and six months post-treatment (T2). Patients with confirmed PTB from a previous study who were placed on anti-TB medication were followed up and screened for CPA at T1 and T2 by assessing their symptoms, evaluating their quality of life, and screening them for Aspergillus infection by performing antibody testing and cultures. CPA was defined by the Global Action for Fungal Infections (GAFFI) diagnostic algorithm. Forty-one patients were enrolled, of whom thirty-three patients (80%) and twenty-eight patients (68%) were resurveyed at T1 and T2, respectively. The rate of new CPA was 3.3% (1/33) and 7.4% (2/27) at T1 and T2, respectively, with an overall incidence of 10.7% (3/28) among the patients at both T1 and T2. A positive Aspergillus-specific antibody test was an indicator for CPA in all three patients. Aspergillus-specific antibody screening during and after the end of an anti-TB treatment regimen may be important for early detection of CPA in high-PTB-burden settings.

Comparison of Aspergillus-specific antibody cut-offs for the diagnosis of aspergillosis.

Aspergillus diseases are frequently encountered in patients who are immunocompromised. Without a prompt diagnosis, the clinical consequences may be lethal. Aspergillus-specific antibodies have been widely used to facilitate the diagnosis of Aspergillus diseases. To date, universally standardized cut-off values have not been established. This study aimed to investigate the cut-off values of Aspergillus-specific antibodies and perform a narrative review to depict the geographic differences in the Taiwanese population. We analyzed enrolled 118 healthy controls, 29 patients with invasive aspergillosis (IA), chronic pulmonary aspergillosis (CPA), and allergic bronchopulmonary aspergillosis (ABPA) and 99 with disease control, who were tested for Aspergillus fumigatus and Aspergillus niger-specific IgG and IgE using ImmunoCAP. 99 participants not fulfilling the diagnosis of IA, CPA, and ABPA were enrolled in the disease control group. The duration of retrieval of medical records from June 2018 to September 2021. Optimal cut-offs and association were determined using receiver operating characteristic curve (ROC) analysis. We found that patients with CPA had the highest A. fumigatus-specific IgG levels while patients with ABPA had the highest A. fumigatus-specific IgE, and A. niger-specific IgG and IgE levels. In patients with CPA and ABPA, the optimal cut-offs of A. fumigatus-specific IgG and A. niger-specific IgG levels were 41.6, 40.8, 38.1, and 69.9 mgA/l, respectively. Geographic differences in the cut-off values of A. fumigatus-specific IgG were also noted. Specifically, the levels were different in eco-climatic zones. We identified the optimal cut-offs of Aspergillus-specific antibodies to facilitate a precise diagnosis of aspergillosis. The observed geographic differences of the antibody levels suggest that an eco-climatic-specific reference is needed to facilitate a prompt and accurate diagnosis of aspergillosis.

P459 The Aspergillus lateral flow assay for the diagnosis of chronic pulmonary aspergillosis

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PMObjectivesChronic pulmonary aspergillosis (CPA) is an uncommon and problematic pulmonary disease, complicating many other respiratory disorders. Measurement of Aspergillus-specific IgG antibodies had a higher sensitivity than either IgM, IgA, or IgE and it should therefore be considered the most appropriate test for screening CPA. Aspergillus-specific IgG antibody levels have been successfully used to monitor the response of CPA to medical therapy. Recently, a novel rapid test for Aspergillus-specific IgG antibody from Dynamiker Biotechnology (Tianjin) Co., Ltd. was released as a screening test of CPA. It is a fluorescent immunochromatographic cassette test using a monoclonal antibody against Aspergillus-specific IgG antibody and Europium nanoparticles (Eu NP) (Fig. 1). It is a semi-quantitative test which was easy to operate, rapid with portable detection devices, and can be widely accepted by clinical and primary medical (Fig. 2). We collect clinical samples to verify the detection performance of the Dynamiker Quic™Aspergillus-specific IgG antibody (LFA) test.MethodsIn total, 102 patients were included and 42 patients were diagnosed with CPA. The pathogen was identified from sputum, BALF culture, lung resection surgery, bronchos copy biopsy, percutaneous lung biopsy and BALF GM assay.ResultsThe sensitivity, specificity, PLR, NLP and Kappa index of the IgG antibody test were 85.6%,94.4%,14.0%,0.23% and 0.72, respectively.ConclusionsThe current work indicates that the Dynamiker Quic™ Aspergillus specific IgG antibody (LFA) test shows a promising application in the diagnosis of CPA. The results are accurate and reliable, and it could be used as an aid for the early rapid screening test of CPA.

Seroprevalence of Aspergillus-Specific IgG Antibody among Mozambican Tuberculosis Patients.

Background: Chronic pulmonary aspergillosis (CPA) is a life-threatening sequel in patients with pulmonary tuberculosis (PTB). Aspergillus-specific IgG antibody is a useful diagnostic biomarker supporting CPA diagnosis, especially in countries with limited health recourses. Methods: We conducted a prospective pilot study to assess the seroprevalence of Aspergillus-specific IgG antibodies among 61 Mozambican tuberculosis patients before, during, and after the end of TB treatment. Aspergillus-specific IgG antibody levels were measured using the ImmunoCAP®. Results: In this study, 3 out of 21 HIV-negative PTB patients had a positive Aspergillus-specific IgG antibody level before, during, and after the end of TB treatment. Antibody levels were 41.1, 45.5, and 174 mg/L at end of treatment (EOT), respectively. Additionally, two HIV-negative PTB patients with negative Aspergillus-specific IgG antibody levels at baseline became seropositive at EOT (41.9 and 158 mg/L, respectively). Interestingly, none of the HIV-positive PTB patients (40/61) had a positive Aspergillus-specific IgG antibody level at any time, neither at baseline nor at EOT. Probable CPA was diagnosed in one HIV-negative patient (5%; 1/20). Conclusion: Seroprevalence of Aspergillus-specific IgG antibody may differ between HIV-negative and HIV-positive Mozambican PTB patients. Future studies evaluating post-tuberculosis lung disease should integrate CPA as a life-threatening sequel to PTB.

Chronic Pulmonary Aspergillosis - Case Series and Review of Indian Literature

Aspergillus species, especially Aspergillus fumigatus, can cause varied pulmonary manifestations depending on the host immune status and duration of infection. Chronic pulmonary aspergillosis (CPA) is an under-reported entity, and its diagnosis remains a diagnostic challenge for clinicians. CPA can have varied presentations including chronic cavitary pulmonary aspergillosis (CCPA), subacute invasive pulmonary aspergillosis, and chronic fibrosing pulmonary aspergillosis. Underlying lung diseases such as chronic obstructive pulmonary disease and sequelae of pulmonary tuberculosis predisposes these individuals to CPA. These cases can present as chronic cough with hemoptysis even requiring emergency bronchial artery embolization. Here, we present a series of four CCPA cases who were diagnosed on the basis of clinico-radiological features and the Aspergillus-specific IgG antibody levels. A review of case series published in India is also presented.

Selection and characterization of two monoclonal antibodies specific for the Aspergillus flavus major antigenic cell wall protein Aflmp1

Aspergillus flavus is a major fungal pathogen of plants and an opportunistic pathogen of humans. In addition to the direct impact of infection, it produces immunosuppressive and carcinogenic aflatoxins. The early detection of A.flavus is therefore necessary to diagnose and monitor fungal infection, to prevent aflatoxin contamination of food and feed, and for effective antifungal therapy. Aspergillus-specific monoclonal antibodies (mAbs) are promising as diagnostic and therapeutic reagents for the tracking and treatment of Aspergillus infections, respectively. However, A.flavus has a complex cell wall composition and dynamic morphology, hindering the discovery of mAbs with well-characterized targets. Here we describe the generation and detailed characterization of mAb5.52 (IgG2aκ) and mAb17.15 (IgG1κ), which bind specifically to the highly immunogenic cell wall antigen A.flavus mannoprotein 1 (Aflmp1). Both mAbs were generated using hybridoma technology following the immunization of mice with a recombinant truncated version of Aflmp1 (ExD, including the homologous CR4 domain) produced in bacteria. We show that mAb5.52 and mAb17.15 bind specifically to A.flavus and A.parasiticus cell wall fragments (CWFs), with no cross-reaction to CWFs from other fungal pathogens. Immunofluorescence microscopy revealed that both mAbs bind to the surface of Aspergillus hyphae and that mAb17.15 also binds to spores. The epitope for both mAbs is localized within the CR4 region of the Aflmp1 protein. These Aspergillus-specific mAbs may be useful for the early detection of fungal infection in food/feed crops, for serodiagnosis in patients with invasive aspergillosis caused by A.flavus infection and for the development of antibody-expressing disease-resistant crops.

Antibody-guided in vivo imaging of Aspergillus fumigatus lung infections during antifungal azole treatment

Invasive pulmonary aspergillosis (IPA) is a life-threatening lung disease of immunocompromised humans, caused by the opportunistic fungal pathogen Aspergillus fumigatus. Inadequacies in current diagnostic procedures mean that early diagnosis of the disease, critical to patient survival, remains a major clinical challenge, and is leading to the empiric use of antifungal drugs and emergence of azole resistance. A non-invasive procedure that allows both unambiguous detection of IPA and its response to azole treatment is therefore needed. Here, we show that a humanised Aspergillus-specific monoclonal antibody, dual labelled with a radionuclide and fluorophore, can be used in immunoPET/MRI in vivo in a neutropenic mouse model and 3D light sheet fluorescence microscopy ex vivo in the infected mouse lungs to quantify early A. fumigatus lung infections and to monitor the efficacy of azole therapy. Our antibody-guided approach reveals that early drug intervention is critical to prevent complete invasion of the lungs by the fungus, and demonstrates the power of molecular imaging as a non-invasive procedure for tracking IPA in vivo.

Diagnostic accuracy of Aspergillus-specific antibodies for chronic pulmonary aspergillosis: A systematic review and meta-analysis.

We performed this study to provide the latest evidence of the diagnostic accuracy of all Aspergillus antibodies for chronic pulmonary aspergillosis (CPA). In this meta-analysis, we searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, and other databases, until 19 March 2020, for studies that examined the diagnostic accuracy of each Aspergillus-specific antibody for CPA and assessed the risk of bias using the revised Quality Assessment of Diagnostic Accuracy Studies-2 tool. We integrated the results using a hierarchical summary receiver operating characteristic (HSROC) model and calculated the point estimates of specificity with sensitivity fixed at 0.90 using the HSROC curve. We identified 32 published and one unpublished studies, including 75 studies on five antibody test types: 18 of precipitin test (2810 participants), 46 of IgG (8197), three of IgA (283), six of IgM (733) and two of combined IgG and IgM (IgG+IgM) (920). The results of specificity with sensitivity fixed at 0.90 were as follows: precipitin test, 0.93 (95% credible intervals: 0.86, 1.00); IgG, 0.90 (0.86, 0.95); IgA, 0.74 (0.00, 1.00); IgM, 0.50 (0.37, 0.53); IgG+IgM, 0.47 (0.00, 1.00). However, the precipitin test showed imprecision and instability in the sensitivity analysis. Most studies had a high risk of bias due to the case-control design. Although there is lack of applicability for malignancy or immunosuppressive patients, our study suggests a preference for IgG over other antibody tests in CPA screening. Particularly, IgG should be used as an adjunct when ruling out CPA.

Effect of patient immunodeficiencies on the diagnostic performance of serological assays to detect Aspergillus-specific antibodies in chronic pulmonary aspergillosis

BackgroundPrevalence of chronic pulmonary aspergillosis (CPA) is ~3 million patients worldwide, and detection of Aspergillus-specific antibody is a critical diagnostic component. Some patients with CPA have subtle immune deficits possibly contributing to poor Aspergillus antibody production and false negative results.Materials/methodsWe analyzed patient data from 167 cases of clinically confirmed CPA previously evaluated by ImmunoCAP Aspergillus-specific IgG EIA, Bordier ELISA and LDBio Aspergillus IgG/IgM ICT lateral flow assay, to identify deficiencies in: mannose binding lectin (MBL), IgG, IgA, IgM, IFN gamma, IL12 or IL17 production, and/or low cell marker counts (CD4, CD19, CD56). We defined patients as ‘sero-negative’ if ImmunoCAP Aspergillus IgG was consistently and repeatedly negative (<40 mg A/L). ‘Sero-positive’ was defined as all other CPA cases.ResultsWe found the rate of false negatives by ImmunoCAP Aspergillus IgG EIA (n = 23) to be more prevalent in patients with immunodeficiency markers, especially multiple defects. MBL deficiency combined with low CD19 cells (p < 0.001), pneumococcal antibody levels (p = 0.043), IgM (p = 0.047) or three combined (p = 0.001–0.018) or all four together (p = 0.018) were significant. The performance LDBio Aspergillus IgG/IgM ICT appears to be relatively unaffected by immunodeficiency (92.7% of ImmunoCap sero-negatives were positive). The Bordier assay performed significantly better than the ImmunoCAP assay (P = 0.0016) for sero-negative CPA cases.ConclusionsIn select cases of CPA, ImmunoCAP EIA yields a false negative result, making serological diagnosis difficult. ImmunoCAP false negatives are more prevalent in patients with multiple immunological defects, who may still be positive with the LDBio Aspergillus ICT or Bordier EIA.

Evaluation of the LDBio Aspergillus ICT lateral flow assay for serodiagnosis of allergic bronchopulmonary aspergillosis.

Early recognition and diagnosis of allergic bronchopulmonary aspergillosis (ABPA) is critical to improve patient symptoms, and antifungal therapy may prevent or delay progression of bronchiectasis and development of chronic pulmonary aspergillosis. A recently commercialized lateral flow assay (Aspergillus ICT) (LDBio Diagnostics, Lyons, France) detects Aspergillus-specific antibodies in <30 minutes, requiring minimal laboratory equipment. We evaluated this assay for diagnosis of ABPA compared to diseased (asthma and/or bronchiectasis) controls. ABPA and control sera collected at the National Aspergillosis Centre (Manchester, UK) and/or from the Manchester Allergy, Respiratory and Thoracic Surgery research biobank were evaluated using the Aspergillus ICT assay. Results were read both visually and digitally (using a lateral flow reader). Serological Aspergillus-specific IgG and IgE, and total IgE titres were measured by ImmunoCAP. For 106 cases of ABPA versus all diseased controls, sensitivity and specificity for the Aspergillus ICT were 90.6% and 87.2%, respectively. Sensitivity for 'proven' ABPA alone (n = 96) was 89.8%, and 94.4% for 'presumed' ABPA (n = 18). 'Asthma only' controls (no bronchiectasis) and 'bronchiectasis controls' exhibited 91.4% and 81.7% specificity, respectively. Comparison of Aspergillus ICT result with Aspergillus-specific IgG and IgE titres showed no evident immunoglobulin isotype bias. Digital measurements displayed no correlation between ImmunoCAP Aspergillus-specific IgE level and ICT test line intensity. The Aspergillus ICT assay exhibits good sensitivity for ABPA serological screening. It is easy to perform and interpret, using minimal equipment and resources; and provides a valuable simple screening resource to rapidly distinguish more serious respiratory conditions from Aspergillus sensitization alone.

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

BackgroundChronic 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.MethodsThe 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.ResultsA 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.ConclusionsThe 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 registrationNCT03027089. Registered 20 January 2017.