Innate and Adaptive Immune Defects in Chronic Pulmonary Aspergillosis

Innate and adaptive immune responses in subjects with CPA secondary to post-pulmonary tuberculosis lung abnormalities

BACKGROUND

Post-tuberculosis lung abnormality (PTLA) is the most common risk factor for chronic pulmonary aspergillosis (CPA), and 14%-25% of the subjects with PTLA develop CPA. The pathogenesis and the host immune response in subjects with PTLA who develop CPA need to be better understood.

METHODS

We prospectively compared the innate and adaptive immune responses mounted by patients of PTLA with or without CPA (controls). We studied the neutrophil oxidative burst (by dihydrorhodamine 123 test), classic (serum C3 and C4 levels) and alternative (mannose-binding lectin [MBL] protein levels) complement pathway, serum immunoglobulins (IgG, IgM and IgA), B and T lymphocytes and their subsets in subjects with PTLA with or without CPA.

RESULTS

We included 111 subjects (58 CPA and 53 controls) in the current study. The mean ± SD age of the study population was 42.6 ± 15.7 years. The cases and controls were matched for age, gender distribution and body weight. Subjects with CPA had impaired neutrophil oxidative burst, lower memory T lymphocytes and impaired Th-1 immune response (lower Th-1 lymphocytes) than controls. We found no significant difference between the two groups in the serum complement levels, MBL levels, B-cell subsets and other T lymphocyte subsets.

CONCLUSION

Subjects with CPA secondary to PTLA have impaired neutrophil oxidative burst and a lower Th-1 response than controls.

Aspergillus nodules: Natural history and the effect of antifungals

BACKGROUND

Aspergillus nodules are classified as a subset of chronic pulmonary aspergillosis. The optimal management approach is not known as their natural evolution following biopsy, the rate of progression to chronic cavitary pulmonary aspergillosis (CCPA) and the effect of antifungal treatment have not been described.

OBJECTIVES

To describe the clinical course of patients diagnosed with Aspergillus nodules and the effect of antifungal treatment.

PATIENTS/METHODS

We present a series of 23 patients with histologically confirmed Aspergillus nodules and describe serial imaging, antifungal treatment and progression to other diagnoses.

RESULTS

Thirteen patients were diagnosed after a CT-guided biopsy and 10 after surgical resection. Among those who had CT-guided biopsy, 8 did not receive antifungal treatment; the nodule was stable or smaller in all cases on subsequent CT scan after a mean of 15.5 months. However, one patient developed squamous cell carcinoma after 16 months and another developed CCPA after 7 months. Among the 5 patients who received antifungals for at least 4 weeks, the nodule was smaller in 1 and stable in 4. One patient developed CCPA 3 years after the biopsy. No patient who had a surgical resection subsequently had a CCPA diagnosis.

CONCLUSION

Most Aspergillus nodules remained stable or improved following biopsy, irrespective of the effect of antifungals. However, CCPA can develop occasionally in patients with Aspergillus nodules and ongoing radiological follow-up may be warranted when the nodule is not resected.

Aspergillus and the Lung

The filamentous fungus Aspergillus causes a wide spectrum of diseases in the human lung, with Aspergillus fumigatus being the most pathogenic and allergenic subspecies. The broad range of clinical syndromes that can develop from the presence of Aspergillus in the respiratory tract is determined by the interaction between host and pathogen. In this review, an oversight of the different clinical entities of pulmonary aspergillosis is given, categorized by their main pathophysiological mechanisms. The underlying immune processes are discussed, and the main clinical, radiological, biochemical, microbiological, and histopathological findings are summarized.

Chronic Pulmonary Aspergillosis: Clinical Presentation and Management

Chronic pulmonary aspergillosis (CPA) refers to a number of clinical syndromes resulting from the presence and local proliferation of Aspergillus organisms in the lungs of patients with chronic lung disease. CPA is more common than was realized two decades ago. Recognition remains poor, despite recent studies from many countries highlighting the high prevalence in at-risk populations. In low- and middle-income countries, CPA may be misdiagnosed and treated as tuberculosis (TB). In addition, CPA may develop following successful TB treatment. The coronavirus disease pandemic has resulted in significant disruption to provision of TB care, likely leading to more extensive lung damage, which could increase the risk for CPA.Although CPA refers to various syndromes, the classic presentation is that of chronic cavitary pulmonary aspergillosis, which manifests as one or more progressive cavities with or without a fungal ball, accompanied by systemic and respiratory symptoms for at least 3 months. Diagnosis relies on Aspergillus immunoglobulin G in serum, as sputum culture lacks sensitivity. Differential diagnosis includes mycobacterial infection, bacterial lung abscess or necrotizing pneumonia, lung cancer, and endemic fungi.The aim of antifungal treatment in CPA is to improve symptoms and quality of life, and to halt progression, and possibly reverse radiological changes. Current recommendations suggest treatment for 6 months, although in practice many patients remain on long-term treatment. Improvement may manifest as weight gain and improvement of symptoms such as productive cough, hemoptysis, and fatigue. Surgical management should be considered in cases of diagnostic uncertainty, in significant hemoptysis, and when there is concern for lack of response to therapy. Itraconazole and voriconazole are the first-line azoles, with more experience now accumulating with posaconazole and isavuconazole. Side effects are frequent and careful monitoring including therapeutic drug monitoring is essential. Intravenous antifungals such as echinocandins and amphotericin B are used in cases of azole intolerance or resistance, which often develop on treatment. Relapse is seen after completion of antifungal therapy in around 20% of cases, mostly in bilateral, high-burden disease.Several research priorities have been identified, including characterization of immune defects and genetic variants linked to CPA, pathogenetic mechanisms of Aspergillus adaptation in the lung environment, the contribution of non-fumigatus Aspergillus species, and the role of new antifungal agents, immunotherapy, and combination therapy.

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.

Identification of distinct immunophenotypes in chronic pulmonary aspergillosis using cluster analysis

BACKGROUND

Whether chronic pulmonary aspergillosis (CPA) has different immunophenotypes remains unknown.

OBJECTIVE

To identify different CPA immunophenotypes using cluster analysis.

METHODS

We used a subject-centred multivariate clustering approach without prior assumptions to identify CPA phenotypes. We retrospectively included the data of treatment-naïve subjects with CPA and excluded subjects with asthma and allergic bronchopulmonary aspergillosis (ABPA). We performed a scalable two-step cluster analysis using the log-likelihood distance measures to identify CPA phenotypes based on the blood immunological profile (total IgE, eosinophil count and Aspergillus-specific IgE and IgG).

RESULTS

We included 351 CPA subjects and found two clusters. Cluster 2 (n = 118) had significantly higher serum total IgE, peripheral blood eosinophil count, and serum A. fumigatus-specific IgE and IgG than cluster 1 (n = 233). Cluster 2 subjects had a lower FEV1:FVC ratio on spirometry and were more likely to have a fungal ball (88 [74.6%] vs. 145 (62.2%), p = .023) on the CT thorax than cluster 1. After treatment discontinuation, cluster 2 had a longer median (interquartile range) time to relapse than cluster 1 (11.5 [7.3-27.4] vs. 4 [1.1-8.9] months, p = .005).

CONCLUSION

We identified two distinct CPA phenotypes, type-2 dominant and non-type-2, with different clinical and radiological findings and treatment outcomes. Future studies should confirm our findings and investigate different treatment strategies based on CPA phenotypes.

Efficacy of Intrabronchial Voriconazole Instillation for Inoperable Pulmonary Aspergilloma: A Pilot Randomized Controlled Trial

<b><i>Background:</i></b> Endobronchial administration of voriconazole is a potential therapeutic option for inoperable aspergilloma. <b><i>Objective:</i></b> This study aimed to assess the efficacy of endobronchial instillation of voriconazole for inoperable pulmonary aspergilloma. <b><i>Method:</i></b> Patients with mild to moderate hemoptysis, due to inoperable aspergilloma, were randomized to receive either medical therapy (MT) alone or bronchoscopic instillation of voriconazole with MT and followed up till 3 months. The primary objective of this study was to compare the percentage of patients achieving reduction in the severity of hemoptysis assessed on visual analogue scale (VAS) in intervention and control arm at 3 months. <b><i>Results:</i></b> This study included 60 patients (female = 47) with mean (SD) age of 40.6 (13.2) years who were randomized to receive either bronchoscopic instillation of voriconazole (<i>n</i> = 30) or MT alone (<i>n</i> = 30). At 3-month follow-up, the primary objective was achieved in 26/30 (86.7%) patients in intervention group as compared to 11/30 (36.7%) in the control group (<i>p</i> value &#x3c;0.0001). The VAS score at 3 months was significantly lower in voriconazole group 13.9 (9.3) mm as compared to MT alone group 22.3 (11.5) mm, <i>p</i> value of 0.003. Bronchoscopic instillation of voriconazole was also associated with reduction in cough severity and size of the aspergilloma; however, there was no benefit of this therapy in terms of requirement of hospitalization and BAE. <b><i>Conclusions:</i></b> Our study shows that for nonoperable aspergilloma, bronchoscopic instillation of voriconazole is associated with reduction in the severity of hemoptysis. This therapy should be evaluated in large multi-center trials.

Defective interferon-gamma production is common in chronic pulmonary aspergillosis

BACKGROUND

Immune defects in chronic pulmonary aspergillosis (CPA) are poorly characterised. We compared peripheral blood cytokine profiles in patients with CPA vs healthy controls and explored the relationship with disease severity.

METHODS

Interferon-gamma (IFNγ), IL-17, TNFα, IL-6, IL-12 and IL-10 were measured after in vitro stimulation of whole blood with lipopolysaccharide (LPS), phytohaemagglutinin (PHA), β-glucan, zymosan (ZYM), IL-12 or IL-18, and combinations. Clinical parameters and mortality were correlated with cytokine production.

RESULTS

Cytokine profiles were evaluated in 133 patients (57.1% male, mean age 61 years). In comparison to controls, patients with CPA had significantly reduced production of IFNγ in response to stimulation with β-glucan+IL-12 (312 vs 988 pg/ml), LPS+IL-12 (252 vs 1033 pg/ml), ZYM+IL-12 (996 vs 2347 pg/ml), and IL-18+IL-12 (7193 vs 12330 pg/ml). Age >60 (p=0.05, HR 1.71, 95%CI 1.00-2.91) and COPD (p=0.039, HR 1.69, 95%CI 1.03-2.78) were associated with worse survival, whereas high IFNγ production in response to beta-glucan+IL-12 stimulation (p=0.026, HR 0.48, 95%CI 0.25-0.92) was associated with reduced mortality.

CONCLUSION

Patients with CPA show impaired IFNγ production in peripheral blood in response to stimuli. Defective IFNγ production ability correlates with worse outcomes. Immunotherapy with IFNγ could be beneficial for patients showing impaired IFNγ production in CPA.

Differences in the clinical characteristics of chronic pulmonary aspergillosis according to spirometric impairment

The clinical features by declining lung function remain uncharacterized in chronic pulmonary aspergillosis (CPA) patients. We investigated the clinical characteristics of CPA patients based on spirometric impairments (restrictive spirometric pattern [RSP] and obstructive spirometric pattern [OSP]) and their severity. We retrospectively analyzed medical records of CPA patients who underwent pulmonary function tests from March 2017 to February 2020. We used Global Lung Initiative 2012 equations with lower limit of normal. The clinical characteristics of patients with RSP were compared to those with OSP. Additionally, RSP patients’ characteristics were analyzed according to forced vital capacity (FVC) tertile, and OSP patients’ characteristics were analyzed according to forced expiratory volume in 1 second (FEV₁) tertile. Among the 112 patients with CPA (52 [46%] with RSP and 60 [54%] with OSP), body mass index (BMI) was significantly lower in patients with RSP than in those with OSP (17.6 kg/m² versus 20.3 kg/m²; P = 0.003), and non-tuberculous mycobacterial disease was more frequently observed in patients with RSP than in those with OSP (28.8% versus 11.7%; P = 0.004). Additionally, for patients with RSP, younger age and bilateral pulmonary lesions were more frequently observed in the first tertile group than in the other groups (P for trend: 0.025 and 0.001, respectively). For patients with OSP, low BMI, paracavitary infiltrates, and elevated WBC count were more frequently observed in the first tertile group than in the other groups (P for trend: < 0.001, 0.011, and 0.041, respectively). Differences in the clinical features of CPA patients were identified according to heterogeneous spirometric patterns and their severity. Further studies are needed to investigate the clinical significance of these findings.

Chronic Pulmonary Aspergillosis: Disease Severity Using Image Analysis and Correlation with Systemic Proinflammation and Predictors of Clinical Outcome

(1) Background: The presentation of chronic pulmonary aspergillosis (CPA) ranges from single granuloma to fibrosis in the affected lung. CPA can be divided into five categories according to European Respirology Society (ERS) guidance but is usually assessed by clinical physicians. Computer-based quantitative lung parenchyma analysis in CPA and its correlation with clinical manifestations, systemic inflammation, and angiogenesis have never been investigated. (2) Method: Forty-nine patients with CPA and 36 controls were prospectively enrolled. Pulmonary function tests (forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), and FEV₁/FCV) and biomarkers in the peripheral blood (the chemokines interleukin (IL)-1B, IL-6, IL-10, IL-8, CRP, ESR, MMP1, MMP7, MMP8, TNF-α, calprotectin, SDF-1α, and VEGFA) were measured before antifungal treatment. The disease severity was categorized into mild, moderate, and severe based on chest computed tomography (CT) images. The oxygen demand and overall mortality until the end of the study were recorded. Quantitative parenchyma analysis was performed using the free software 3Dslicer. (3) Results: The results of quantitative parenchyma analysis concorded with the visual severity from the chest CT, oxygen demand, FVC, and FEV₁ in the study subjects. The decrease in kurtosis and skewness of the lung density histograms on CT, increase in high attenuation area (HAA), and reduced lung volume were significantly correlated with increases in the PMN %, CRP, IL-1B, SDF-1α, MMP1, and Calprotectin in peripheral blood in the multivariable regression analysis. TNF-α and IL-1B at study entry and the CPA severity from either a visual method or computer-based evaluation were predictors of long-term mortality. (4) Conclusion: The computer-based parenchyma analysis in CPA agreed with the categorization on a visual basis and was associated with the clinical outcomes, chemokines, and systemic proinflammation profiles.

Impact of high baseline Aspergillus-specific IgG levels on weight and quality-of-life outcomes of patients with chronic pulmonary aspergillosis

This study aimed to evaluate the impact of quantitative baseline Aspergillus-specific immunoglobulin G (IgG) serum levels on weight changes of patients with chronic pulmonary aspergillosis (CPA) under antifungal treatment. We retrospectively reviewed data of patients diagnosed with CPA between April 2015 and March 2018 at the National Aspergillosis Centre (Manchester, UK). All patients were on continued antifungal treatment for 12 months. Data on Aspergillus-specific IgG levels, St George's quality of life (SGQoL) variables and weight at baseline, 6 months and 12 months were extracted. We defined a high serum Aspergillus-specific IgG as ≥ 200 mg/l (Group A) and low level < 200 mg/l (Group B). Forty-nine patients (37 male; 12 female), median age 65 years (range: 29-86) were studied. Overall, 33% (n = 16) of the patients were in Group A. The baseline characteristics between the two groups were similar. The median Charlson comorbidity index was 4 (range: 0-5) and 3 (range: 0-9) for Group A and Group B, respectively (P = .543). There was a sustained decline in median Aspergillus IgG levels from baseline, through 6 month to 12 months of continues therapy from 170 (range: 20-1110) to 121 (range: 20-1126), and finally 107 (15-937) mg/l, respectively (P < .001). Group A patients gained more weight at 6 months (9/15 [60%] vs. 7/33 [21%], P = .012) and at 12 months of treatment (9/15 [60%] vs. 7/33 [22%]), and more patients in Group B lost weight ((13/33 [41%] vs. 1/15 [7%]), P = .015). However, there was no difference in QoL outcomes across groups at 6 (P = .3) and 12 (P = .7) months. A very high Aspergillus IgG may confer a higher likelihood of weight gain as a key, objective marker of clinical response, if patients can tolerate 12 months of antifungal therapy.

Diagnostic value of serum human Galactomannan aspergillus antigen and 1,3-beta-D-glucan in immunocompromised patient suspected fungal infection

BACKGROUND

The prevalence of fungal infection (FI) in developing countries is high, but the diagnosis of FI is still challenging to determine, so it is needed evaluation of biomarkers other than microbiological culture, because the culture has low sensitivity, high cost, not available in every laboratory and needs a long time. The detection of human galactomannan Aspergillus antigen (GAL) and 1,3-beta-D-glucan (BDG) on the fungal cell wall could be the promising biomarkers for fungal infection. Neutropenia, lymphopenia and CD4T cells in the immunocompromised patients are essential factors, but these cell associations with BDG and GAL levels have not been evaluated yet. The study aimed to evaluate GAL and BDG for detecting fungal infection and their association with total leucocyte count, neutrophil, monocyte, lymphocyte and CD4T cells.

METHOD

A cross-sectional study was conducted among 86 patient with suspected FI. Fungal infection established using EORTC/MSG criteria. Serology test performed using ELISA. Leucocyte cells were measured using a haematology autoanalyser, and CD4T cells were analysed using BD FACSPresto. Statistical analysis obtained using Spearman's correlation coefficient, ROC curve analysis and 2 × 2 contingency table.

RESULTS

Serum Galactomannan and BDG had a significant correlation with CD4T cells and total lymphocyte count (p < 0.05). The cut-off OD GAL >0.3 had sensitivity 54.6%, specificity 87.5% and AUC 0.71; meanwhile, the BDG cut-off >115.78 pg/ mL had sensitivity 71.2%, specificity 52.4% and AUC 0.63 for detecting fungal infection.

CONCLUSIONS

The immunocompromised patients can undergo GAL for determining the diagnose of FI. The lower the CD4T cells and total lymphocyte count, the higher the GAL and BDG serum levels.

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

Background

Prevalence 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/methods

We 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.

Results

We 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.

Conclusions

In 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.

•

Low or undetectable Aspergillus IgG is associated with, usually, several minor immunological defects.

•

Aspergillus IgG/IgM lateral flow assay is more sensitive than ImmunoCAP for CPA with or without subtle immunodeficiency.

•

CPA patients may have Aspergillus IgG detectable with different assays.

Prevalence of Vitamin D Deficiency in Treatment-Naïve Subjects with Chronic Pulmonary Aspergillosis

The association of vitamin D deficiency in the pathogenesis of invasive and allergic pulmonary aspergillosis is known. Whether vitamin D deficiency is prevalent in chronic pulmonary aspergillosis (CPA) remains unknown. We evaluated the prevalence of vitamin D deficiency in subjects with CPA. We compared the clinicoradiological features, microbiology, the immunological response, and the severity of CPA in those with or without vitamin D deficiency. We measured plasma vitamin D levels in 230 consecutive treatment-naïve subjects with CPA and 78 controls (28 with prior tuberculosis (TB); 50 healthy controls). We defined vitamin D deficiency as 25(OH)D3 level <20 ng/mL. The mean (95% confidence intervals (CI)) levels of plasma vitamin D levels were 19.5 (17.6–21.4), 18.6 (13.9–23.3), and 15.3 (12.6–17.9) ng/mL in subjects with CPA, diseased controls, and healthy controls, respectively; and the levels were not different between the groups. The prevalence of vitamin D deficiency in subjects with CPA was 65% (n = 150) and was also not different between healthy (70%) or diseased (61%) controls. We did not find any difference in the clinicoradiological features, microbiology, immunological response, and severity of CPA between vitamin D sufficient and deficient groups. The prevalence of vitamin D deficiency is high in subjects with CPA, albeit similar to controls. Vitamin D deficiency does not affect the disease severity in subjects with CPA.

Clinical Characteristics and Treatment Outcomes of Pathologically Confirmed Aspergillus Nodules

Aspergillus nodules represent a subtype of chronic pulmonary aspergillosis, but details on their characteristics and outcomes are limited. We evaluated 80 patients with pathologically confirmed Aspergillus nodules between January 2009 and December 2016. The median age of the patients was 59 years, and 46 (58%) were women. Seventy-three (91%) patients were surgically diagnosed with Aspergillus nodules and the remaining seven (9%) patients were diagnosed by percutaneous transthoracic needle biopsy. The median long-axis diameter of nodules was 22 mm, and nodules had an internal cavity in 49 (61%) patients. Spiculation and calcification were observed in 20% and 39% of patients, respectively. Ninety percent (18/20) of nodules showed uptake on positron emission tomography. Serum Aspergillus precipitin IgG antibody was positive in 42% (10/24) of tested patients. Seventy-three (91%) patients underwent surgery without (n = 58) or with (n = 15) adjuvant antifungal therapy, and the remaining seven (9%) patients received antifungal therapy alone (n = 5) or no treatment (n = 2). Three patients experienced postoperative pulmonary complications: pneumothorax, hemoptysis, and acute lung injury (n = 1 each). There was no recurrence during the median follow-up period of 36.8 months. In conclusion, surgery could be a treatment strategy worth considering for most Aspergillus nodules. However, given that our study population was heterogeneous, further well-designed studies are need.

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.

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.

Targeting intrinsic cell death pathways to control fungal pathogens

Fungal pathogens pose an increasing threat to public health. Limited clinical drug regimens and emerging drug-resistant isolates challenge infection control. The global burden of human fungal pathogens is estimated at 1 billion infections and 1.5 million deaths annually. In addition, plant fungal pathogens increasingly threaten global food resources. Novel strategies are needed to combat emerging fungal diseases and pan-resistant fungi. An untapped mechanistically novel approach is to pharmacologically activate the intrinsic cell death pathways encoded by pathogenic fungi. This strategy is analogous to new anti-cancer therapeutics now entering the clinic. Here we summarize the best understood examples of cell death mechanisms encoded by pathogenic fungi, contrast these to mammalian cell death pathways, and highlight the gaps in knowledge towards identifying potential death effectors as druggable targets.

Case Definition of Chronic Pulmonary Aspergillosis in Resource-Constrained Settings

Chronic pulmonary aspergillosis (CPA) is a recognized complication of pulmonary tuberculosis (TB). In 2015, the World Health Organization reported 2.2 million new cases of nonbacteriologically confirmed pulmonary TB; some of these patients probably had undiagnosed CPA. In October 2016, the Global Action Fund for Fungal Infections convened an international expert panel to develop a case definition of CPA for resource-constrained settings. This panel defined CPA as illness for >3 months and all of the following: 1) weight loss, persistent cough, and/or hemoptysis; 2) chest images showing progressive cavitary infiltrates and/or a fungal ball and/or pericavitary fibrosis or infiltrates or pleural thickening; and 3) a positive Aspergillus IgG assay result or other evidence of Aspergillus infection. The proposed definition will facilitate advancements in research, practice, and policy in lower- and middle-income countries as well as in resource-constrained settings.

Special Issue: Host-Fungus Interactions

The clinical presentation of fungal disease is strongly determined by the underlying immune defect present [...].

The Management of Chronic Pulmonary Aspergillosis: The UK National Aspergillosis Centre Approach

Purpose of Review

Chronic pulmonary aspergillosis (CPA) is a serious long-term fungal disease of the lung with a worldwide prevalence. Treatment of CPA is not straightforward given the often-multiple associated co-morbidities, complex clinical picture, drug interactions, toxicities and intolerances.

Recent Findings

First line treatment is oral itraconazole or voriconazole. In the event of intolerance or toxicity, patients may be swapped from itraconazole to voriconazole or vice versa. In the event of resistance or further intolerance, third line treatment with posaconazole could be initiated. In those with pan-azole resistance, short-term courses of intravenous liposomal amphotericin B or micafungin are fourth line therapy, keeping in mind the nephrotoxic effects of amphotericin B.

Summary

The available evidence for current treatments in CPA is limited and based mostly on retrospective cohort studies. There is a real need to raise awareness of this devastating disease to enable early treatment as well as prospective drug trials and studies to identify potential patient factors that correlate with progression, severity and overall outcomes in order to target future therapies.