Cytokine profiling of 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.

Novel Host Pathways Govern Epithelial Cell Invasion of Aspergillus fumigatus

Invasive aspergillosis is initiated when Aspergillus fumigatus adheres to and invades the pulmonary epithelial cells that line the airways and alveoli. To gain deeper insight into how pulmonary epithelial cells respond to A. fumigatus invasion, we used transcriptome sequencing (RNA-seq) to determine the transcriptional response of the A549 type II alveolar epithelial cell line to infection with strains CEA10 and Af293, two clinical isolates of A. fumigatus. Upstream regulator analysis of the data indicated that while both strains activated virtually identical host cell signaling pathways after 16 h of infection, only strain CEA10 activated these pathways after 6 h of infection. Many of the pathways that were predicted to be activated by A. fumigatus, including the tumor necrosis factor (TNF), interleukin-1α (IL-1α), IL-1β, IL-17A, Toll-like receptor 2 (TLR2), and TLR4 pathways, are known to be critical for the host defense against this fungus. We also found that the platelet-derived growth factor BB (PDGF BB) and progesterone receptor (PGR) pathways were activated by A. fumigatus. Using pharmacologic inhibitors, we determined that blocking the PDGF receptor or PGR inhibited the endocytosis of both strains of A. fumigatus in an additive manner. Both the PDGF BB and PGR pathways are also predicted to be activated by infection of A549 cells with other molds, such as Rhizopus delemar and Rhizopus oryzae. Thus, these pathways may represent a common response of pulmonary epithelial cells to mold infection. IMPORTANCE Invasive aspergillosis is a deadly invasive fungal infection that initiates when Aspergillus fumigatus spores are inhaled and come into contact with the epithelial cells that line the airways and alveoli. Understanding this fungus-host interaction is important for the development of novel therapeutics. To gain a deeper understanding of how these airway epithelial cells respond to A. fumigatus during infection, we used RNA-seq to determine the transcriptional response of alveolar epithelial cells to infection with two different clinical isolates of A. fumigatus. Our analysis identified new host response pathways that have not previously been tied to infection with A. fumigatus. Pharmacological inhibition of two of these pathways inhibited the ability of A. fumigatus to invade airway epithelial cells. These two pathways are also predicted to be activated by infection with other filamentous fungi. Thus, these pathways may represent a common response of alveolar epithelial cells to mold infection.

Race and ethnicity: Risk factors for fungal infections?

Racial and ethnic identities, largely understood as social rather than biologic constructs, may impact risk for acquiring infectious diseases, including fungal infections. Risk factors may include genetic and immunologic differences such as aberrations in host immune response, host polymorphisms, and epigenomic factors stemming from environmental exposures and underlying social determinants of health. In addition, certain racial and ethnic groups may be predisposed to diseases that increase risk for fungal infections, as well as disparities in healthcare access and health insurance. In this review, we analyzed racial and ethnic identities as risk factors for acquiring fungal infections, as well as race and ethnicity as they relate to risk for severe disease from fungal infections. Risk factors for invasive mold infections such as aspergillosis largely appear related to environmental differences and underlying social determinants of health, although immunologic aberrations and genetic polymorphisms may contribute in some circumstances. Although black and African American individuals appear to be at high risk for superficial and invasive Candida infections and cryptococcosis, the reasons for this are unclear and may be related to underling social determinants of health, disparities in access to healthcare, and other socioeconomic disparities. Risk factors for all the endemic fungi are likely largely related to underlying social determinants of health, socioeconomic, and health disparities, although immunologic mechanisms likely play a role as well, particularly in disseminated coccidioidomycosis.

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.

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.

The Serum Level of IL-1B Correlates with the Activity of Chronic Pulmonary Aspergillosis

Background

Until now, there have been no objective criteria to determine the activity of chronic pulmonary aspergillosis (CPA). This study aims to analyze the correlation between serum level of IL-1B and the activity of CPA and to determine whether serum IL-1B could be used to assess the activity of CPA.

Methods

A total of 469 newly diagnosed CPA patients were enrolled. Correlation analysis in the whole subjects showed that only IL-1B level was associated with the activity of CPA. Then, 381 cases with factors significantly affecting IL-1B expression was excluded through multiple linear regression; the remaining 88 patients were divided into high IL-1B group and low IL-1B group, according to the median value of serum IL-1B, for subgroup analysis. A retrospective comparative analysis was subsequently performed between the two groups, including the clinical manifestation, microbiology and laboratory tests results, and imaging findings. We further investigated the relationship between IL-1B levels and CT characteristic which acted as the indicator of CPA activity, as well as changes in IL-1B level before and after surgery.

Results

For all patients, correlation analysis revealed that IL-1B level correlated with both cavitary diameter (P=0.035) and aspergilloma size (P<0.047) but not with the thickness of the cavity (P=0.479). In subgroup comparative analysis, CT characteristics suggested that high activity of CPA, such as cavitary (27/44 vs 13/44, P=0.003) and aspergilloma lesions (25/44 vs. 11/44, P<0.002), were more frequently found in high IL-1B group. The cavity diameter (P<0.001), aspergilloma size (P=0.006), and cavity wall thickness (P=0.023) were significantly different between the two groups. When Spearman correlation analysis was performed once again in subgroup, an even stronger relationship of serum IL-1B with the cavity diameter (Rs=0.501, P=0.002) and aspergilloma size (Rs=0.615, P=0.001) was observed. Interestingly, a significant reduction of IL-1B level was observed after successful resection of CPA lesions.

Conclusion

Higher level of serum IL-1B is associated with more severe cavitary and aspergilloma lesions, which are indicative of more active CPA. In addition, IL-1B level reduced accordingly after lesion resection. Measuring IL-1B level therefore could be served as a convenient method to monitor the activity of CPA and be a potential predictive/prognostic marker for treatment response.

Characteristics of Sinus Fungus Ball: A Unique Form of Rhinosinusitis

Objective:

The purpose of this study was to investigate the characteristics of this unique form of rhinosinusitis.

Methods:

Ninety-one patients with sinus fungus balls were evaluated for clinical characteristics. Nasal tissues obtained from 38 patients with sinus fungus ball, along with 26 controls were used for histopathological, cytokines/chemokines, western blotting, and genetic analyses.

Results:

Patients with fungus balls had significantly more females and their age was older. The presentation of fungus ball was predominantly unilateral (97.8%). Thirty-three patients (36.3%) had risk factors for fungal infection. Macrophage and neutrophil dominated cellular infiltration was found in nasal tissues of fungus ball patients. A tendency of reduced tight junction staining (e-cadherin) and protein expression was found. Interleukin 8 (IL8) and granulocyte colony stimulating factor (G-CSF) significantly increased in sinus fungus ball tissue homogenates when compared with those from controls. Higher prevalence of a single single nucleotide polymorphism (SNP) with E-cadherin was found in the patients with fungus ball.

Conclusions:

We found that patients with sinus fungus ball had robust immune responses, allowing recruitment and activation of macrophages and neutrophils. However, patients with sinus fungus ball could have genetic or acquired weakness in immunity. The fungal hyphae were localized and accumulated within single sinus instead of being eradicated by host.

Immunobiological Activity of Synthetically Prepared Immunodominant Galactomannosides Structurally Mimicking Aspergillus Galactomannan

The study is oriented at the in vitro evaluation of the immunobiological activity and efficacy of synthetically prepared isomeric pentasaccharides representing fragments of Aspergillus fumigatus cell-wall galactomannan and containing β-(1→5)-linked tetragalactofuranoside chain attached to O-6 (GM-1) or O-3 (GM-2) of a spacer-armed mannopyranoside residue. These compounds were studied as biotinylated conjugates which both demonstrated immunomodulatory activities on the RAW 264.7 cell line murine macrophages as in vitro innate immunity cell model. Immunobiological studies revealed time- and concentration-dependent efficient immunomodulation. The proliferation of RAW 264.7 macrophages was induced at higher concentration (100 µg/mL) of studied glycoconjugates and longer exposure (48 h), with more pronounced efficacy for GM-1. The increase of proliferation followed the previous increase of IL-2 production. The cytokine profile of the macrophages treated with the glycoconjugates was predominantly pro-inflammatory Th1 type with significant increase of TNFα, IL-6, and IL-12 release for both glycoconjugates. The RAW 264.7 macrophages production of free radicals was not significantly affected by glycoconjugates stimulation. The phagocytic activity of RAW 264.7 cells was reduced following GM-1 treatment and was significantly increased after 24 h stimulation with GM-2, contrary to 48 h stimulation. Moreover, the synthetically prepared galactomannoside derivatives have been evaluated as efficient serodiagnostic antigens recognized by specific Ig isotypes, and significant presence of specific IgM antibodies in serum of patients suffering from vulvovaginitis was observed.

Allergic Bronchopulmonary Aspergillosis: A Perplexing Clinical Entity

In susceptible individuals, inhalation of Aspergillus spores can affect the respiratory tract in many ways. These spores get trapped in the viscid sputum of asthmatic subjects which triggers a cascade of inflammatory reactions that can result in Aspergillus-induced asthma, allergic bronchopulmonary aspergillosis (ABPA), and allergic Aspergillus sinusitis (AAS). An immunologically mediated disease, ABPA, occurs predominantly in patients with asthma and cystic fibrosis (CF). A set of criteria, which is still evolving, is required for diagnosis. Imaging plays a compelling role in the diagnosis and monitoring of the disease. Demonstration of central bronchiectasis with normal tapering bronchi is still considered pathognomonic in patients without CF. Elevated serum IgE levels and Aspergillus-specific IgE and/or IgG are also vital for the diagnosis. Mucoid impaction occurring in the paranasal sinuses results in AAS, which also requires a set of diagnostic criteria. Demonstration of fungal elements in sinus material is the hallmark of AAS. In spite of similar histopathologic features, co-existence of ABPA and AAS is still uncommon. Oral corticosteroids continue to be the mainstay of management of allergic aspergillosis. Antifungal agents play an adjunctive role in ABPA as they help reduce the fungal load. Saprophytic colonization in cavitary ABPA may lead to aspergilloma formation, which could increase the severity of the disease. The presence of ABPA, AAS, and aspergilloma in the same patient has also been documented. All patients with Aspergillus-sensitized asthma must be screened for ABPA, and AAS should always be looked for.

Development of chronic pulmonary aspergillosis in adult asthmatics with ABPA

BACKGROUND

Chronic pulmonary aspergillosis (CPA) is an occasional complication of allergic bronchopulmonaryaspergillosis (ABPA) but the transition is poorly understood.

METHODS

All patients referred to the UK's National Aspergillosis Centre with CPA between May 2009 and June 2012 were screened with serum total IgE and anti-Aspergillus IgE for a dual diagnosis of ABPA and CPA. Those patients suspected of having both conditions were re-evaluated and their imaging reviewed.

RESULTS

Of 407 referred patients, 42 screened positive and 22 were confirmed as having both ABPA and CPA. Asthma was present from early childhood in 19 (86%), the median interval between ABPA and onset of CPA was 7.5 years; one patient developed ABPA and CPA simultaneously. Aspergillus IgG levels varied from 23 to 771 mg/L, median 82 mg/L. All 22 patients had bronchiectasis. In patients with ABPA, CT typically demonstrated varicose or cystic bronchiectasis primarily affecting segmental and proximal subsegmental upper lobe bronchi. Other findings included mucoid impaction and centrilobular nodules. Radiological changes associated with CPA included pleural thickening which was often bilateral and accentuated by adjacent hypertrophied extrapleural fat, upper lobe volume loss, thick walled apical cavities, some of which contained aspergillomas, and cavitating pulmonary nodules. CPA secondary to ABPA has more subtle radiological appearances than when due to other underlying diseases.

CONCLUSIONS

CPA may complicate ABPA and have distinct radiology features, in addition to bronchiectasis. A novel biomarker is required to anticipate this serious complication, as current serology is not specific enough.

Serum Inflammatory Cytokine Markers of Invasive Fungal Infection in Previously Immunocompetent Battle Casualties

BACKGROUND

Invasive fungal infection (IFI) is described increasingly in individuals experiencing high-energy military trauma. Hallmarks of successful treatment involve aggressive surgical debridement and early initiation of systemic antimicrobial therapy. Currently, intravenous anti-fungal therapy commences based on appearance of wounds and patient's clinical course. Whereas some clinical protocols exist to predict which critically injured patients should receive anti-fungal therapies, there are no established serum markers associated with IFI. Our hypothesis is that serum inflammatory cytokines exist that can assist in identifying individuals at risk for IFI.

METHODS

This is a retrospective case control study at a single institution. Nine patients with IFI (Saksenaea vasiformis, Fusarium sp., Graphium sp., Scedosporium sp., Aspergillus sp., Mucor sp., and Alternaria sp.) after battlefield trauma were matched to nine individuals with similar injury patterns whose laboratory results were negative for IFI. The combination of serum inflammatory cytokines from the first and second debridements was examined with multiplex platform proteomic analysis. We defined statistical significance as a two-tailed α<0.05 after adjusting for multiple comparisons using the false discovery rate method. This model was refined further with correlation-based filter selection and the area under the curve of the receiver operating characteristics (AUROC) was tested.

RESULTS

Both groups had similar Injury Severity Scores (ISS) (mean±standard deviation [SD]) (26.8±15.5 vs. 29.2±16.8, p=0.766). Elevated RANTES (regulated on activation, normal T cell expressed and secreted) alone (10,492.8±4,450.1 vs. 5,333.3±4,162.2, p=0.006) correlated with IFI. Also, the combination of persistent elevations in RANTES, interleukin (IL)-2R, and IL-15 was a robust model for predicting IFI with the AUROC being 0.9.

CONCLUSIONS

Elevation in serum cytokines, particularly RANTES, correlated with IFI in this small group of patients. This demonstrates the potential of future rapid serum testing for early initiation and guidance of anti-fungal therapies.

Host genetics and opportunistic fungal infections

Current knowledge on the human pathophysiology of fungal infections highlights the crucial role of genetic pitfalls in specific immunity pathways that determine, together with other risk factors, the predisposition to and clinical outcome of fungal disease. In several studies, associations between gene polymorphisms and genetic errors have been implicated in an immunodeficiency phenotype and an increased incidence of opportunistic fungal diseases. The major challenge is to fully understand the complex interactions between genetic variations and multiple factors, and their relative contributions to the final clinical fungal disease phenotype. The aim of this review is to present updated knowledge on immunity genetics and susceptibility to medically relevant fungal diseases, such as those caused by Candida, Aspergillus, and certain other more rare fungi.

Adaptive immunity to fungi

Life-threatening fungal infections have risen sharply in recent years, owing to the advances and intensity of medical care that may blunt immunity in patients. This emerging crisis has created the growing need to clarify immune defense mechanisms against fungi with the ultimate goal of therapeutic intervention. We describe recent insights in understanding the mammalian immune defenses that are deployed against pathogenic fungi. We focus on adaptive immunity to the major medically important fungi and emphasize three elements that coordinate the response: (1) dendritic cells and subsets that are mobilized against fungi in various anatomical compartments; (2) fungal molecular patterns and their corresponding receptors that signal responses and shape the differentiation of T-cell subsets and B cells; and, ultimately (3) the effector and regulatory mechanisms that eliminate these invaders while constraining collateral damage to vital tissue. These insights create a foundation for the development of new, immune-based strategies for prevention or enhanced clearance of systemic fungal diseases.

Chronic pulmonary aspergillosis

Chronic pulmonary aspergillosis (CPA) is a group of consuming diseases usually presenting with prolonged and relapsing cough, dyspnoea and weight loss. Acute symptoms such as haemoptysis and bronchial or pulmonary haemorrhage may occasionally occur. CPA affects patients with underlying pulmonary conditions, for example, chronic obstructive pulmonary disease or mycobacteriosis or common immunosuppressive conditions such as diabetes. Precise epidemiology is unknown, and while prevalence is considered low the chronic and relapsing nature of the disease challenges the treating physician. Diagnostics largely rely on serologic Aspergillus precipitins and findings on thoracic computed tomography. The latter are manifold comprising cavity formation, pleural involvement and sometimes aspergilloma. Other markers for aspergillosis are less helpful, in part due to the non- or semi-invasive nature of these forms of Aspergillus infection. Various antifungals were shown to be effective in CPA treatment. Azoles are the most frequently applied antifungals in the outpatient setting, but are now compromised by findings of Aspergillus resistance. Long-term prognosis is not fully elucidated and may be driven by the underlying morbidities. Prospective registry-type studies may be suitable to systematically broaden our CPA knowledge base. This article gives an overview of the available literature and proposes a clinical working algorithm for CPA management.

Inflammation in aspergillosis: the good, the bad, and the therapeutic

Aspergillosis includes a spectrum of diseases caused by different Aspergillus spp. New insights into the cellular and molecular mechanisms of resistance and immune tolerance to the fungus in infection and allergy have been obtained in experimental settings. The fact that virulence factors, traditionally viewed as fungal attributes, are contingent upon microbial adaptation to various environmental stresses encountered in the human host implies that the host and fungus are jointly responsible for pathogenicity. Ultimately, despite the occurrence of severe aspergillosis in immunocompromised patients, clinical evidence indicates that aspergillosis also occurs in the setting of a heightened inflammatory response, in which immunity occurs at the expense of host damage and pathogen eradication. Thus, targeting pathogenicity rather than microbial growth, tolerance rather than resistance mechanisms of defense may pave the way to targeted anti-inflammatory strategies in difficult-to-treat patients. The challenge now is to translate promising results from experimental models to the clinic.

Renal allograft recipients fail to increase interferon-γ during invasive fungal diseases

Invasive fungal diseases are a major cause of death in renal allograft recipients. We previously reported that adjunctive recombinant human interferon-γ therapy has clinical utility for invasive fungal diseases after renal transplantation. We have now developed a rapid peripheral blood-based quantitative real-time PCR assay that enables accurate profiling of cytokine imbalances. Our preliminary studies in renal transplant patients with invasive fungal diseases suggest that they fail to mount an adequate interferon-γ response to the fungal infection. In addition, they have reduced IL-10 and increased TNF-α when compared to stable renal transplant patients. These preliminary cytokine profiling-based observations provide a possible explanation for the therapeutic benefit of adjunctive human interferon-γ therapy in renal allograft recipients with invasive fungal diseases.

Systemic biomarkers of inflammation and haemostasis in patients with chronic necrotizing pulmonary aspergillosis

Background

The purpose of this study was to investigate mediators of inflammation and haemostasis in patients with chronic necrotizing pulmonary aspergillosis (CNPA), a locally, destructive process of the lung due to invasion by Aspergillus species.

Methods

Measurements of selected biomarkers in 10 patients with CNPA and 19 healthy, matched controls were performed with enzyme-linked immunosorbent assay (ELISA) and multiplex methodology. The gene expressions of relevant biomarkers were analyzed with real-time quantitative RT-PCR.

Results

Increased concentrations of circulating mediators of inflammation interleukin (IL)-6, IL-8, RANTES, TNF-α, ICAM-1 and mediators involved in endothelial activation and thrombosis (vWF, TF and PAI-1) were observed in patients with CNPA. The concentration of the anti-inflammatory cytokine IL-10 was increased both in plasma and in PBMC in the patient population. The gene expression of CD40L was decreased in PBMC from the patient group, accompanied by decreased concentrations of soluble (s) CD40L in the circulation.

Conclusions

The proinflammatory response against Aspergillus may be counteracted by reduced CD40L and sCD40L, as well as increased IL-10, which may compromise the immune response against Aspergillus in patients with CNPA.

Association of interleukin-15 single nucleotide polymorphisms with resistance to brucellosis among Iranian patients

Interleukin (IL)-15, a Th1-related cytokine, triggers inflammatory cells' recruitment and increases the expression of interferon gamma (IFN-γ), which is an important cytokine in the immunity against brucellosis. Different single-nucleotide polymorphisms (SNPs) have been observed in the IL-15 gene, so this study aimed to investigate the probable association between these SNPs and susceptibility to brucellosis among Iranian patients. A total of 190 patients with brucellosis and 83 healthy milk farmers who consumed contaminated raw milk and dairy products from animals involved with brucellosis were included in this study. All the patients and the controls were genotyped for four IL-15 polymorphisms at positions 267, 367, 13687 and 14035 using polymerase chain reaction-restriction fragment length polymorphisms. The 267C and 13687A alleles, haplotypes CGCT and CAAA and the 267CC and 13687AA genotypes were significantly more frequent in the controls than in the patients (P = 0.014, 0.03, 0.006, 0.024, 0.026 and 0.01, respectively), so the variation in the IL-15 gene may be one of the factors affecting the resistance to brucellosis. In contrast, the frequency of haplotypes CGCA and TACT was significantly higher in patients compared with controls (P = 0.015 and 0.007, respectively), and interestingly the last one was observed only in the patients; therefore, it may serve as a predictive factor for brucellosis. In conclusion, it could be suggested that IL-15 genetic variants can affect resistance or susceptibility to human brucellosis among Iranian patients.

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

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

Link between CFTR mutations and ABPA: a systematic review and meta-analysis

Summary  There is a biological plausibility on the link between cystic fibrosis transmembrane conductance regulator (CFTR) mutations and allergic bronchopulmonary aspergillosis (ABPA). The aim of the systematic review was to investigate this link by determining the frequency of CFTR mutations in ABPA. We searched the PubMed and EmBase databases for studies reporting CFTR mutations in ABPA. We pooled the odds ratio (OR) and 95% confidence intervals (CI) from individual studies using both fixed and random effects model. Statistical heterogeneity was evaluated using the I(2) test and the Cochran-Q statistic. Publication bias was assessed using both graphical and statistical methods. Our search yielded four studies (79 ABPA, 268 controls). The odds of encountering CFTR mutation was higher in ABPA compared with the control group (OR 10.39; 95% CI, 4.35-24.79) or the asthma population (OR 5.53; 95% CI 1.62-18.82). There was no evidence of statistical heterogeneity or publication bias. There is a possible pathogenetic link between CFTR mutations and ABPA. However, because of the small numbers of patients, further studies are required to confirm this finding. Future studies should adopt a uniform methodology and should screen for the entire genetic sequence of the CFTR gene.

Human NK cells display important antifungal activity against Aspergillus fumigatus, which is directly mediated by IFN-γ release

Despite the strong interest in the NK cell-mediated immunity toward malignant cells and viruses, there is a relative lack of data on the interplay between NK cells and filamentous fungi, especially Aspergillus fumigatus, which is the major cause of invasive aspergillosis. By studying the in vitro interaction between human NK cells and A. fumigatus, we found only germinated morphologies to be highly immunogenic, able to induce a Th1-like response, and capable of upregulating cytokines such as IFN-γ and TNF-α. Moreover, priming NK cells with human rIL-2 and stimulating NK cells by direct NK cell-pathogen contact were essential to induce damage against A. fumigatus. However, the most interesting finding was that NK cells did not mediate anti-Aspergillus cytotoxicity through degranulation of their cytotoxic proteins (perforin, granzymes, granulysine), but via an alternative mechanism involving soluble factor(s). To our knowledge, our study is the first to demonstrate that IFN-γ, released by NK cells, directly damages A. fumigatus, attributing new properties to both human NK cells and IFN-γ and suggesting them as possible therapeutic tools against IA.

Impact of Aspergillus fumigatus in allergic airway diseases

For decades, fungi have been recognized as associated with asthma and other reactive airway diseases. In contrast to type I-mediated allergies caused by pollen, fungi cause a large number of allergic diseases such as allergic bronchopulmonary mycoses, rhinitis, allergic sinusitis and hypersensitivity pneumonitis. Amongst the fungi, Aspergillus fumigatus is the most prevalent cause of severe pulmonary allergic disease, including allergic bronchopulmonary aspergillosis (ABPA), known to be associated with chronic lung injury and deterioration in pulmonary function in people with chronic asthma and cystic fibrosis (CF). The goal of this review is to discuss new understandings of host-pathogen interactions in the genesis of allergic airway diseases caused by A. fumigatus. Host and pathogen related factors that participate in triggering the inflammatory cycle leading to pulmonary exacerbations in ABPA are discussed.

Genetic susceptibility to Aspergillus fumigatus infections

Invasive aspergillosis mostly caused by the opportunistic mould Aspergillus fumigatus is characterized by high morbidity and mortality in risk group patients. Several ethno-pathological factors promote the development and the course of this fungal infection like neutropenia, T-cell depletion, CD34-selected stem cell products, corticosteroid therapy, or cytomegalovirus infections. Furthermore, a growing number of defined single nucleotide polymorphisms affiliated to genes affecting the innate immune response has been described which genetically determine susceptibility to A. fumigatus. Thereby, it concerns a broad band ranging from genes encoding for cytokines or chemokines, their respective receptors to those of toll-like receptors including further genes involved in recognition and defence of pathogens by the innate immune system. Here, we summarize in detail the current knowledge about genetic markers correlated with invasive aspergillosis and their relevance for the developing and outcome of infections with A. fumigatus.

Serum markers for allergic bronchopulmonary aspergillosis in cystic fibrosis: State of the art and further challenges

Allergic bronchopulmonary aspergillosis (ABPA), which results from hypersensitivity, primarily to Aspergillus, represents a severe complication in patients suffering from asthma or cystic fibrosis (CF). Since early treatment of ABPA is supposed to prevent long-term damages, ABPA has to be diagnosed promptly. However, this diagnosis is not straightforward due to clinical and radiological features of ABPA overlapping with those of CF. Despite ABPA specific diagnosis criteria proposed by the Cystic Fibrosis Foundation in 2003, making a definitive ABPA diagnosis in CF patients remains a challenge. Recent advances in the immunopathogenesis of ABPA have initiated the development of new serological tests, such as the recently reported detection of specific IgE to recombinant A. fumigatus allergens, or Thymus- and activation-regulated chemokine (TARC / CCL17), both of which are of value in the diagnosis of APBA. We review in this paper the serum markers that can advance ABPA diagnosis in CF patients, ranging from the well known criteria (anti-A. fumigatus IgE, IgG, and precipitins) to the recent biomarkers (IgE towards recombinant A. fumigatus allergens or TARC detection). Taking into account the up-dated physiopathology of ABPA, we discuss their place and their usefulness, especially TARC, to improve early ABPA detection and monitoring in CF patients.

Immunity to fungal infections

Fungal diseases represent an important paradigm in immunology, as they can result from either a lack of recognition by the immune system or overactivation of the inflammatory response. Research in this field is entering an exciting period of transition from studying the molecular and cellular bases of fungal virulence to determining the cellular and molecular mechanisms that maintain immune homeostasis with fungi. The fine line between these two research areas is central to our understanding of tissue homeostasis and its possible breakdown in fungal infections and diseases. Recent insights into immune responses to fungi suggest that functionally distinct mechanisms have evolved to achieve optimal host-fungus interactions in mammals.

Aspergillus fumigatus Bronchopneumonia in a Hellenic Shepherd Dog

A 3 yr old intact female Hellenic shepherd dog was referred due to depression, partial anorexia, fever, and a mild productive cough of 2 mo duration. Thoracic radiographs showed increased opacity of all of the left lung lobes. Upon bronchoscopy, a sanguineous, purulent discharge was detected in the tracheal lumen with hyperplastic tissue narrowing the left main stem bronchus. Cultures were positive for bacteria (Bacillus spp. and Clostridium spp.) but negative for fungi. Due to the severity of the lesions, a complete left lung pneumonectomy was performed. Histopathological examination of the excised lung tissues revealed a severe granulomatous bronchopneumonia with numerous alveolar macrophages laden with structures stained positively by periodic acid-Schiff and Grocott stain that had morphology consistent with fungi. PCR and sequencing of internal transcribed spacer regions 1 and 2 from genetic material extracted from paraffin-embedded pulmonary tissue confirmed the presence of Aspergillus fumigatus. Itraconazole was administrated for 5.5 mo and the dog was clinically normal 26 mo after surgery.

Immunogenetics of invasive aspergillosis

Invasive aspergillosis is one of the most important infections in hematopoietic stem cell transplant recipients, with an incidence rate of 5-15% and an associated mortality of 30-60%. It remains unclear why certain patients develop invasive aspergillosis while others, undergoing identical transplant regimen and similar post transplant immunosuppression, do not. Over the last decade, pattern recognition receptors such as Toll-like receptors (TLRs) and the C-type lectin receptors (CLRs) have emerged as critical components of the innate immune system. By detecting specific molecular patterns from invading microbes and initiating inflammatory and subsequent adaptive immune responses, pattern recognition receptors are strategically located at the molecular interface of hosts and pathogens. Polymorphisms in pattern recognition receptors and downstream signaling molecules have been associated with increased or decreased susceptibility to infections, suggesting that their detection may have an increasing impact on the treatment and prevention of infectious diseases in the coming years. Infectious risk stratification may be particularly relevant for patients with hematologic malignancies, because of the high prevalence and severity of infections in this population. This review summarizes the innate immune mechanisms involved in Aspergillus fumigatus detection and the role of host genetic polymorphisms in susceptibility to invasive aspergillosis.

Indolent infectious tenosynovitis afflicting rheumatoid patients treated with tumor necrosis factor inhibitors: case report

Tumor necrosis factor (TNF) is a cytokine associated with the pathogenesis of rheumatoid arthritis. Tumor necrosis factor inhibitors have become important biological treatments that favorably alter the natural history of rheumatoid disease. Side effects include an increased risk of malignancy and infection, particularly tuberculosis. We present 2 patients with rheumatoid arthritis on TNF inhibitors in whom flares of wrist tenosynovitis, initially diagnosed as rheumatoid disease exacerbations, were caused by infections with uncommon opportunistic pathogens. Diagnostic and treatment recommendations for this subset of rheumatoid patients are discussed.

The effects of antifungal therapy on severe asthma with fungal sensitization and allergic bronchopulmonary aspergillosis

BACKGROUND AND OBJECTIVE

Very little is known about the response rates to or appropriateness of treatment for patients with allergic fungal diseases of the lung. This study assessed the effect of antifungal therapy in patients with severe asthma with fungal sensitization (SAFS) and allergic bronchopulmonary aspergillosis (ABPA).

METHODS

A retrospective cohort study of 33 adult patients who fulfilled the criteria for either SAFS (n = 22) or ABPA (n = 11) was conducted. All patients had received antifungal therapy for at least 6 months. The primary study end point was the effect of antifungal therapy on patients' lung function.

RESULTS

Overall, total IgE values and radioallergosorbent test (RAST) for A. fumigatus markedly decreased after 6 months of therapy in both SAFS and ABPA patients (P = 0.004 and P = 0.005, respectively). Reduction was seen in the eosinophil count (P = 0.037), dose of oral steroids (P = 0.043) and courses of systemic steroids required (P = 0.041). Lung function also improved (P = 0.016). Four of 10 patients discontinued oral steroids after 6 months of therapy. Reduction in IgE levels (P = 0.015) and RAST for A. fumigatus was also observed (P = 0.006) for those patients treated for at least 1 year with antifungal drugs.

CONCLUSIONS

Both ABPA and SAFS patients benefited from oral antifungal therapy. The antifungal therapy may act by reducing the antigenic load, interacting with corticosteroids or by a direct immunological effect.

Genetic variability of innate immunity impacts human susceptibility to fungal diseases

Fungi are a major threat in immunocompromised patients. Despite presenting similar degrees of immunosuppression, not all individuals at-risk ultimately develop fungal diseases. The traditional view of immune suppression as a key risk factor for susceptibility to fungal infections needs to be accommodated within new conceptual advances on host immunity and its relationship to fungal disease. The critical role of the immune system emphasizes the contribution of host genetic polymorphisms to fungal disease susceptibility. This review highlights the present knowledge on innate immunity genetics that associates with susceptibility to fungal diseases.

Health effects of Aspergillus in food and air

This review summarizes the health aspects of the medically important fungal genus Aspergillus. The morphology and systematics of the genus are explained as well as its biogeography. Major mycotoxins, the aspergilli that produce them, affected crops, and symptoms of the toxicoses are summarized, as are the major mycoses caused by aspergilli. The current status of the relationship between Aspergillus in the indoor environment and health issues are discussed.

NAC is associated with additional alleviation of lung injury induced by invasive pulmonary aspergillosis in a neutropenic model

AIM

Neutropenic individuals are at high risk for invasive pulmonary aspergillosis (IPA), a life-threatening infection. To evaluate the therapeutic potential of antioxidants, IPA was induced in neutropenic mice and the effect of N-acetyl-l-cysteine (NAC) on oxidative stress levels and lung injury was analyzed.

METHODS

Mice were pretreated with three daily intraperitoneal injections of 150 mg/kg cyclophosphamide, followed by intratracheal inoculation with 4.5x10(6) conidia of Aspergillus fumigatus. The infected mice were then randomly assigned to an amphotericin B (AMB) group, an AMB plus NAC group, or an untreated control (C) group. In each group, the duration of treatment was 24, 48, or 72 h, and activities such as appearance, feeding, and dermal temperature were observed throughout the experiment. Sera and lung tissues were collected and analyzed by quantitative enzyme-linked immunosorbent assay (ELISA) for total protein, superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-alpha), and interleukin-10 (IL-10) levels. The wet/dry weight ratio of the lung was also calculated and lung sections were stained with hematoxylin-eosin for pathological examination and with methenamine silver stain for fungus detection.

RESULTS

Compared with the mice untreated with NAC, mice in the AMB plus NAC group had increased SOD and reduced MDA levels both systemically and locally at 24, 48, and 72 h after inoculation with conidia. NAC treatment also decreased the pulmonary protein content at 48 and 72 h and the lung wet/dry weight ratio at 24 and 48 h. Additionally, NAC enhanced pulmonary production of TNF-alpha and IL-10 at 24 h and 48 h.

CONCLUSION

In combination with antifungal therapy, NAC treatment can alleviate oxidative stress and lung injury associated with IPA in neutropenic mice.Acta Pharmacologica Sinica (2009) 30: 980-986; doi: 10.1038/aps.2009.83.

Allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is an immunologic pulmonary disorder caused by hypersensitivity to Aspergillus fumigatus. Clinically, a patient presents with chronic asthma, recurrent pulmonary infiltrates, and bronchiectasis. The population prevalence of ABPA is not clearly known, but the prevalence in asthma clinics is reported to be around 13%. The disorder needs to be detected before bronchiectasis has developed because the occurrence of bronchiectasis is associated with poorer outcomes. Because many patients with ABPA may be minimally symptomatic or asymptomatic, a high index of suspicion for ABPA should be maintained while managing any patient with bronchial asthma whatever the severity or the level of control. This underscores the need for routine screening of all patients with asthma with an Aspergillus skin test. Finally, there is a need to update and revise the criteria for the diagnosis of ABPA. This review summarizes the advances in the diagnosis and management of ABPA using a systematic search methodology.

An aspergilloma caused by Aspergillus flavus

Chronic pulmonary aspergillosis is broad term encompassing chronic cavitary, chronic fibrosing pulmonary aspergillosis and aspergilloma. All affect patients with structural lung diseases and many have subtle genetic immune defects. Almost all cases are caused by Aspergillus fumigatus. Here we report a patient with an aspergilloma which had Aspergillus flavus recovered from a surgical specimen and serum containing detectable precipitating antibody.

Distinct alleles of mannose-binding lectin (MBL) and surfactant proteins A (SP-A) in patients with chronic cavitary pulmonary aspergillosis and allergic bronchopulmonary aspergillosis

BACKGROUND

Distinct host immune status predisposes to different forms of pulmonary aspergillosis.

METHODS

Patients with chronic cavitary pulmonary aspergillosis (CCPA; n=15) or allergic bronchopulmonary aspergillosis (ABPA; n=7) of Caucasian origin were screened for single nucleotide polymorphisms (SNPs) in the collagen region of surfactant proteins A1 (SP-A1) and A2 (SP-A2) and mannose binding lectin (MBL).

RESULTS

The T allele at T1492C and G allele at G1649C of SP-A2 were observed at slightly higher frequencies in ABPA patients (86% and 93%) than in controls (63% and 83%), and the C alleles at position 1492 and 1649 were found in higher frequencies in CCPA patients (33% and 25%) than in ABPA patients (14% and 7%) (all p>0.05). However, the CC genotype at position 1649 of SP-A2 was significantly associated with CCPA (chi(2)=7.94; p(corr)< or =0.05). Similarly, ABPA patients showed a higher frequency of the TT genotype (71%) at 1492 of SP-A2 than controls (43%) and CCPA patients (41%) (p>0.05). In the case of MBL, the T allele (OR=3.1, range 1.2-8.9; p< or =0.02) and CT genotype (chi(2)=6.54; p(corr)< or =0.05) at position 868 (codon 52) were significantly associated with CCPA, but not with ABPA. Further analysis of genotype combinations at position 1649 of SP-A2 and at 868 of MBL between patient groups showed that both CC/CC and CC/CT SP-A2/MBL were found only in CCPA patients, while GG/CT SP-A2/MBL was significantly higher in CCPA patients in comparison to ABPA patients (p< or =0.05). SNPs analysed in SP-A1 did not differ between cases and controls.

CONCLUSIONS

Distinct alleles, genotypes and genotype combinations of SP-A2 and MBL may contribute to differential susceptibility of the host to CCPA or ABPA.

Voriconazole treatment for subacute invasive and chronic pulmonary aspergillosis

BACKGROUND

Voriconazole is a novel triazole antifungal with a broad spectrum including Aspergillus species. We conducted an open, noncomparative multicenter study to evaluate the efficacy and safety of voriconazole in subacute invasive and chronic pulmonary aspergillosis (CPA).

METHODS

Patients without profound neutropenia and a proven or probable diagnosis of subacute invasive aspergillosis (IA) or CPA received voriconazole 200 mg twice daily for a period of 4-24 weeks as primary or salvage therapy. Dose escalation was allowed if efficacy was suboptimal, and toleration and safety were satisfactory. Response was assessed by clinical, radiological and mycological changes. A complete or partial response in subacute IA and improved or stable in CPA were assessed as favorable responses.

RESULTS

Of 39 patients treated, 36 were assessable. The majority of patients had subacute IA (n = 21), proven in all 11 extra-pulmonary and in 23/25 (92%) of the pulmonary cases. Voriconazole was given as primary therapy in 22 (61%). All patients receiving salvage therapy (n = 14) had refractory IA, having failed itraconazole or amphotericin B (AmB) or both. Overall, a complete or partial response was seen in 9/21(43%) of subacute IA and improved or stable in 12/15 (80%) of those with CPA. Adverse events, mainly liver function test abnormalities, skin reactions, and visual disturbances were mild and transient, leading to early discontinuation of treatment in 5 cases.

CONCLUSIONS

In patients with subacute IA and CPA, voriconazole was efficacious as salvage or primary therapy.