Identification and incidence of fungal strains in chronic rhinosinusitis patients

STAT6 Blockade Abrogates Aspergillus-Induced Eosinophilic Chronic Rhinosinusitis and Asthma, A Model of Unified Airway Disease

Unified airway disease, including concurrent asthma and chronic rhinosinusitis (CRS), is a common, but poorly understood disorder with no curative treatment options. To establish a murine model of chronic unified eosinophilic airway inflammation, mice were challenged with Aspergillus niger, and sinonasal mucosa and lung tissue were evaluated by immunohistochemistry, flow cytometry, and gene expression. Inhalation of A niger conidia resulted in a Th2-biased lung and sinus inflammation that typifies allergic asthma and CRS. Gene network and pathway analysis correlated with human disease with upregulation of not only the JAK-STAT and helper T-cell pathways, but also less expected pathways governing the spliceosome, osteoclast differentiation, and coagulation pathways. Utilizing a specific inhibitor and gene-deficient mice, we demonstrate that STAT6 is required for mycosis-induced sinus inflammation. These findings confirm the relevance of this new model and portend future studies that further extend our understanding of the immunopathologic basis of airway mycosis and unified airway disease.

Antibodies to Molds and Satratoxin in Individuals Exposed in Water-Damaged Buildings

Immunoglobulin (Ig)A, IgM, and IgG antibodies against Penicillium notatum, Aspergillus niger, Stachybotrys chartarum, and satratoxin H were determined in the blood of 500 healthy blood donor controls, 500 random patients, and 500 patients with known exposure to molds. The patients were referred to the immunological testing laboratory for health reasons other than mold exposure, or for measurement of mold antibody levels. Levels of IgA, IgM, and IgG antibodies against molds were significantly greater in the patients (p < 0.001 for all measurements) than in the controls. However, in mold-exposed patients, levels of these antibodies against satratoxin differed significantly for IgG only (p < 0.001), but not for IgM or IgA. These differences in the levels of mold antibodies among the 3 groups were confirmed by calculation of z score and by Scheffé's significant difference tests. A general linear model was applied in the majority of cases, and 3 different subsets were formed, meaning that the healthy control groups were different from the random patients and from the mold-exposed patients. These findings indicated that mold exposure was more common in patients who were referred for immunological evaluation than it was in healthy blood donors. The detection of antibodies to molds and satratoxin H likely resulted from antigenic stimulation of the immune system and the reaction of serum with specially prepared mold antigens. These antigens, which had high protein content, were developed in this laboratory and used in the enzyme-linked immunosorbent assay (ELISA) procedure. The authors concluded that the antibodies studied are specific to mold antigens and mycotoxins, and therefore could be useful in epidemiological and other studies of humans exposed to molds and mycotoxins.

Causal inference regarding infectious aetiology of chronic conditions: a systematic review

BACKGROUND

The global burden of disease has shifted from communicable diseases in children to chronic diseases in adults. This epidemiologic shift varies greatly by region, but in Europe, chronic conditions account for 86% of all deaths, 77% of the disease burden, and up to 80% of health care expenditures. A number of risk factors have been implicated in chronic diseases, such as exposure to infectious agents. A number of associations have been well established while others remain uncertain.

METHODS AND FINDINGS

We assessed the body of evidence regarding the infectious aetiology of chronic diseases in the peer-reviewed literature over the last decade. Causality was assessed with three different criteria: First, the total number of associations documented in the literature between each infectious agent and chronic condition; second, the epidemiologic study design (quality of the study); third, evidence for the number of Hill's criteria and Koch's postulates that linked the pathogen with the chronic condition. We identified 3136 publications, of which 148 were included in the analysis. There were a total of 75 different infectious agents and 122 chronic conditions. The evidence was strong for five pathogens, based on study type, strength and number of associations; they accounted for 60% of the associations documented in the literature. They were human immunodeficiency virus, hepatitis C virus, Helicobacter pylori, hepatitis B virus, and Chlamydia pneumoniae and were collectively implicated in the aetiology of 37 different chronic conditions. Other pathogens examined were only associated with very few chronic conditions (≤ 3) and when applying the three different criteria of evidence the strength of the causality was weak.

CONCLUSIONS

Prevention and treatment of these five pathogens lend themselves as effective public health intervention entry points. By concentrating research efforts on these promising areas, the human, economic, and societal burden arising from chronic conditions can be reduced.

Potential role of Alternaria and Cladosporium species in canine lymphoplasmacytic rhinitis

OBJECTIVES

To evaluate the possible role of Alternaria and Cladosporium species in the pathogenesis of canine lymphoplasmacytic rhinitis by comparing the amount of specific fungal DNA in nasal mucosal biopsies between dogs without nasal neoplasia and those with lymphoplasmacytic rhinitis or nasal neoplasia.

METHODS

Quantitative real-time polymerase chain reaction (qPCR) assays detecting DNA from Alternaria and Cladosporium fungi were applied to nasal mucosal biopsies collected from dogs with lymphoplasmacytic rhinitis (n = 8), dogs with nasal neoplasia (n = 10) and control animals (n = 10). A copy number for each sample was calculated using a standard curve of known copy number and differences amongst groups were assessed using Kruskal-Wallis tests.

RESULTS

No significant difference was found between the groups. Low levels of Alternaria DNA (10-100 copies/PCR) were detected in one sample; very low levels of DNA (<10 copies/qPCR) were detected in 6 samples, and 21 samples were negative. Low levels of Cladosporium DNA were detected in 2 samples; very low levels of DNA in 18; and 8 were negative.

CLINICAL SIGNIFICANCE

Results of this study reveal that Alternaria and Cladosporium species are part of the canine nasal flora, and that these fungi are probably not involved in the pathogenesis of lymphoplasmacytic rhinitis.

Cross-reactivity of Aspergillus, Penicillium, and Stachybotrys antigens using affinity-purified antibodies and immunoassay

In this study, the author examined the cross-reactivities of Stachybotrys chartarum, Aspergillus niger/fumigatus, and Penicillium notatum with affinity-purified rabbit sera. The molds were grown for expression of maximum numbers of antigens, after which they were extracted and mixed with commercially available extracts. The mixture was used for antibody preparation in rabbits, measurement of antibody levels, and for the demonstration of the degree of cross-reactivity. Control rabbits were injected with saline, yet they produced significant levels of immunoglobulin G antibodies against all mold extracts tested. The author interpreted this result to mean that sera obtained from rabbits immunized with pure mold extracts likely reflected cross-reactivity with other molds. Therefore, only affinity-purified antibodies and the most sensitive immunoassay technique (i.e., enzyme-linked immunosorbent assay [ELISA]) were used for the cross-inhibition studies. The antigenic cross-reactivities were as follows: (a) between Aspergillus and Penicillium, 19.6-21.0%; (b) between Stachybotrys and Aspergillus, 8.2-8.7%; and (c) between Stachybotrys and Penicillium, 7.0-9.6%. The findings of this study demonstrate that cross-reactivity studies between different molds require the use of affinity-purified antibodies and a sensitive and quantitative assay with untreated antigens. With the use of such an assay, it was determined that the cross-reactivity between Stachybotrys, Aspergillus, and Penicillium was at approximately 10%, which is less widespread than previously believed.