Allergenic cross-reactivity of Curvularia lunata with other airborne fungal species

Survey of Sensitization to Common Fungi in an Allergic Dog Population: The Need for Further Focus on Sensitization and Allergy to Fungi in Veterinary Medicine

Most fungal species are commensals and non-pathogenic to plants, humans, or animals. However, several species of the Alternaria, Aspergillus, Trichophyton, and Microsporum genera are common causes of disease, even for immunocompetent individuals. Besides mucosal damage, fungi may contribute to a skin barrier impairment, favoring sensitization and allergy development. A total of 68 allergic dogs were selected from a veterinary dermatology and allergy outpatient consultation for conditions related to both Malassezia overgrowth and other fungal complications. The allergy diagnosis was made through anamnesis and current clinical criteria, with the involved allergenic species being identified by intradermal tests (IDTs) and allergen-specific immunoglobulin E (sIgE) determination in serum. Dermatophagoides farinae, Dactylis glomerata, and Malassezia pachydermatis showed as the higher sensitization species from house dust mites, grass pollen, and fungi, respectively. Significant correlations at p < 0.05 were found between sensitization to Dactylis glomerata and Phleum pratense grass pollens, Dermatophagoides farinae and Dermatophagoides pteronyssinus, Acarus siro, Tyrophagus putrescentiae, and Lepidoglyphus destructor dust/storage mites, and between fungi like Aspergillus mix and Penicillium or Alternaria alternata. A significant correlation was also found between sensitization to the Aspergillus mix and D. farinae, D. pteronyssinus, or A. siro. Rather severe dermatitis was observed when a positive IDT to Malassezia pachydermatis was found, regardless of the detection of circulating sIgE, allowing us to consider the usefulness of both the IDT and the sIgE for a systematic diagnosis of allergy to fungi.

Allergy to fungi: Advances in the understanding of fungal allergens

Allergic diseases are a major health problem due to their increasing incidence and high prevalence worldwide. Asthma has several aetiologies, and allergy plays an important role in its development in approximately 60% of adults and 80% of children and adolescents. Although the link between aeroallergen sensitization and asthma exacerbations has been long recognized, the investigations of the triggering allergens may be superficial in many asthma cases. The main allergenic sources related to asthma, and other allergic diseases, are pollens, mites, fungi, and animal epithelia. Fungi are considered the third most frequent cause of respiratory pathologies. Asthma caused by several fungi species may have a bad prognosis in some cases due to its severity and difficulty in avoidance methods. Despite the recognised relevance of fungi in respiratory allergies, the knowledge about fungal allergens seems to be scarce, with few descriptions of new allergens, compared to other allergenic sources. The study of major, minor, and cross-reactive fungal allergens, and their relevance in the allergic disease, might be crucial, not only to accurately diagnose these allergies, but also to predict exacerbations and responses to therapies, as well as for the development of personalized treatment plans in a fast-changing climate scenario.

Mechanisms of Alternaria pathogenesis in animals and plants

Alternaria species are cosmopolitan fungi darkly pigmented by melanin that infect numerous plant species causing economically important agricultural spoilage of various food crops. Alternaria spp. also infect animals, being described as entomopathogenic fungi but also infecting warm-blooded animals, including humans. Their clinical importance in human health, as infection agents, lay in the growing number of immunocompromised patients. Moreover, Alternaria spp. are considered some of the most abundant and potent sources of airborne sensitizer allergens causing allergic respiratory diseases, as severe asthma. Among the numerous strategies deployed by Alternaria spp. to attack their hosts, the production of toxins, carrying critical concerns to public health as food contaminant, and the production of hydrolytic enzymes such as proteases, can be highlighted. Alternaria proteases also trigger allergic symptoms in individuals with fungal sensitization, acting as allergens and facilitating antigen access to the host subepithelium. Here, we review the current knowledge about the mechanisms of Alternaria pathogenesis in plants and animals, the strategies used by Alternaria to cope with the host defenses, and the involvement Alternaria allergens and mechanisms of sensitization.

A review on aero-allergen induced allergy in India

Allergic diseases such as bronchial asthma, rhinitis and eczema are an important public health issue globally in 21st century. Their prevalence and impact in India is high, in terms of total numbers of people affected. Due to diverse climate and lifestyle, the Indian population is exposed to a rich and varied range of aerobiological particles. In the last two decades in India, 83 pollens, 34 fungi, six dust mite and 19 insect species were reported as allergenic, often contributing to heavy allergenic exposure in indoor and outdoor environments. There are currently few practitioners who offer allergy diagnosis and treatment in India, but there is active basic and molecular research aiming to improve the health of allergic patients. This review explores the field of aero-allergy in India during the last two decades, with special emphasis on prevalence across various centres and relevant scientific advances such as genetic associations and new therapeutics. This review will be helpful for clinicians to select aero-allergens for sensitisation testing in patients suffering from symptoms in different regions of India, and to support patients undertaking prophylaxis of allergic symptoms in India according to local environmental conditions. This study also helps to define patient selection for allergy testing and the role of test results in guiding allergic disease management in the Indian context. Finally, we summarize genetic findings relevant to aero-allergy in India and discuss the development of novel therapeutics for investigation and management of aero-allergy in India.

Allergy to Fungi in Veterinary Medicine: Alternaria, Dermatophytes and Malassezia Pay the Bill!

The fungal kingdom comprises ubiquitous forms of life with 1.5 billion years, mostly phytopathogenic and commensals for humans and animals. However, in the presence of immune disorders, fungi may cause disease by intoxicating, infecting or sensitizing with allergy. Species from the genera Alternaria, Aspergillus and Malassezia, as well as dermatophytes from the genera Microsporum, Trichophyton and Epidermophyton, are the most commonly implicated in veterinary medicine. Alternaria and Malassezia stand as the most commonly associated with either allergy or infection in animals, immediately followed by Aspergillus, while dermatophytes are usually associated with the ringworm skin infection. By aiming at the relevance of fungi in veterinary allergy it was concluded that further research is still needed, especially in the veterinary field.

Spectrum of Allergens and Allergen Biology in India

The growing prevalence of allergy and asthma in India has become a major health concern with symptoms ranging from mild rhinitis to severe asthma and even life-threatening anaphylaxis. The "allergen repertoire" of this subcontinent is highly diverse due to the varied climate, flora, and food habits. The proper identification, purification, and molecular characterization of allergy-eliciting molecules are essential in order to facilitate an accurate diagnosis and to design immunotherapeutic vaccines. Although several reports on prevalent allergens are available, most of these studies were based on preliminary detection and identification of the allergens. Only a few of these allergen molecules have been characterized by recombinant technology and structural biology. The present review first describes the composition, distribution pattern, and natural sources of the predominant allergens in India along with the prevalence of sensitization to these allergens across the country. We go on to present a comprehensive report on the biochemical, immunological, and molecular information on the allergens reported so far from India. The review also covers the studies on allergy- related biosafety assessment of transgenic plants. Finally, we discuss the allergen-specific immunotherapy trials performed in India.

Spontaneous Regression of Allergic Bronchopulmonary Mycosis Due to Curvularia lunata

Allergic bronchopulmonary mycosis (ABPM) is a pulmonary hypersensitivity disease mainly caused by Aspergillus fumigatus. The mainstay treatment for ABPM is systemic corticosteroid therapy. A 25-year-old man presented with pulmonary infiltrates. His peripheral eosinophil, total serum IgE, and serum Aspergillus-specific IgE levels were elevated. The patient tested positive in a skin test for Aspergillus. However, sputum cultures revealed a Curvularia lunata infection. We therefore diagnosed ABPM possibly caused by C. lunata, which is rare in Japan. The clinical state of the patient improved under observation. Identification of the causative fungus is an important aspect of the ABPM diagnosis.

Alternaria alternata allergens: Markers of exposure, phylogeny and risk of fungi-induced respiratory allergy

Alternaria alternata spores are considered a well-known biological contaminant and a very common potent aeroallergen source that is found in environmental samples. The most intense exposure to A. alternata allergens is likely to occur outdoors; however, Alternaria and other allergenic fungi can colonize in indoor environments and thereby increase the fungal aeroallergen exposure levels. A consequence of human exposure to fungal aeroallergens, sensitization to A. alternata, has been unequivocally associated with increased asthma severity. Among allergenic proteins described in this fungal specie, the major allergen, Alt a 1, has been reported as the main elicitor of airborne allergies in patients affected by a mold allergy and considered a marker of primary sensitization to A. alternata. Moreover, A. alternata sensitization seems to be a triggering factor in the development of poly-sensitization, most likely because of the capability of A. alternata to produce, in addition to Alt a 1, a broad and complex array of cross-reactive allergens that present homologs in several other allergenic sources. The study and understanding of A. alternata allergen information may be the key to explaining why sensitization to A. alternata is a risk factor for asthma and also why the severity of asthma is associated to this mold. Compared to other common environmental allergenic sources, such as pollens and dust mites, fungi are reported to be neglected and underestimated. The rise of the A. alternata allergy has enabled more research into the role of this fungal specie and its allergenic components in the induction of IgE-mediated respiratory diseases. Indeed, recent research on the identification and characterization of A. alternata allergens has allowed for the consideration of new perspectives in the categorization of allergenic molds, assessment of exposure and diagnosis of fungi-induced allergies.

Alt a 15 is a new cross-reactive minor allergen of Alternaria alternata

Alternaria alternata is one of the most common saprophytes worldwide that is clinically and epidemiologically associated with severe asthma. Therefore, the identification and characterization of all A. alternata allergens are of major clinical importance. This study describes a new cross-reactive A. alternata allergen that was officially named Alt a 15 by the official Allergen Nomenclature Subcommittee. The complete coding region for Alt a 15 was amplified using 5' and 3' rapid amplification of cDNA ends and PCR. The recombinant protein was produced in Escherichia coli as a 65-kDa fusion protein, and the protein sequence exhibits high homology with several important fungal allergens. Immunoblotting analyses revealed that IgE antibodies from A. alternata-sensitized patients (n=59) bound to rAlt a 15 with a prevalence of 10.2%. All patients who presented sIgE to rAlt a 15 were apparently poly-sensitized to A. alternata and C. lunata. The extensive cross-reactivity between A. alternata and C. lunata serine proteases was confirmed using immunoblotting inhibition assays. Overall, Alt a 15 is an important new cross-reactive allergen of A. alternata that explains some allergies to A. alternata without Alt a 1 sensitization and initial diagnostic errors for allergies to Alternaria. This molecule may improve the accuracy of the diagnosis, the understanding, and the management of IgE-mediated fungal diseases.

Identification of B cell epitopes of alcohol dehydrogenase allergen of Curvularia lunata

Background/Objective

Epitope identification assists in developing molecules for clinical applications and is useful in defining molecular features of allergens for understanding structure/function relationship. The present study was aimed to identify the B cell epitopes of alcohol dehydrogenase (ADH) allergen from Curvularia lunata using in-silico methods and immunoassay.

Method

B cell epitopes of ADH were predicted by sequence and structure based methods and protein-protein interaction tools while T cell epitopes by inhibitory concentration and binding score methods. The epitopes were superimposed on a three dimensional model of ADH generated by homology modeling and analyzed for antigenic characteristics. Peptides corresponding to predicted epitopes were synthesized and immunoreactivity assessed by ELISA using individual and pooled patients' sera.

Result

The homology model showed GroES like catalytic domain joined to Rossmann superfamily domain by an alpha helix. Stereochemical quality was confirmed by Procheck which showed 90% residues in most favorable region of Ramachandran plot while Errat gave a quality score of 92.733%. Six B cell (P1–P6) and four T cell (P7–P10) epitopes were predicted by a combination of methods. Peptide P2 (epitope P2) showed E(X)₂GGP(X)₃KKI conserved pattern among allergens of pathogenesis related family. It was predicted as high affinity binder based on electronegativity and low hydrophobicity. The computational methods employed were validated using Bet v 1 and Der p 2 allergens where 67% and 60% of the epitope residues were predicted correctly. Among B cell epitopes, Peptide P2 showed maximum IgE binding with individual and pooled patients' sera (mean OD 0.604±0.059 and 0.506±0.0035, respectively) followed by P1, P4 and P3 epitopes. All T cell epitopes showed lower IgE binding.

Conclusion

Four B cell epitopes of C. lunata ADH were identified. Peptide P2 can serve as a potential candidate for diagnosis of allergic diseases.

Mutated glutathione-S-transferase reduced airway inflammation by limiting oxidative stress and Th2 response

Oxidative stress is an important factor in the pathogenesis of asthma. Furthermore, antioxidants like GST are reduced in asthma patients. In the present study, the therapeutic effects of exogenous GST and mGST were evaluated in a mice model. GST mutated at residues 21/27 has reduced IgE binding with similar enzyme activity as that of GST. To evaluate the therapeutic effects of GST, BALB/c mice were immunized and challenged with ovalbumin. Mice were given GST, mGST, and alpha-lipoic acid by inhalation and sacrificed on Day 31 to evaluate inflammation and oxidative stress. Mice treated with mGST showed significantly reduced total cell count (P<0.01) and eosinophils (P<0.01) in BALF compared to GST- or PBS-treated groups. The lung inflammation score was lowest for the mGST-treated group along with reduced IL-4 (P<0.01) and OVA-specific IgE than other groups. Oxidative stress as per the lipid peroxidation level in BALF of mGST-treated mice was reduced significantly in comparison to PBS- or GST-treated mice. In conclusion, inhalation of mGST reduced airway inflammation in mice. Mutated GST with reduced allergenicity has better therapeutic potential and can be explored as an adjunct therapy in asthma.

Alternaria measures in inner-city, low-income housing by immunoassay and culture-based analysis

BACKGROUND

Sensitivity to Alternaria allergens has been associated with severe asthma and life-threatening exacerbations, and a high prevalence of Alternaria sensitivity has been reported among inner-city populations. Traditionally, epidemiologic studies have measured indoor Alternaria concentrations by cultural analyses; however, the number of viable spores may not be a good proxy for allergen levels. Furthermore, other genera share epitopes with Alternaria that may contribute to the allergenic effect.

OBJECTIVE

To compare measures of Alternaria antigen by enzyme-linked immunosorbent assay with measures of Alternaria and cross-reactive genera (Ulocladium, Curvularia, Epicoccum, and Stemphylium) by cultural analysis.

METHOD

Antigen assays and cultural analyses were performed on vacuum-collected bed dust samples collected between June 18, 2002, and February 9, 2004, from 3 inner-city, low-income public housing developments.

RESULTS

Alternaria antigen was found in all bed dust samples regardless of season. However, culturable Alternaria, Ulocladium, Curvularia, Epicoccum, and Stemphylium were only found in 50%, 35%, 6%, 11%, and 0% of bed samples, respectively. No correlations were found between Alternaria antigen and culturable concentrations of Alternaria or of its cross-reactive genera except for marginal correlation with Ulocladium culturable concentrations.

CONCLUSIONS

The results confirm that exposure to Alternaria antigens and allergens can occur even in the absence of culturable Alternaria or its cross-reactive genera, so further refinement and use of assays are essential for characterizing the distribution and determinants of indoor fungal allergen levels forsensitive populations.

Molecular and immunological characterization of cytochrome c: a potential cross-reactive allergen in fungi and grasses

BACKGROUND

Recombinant allergens are required for component-resolved diagnosis/therapy of allergic disorders. The study was aimed to express and characterize an allergenic protein from Curvularia lunata and study its cross-reactivity.

METHODS

A clone encoding a 12-kDa protein screened from the cDNA library of C. lunata was sequenced and expressed in pET22b+ vector. The purified protein was characterized by biophysical and immunological methods.

RESULTS

The sequence of gene encoding a 12-kDa protein showed homology to cytochrome c. It was expressed in Escherichia coli yielding 0.5 mg protein/l culture and designated as Cur l 3. The absorption and circular dichroism spectrum of Cur l 3 were similar to horse cytochrome c and the protein reacted with cytochrome c antibody. ELISA with different fungal-positive patients' sera showed > or = 3 times specific IgE to Cur l 3 compared with healthy controls. Mice anti-Cur l 3 reacted with tropical and temperate grass extracts. Protein also reacted with grass-positive patients' sera. In vitro stimulation of peripheral blood mononuclear cells from C. lunata, fungi or grass-positive patients with it released significant levels of Th2 cytokines. In vivo testing of this protein in allergic patients showed marked positive skin reactivity in 60% fungal and 43% grass-positive cases. Cross inhibition assays (EC(50)) demonstrated allergenic cross-reactivity of Cur l 3 with fungi and grasses.

CONCLUSIONS

Cytochrome c, a major allergen from C. lunata was cloned, sequenced and expressed. It was identified as a cross-reactive allergen among fungi and grasses and has potential for clinical application.

Analytical bias of cross-reactive polyclonal antibodies for environmental immunoassays of Alternaria alternata

BACKGROUND

Alternaria alternata is recognized as an important aeroallergen indoors and outdoors, and exposure to the fungus has been identified as a risk factor for asthma. Two recent publications concluded that 95% to 99% of American homes contained detectable amounts of Alternaria antigens when analyzed with a polyclonal antibody (pAb)-based ELISA.

OBJECTIVES

We investigated the cross-reactivity of the commercially available pAbs that were used in those studies.

METHODS

Reactivity to 24 fungal species commonly found in indoor environments was analyzed by inhibition ELISA by using solid-phase A alternata antigen. The pAbs were also tested by immunoblotting and halogen immunoassay for a subgroup of fungi.

RESULTS

Spores of 7 fungi including species of Alternaria, Ulocladium, Stemphylium, Epicoccum, Drechslera, and Exserohilum strongly inhibited the binding of the pAbs when tested by ELISA. Six other fungi reacted in the ELISA at a lower level, and 11 fungal species including several Penicillium, Aspergillus, Fusarium, and Cladosporium species failed to show inhibition. The immunoblots and the halogen immunoassay staining confirmed the cross-reactivity patterns of the ELISA.

CONCLUSION

The pAbs against A alternata were found to cross-react broadly with related and nonrelated fungi. The prevalence data previously reported for A alternata should be considered to be fungal-reactive rather than A alternata-specific.

The spectrum of fungal allergy

Fungi can be found throughout the world. They may live as saprophytes, parasites or symbionts of animals and plants in indoor as well as outdoor environment. For decades, fungi belonging to the ascomycota as well as to the basidiomycota have been known to cause a broad panel of human disorders. In contrast to pollen, fungal spores and/or mycelial cells may not only cause type I allergy, the most prevalent disease caused by molds, but also a large number of other illnesses, including allergic bronchopulmonary mycoses, allergic sinusitis, hypersensitivity pneumonitis and atopic dermatitis; and, again in contrast to pollen-derived allergies, fungal allergies are frequently linked with allergic asthma. Sensitization to molds has been reported in up to 80% of asthmatic patients. Although research on fungal allergies dates back to the 19th century, major improvements in the diagnosis and therapy of mold allergy have been hampered by the fact that fungal extracts are highly variable in their protein composition due to strain variabilities, batch-to-batch variations, and by the fact that extracts may be prepared from spores and/or mycelial cells. Nonetheless, about 150 individual fungal allergens from approximately 80 mold genera have been identified in the last 20 years. First clinical studies with recombinant mold allergens have demonstrated their potency in clinical diagnosis. This review aims to give an overview of the biology of molds and diseases caused by molds in humans, as well as a detailed summary of the latest results on recombinant fungal allergens.

Novel insights in the use of hydrolytic enzymes secreted by fungi with biotechnological potential

Entomopathogenic and mycoparasitic fungi synthesize hydrolytic enzymes such as chitinases, proteinases and beta-glucanases. These enzymes can act synergistically, helping fungi to control insect pests and pathogens that attack productive crops, and offer potential economic benefit to agribusiness. A number of hydrolytic enzymes have also been utilized in industrial applications. This review focuses on biochemical and structural analyses of fungal enzymes, together with current research information on secretion mechanisms.

Cloning, recombinant expression and activity studies of a major allergen "enolase" from the fungus Curvularia lunata

Recombinant allergens are required to study allergy at the molecular level and are helpful tools for the improvement of diagnosis and therapy. In the present study, enolase was expressed from Curvularia lunata and analyzed for its immunological reactivity as an allergen. cDNA library was synthesized in lambda zap vector and screened with sera obtained from C. lunata allergic patients. A cDNA clone with an ORF of 1.3 kb showed homology to enolases from different fungal sources. It was expressed in E. coli, purified from inclusion bodies yielding 0.5 mg/L and showed enzyme activity of 48 units/mg. It resolved as 48-kDa band on SDS-PAGE and was recognized by all the individual Curvularia positive patient sera in immunoblot and ELISA. r Cur l 2 stimulated patients' PBMCs and supernatant of these cells showed elevated levels of Th 2 cytokines. Ten B cell epitopes were predicted using computational software and one showed 90% homology to an important IgE epitope of Cla h 6. The various parameters predicted by computational approach can be validated later as a future study to draw conclusive evidence about putative antigenic epitopes. This can further help in generating knowledge about residues important for IgE binding and developing therapeutic modalities.

Allergy and "toxic mold syndrome"

BACKGROUND

"Toxic mold syndrome" is a controversial diagnosis associated with exposure to mold-contaminated environments. Molds are known to induce asthma and allergic rhinitis through IgE-mediated mechanisms, to cause hypersensitivity pneumonitis through other immune mechanisms, and to cause life-threatening primary and secondary infections in immunocompromised patients. Mold metabolites may be irritants and may be involved in "sick building syndrome." Patients with environmental mold exposure have presented with atypical constitutional and systemic symptoms, associating those symptoms with the contaminated environment.

OBJECTIVE

To characterize the clinical features and possible etiology of symptoms in patients with chief complaints related to mold exposure.

METHODS

Review of patients presenting to an allergy and asthma center with the chief complaint of toxic mold exposure. Symptoms were recorded, and physical examinations, skin prick/puncture tests, and intracutaneous tests were performed.

RESULTS

A total of 65 individuals aged 1 1/2 to 52 years were studied. Symptoms included rhinitis (62%), cough (52%), headache (34%), respiratory symptoms (34%), central nervous system symptoms (25%), and fatigue (23%). Physical examination revealed pale nasal mucosa, pharyngeal "cobblestoning," and rhinorrhea. Fifty-three percent (33/62) of the patients had skin reactions to molds.

CONCLUSIONS

Mold-exposed patients can present with a variety of IgE- and non-IgE-mediated symptoms. Mycotoxins, irritation by spores, or metabolites may be culprits in non-IgE presentations; environmental assays have not been perfected. Symptoms attributable to the toxic effects of molds and not attributable to IgE or other immune mechanisms need further evaluation as to pathogenesis. Allergic, rather than toxic, responses seemed to be the major cause of symptoms in the studied group.

Allergens of the entomopathogenic fungus Beauveria bassiana

Background

Beauveria bassiana is an important entomopathogenic fungus currently under development as a bio-control agent for a variety of insect pests. Although reported to be non-toxic to vertebrates, the potential allergenicity of Beauveria species has not been widely studied.

Methods

IgE-reactivity studies were performed using sera from patients displaying mould hypersensitivity by immunoblot and immunoblot inhibition. Skin reactivity to B. bassiana extracts was measured using intradermal skin testing.

Results

Immunoblots of fungal extracts with pooled as well as individual sera showed a distribution of IgE reactive proteins present in B. bassiana crude extracts. Proteinase K digestion of extracts resulted in loss of IgE reactive epitopes, whereas EndoH and PNGaseF (glycosidase) treatments resulted in minor changes in IgE reactive banding patterns as determined by Western blots. Immunoblot inhibitions experiments showed complete loss of IgE-binding using self protein, and partial inhibition using extracts from common allergenic fungi including; Alternaria alternata, Aspergillus fumigatus, Cladosporium herbarum, Candida albicans, Epicoccum purpurascens, and Penicillium notatum. Several proteins including a strongly reactive band with an approximate molecular mass of 35 kDa was uninhibited by any of the tested extracts, and may represent B. bassiana specific allergens. Intradermal skin testing confirmed the in vitro results, demonstrating allergenic reactions in a number of individuals, including those who have had occupational exposure to B. bassiana.

Conclusions

Beauveria bassiana possesses numerous IgE reactive proteins, some of which are cross-reactive among allergens from other fungi. A strongly reactive potential B. bassiana specific allergen (35 kDa) was identified. Intradermal skin testing confirmed the allergenic potential of B. bassiana.

Clinical use of immunoassays in assessing exposure to fungi and potential health effects related to fungal exposure

OBJECTIVE

To review and summarize current evidence regarding the proper role of immunoassays in clinical assessments of exposure to fungi and health effects related to fungal exposure.

DATA SOURCES

We reviewed relevant scientific investigations and previously published reviews concerning this topic.

STUDY SELECTION

The authors' clinical, laboratory, and public health experiences were used to evaluate relevant data for scientific merit.

RESULTS

Testing to determine the presence of IgE to specific fungi may be a useful component of a complete clinical evaluation in the diagnosis of illnesses that can be caused by immediate hypersensitivity such as allergic rhinitis and asthma. Detection of IgG to specific fungi has been used as a marker of exposure to agents that may cause illnesses such as hypersensitivity pneumonitis. However, the ubiquitous nature of many fungi and the lack of specificity of fungal antigens limit the usefulness of these types of tests in the evaluation of potential building-related illness and fungal exposure. Specific serologic tests (such as tests for cryptococcal antigen, coccidioidal antibody, and Histoplasma antigen) have been shown to be useful in the diagnosis of some fungal infections, but these are the exception not the rule.

CONCLUSIONS

There is currently not enough scientific evidence to support the routine clinical use of immunoassays as a primary means of assessing environmental fungal exposure or health effects related to fungal exposure. Health care providers who care for persons expressing concerns about the relationship of symptoms to potential exposure to fungi are advised to use immunoassay results with care and only as an adjunct to a comprehensive approach to patient care.

Identification of serine protease as a major allergen of Curvularia lunata

BACKGROUND

Several proteins from Curvularia lunata have been identified as important fungal allergens. It will be worthwhile to study the functional aspects of these allergens. The present study aimed at purifying a major allergen and determining its biological function.

METHODS

Concanavalin A and Superdex 75 were used to purify Cur l 1 major allergen from C. lunata. Cur l 1 activity was determined qualitatively and quantitatively. Serine protease inhibitors and specific substrate was used to determine the biological function of the protein.

RESULTS

Concanavalin A-bound fraction showed five allergenic proteins, which on Superdex G-75 purification gave a homogenous Cur l 1 protein. Cur l 1 showed IgE reactivity with 80% of the C. lunata hypersensitive patient's sera indicating it to be a major allergen. It showed protease activity on different substrates. Cur l 1's amino terminal sequence, GLTQKSAPWGLGADTIVAVELDSY, showed homology with the alkaline serine protease precursor. Phenylmethylsulfonylfluoride, pefabloc, aprotinin and leupeptin inhibited 70-80% enzymatic activity of Cur l 1 and no inhibition was observed with ethylenediaminetetraacetic acid (EDTA). A dose-dependent hydrolysis of Nalpha-benzoyl-l-arginine ethyl ester-hydrochloride, a specific serine protease substrate was obtained with Cur l 1.

CONCLUSION

A major glycoprotein allergen Cur l 1 was purified to homogeneity from C. lunata. Amino terminal sequence and biochemical assays identified it as a serine protease.

Curvularia—favorable response to oral itraconazole therapy in two patients with locally invasive phaeohyphomycosis

Curvularia species are ubiquitous and occasionally lead to infections in humans. In immunosuppressed patients, infections are often serious, and systemic dissemination is not uncommon. The optimal antifungal therapy is unclear. I here present two cases, a healthy man with locally invasive, mulicentric paranasal fungal sinusitis, and a case of progressive verrucal distal onychomycosis that developed while the patient was undergoing accelerated chemotherapy for non-Hodgkin's lymphoma. Both patients showed excellent responses to treatment with itraconazole suspension. Oral itraconazole may provide a safe and effective alternative for patients with locally invasive non-disseminated mycoses due to Curvularia species.