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Whole Allergen

m16 Curvularia lunata

m16 Curvularia lunata Scientific Information

Type:

Whole Allergen

Display Name:

Curvularia lunata

Route of Exposure:

Inhalation

Family:

Pleosporaceae

Species:

lunata

Latin Name:

Curvularia lunata

Other Names:

Cochliobolus lunatus; head mold of grasses, rice and sorghum

Summary

Curvularia lunata (Cochliobolus lunatus) is a ubiquitous mold of the Order Pleosporales, mostly found in plant materials and soil worldwide. It is a known plant and human pathogen. The particles causing allergic reactions are spores found in the environment.

Asthma, allergic rhinitis, allergic Bronchopulmonary Mycosis and allergic fungal sinusitis are the main clinical presentations of C. lunata allergy. This mold is also able to cause opportunistic disease. Cross reactivity with other molds, especially if taxonomically close, may occur.

Allergen

Nature

The Genus Curvularia is a group of common fungi showing a wide range of interactions with other life forms, including pathogenic interactions with plants and humans (1). Curvularia lunata is found ubiquitously in soil (2); it is the anamorph (asexual form) of the fungus Cochliobolus lunatus (teleomorph, the sexual form) (3). In culture, C. lunata presents with brown colonies, producing brown septate conidiophores. The conidia also brown, constituted by 3–4 cells, straight or pyriform in shape; they may have a large and curved center, and range in size from 7 to 21 μm (4).

C. lunata is an agent of disease in plants, such as tomatoes (5), rice (6), crowfoot grass (7), sorghum (4, 8), sugar cane and corn (1).

There is considerable overlap between peak fungal activity season and other allergens such as grass and weed pollens, often masking the pathology caused by fungal spores in multi-sensitized people (9). Curvularia spp. spores were the fourth most commonly detected during a study spanning a 2-year period (around 5 of the total spores), and showed a distinct seasonality with peaks between July and October (10)

Taxonomy 

Taxonomic tree of Curvularia genus (11)

Domain

Eukaryota

Kingdom

Fungi

Phylum

Ascomycota

Subphylum

Pezizomycotina

Class

Dothideomycetes

Order

Pleosporales

Family

Pleosporaceae

Genus

Curvularia

Taxonomic tree of Curvularia genus (11)

Tissue

Spores release detectable amounts of allergens both prior to and following germination (9, 10, 12). The conidia (spores) are able to bind IgE (13). C. lunata spores were isolated from 83% of residences, predominantly from air filters (14).

Epidemiology

Worldwide distribution 

Allergic diseases associated with Curvularia lunata have been described in many countries, including across South East Asia (Malaysia and Singapore) (15), Japan (16), North America (14), Australia (8) and India (10).

Environmental Characteristics

Worldwide distribution 

Curvularia spp. can be found worldwide (3, 6).

Route of Exposure

Main

Inhalation of spores (9, 10).

Detection

Main methods

Personal volumetric petri plate sampler (10).

Measures

The concentrations of Curvularia spp. spores ranged between 78-246 CFU/m3 (10)

Clinical Relevance

Allergic rhinitis

In a study of 9,923 patients with a history of asthma, allergic rhinitis (AR) or atopic dermatitis (AD), sensitization to C. lunata (determined by skin-prick tests) significantly increased the risk of both asthma and AR, but not AD. The study also showed that C. lunata hypersensitivity was correlated with higher frequency of wheezing episodes, probability of attending a clinic and exacerbation of asthma symptoms (15).

Other diseases

A 25-year old patient with a history of bronchial asthma presented with a productive cough lasting several months; C. lunata was diagnosed as the cause of the allergic bronchopulmonary mycosis (16). This infection has also been described in two patients from an Australian report (McAleer 1981).

Curvularia lunata was frequently isolated from patients diagnosed with allergic fungal sinusitis (AFS) (14).

C. lunata can also cause disease in immunocompromised patients (17) and was described as the cause of a fatal cerebral infection in a 21-year old immunocompetent patient with a history of asthma (2).

Diagnostics Sensitization

The presence of allergen-specific antibodies is usually determined by skin prick tests (SPTs) and serology for IgE (9, 10). In a study carried out in atopic subjects, the incidence of mold allergy was 44%, with C. lunata one of the most frequently identified mold agents (18). In another study of 150 patients, SPT reactions to C. lunata allergens in patients with respiratory allergies varied in positivity, with 34% of patients showing mild to moderately positive reactions, 10.7% showing moderately positive reactions and 2% showing highly positive skin reactions (10). In the same study, the serum of SPT+ (positive) patients was tested by ELISA for the presence of IgE specific for the fungal antigens that caused the positive skin reactions. This showed 69.2% concordance for C. lunata antigens when comparing the skin-prick tests and the ELISA in vitro immunoassay (10).

Prevention and Therapy

Allergen immunotherapy

Immunotherapy is currently not recommended for patients allergic to molds, due to complexities of the allergens and patient co-allergies (9).

Prevention strategies 

Avoidance is difficult to achieve (9), due to the wide range of environments in which C. lunata can be found (3).

Molecular Aspects

Allergenic molecules

A study identified four epitopes of C. lunata alcohol dehydrogenase (ADH), all of which were recognized by serum of patients with hypersensitivity to C. lunata (19). In another study, a 12 kDa protein was identified as C. lunata cytochrome c; skin reactivity tests showed positive reactions to this protein in 60% of mold-sensitized patients (20).An Alternaria alternata antigen, Alt a 1, has been identified in culture filtrates of C. lunata (21).

Cross-reactivity

Cross-reactivity has been demonstrated to other molds. In a study carried out on 668 serum samples from patients which who had previously recorded at least one IgE positivity to fungal antigens, associations were observed between the patterns of IgE sensitization and fungal phylogenetic relationships. Using a panel of 17 fungal extracts including C. lunata, some samples were only positive to one fungal species, whereas many were multi-sensitized. The results suggest that the associations are likely due to antigen cross-reactivity between fungal species, not uncommon in more closely related species (22). Cross-reactivity was also demonstrated in immunoblots with an Epicoccum purpurascens 33.5 kDa allergen, Epi p 1 (23). An Alternaria alternata antigen, Alt a 1, has been demonstrated to show reactivity to specific serum of all species of the Pleosporaceae family (21). C. lunata cytochrome c, a 12kDa protein, showed cross-reactivity with other fungal allergens (20).

Compiled By

Author: RubyDuke Communications

Reviewer: Dr. Christian  Fischer

 

Last reviewed:January 2022

References
  1. Manamgoda D. A taxonomic and phylogenetic re-appraisal of the genus Curvularia (Pleosporaceae): human and plant pathogens. Phytotaxa. 2015;212:175-98.
  2. Carter E, Boudreaux C. Fatal cerebral phaeohyphomycosis due to Curvularia lunata in an immunocompetent patient. J Clin Microbiol. 2004;42(11):5419-23.
  3. CABI. Cochliobolus lunatus (head mould of grasses, rice and sorghum) Wallingford, UK 2021 [cited 2021 13.12.21]. Available from: https://www.cabi.org/isc/datasheet/14690.
  4. Akram W, Anjum T, Ahmad A, Moeen R. First Report of Curvularia lunata Causing Leaf Spots on Sorghum bicolor from Pakistan. Plant Disease. 2014;98(7):1007-.
  5. AbdElfatah HS, Sallam NMA, Mohamed MS, Bagy H. Curvularia lunata as new causal pathogen of tomato early blight disease in Egypt. Mol Biol Rep. 2021;48(3):3001-6.
  6. Kusai NA, Mior Zakuan Azmi M, Zulkifly S, Yusof MT, Mohd Zainudin NAI. Morphological and molecular characterization of Curvularia and related species associated with leaf spot disease of rice in Peninsular Malaysia. Rendiconti Lincei. 2016;27(2):205-14.
  7. Suthiphasilp V, Raksat A, Maneerat T, Hadsadee S, Jungsuttiwong S, Pyne SG, et al. Cytotoxicity and Nitric Oxide Production Inhibitory Activities of Compounds Isolated from the Plant Pathogenic Fungus Curvularia sp. Journal of Fungi. 2021;7(6):408.
  8. McAleer R, Kroenert DB, Elder JL, Froudist JH. Allergic bronchopulmonary disease caused by Curvularia lunata and Drechslera hawaiiensis. Thorax. 1981;36(5):338-44.
  9. Twaroch TE, Curin M, Valenta R, Swoboda I. Mold allergens in respiratory allergy: from structure to therapy. Allergy Asthma Immunol Res. 2015;7(3):205-20.
  10. Kochar S, Ahlawat M, Dahiya P, Chaudhary D. Assessment of allergenicity to fungal allergens of Rohtak city, Haryana, India. Allergy Rhinol (Providence). 2014;5(2):56-65.
  11. Uniprot.org. Taxonomy - Cochliobolus lunatus (Filamentous fungus) (Curvularia lunata) 2021 [cited 2021 13.12.21]. Available from: https://www.uniprot.org/taxonomy/5503.
  12. Green BJ, Mitakakis TZ, Tovey ER. Allergen detection from 11 fungal species before and after germination. J Allergy Clin Immunol. 2003;111(2):285-9.
  13. Green BJ, Tovey ER, Beezhold DH, Perzanowski MS, Acosta LM, Divjan AI, et al. Surveillance of Fungal Allergic Sensitization Using the Fluorescent Halogen Immunoassay. J Mycol Med. 2009;19(4):253-61.
  14. Noble JA, Crow SA, Ahearn DG, Kuhn FA. Allergic fungal sinusitis in the southeastern USA: involvement of a new agent Epicoccum nigrum Ehrenb. ex Schlecht. 1824. J Med Vet Mycol. 1997;35(6):405-9.
  15. Sio YY, Pang SL, Say YH, Teh KF, Wong YR, Shah SMR, et al. Sensitization to Airborne Fungal Allergens Associates with Asthma and Allergic Rhinitis Presentation and Severity in the Singaporean/Malaysian Population. Mycopathologia. 2021;186(5):583-8.
  16. Nasu S, Satoh S, Shimizu K, Matsuno O, Morishita H, Yaguchi T, et al. Spontaneous Regression of Allergic Bronchopulmonary Mycosis Due to Curvularia lunata. Intern Med. 2018;57(2):243-6.
  17. Matsumoto T. Chromoblastomycosis and Phaeohyphomycosis. Tropical Infectious Diseases. 2006;2:898-902.
  18. Corey JP, Kaiseruddin S, Gungor A. Prevalence of mold-specific immunoglobulins in a Midwestern allergy practice. Otolaryngol Head Neck Surg. 1997;117(5):516-20.
  19. Nair S, Kukreja N, Singh BP, Arora N. Identification of B cell epitopes of alcohol dehydrogenase allergen of Curvularia lunata. PLoS One. 2011;6(5):e20020.
  20. Sharma V, Singh BP, Gaur SN, Arora N. Molecular and immunological characterization of cytochrome c: a potential cross-reactive allergen in fungi and grasses. Allergy. 2008;63(2):189-97.
  21. Sáenz-de-Santamaría M, Postigo I, Gutierrez-Rodríguez A, Cardona G, Guisantes JA, Asturias J, et al. The major allergen of Alternaria alternata (Alt a 1) is expressed in other members of the Pleosporaceae family. Mycoses. 2006;49(2):91-5.
  22. Soeria-Atmadja D, Onell A, Borgå A. IgE sensitization to fungi mirrors fungal phylogenetic systematics. J Allergy Clin Immunol. 2010;125(6):1379-86.e1.
  23. Bisht V, Arora N, Singh BP, Gaur SN, Sridhara S. Purification and Characterization of a Major Cross-Reactive Allergen from <i>Epicoccum purpurascens</i>. International Archives of Allergy and Immunology. 2004;133(3):217-24.