Immunotherapy for allergic fungal sinusitis

Allergy immunotherapy for allergic fungal respiratory diseases

Background: Allergy immunotherapy (AIT) with fungal extracts is not as straight forward as that with other inhalants. The complexities relate to the number of airborne fungal spores, the limited data on the exposure to the spores of individual species of fungi and their clinical importance, the poor quality of the fungal allergen extracts that are available for the diagnosis and treatment, and the lack of controlled studies establishing dosing and efficacy of AIT with fungal extracts except for Alternaria. Objective: The objective was to review what is known with regard to the role of fungi in causing allergic respiratory diseases as well as the evidence that exists for the role of AIT as a treatment for these conditions. Methods: A search was conducted of PubMed, textbooks, known articles on immunotherapy with fungal extracts, and references derived from these primary sources. Results: Nine immunotherapy studies that used Alternaria or its major allergen Alt a 1 and two studies that used Cladosporium herbarum were identified. When a good quality extract was administered in adequate doses, immunotherapy with Alternaria was as effective as that with other inhalant allergens. There was a suggestion of efficacy with a specially prepared Cladosporium extract, but systemic reactions were common and limited the tolerated dose. The use of immunotherapy as an adjunct treatment for allergic fungal sinusitis is briefly reviewed, but controlled trials are lacking. Conclusion: Fungal immunotherapy should largely be limited to Alternaria alternata and perhaps C. herbarum. Under conditions of demonstrated exposure to a particular species of fungus and with symptoms that correlate with that exposure as well as availability of an apparently potent extract of that fungus to which the patient is sensitive that fungus may be considered for immunotherapy. Fungal (mold) mixes should not be used for diagnosis or therapy.

Pediatric allergic fungal rhinosinusitis: optimizing outcomes

PURPOSE OF REVIEW

Allergic fungal rhinosinusitis (AFRS) is a debilitating condition for children. Despite there being several reviews on this topic in the adult population, there is a paucity of reviews of AFRS in the pediatric literature. This article reviews the recent evidence of pediatric AFRS with the aim to optimize outcomes of pediatric patients with this condition.

RECENT FINDINGS

AFRS is clinically characterized by nasal polyposis, a type I hypersensitivity to fungal epitopes, very thick eosinophilic mucin, and peripheral eosinophilia. Pediatric AFRS has similar clinical characteristics to that in adults but is thought to have a more aggressive nature, with higher serum immunoglobulin E and more frequently bone erosion and malformation of facial bones. Diagnosis of pediatric AFRS is made by using the Bent and Kuhn's criteria developed for adult AFRS. The mainstay of treatment is surgery followed by postoperative corticosteroids. Adjunctive therapies, including topical/oral antifungal agents, allergen immunotherapy and biologics may improve outcomes in pediatric AFRS, but to date the current evidence is limited.

SUMMARY

To optimize the outcome of pediatric AFRS, adequate and early diagnosis and treatment are essential. Appropriate and comprehensive endoscopic sinus surgery to open the sinuses, remove the fungal burden of disease and improve access of the sinuses to postoperative topical corticosteroid remains the standard of care.

Immunotherapy of mold allergy: A review

Mold allergies are common, mainly target the respiratory tract and present as allergic rhinitis and/or bronchial asthma. Molds include a large group of different allergens that induce all types of allergic reactions. Allergen specific immunotherapies (AITs) to molds are common; however, at the present time, they are limited to Alternaria. This review presents not only the benefits but also the problems with such types of AIT based on the literature and our experience.

Fungal raw materials used to produce allergen extracts

OBJECTIVE

To review the topic of fungal raw materials used for the production of allergen extracts and the associated challenges and highlight candidate areas for development before standardized fungal allergen extracts can be commercially produced.

DATA SOURCES

A PubMed search was performed using focused keywords and combined with a review of regulatory documents and industry guidelines. Several books on mycology also were consulted.

STUDY SELECTIONS

The information obtained through the literature, books, and industry was scrutinized and combined with personal experience and expertise to write this article.

RESULTS

Fungi are complex ubiquitous organisms on Earth. They are beneficial and detrimental for humans. Fungi can cause hypersensitivity reactions, including types I, III, and IV. The procurement of fungal raw materials to prepare allergen extracts for diagnosis and possible allergen immunotherapy is complex owing to the intrinsic nature of fungi and their complex genome. Allergen manufacturers produce allergen extracts with variable qualitative and quantitative compositions, which can lead to unpredictable clinical outcomes.

CONCLUSION

The clinician should be aware of the factors responsible for the qualitative and quantitative compositions of fungal allergen extracts and the reasons that currently preclude their standardization. Scientific advances and collaboration and cooperation between allergen manufacturing companies and regulatory agencies are necessary to improve the quality and consistency of fungal extracts. Moreover, clinicians should understand the limitations of currently available fungal extracts.

Distinguishing the dominant species of pathogen in maxillary sinusitis by sequencing DNA dataset analysis

This study determined the microbial composition in maxillary sinusitis and determined the predominant fungal and bacterial species. Samples were obtained from 11 patients with fungal sinusitis and 2 healthy patients. The 13 samples were sequenced using an Illumina Hi-Seq 2000, and mapping to the human, bacterial, and the fungal genomes were based on several steps. Bioinformatics and statistical analyses were then performed for bacterial and fungal expressions in the samples. All samples were cultures for fungal growth. The sequencing data revealed that Aspergillus flavus and Aspergillus oryzae were the dominant fungal strains in the rhinosinusitis samples, and Bacillus cereus and Bacillus thuringiensis were the dominant bacterial strains. Indeed, the fungi and bacteria were associated with the development of fungal rhinosinusitis. Furthermore, B. cereus and B. thuringiensis may cooperate with Pseudomonas aeruginosa to inhibit the growth of fungal mycelia. Knowledge of the microbial composition can provide a diagnostic reference for patients with maxillary sinusitis.

Allergen Immunotherapy in an HIV+ Patient with Allergic Fungal Rhinosinusitis

Patients with HIV/AIDS can present with multiple types of fungal rhinosinusitis, fungal balls, granulomatous invasive fungal rhinosinusitis, acute or chronic invasive fungal rhinosinusitis, or allergic fungal rhinosinusitis (AFRS). Given the variable spectrum of immune status and susceptibility to severe infection from opportunistic pathogens it is extremely important that clinicians distinguish aggressive fungal invasive fungal disease from the much milder forms such as AFRS. Here we describe a patient with HIV and AFRS to both remind providers of the importance of ruling out invasive fungal disease and outline the other unique features of fungal sinusitis treatment in the HIV-positive population. Additionally we discuss the evidence for and against use of allergen immunotherapy (AIT) for fungal disease in general, as well as the evidence for AIT in the HIV population.

Immunotherapy in allergic fungal sinusitis: The controversy continues. A recent review of literature

Allergic fungal sinusitis (AFS), also referred to as allergic fungal rhinosinusitis (AFRS), is a noninvasive, eosinophilic form of recurrent chronic allergic hypertrophic rhinosinusitis. AFS has distinct clinical, histopathological, and prognostic findings that differentiate it from other forms of sinusitis. The core pathogenesis and optimum treatment strategies remain debated. Concerns surround the use of immunotherapy for AFS because allergen-specific immunoglobulin G (IgG) induced by immunotherapy could theoretically incite a Gell and Coombs type III (complex mediated) reaction. Type I hypersensitivity is established by high serum levels of allergen-specific IgE to various fungal antigens and positive Bipolaris skin test results. Type III hypersensitivity is established by an IgG-mediated process defined by the presence of allergen-specific IgG that forms complexes with fungal antigen inducing an immunologic inflammatory response. These reveal the multiple immunologic pathways through which AFS can impact host responses. Recent literature establishing benefits of fungal immunotherapy and no evidence of type III–mediated reactions, severe local reactions, or delayed reactions, indicate that application of AFS desensitization is a reasonable therapeutic strategy for this difficult to manage entity. Our review should encourage further clinical acceptance of AFS desensitization because the existing literature on this subject shows benefits of fungal immunotherapy and no evidence of type III–mediated reactions, severe local reactions, or delayed reactions.