Fungi and allergic lower respiratory tract diseases.
J Allergy Clin Immunol. 2012 Feb;129(2):280-91
Authors: Knutsen AP, Bush RK, Demain JG, Denning DW, Dixit A, Fairs A, Greenberger PA, Kariuki B, Kita H, Kurup VP, Moss RB, Niven RM, Pashley CH, Slavin RG, Vijay HM, Wardlaw AJ
Abstract
Asthma is a common disorder that in 2009 afflicted 8.2% of adults and children, 24.6 million persons, in the United States. In patients with moderate and severe persistent asthma, there is significantly increased morbidity, use of health care support, and health care costs. Epidemiologic studies in the United States and Europe have associated mold sensitivity, particularly to Alternaria alternata and Cladosporium herbarum, with the development, persistence, and severity of asthma. In addition, sensitivity to Aspergillus fumigatus has been associated with severe persistent asthma in adults. Allergic bronchopulmonary aspergillosis (ABPA) is caused by A fumigatus and is characterized by exacerbations of asthma, recurrent transient chest radiographic infiltrates, coughing up thick mucus plugs, peripheral and pulmonary eosinophilia, and increased total serum IgE and fungus-specific IgE levels, especially during exacerbation. The airways appear to be chronically or intermittently colonized by A fumigatus in patients with ABPA. ABPA is the most common form of allergic bronchopulmonary mycosis (ABPM); other fungi, including Candida, Penicillium, and Curvularia species, are implicated. The characteristics of ABPM include severe asthma, eosinophilia, markedly increased total IgE and specific IgE levels, bronchiectasis, and mold colonization of the airways. The term severe asthma associated with fungal sensitization (SAFS) has been coined to illustrate the high rate of fungal sensitivity in patients with persistent severe asthma and improvement with antifungal treatment. The immunopathology of ABPA, ABPM, and SAFS is incompletely understood. Genetic risks identified in patients with ABPA include HLA association and certain T(H)2-prominent and cystic fibrosis variants, but these have not been studied in patients with ABPM and SAFS. Oral corticosteroid and antifungal therapies appear to be partially successful in patients with ABPA. However, the role of antifungal and immunomodulating therapies in patients with ABPA, ABPM, and SAFS requires additional larger studies.
Mendelian traits causing susceptibility to mucocutaneous fungal infections in human subjects.
J Allergy Clin Immunol. 2012 Feb;129(2):294-305
Authors: Engelhardt KR, Grimbacher B
Abstract
Mucocutaneous candidiasis and dermatophyte infections occur either in isolation or alongside other symptoms in patients with various primary immunodeficiency diseases with diverse genetic defects, which result in impaired IL-17 immunity, IL-22 immunity, or both. In patients with chronic mucocutaneous candidiasis, disease-associated polymorphisms in DECTIN1 act on the level of fungal recognition, whereas mutations in caspase recruitment domain-containing protein 9 (CARD9) disturb the subsequent spleen tyrosine kinase 2-CARD9/BCL10/MALT1-driven signaling cascade, impairing nuclear factor κB-mediated maturation of antigen-presenting cells and priming of naive T cells to differentiate into the T(H)17 cell lineage. T(H)17-priming cytokines signal through the transcription factor signal transducer and activator of transcription (STAT) 3, which in turn induces the T(H)17 lineage-determining transcription factor retinoic acid-related orphan receptor γt. Dominant-negative mutations in STAT3 result in reduced numbers of T(H)17 cells, causing localized candidiasis in patients with hyper-IgE syndrome. In patients with chronic mucocutaneous candidiasis, gain-of-function STAT1 mutations shift the cellular response toward T(H)17 cell-inhibiting cytokines. T(H)17 cells secrete IL-17 and IL-22, which are cytokines with potent antifungal properties, including production of antimicrobial peptides and activation and recruitment of neutrophils. Neutrophils mediate microbial killing through phagocytosis, degranulation, and neutrophil extracellular traps. Mutations in IL17F and IL17R in patients with chronic mucocutaneous candidiasis, as well as neutralizing autoantibodies against IL-17 and IL-22 in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy, directly impair IL-17 and IL-22 immunity.
New approaches to personalized medicine for asthma: Where are we?
J Allergy Clin Immunol. 2012 Feb;129(2):327-34
Authors: Weiss ST
Abstract
Access to an electronic medical record is essential for personalized medicine. Currently, only 40% of US physicians have such access, but this is rapidly changing. It is expected that 100,000 Americans will have their whole genome sequenced in 2012. The cost of such sequencing is rapidly dropping, and is estimated to be $1000 by 2013. These technological advances will make interpretation of whole genome sequence data a major clinical challenge for the foreseeable future. At present, a relatively small number of genes have been identified to determine drug treatment response phenotypes for asthma. It is anticipated that this will dramatically increase over the next 10 years as personalized medicine becomes more of a reality for asthma patients.
Advances in mechanisms of asthma, allergy, and immunology in 2011.
J Allergy Clin Immunol. 2012 Feb;129(2):335-41
Authors: Boyce JA, Bochner B, Finkelman FD, Rothenberg ME
Abstract
2011 was marked by rapid progress in the identification of basic mechanisms of allergic disease and the translation of these mechanisms into human cell systems. Studies published in the Journal of Allergy and Clinical Immunology this year provided new insights into the molecular determinants of allergenicity, as well as the environmental, cellular, and genetic factors involved in sensitization to allergens. Several articles focused on mechanisms of allergen immunotherapy and the development of novel strategies to achieve tolerance to allergens. Additional studies identified substantial contributions from T(H)17-type cells and cytokines to human disease pathogenesis. Finally, new therapeutic applications of anti-IgE were identified. The highlights of these studies and their potential clinical implications are summarized in this review.
