Aspergillus fumigatus, IgG Antibodies, Serum
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Aspergillus fumigatus is one of the causative agents of hypersensitivity pneumonitis (HP), as well as invasive lung disease with cavitation or pneumonitis and allergic bronchopulmonary disease.(1) Other causative microorganisms of HP include Micropolyspora faeni and Thermoactinomyces vulgaris. The development of HP and allergic bronchopulmonary disease caused by Aspergillus fumigatus is accompanied by an immune response to Aspergillus fumigatus antigens with production of IgG or IgE antibodies, respectively. While the immunopathogenesis of HP and allergic bronchopulmonary disease is not known, several immune mechanisms are postulated to play a role, including both cellular and humoral mechanisms.
Evaluation of patients suspected of having lung disease caused by Aspergillus fumigatus
Elevated concentrations of IgG antibodies to Aspergillus fumigatus, Thermoactinomyces vulgaris, or Micropolyspora faeni in patients with signs and symptoms of hypersensitivity pneumonitis may be consistent with disease caused by exposure to 1 or more of these organic antigens.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
IgG antibodies to Aspergillus fumigatus, Thermoactinomyces vulgaris, or Micropolyspora faeni may be found in sera from healthy individuals; the presence of these specific antibodies is not sufficient to establish the diagnosis of hypersensitivity pneumonitis (HP).
Elevated concentration of antibodies to Aspergillus fumigatus may be also found in patients with invasive aspergillosis and cavitary lung disease.
The concentrations of antibodies to these antigens may decrease following treatment, although elevated concentrations may persist in treated patients.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
<4 years: not established
> or =4 years: < or =102 mg/L
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Fink JN, Zacharisen MC: Chapter 69: Hypersensitivity pneumonitis. In Allergy Principles and Practice. Vol 1. Fifth edition. Edited by E Middleton Jr, CE Reed, EF Ellis, et al. St. Louis, Mosby Year Book Inc, 1998
2. Girard M, Lacasse Y, Cormier Y: Hypersensitivity pneumonitis. Allergy 2009;64:322-334
3. Grunes D, Beasley MB: Hypersensitivity pneumonitis: A review and update of histologic findings. J Clin Pathol 2013;66:888-895