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HelpEpic Test Code LAB2407 Aspergillus fumigatus, IgG Antibodies, Serum
Additional Codes
MML Code: SASP
NY State Approved
YesPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Reporting Name
Aspergillus fumigatus, IgG Ab, SMethod Name
Fluorescence Enzyme Immunoassay (FEIA)
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 21 days | |
| Frozen | 21 days |
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Blood Tube Draw Volume
Min 50% draw volume
Specimen Type
SerumSpecimen Minimum Volume
0.3 mL
Reference Values
<4 years: not established
≥4 years: ≤102 mg/L
Report Available
2 to 4 daysDay(s) Performed
Monday through Friday
CPT Code Information
86606
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | Reject |
Useful For
Evaluation of patients suspected of having hypersensitivity pneumonitis (HP) induced by exposure to Aspergillus fumigatus
Evaluation of patients suspected of having HP who have documented environmental exposures to high-humidity environments
Clinical Information
Hypersensitivity pneumonitis (HP) is a type of interstitial lung disease caused by an immune-mediated response to inhaled environmental antigens.(1) Patients with HP commonly display symptoms of cough, dyspnea, and midinspiratory squeaks. Patients may present with an acute onset of symptoms (within hours of antigen exposure) or a chronic onset (which may occur over a course of weeks to months). The nature of an individual’s disease course will be affected by several factors, including quantity of inhaled antigen, intensity/frequency of exposure, and genetic background. The epidemiology of HP is also challenging to understand, as incidence and prevalence of the disease varies with geographic areas, climate, and local customs. While the immunopathogenesis of HP is not completely understood, it is presumed to involve both type III and type IV hypersensitivity reactions, with the type III reaction characterized by the presence of IgG antibodies specific for the inciting antigen.
There are many antigens, both organic and inorganic, that have been associated with development of HP.(2) Causative organic antigens include a wide array of bacteria, mycobacteria, fungi, and animal proteins. Aspergillus fumigatus is a fungus found in locations with high humidity, including soil, greenhouses, and compost heaps. It is fairly ubiquitous and may even be found in household dust. Some individuals exposed to A fumigatus, particularly those individuals with routine exposure to high-humidity environments, may develop IgG antibodies against this antigen, which could lead to development of HP.
Clinical practice guidelines for HP include a diagnostic algorithm which focuses on exposure identification, imaging evaluation, and bronchoalveolar lavage/histopathology.(3) Detection of IgG antibodies specific for certain environmental antigens can help to document the causative exposure for an individual. This is critical, as an important treatment for these patients is antigen avoidance. However, IgG testing is only useful as supportive information for the diagnosis of HP; a positive result only indicates sensitization to the antigen and a negative result does not exclude the possibility that a patient with HP may be sensitized to another antigen.
Interpretation
Positive results for IgG antibodies to Aspergillus fumigatus, in patients with signs and symptoms of hypersensitivity pneumonitis, may be consistent with sensitization to this fungus.
Cautions
Positive results for IgG antibodies to Aspergillus fumigatus may be found in sera from healthy individuals who are sensitized to this fungus but do not display symptoms consistent with hypersensitivity pneumonitis (HP).
Negative results for IgG antibodies to A fumigatus do not exclude HP as a diagnosis; patients with clinical symptoms consistent with HP may be sensitized to a different antigen.
Elevated concentration of antibodies to A fumigatus may be also found in patients with invasive aspergillosis and cavitary lung disease.