Management of Elevated Aspergillus IgG Antibody

Diagnostic Workup Required

The European Respiratory Society recommends obtaining a CT scan of the chest with contrast to look for cavitation, fungal balls, pleural thickening, pericavitary infiltrates, or nodular lesions in patients with elevated Aspergillus IgG antibody 1, 2
The Infectious Diseases Society of America suggests assessing symptom duration, with chronic pulmonary aspergillosis (CPA) requiring ≥3 months of chronic pulmonary symptoms or progressive radiographic abnormalities 3, 4
The European Respiratory Society recommends confirming minimal or no immunocompromise, with an arbitrary cutoff of ≤10 mg prednisolone daily or equivalent, and looking for underlying lung disease such as prior tuberculosis, COPD, bronchiectasis, sarcoidosis, or prior mycobacterial infection 1, 5

The Infectious Diseases Society of America recommends observing without antifungal therapy if there are no pulmonary symptoms, no weight loss, no significant fatigue, and no progressive loss of lung function, with follow-up every 3-6 months with repeat imaging and clinical assessment 3, 4
The Infectious Diseases Society of America suggests initiating antifungal therapy for a minimum of 6 months if any of the following are present: pulmonary symptoms, constitutional symptoms, progressive loss of lung function, or radiographic progression 3, 4
The Infectious Diseases Society of America recommends first-line treatment options, in order of preference, as oral itraconazole with therapeutic drug monitoring (TDM), oral voriconazole with TDM, and posaconazole as third-line for adverse events or clinical failure 3, 4, 6

The European Respiratory Society notes that antibody titers generally fall slowly with successful therapy, but rarely become undetectable unless continuous therapy is given for years 1, 2
The European Respiratory Society warns that a sharply rising antibody titer indicates therapeutic failure or relapse, and recommends repeating the test before changing therapy to exclude laboratory error 1, 2

The European Respiratory Society notes that false negatives can occur in patients with CPA who have hypogammaglobulinemia or selective inability to produce Aspergillus IgG antibody, and recommends performing Aspergillus IgE testing, using alternative IgG tests, or pursuing other diagnostic methods in such cases 1, 2
The European Respiratory Society advises against measuring IgA or IgM antibodies due to insufficient data supporting their clinical utility 1, 2
The European Respiratory Society warns of potential cross-reactivity with Histoplasma or Coccidioides species, though this is of limited concern in Europe 1, 2