Table 1. Use of the Galactomannan Antigenemia Test for Monitoring at Risk Patients

Population: Prolonged neutropenia, allogeneic SCT

Frequency: Two or three times weekly during high level immunosuppression

Criteria for positivity:

Two consecutive serum specimens with GMI > 0.5
Always repeat the test before implementing therapy for invasive aspergillosis

Considerations:

The galactomannan antigenemia EIA does not replace other tests in the workup of invasive aspergillosis
Antibiotics produced by Penicillium spp. may cause false-positivity
Medications/IV additives containing materials produced by Aspergillus (sodium gluconate) or Penicillium (certain antibiotics) may cause false-positivity
Histoplasmosis (and other endemic mycoses) may cause false-positivity
Mold-active antifungal drugs may cause false-negativity: repeat the test before implementing therapy for invasive aspergillosis
Falsely-positivity or falsely-negativity may occur for other reasons: clinical correlation is imperative

Table 2. Causes for False-Positivity or Cross Reactivity in the Galactomannan Antigenemia Test

False-positivity caused by galactomannan contamination

Cross-reactivity caused by similar cell wall galactomannan

Piperacillin-tazobactam

Amoxacillin-clavulanate

Other beta-lactam antibiotics

Plasmalyte (sodium gluconate)

Other intravenous hydration or nutrition fluids containing sodium gluconate

Possibly cotton, cardboard, soybean protein

Penicillum spp. including P. marneffei

Histoplasma capsulatum

Geotrichum

Neosartoria

Possibly Paecilomyces, Alternaria, Trychophyton, Botrytis, Wallemia, Cladosporium, Bifidobacterium

Table 3. Diagnosis of Invasive Pulmonary Aspergillosis using the Galactomannan Antigenemia EIA on BAL Specimens

Population	Cutoff 0.5		Cutoff 1.0		Reference
Population	Sensitivity-%	Specificity-%	Sensitivity-%	Specificity-%
Hematology	Not stated	Not stated	100	100	(28)
Bone marrow transplant	76	94	61	98	(29)
Solid organ transplant	100	84	100	91	(30)
Solid organ transplant	67	95	67	98	(31)
Intensive Care Unit	88	87	Not Stated	Not Stated	(33)
Nonimmunocompromised	100	78	100	88	(32)

Table 4. Use of the Galactomannan Antigenemia Test for Diagnosis of Invasive Aspergillosis

BAL and serum for evaluation of suspected pulmonary invasive aspergillosis

Validate positive result by repeat testing before starting empiric therapy

Search for other evidence of invasive aspergillosis

· CT scan of lungs and sinuses and

· Histopathology and culture

Evaluate for causes for inaccurate results

· Galactomannan contamination

· Cross-reactive mycosis

· Mold-active antifungal therapy

Figure 1. Galactomannan antigenemia detection in the Platelia® Aspergillus EIA. The test specimen in heated at 100° C. for 3 minutes in the presence of 4% ethylenediaminetetraacetic acid (EDTA), after which the supernatant is removed and mixed with the enzyme labeled detector antibody. This mixture is incubated in the microplate wells precoated with the capture antibody. Then the plates are incubated with a chromogenic substrate, tetramethylbenzidine (TMB). If antigen is present color develops, which is recorded using a microplate reader.

Figure 2. Galactomannan antigenemia EIA on BAL fluid (BALF) versus serum. These represent data for 33 cases in which either BAL or serum, obtained within one week of one another, were positive. All 33 BAL specimens but only 9 of 33 serums specimens (27%) were positive. In 29 of the 33 (88%) BAL specimens the result was >1.0.