Galactomannan, Serum

Galactomannan is a polysaccharide cell wall component that is released by Aspergillus organisms during fungal growth.

Galactomannan test is a non-invasive test that aids in the diagnosis of Invasive Aspergillosis (IA) – a  and severe infection. In conjunction with other diagnostic tests and clinical signs of disease, it is an aid in the effective early treatment of disease.

Definitive diagnosis of Invasive Aspergillosis (IA) requires histo-pathological evidence or a positive culture finding. However since the patient is critically ill in IA, it is impossible to obtain a deep tissue sample and culture findings have also reported low sensitivity. During these circumstances, diagnosis is based on clinical symptoms like cough, chest pain, dyspnea along with tests like Galactomannan and radiology findings like CT Scan.

• The test has a quick turn-around time and can be detected 7 days before the onset of diagnostic clues.
• Galactomannan antigen levels drop in response to treatment (antimicrobial therapy).
• Monitoring of levels can help in beginning antifungal therapy before life-threatening infection occurs.

A serum galactomannan (GM) antigen test has been widely used to

• Diagnose invasive pulmonary aspergillosis (IA).
• Establish a baseline serum level and tests are done regularly to check for any increase in levels which could indicate an infection.

Other names: Galactomannan, Galactomannan test, 1-3 β-D-glucan test, Galactomannan Antigen, Fungal antigen test, invasive pulmonary aspergillosis

Invasive Aspergillosis is a severe infection that occurs in patients at risk. Risk includes: 

1. Patients with prolonged neutropenia (when you have lower than the normal levels of neutrophils in the blood – typically happens during an infection or from cancer treatment)
2. Patients who have undergone transplant
3. Prolonged use of steroid treatment