The Galactomannan Test: On Beam Balance of Pros & Cons

The polysaccharide known as galactomannan (GM) found in cell wall of Aspergillus has gained popularity as a method of diagnosing invasive aspergillosis. GM testing has made possible the early diagnosis and timely antifungal treatment initiation in suspected patients.

GM can be seen in the serum prior to the onset of clinical symptoms. Furthermore, GM levels in BAL fluid appeared earlier than in serum, therefore detecting GM in BAL is a suggested method to identify invasive pulmonary aspergillosis.

In addition, the European Organization for Research and Treatment of Cancer/Mycosis Study Group (EORTC/MSG) recommends the identification of GM as a stand-alone microbiological criterion for the diagnosis of probable patients in association with clinical and host factors.

Invasive aspergillosis is difficult to diagnose since clinical signs are frequently vague and traditional diagnosis is uncommon and complicated. There are currently few diagnostic methods available in mycology. The GM test should be used to aid in diagnosis and is accessible in many locations worldwide. Nonetheless, it is important to take into account the low positive predictive value.

Determining the assay's operational features in particular subpopulations should be a priority because they can differ greatly. In the future, further research is needed to assess different kinds of samples for screening of fungal infections.

The Galactomannan test is currently balancing the pros and cons, however in order to define the probability of invasive aspergillosis, greater precision needs to be developed.

References

1. Avcu G, Karapinar DY. A Review of a Diagnostic Tool: Galactomannan. J Immunol Sci. 2018; 2(5): 38-42.

2. Arikan Akdagh S et al.Diagnosis of Invasive Fungal Diseases in Hematological Malignancies: A Critical Review of Evidence and Turkish Expert Opinion.Turk J Hematol 2014;31:342-346.

3. Archana Keche, Girish Patil, Ranganath T. Ganga, Dibakar Sahu.Galactomannan Antigen Assay for the Diagnosis of Invasive Aspergillosis: A Study from a Tertiary Care Hospital of Central India. J Pure Appl Microbiol. 2024;18(2):878-885.

4. Malhotra S, Kumari R, Chauhan AK, et al. Diagnostic value of galactomannan antigen test in serum and bronchoalveolar lavage fluid sample from suspected patients of invasive pulmonary aspergillosis. Indian J Pathol Microbiol. 2021;64(4):732-734.

5. Patterson T.F., Thompson G.R., III, Denning D.W., Fishman J.A., Hadley S., Herbrecht R., Kontoyiannis D.P., Marr K.A., Morrison V.A., Nguyen M.H., et al. Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the Infectious Diseases Society of America. Clin. Infect. Dis. 2016;63:e1–e60.

6. De Pauw B, Walsh TJ, Donnelly JP, Stevens DA, Edwards JE, Calandra T, et al. Revised definitions of invasive fungal disease from the european organization for research and treatment of cancer/invasive fungal infections cooperative group and the national institute of allergy and infectious diseases mycoses study group (eortc/msg) consensus group. Clin Infect Dis. 2008;46:1813–21.

7. Donnelly JP, Chen SC, Kauffman CA et al.Revision and update of the consensus definitions of invasive fungal disease from the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium. Clin Infect Dis 2020; 71:1367–76.