Screening for Galactomannan and Anti-Aspergillus Antibodies in Haematological Patients Suspected for Developing Invasive Aspergillosis

E. Ratkov1, A. Vidovic2, N. Suvajdzic Vukovic2, A. Dzamic1, V. Arsic Arsenijevic1

Author address: 

1Institute of Microbiology and Immunology, BELGRADE, Serbia 2Institute of Hematology, Clinical Center of Serbia, BELGRADE, Serbia

Abstract: 

Invasive fungal infections (IFI) continue to cause considerable morbidity and mortality in patients with haematological malignancies. Since late 1980s, the epidemiology of IFI has changed with a trend towards a reduction in invasive infections caused by opportunistic yeasts and an increase in invasive mould infections, particularly caused by Aspergillus spp. Invasive aspergillosis (IA) can involve any organ, but most commonly involves sinopulmonary tract reflecting inhalation as the principal portal of entry. Survival of patients from such lifethreatening disease depends on early diagnosis, but clinical manifestations of IA and standard laboratory methods are often unable to diagnose the infection in its early stages. Therefore, serology tests present a good alternative for early diagnosis of IA. Glactomannan (GM) is a major aspergillus cell-wall constituent released during fungal growth, while antibodies are produced during fungal infection and both of them can be detected in human body fluids. Objectives: The aim of this study was to investigate cumulative diagnostic potential of screening for GM and anti-Aspergillus antibodies in adult hematological patients at high risk for developing IA. Methods: From November 2007 through February 2009 serum GM and anti-Aspergillus antibody levels were measured in 150 adult patients with heamatological malignancies hospitalized at Institute of Hematology, Clinical Center of Serbia. Circulating Aspergillus GM was detected using a sandwich ELISA test (Platelia Aspergillus EIA, Bio-Rad, France). The detection of anti-Aspergillus antibody was performed using ELISA test (Serion Elisa classic, Virion/Serion, Germany). Results: A total of 371 serum samples from 150 patients were collected and analyzed for presence of GM and anti-Aspergillus antibodies. Both GM and anti-Aspergillus antibodies were negative in 79/150 (52.66%). GM was found positive in 25.3% (38/150). The GM index in positive serum samples ranged from 0.54 to 9.73 (mean 4.90). 36.8% (14/38) of GM positive patients was died as a result of IA, in the moment of reporting results. In GM positive patients anti-Aspergillus antibodies were detected in 47.37% (18/38). All three classes of antibodies were positive in 2.63% (1/38), both IgA and IgG were positive in 2.63% (1/38), IgM and IgG in 13.16% (5/38), IgA in 2.63% (1/38), IgM in 7.89% (3/38) and IgG in 18.42% (7/38). Only anti- Aspergillus antibodies were positive in 33/150 (22%). Conclusion: In almost ¼ haematological patients GM was positive, and half of GM positive patients also had detectible humoral immune response, while 1/5 of patients has only antibody without GM. Early diagnosis of IA still presents a challenge. Combination of several non-culture assays is necessary for laboratory diagnosis of IA in high risk patients. No single test is sufficient for diagnosis. For better correlation of laboratory findings with clinical diagnosis further investigations are necessary and will lead to improved outcomes of IA in the future.
2009

abstract No: 

P154

Full conference title: 

4th Trends in Medical Mycology
    • TIMM 4th (2012)