Galactomannan antigen as one of the markers for the diagnosis of invasive aspergillosis

Abstract

The article deals with the state of the early clinical and laboratory diagnostics problem of invasive form of aspergillosis. Aim. To analyze current views on the possibilities of different methods of invasive aspergillosis diagnostics, in particular the determination of galactomannan antigen in biological liquids, and to evaluate errors in its diagnostics. Material and Methods. The results of modern scientific research are summarized on the basis of analysis of 34 literature sources and of practical experience of determination of galactomannan antigen of Aspergillus using the Platelia ™ Aspergillus Ag test system (Bio-Rad Laboratories, USA). Results and Discussion. Verification of invasive aspergillosis is complicated, and early diagnostics is an important precondition for successful treatment. The diagnostic algorithm involves a complex set of instrumental and laboratory methods. Today there are no uniform diagnostic criteria and standardization of laboratory diagnostics of invasive aspergillosis, which leads to uncertainty in interpretation of the results of laboratory tests of the patient. The existing direct and indirect methods are limited in sensitivity and specificity and can lead to both false-negative and false-positive results, especially in a one-off study. In Ukraine, there is an urgent need to identify galactomannan in high-risk patients, particularly cancer patients. Large-scale randomized trials indicate a number of factors that may affect the results of a study and, therefore, the quality of diagnosis. Conclusions. To improve the quality of invasive aspergillosis diagnostics, it is important to introduce not only direct microbiological methods but also indirect ones, particularly the identification of galactomannan antigen. In case of clinical suspicion of invasive aspergillosis and a negative test result for the presence of galactomannan antigen, the test should be repeated three days in a row to eliminate false-negative results. In order to obtain adequate test results, standard operating procedures must be followed at all stages of the determination of galactomannan antigen.

Keywords

• invasive aspergillosis, diagnostics, galactomannan antigen, laboratory errors.