GALACTOMANNAN IN POLYP TISSUE AS A DIAGNOSTIC MARKER OF FUNGAL COMPONENT IN CHRONIC RHINOSINUSITIS WITH NASAL POLYPOSIS
In recent years “fungal hypothesis” has been discussed among a set of theories of chronic rhinosinusitis (CRS) with nasal polyposis pathogenesis mechanisms. According to this hypothesis, mould cause not less than 80-90% of CRS with nasal polyposis cases. Fungi are often not revealed in polyp tissue by histological and microbiological analysis. In this regard development of methods for galactomannan detection in polyp tissue is of great importance today. There was an idea to use galactomannan (a polysaccharide antigen of a fungal cell wall) as a marker of fungal antigen presence in polyp tissue. Aim: studying of galactomannan frequency in polyp tissue and its role in the local and systemic immune response in CRS patients with nasal polyposis. As a result of the work it was confirmed that fungal isolation from nasal cavity yields little information. There was no statistically significant difference between CRS patients with nasal polyposis, patients with persistent allergic rhinitis (PAR) and healthy individuals. Fungi were isolated from polyp tissue of 6 CRS patients with nasal polyposis (21%). Mycelial fungi concentration was low (single CFU), and taxonomical diversity was low too. For the first time colonization of polyp tissue by yeast fungus Pichia farinosa was revealed. Its concentration was high and reached 10 <sup>4</sup>-10 <sup>6</sup> CFU/g of polyp. Galactomannan was found in polyp tissue of 18 (62%) CRS patients. Statistically significant positive correlation between presence of galactomannan in polyp tissue, frequency and concentration of G and E antibodies to A. fumigatus and its major allergens Asp f1 and Asp f2, but not ECP and IL-5 was revealed. Thus, the method of galactomannan detection in polyp tissue can become essential addition in diagnostics of CRS phenotype along with other methods (mycological analysis, histomorphological analysis of polyp biopsy material, radiological analysis).