Investigation of mold fungi in air samples of elementary schools and evaluation of allergen-specific IgE levels in students' sera

Abstract

Atmospheric fungal spores play important role in allergic reactions in atopic individuals. Monitorization of those spores found in the environment of atopic cases is crucial for the choice of the antigens that will be included in allergen screening procedures and precautions to be taken against mold-originated health problems. Since most of the people spend plenty of time indoors in recent years, the effects of exposure to indoor air fungi on human health have gained importance. This study was aimed to investigate the indoor air mold distribution of elementary schools in Denizli province (located in west Anatolia, Turkey) and to compare the allergen-specific IgE levels of children against the most frequently detected mold genus. A questionnaire (MM080) was distributed to the 4967 students (6-8 year-old) attending first and second degrees of 16 different elementary schools with scattered locations in city center. This questionnaire form included the questions related to the general information about the child, school environment, allergic complaints since last year, home environment and nutrition. Response rate to the questionnaire was 51.6% (2565/4967). Air samples were collected from 18 classrooms in March 2009, during which high rates of allergic symptoms were observed according to the questionnaire results. Mold fungi belonging to 10 different genera (Pénicillium spp. 46%; Aspergillus spp. 18%; Cladosporium spp. 17%; Alternaria spp. 15%; Drechslern spp. 1 %; Chrysosporium, Fusarium, Conidiobolus and Cladathecium species 0.5%; unidentified 1%) were isolated from indoor air of classrooms. Since the most frequently detected mold was Pénicillium spp. (46%), the 48 children with atopic symptoms were called to the hospital for the determination of total IgE and Pénicillium specific IgE in their sera. Twenty two students accepted the invitation and serum total IgE (Immulite 2000; Diagnostic Product Corporation, USA) and allergen-specific IgE (Pénicillium brevicompactum, Pénicillium camemberti, Pénicillium chrysogenum, Pénicillium commune, Pénicillium expansum, Pénicillium fréquentons, Pénicillium glaucum, Pénicillium notatum, Pénicillium roquefortivz Pénicillium viridicatum) (RIDASCREEN; R-Biopharm AG, Germany) levels were determined in those children. Total IgE levels above reference ranges were detected in 41 % (9/22) of the screened sera samples. P.roqueforti, P.commune and P.camemberti antibodies were higher (Odds ratio as 5.50, 4.0 and 3.75, respectively) in sera with high total IgE levels. No independent variables were determined between individual and/or environmental factors and Penicillium-specific IgE antibodies. It was concluded that those three strains should be chosen as antigens for mold allergy screening tests which will be performed among atopic cases in our region. In conclusion it should be kept in mind that molds have a possible role in the development of allergic symptoms, however, they are not the sole determining factor in this process. In the investigation of the allergic diseases environmental factors should be considered and standardized methods should be applied.