Our data show that the postulated criteria of allergic fungal sinusitis are present in the majority of patients with chronic rhinosinusitis. Either those criteria will be found to be invalid and need to be changed or, indeed, "eosinophilic fungal rhinosinusitis" exists in the majority of patients with chronic rhinosinusitis. Based on our results, fungi and eosinophilic mucin appear to be a standard component of nasal mucus in patients with chronic rhinosinusitis.

In the last 50 years, to our knowledge, only 16 cases of diseases caused by Schizophyllum commune in humans have been reported. Within only 6 months, we found four isolates of this basidiomycetous fungus, obtained from patients suffering from chronic sinusitis. The cultures of the isolated fungi showed neither clamp connections nor fruiting bodies (basidiocarps), which are distinctive features for S. commune, but fast-growing cottony white mycelium only. This was harvested, and DNA was extracted. The internal transcribed spacer region of the ribosomal DNA (rDNA) was amplified with fungus-specific primers, and the PCR products were sequenced. Two strains of S. commune, collected from branches of a European hornbeam (Carpinus betulus) and a tree of heaven (Ailanthus altissima), respectively; four specimens from the herbarium of the Institute of Botany, Karl-Franzens-University Graz; and two strains from internationally known culture collections (CBS 340.81 [ATCC 44201] and CBS 405.96) were investigated in the same way. The sequence data of all strains were compared and showed homology of over 99% in this 660-bp-long fragment of rDNA. With these results, a map of restriction enzyme cutting sites and a primer set specific for S. commune were created for reliable identification of this human pathogenic fungus.Compared to the great number of ascomycetous fungi which are the cause of many diseases, filamentous basidiomycetes that cause infections are reported rarely in the medical literature. Schizophyllum commune Fries 1821 (Schizophyllaceae, Aphyllophorales) is one of them and has been described elsewhere as a suspected cause of onychomycosis (16), basidioneuromycosis (2), an allergic bronchopulmonary mycosis (12), mucoid impaction of the bronchi (1, 5), a fungus ball in the lung (27), an ulcerative lesion of the hard palate (23), a brain abscess (24), and several cases of both maxillary and allergic fungal sinusitis (4,6,14,18,25,28,29). A review of cases has been published by Kamei et al. (13). This worldwide-distributed shelf fungus is found quite frequently in nature throughout the year, although it mostly appears during the cold season (22). The commonly known split-gill fungus is found on decaying wood, where it appears with sessile fan-or kidney-shaped fruiting bodies. Typical for S. commune is the hymenium on the lower side, which consists of longitudinally split gills (lamellae), where masses of basidiospores are produced and released into the air. The fungus is easy to cultivate on most of the media generally used in clinical laboratories. The appearance of fruiting bodies, hyphal clamp connections, and spicules makes identification easy. Nevertheless, monokaryotic clinical isolates lack these unambiguous features, and the mycelium shows up only as a cottony white mass of hyphae without any distinctive marks. In these cases, the fungus is often identified as "Mycelia Sterilia" or misidentified as an ascomycete. In the last few years, many molecular methods, such as PCR, sequencing of segments of the genome,...

The biodiversity of fungi isolated from the nasal mucus of patients suffering from chronic rhinosinusitis and from healthy persons was monitored over 28 months. Mucus samples were obtained by flushing the noses of patients with saline or by endoscopic sinus surgery. Fungi from mucus were cultivated on agar plates. Identification was performed microscopically and by polymerase chain reaction with subsequent sequencing of the ribosomal internal transcribed spacer region. Altogether, 619 strains of fungi were cultivated from 233 subjects. Eighty-one species were identified, with a maximum of nine different species per person. The most prevalent isolates belonged to the genera Penicillium, Aspergillus, Cladosporium, Alternaria and Aureobasidium. Whereas Aspergillus and Penicillium spp. occurred in more or less the same numbers throughout the year, Cladosporium spp., Alternaria spp. and Aureobasidium pullulans showed a significantly higher occurrence during late summer and early autumn.

Fungi can be cultured from nasal mucus as soon as contact with the environmental air exists but they are not persistent in the 1st day of life. However, after 4 months, the situation is similar to the one in adults: fungal cultures can be obtained from almost everyone's nose. Therefore, fungi must be considered a normal content of nasal mucus.

Eosinophilic granulocytes (Eos) are found in great numbers both in the tissue and in the mucus of patients suffering from chronic rhinosinusitis with polyposis (ECRS). Interleukin-16 (IL-16) is known as a highly potent chemotactic and chemoattractant molecule (ED 10-11) for Eos. In an open, explorative, controlled study we examined the presence of IL-16 in mucosa tissue, mucus and serum in patients suffering from ECRS and its association to Eos activation. Tissue and nasal mucus specimen from 10 previously untreated, non allergic ECRS-patients undergoing paranasal sinus surgery and from 10 healthy non sinusitis subjects, undergoing nasal surgery because of anatomic nasal obstruction were investigated by real-time (RT-) PCR targeting human IL-16 mRNA. Haematoxylin-eosin (HE) staining and immunohistochemistry of formalin embedded tissue and mucus were applied for detection and determination of the proportion of activated Eos (aEos) and IL-16. Serum IL-16 was analyzed by enzyme-linked-immunosorbent assay (ELISA). IL-16 mRNA and IL-16 protein levels were elevated in nasal mucus, polyp tissue and in the serum of ECRS patients compared to healthy controls. There was a high proportion of aEos in ECRS patients compared to healthy subjects. Serum IL-16, IL-16 mRNA expression and IL-16 protein in mucus and tissue specimens were significantly associated with the presence of aEos in polyps of ECRS patients. Immunohistochemically IL-16 protein was mainly expressed in aEos, mast cells, lymphocytes and epithelial cells. In conclusion our data indicate that IL-16 may stimulate the migration and persistence of activated Eos in ECRS. IL-16 production in ECRS patients is not mediated by Immunglobuline-E (IgE).