Measurements of NAHA to Assess Indoor Fungal Exposure

Abstract

SESSION TITLE: ILD PostersSESSION TYPE: Poster PresentationsPRESENTED ON: Saturday, March 22, 2014 at 01:15 PM - 02:15 PMPURPOSE: Exposure to fungi is a risk factor for different respiratory diseases. Traditional exposure measurements such as viable counts are time consuming and expensive, and do not take into account the total fungal cell biomass. Analysis of the enzyme β-N-acetylhexosaminidase (NAHA) in airborne samples has been used as a measure of total fungal biomass. This presentation will review this technique and assess its usefulness by presenting data from the domestic fungal exposure of patients with asthma and sarcoidosis, for the latter also in relation to clinical parameters. METHODS: fluorescent readings were expressed as NAHA units (U/m3). Samples were taken in a number of randomly chosen buildings which were later inspected for the presence of fungi (n=162). Measurements were also made in the bedrooms of subjects with asthma (n=80) and sarcoidosis (n=88). For the latter, data were available on their chest x-ray status and the amount of β-glucan (a major fungal cell wall constituent) in broncho-alveolar lavage (BAL). RESULTS: Investigations in buildings demonstrated that fungi were not present at NAHA levels below 20 U/m3. At levels above 30 U/m3 there was a sensitivity of 55% and a specificity of 100% for the presence of fungi. NAHA was higher than controls in homes of persons with nocturnal asthma (31.2 vs 12.5 U/m3, p=0.001). Among .patients with sarcoidosis, the values were also higher compared to controls (34.1 vs 18.9 U/m3, p=0.002). Those with recurrent sarcoidosis had higher values than those where the disease had healed (39.9 vs 12.0, p=0.001. There was a significant relationship between NAHA and the extent of granulomatous infiltration in chest x-rays and the amount of β-glucan in BAL (p=0.001). CONCLUSIONS: The results suggest that measurements of airborne NAHA are suitable to detect the presence of fungi indoors, particularly as it includes fungal cell fragments. The levels relate to the clinical expressions of nocturnal asthma and sarcoidosis. CLINICAL IMPLICATIONS: Measurements of indoor exposure to fungi are useful to describe the risk of nocturnal asthma and sarcoidosis and can also be used to assess the results of remedial actions in buildings. DISCLOSURE: The following authors have nothing to disclose: Ragnar Rylander, Barbara Salobir, Marjeta TerceljNo Product/Research Disclosure Information.