Chan-Yeung M, Enarson DA, Kennedy SM. was significant (r=0.36, p=0.02). There was no association between the prevalence of sIgE, sIgG, and sIgG4 to exposure intensity, smoking or atopic status. Summary These results suggested the living of sIgG and sIgG4 might symbolize a response to CD exposure, and that some unexposed subjects experienced sIgG to CD. Specific IgE might play a role in the development of respiratory symptoms. Keywords: Specific IgE, Specific IgG, Specific IgG4, SB 258585 HCl Corn dust, Exposure Intro Chronic inhalation of grain dust has been shown to cause acute and chronic airway injury characterized by bronchitis and airflow obstruction1C4). Longitudinal studies have shown accelerated deterioration of pulmonary function in these grain dust workers5), the severity of which appears to be related to the concentration of airborne grain dust in the work environment4, 6). In regard to pathogenetic mechanism of corn dust-induced asthma, our earlier report shown that inhalation of corn dust (CD) could induce IgE-mediated bronchoconstriction7). However, there have been a few studies suggesting SB 258585 HCl that endotoxin included in the CD might induce airway swelling, not via immunologic mechanism8, 10). Further studies are needed to determine the part of specific IgG in occupational asthma studies. Our previous study dealing with grain dust-induced occupational asthma11) showed that only three of six individuals had high specific IgE IGFBP4 antibodies to grain dust, while all experienced high specific IgG antibodies, which suggested that sIgG might represent exposure to grain dust. In order to evaluate the medical significance of serum sIgE, sIgG and sIgG4 antibodies and their associations to respiratory dysfunction in CD-induced asthma, we analyzed SB 258585 HCl the prevalence of CD-specific IgE, IgG and IgG4 antibodies by ELISA in 43 CD-exposed workers. The relationship of sIgE, sIgG and IgG4 antibodies was also investigated. MATERIAL AND METHODS Subjects All the 42 subjects exposed to CD were male and worked well for the Dongbang feed market in Suwon, Korea. Of these employees, 31 were process workers who combined the materials as well as carried them. They were classified as group II (intermediate exposure, n=12) and group III (high exposure, n=19) relating to exposure intensity which was measured by a dust air flow sampler (Gilian INS, SB 258585 HCl U.S.A.). Twelve employees were office workers and were classified as group I (low exposure group). Lower respiratory symptoms referred to cough, sputum, chest tightness or shortness of breath. Symptomatic employees were those workers who experienced experienced lower respiratory symptoms during and after CD exposure. Atopy was defined as a positive reactor to more than one of the common inhalant allergens on the skin prick test12). All the subjects gave their educated consent as controlled by Ajou University or college Hospital. Sera Sera from 43 employees were collected and stored at ?20C, as well as sera from control subject matter consisting of 27 individuals who had by no means been exposed to CD, and who SB 258585 HCl had proven negative skin checks to 50 common inhalant allergens including CD extracts. Preparation of extracts CD was from the individuals workplace. It was extracted with phosphate-buffered saline [(PBS, pH 7.5), 1: 5 w/v] at 4C for 1 h followed by centrifugation at 5,000 rpm. The supernatant was dialyzed (the cut-off molecular excess weight was 6,000 Da) against 4 litres of distilled water at 4C for 48 h, approved through the filter (0.2 m pore sized) to exclude bacterial contamination, and lyophilized at ?70C for the preparation of antigens used in ELISA. ELISA ELISA was performed according to the previously explained method8). A 96-well EIA flat-bottomed plate (Dynatec, USA) was filled with 10 g/well CD antigens inside a carbonate buffer (pH 9.6), and coated with the buffer only, which was preliminarily determined while the optimal concentration. After over night incubation at 4C, the plates were washed three times with 0.05M Tween-phosphate-buffered saline (PBST). To each well was added 250 l of 5% bovine serum albumin (BSA)-PBST, which was then incubated for 60 moments at 37C. All three assays were performed in triplicate. Anti-com dust IgG ELISA Fifty microlitres of diluted individuals serum or bad control serum (1/200 in diluent buffer;.