STANDARDISATION OF A METHOD FOR THE DETERMINATION OF SPECIFIC IGE TO SOYBEAN HULL AEROALLERGEN

Soybean hull (SH), was identified as the cause of the asthma epidemics reported in Barcelona in the 1980s and 90s. During soybean unloading in ports, SH-rich dust is released to the air, potentially causing asthma exacerbations. This study aims to establish a method for the detection of SH specific IgE in patients with asthma and to identify the current sensitisation to this aeroallergen in Barcelona. A dissociation-enhanced lanthanide fluorescence immunoassay (DELFIA) was standardised on plates coated with SH extract. The results were reported as fluorescence counts (FC). A ROC curve was generated comparing the results from healthy control patients (HCP) and sensitised asthmatic patients (SAP) to set the limit value for positivity of the method. Then, we analysed sera samples from asthmatic patients recruited in our centre to assess the current degree of sensitisation to SH. A value of 3256 CF showed sensitivity 78.3% and specificity 93% to discriminate between SAP and HCP. To determine the current degree of sensitisation, the study population consisted of 104 patients with asthma (74 women, mean age 51 years) and 31 healthy individuals as control group (15 women, mean age 35 years). In four patients (3.9%) values >3256 CF were obtained, median (range), 1282.9 (0-3709.3). In the control group five individuals (16%) had values >3256 CF, median (range) 1531.6 (0-3618.3). The standardised method has enough sensitivity and specificity to discriminate between SH-sensitised and non-sensitised patients. Current sensitisation to SH in asthmatic population of Barcelona is low.