Allergic sensitization in US bakery workers

As part of a health hazard evaluation (HHE), the National Institute for Occupational Safety and Health (NIOSH) performed a study at a commercial bakery designed to evaluate allergic sensitization to bakery associated allergens (BAA; alpha-amylase, [AA]; wheat, [W], or flour dust, [FD]). Sera was obtained from 96 employees, dichotomized as having low exposure (N=33) or high (or past) exposure (N=63) to BAA. Workers were evaluated for atopy (AlaTOP®, total IgE), and serum-specific IgE (AA, FD, and W; IMMULITE® 2000). There was no significant difference in the prevalence of atopy between groups by AlaTOP® (47% of high exposure vs. 41% of low exposure, p=0.6) or total IgE (3.9 kU/L [high exposure] compared to 3.7 kU/L [low exposure], p=0.5). At an IMMULITE® specific IgE cutoff of > 0.35 kU/L, there was significantly greater prevalence of positive specific IgE to W. When an IMMULITE® positive cutoff of >0.10 was used, significantly greater prevalence (p<0.05) of specific IgE to FD, AA, and W was observed in the high vs. low exposure groups. Atopics had significantly higher rates of sensitization to W and FD at both the 0.1 and 0.35 kU/L levels, and to AA at the 0.1 level. Exposure to BAA puts workers at a higher risk for sensitization to BAA (specific IgE). As has been shown for other occupational allergens (Annals of Allergy, Asthma, & Immunology, 97:196-202, 2006), using the IMMULITE® at a cutoff of 0.10 kU/L vs. 0.35 kU/L appears to increase the sensitivity of the assay.