Occupational sensitization to soy allergens in workers at a processing facility
Article first published online: 4 MAY 2011
© 2011 Blackwell Publishing Ltd
Clinical & Experimental Allergy
Volume 41, Issue 7, pages 1022–1030, July 2011
How to Cite
Green, B. J., Cummings, K. J., Rittenour, W. R., Hettick, J. M., Bledsoe, T. A., Blachere, F. M., Siegel, P. D., Gaughan, D. M., Kullman, G. J., Kreiss, K., Cox-Ganser, J. and Beezhold, D. H. (2011), Occupational sensitization to soy allergens in workers at a processing facility. Clinical & Experimental Allergy, 41: 1022–1030. doi: 10.1111/j.1365-2222.2011.03756.x
- Issue published online: 14 JUN 2011
- Article first published online: 4 MAY 2011
- Submitted 23 September 2010; revised 27 January 2011; accepted 22 February 2011
Background Exposure to soy antigens has been associated with asthma in community outbreaks and in some workplaces. Recently, 135 soy flake processing workers (SPWs) in a Tennessee facility were evaluated for immune reactivity to soy. Allergic sensitization to soy was common and was five times more prevalent than in health care worker controls (HCWs) with no known soy exposure.
Objective To characterize sensitization to soy allergens in SPWs.
Methods Sera that were positive to soy ImmunoCAP (n=27) were tested in IgE immunoblots. Wild-type (WT) and transgenic (TG) antigens were sequenced using nanoscale Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry (nanoUPLC MS/MS). IgE reactivity towards 5-enolpyruvylshikimate-3-phosphate synthase (CP4-EPSP), a protein found in TG soy, was additionally investigated. De-identified sera from 50 HCWs were used as a control.
Results Immunoblotting of WT and TG soy flake extracts revealed IgE against multiple soy antigens with reactivity towards 48, 54, and 62 kDa bands being the most common. The prominent proteins that bound SPW IgE were identified by nanoUPLC MS/MS analysis to be the high molecular weight soybean storage proteins, β-conglycinin (Gly m 5), and Glycinin (Gly m 6). No specific IgE reactivity could be detected to lower molecular weight soy allergens, Gly m 1 and Gly m 2, in soybean hull (SH) extracts. IgE reactivity was comparable between WT and TG extracts; however, IgE antibodies to CP4-EPSP could not be detected.
Conclusions and Clinical Relevance SPWs with specific IgE to soy reacted most commonly with higher molecular weight soybean storage proteins compared with the lower molecular weight SH allergens identified in community asthma studies. IgE reactivity was comparable between WT and TG soy extracts, while no IgE reactivity to CP4-EPSP was observed. High molecular weight soybean storage allergens, Gly m 5 and Gly m 6, may be respiratory sensitizers in occupational exposed SPWs.
Cite this as: B. J. Green, K. J. Cummings, W. R. Rittenour, J. M. Hettick, T. A. Bledsoe, F. M.Blachere, P. D. Siegel, D. M. Gaughan, G. J. Kullman, K. Kreiss, J. Cox-Ganser and D. H. Beezhold, Clinical & Experimental Allergy, 2011 (41) 1022–1030.