Less Symptoms in Lab Workers with More Rat Exposure
High IgG/IgE ratio shown in asymptomatic pharmaceutical workers exposed to high levels of rat allergens
MONDAY, July 3 (HealthDay News) -- Pharmaceutical workers exposed to very high levels of rat allergens have fewer symptoms of allergy and asthma and lower levels of specific IgE than those exposed to lower levels, according to a report in the July issue of the American Journal of Respiratory and Critical Care Medicine.
Meinir Jones, Ph.D., from Imperial College in London, U.K., and colleagues investigated the relationships among workplace exposure to rat aeroallergens by monitoring employees who handle rats at six pharmaceutical companies. They measured production of specific antibodies (IgE, IgG and IgG4), and the prevalence of associated symptoms in 689 workers.
The investigators found that those exposed to the highest level of rat allergens had lower specific IgE levels, higher specific IgG and IgG4 production, and reduced symptoms of exposure.
"Inverse relationships between IgE sensitization and increased specific IgG and IgG4 have been described as representing a 'modified [T helper 2] response,' because both antibody classes require the Th2 cytokine interleukin 4 for their production," the authors write. "Specific IgG4 produced together with specific IgE may reduce the risk of developing work-related chest symptoms compared with when specific IgE is produced alone."