SANTIAGO, SPAIN—Alcohol consumption can raise serum immunoglobulin E (IgE) levels in both atopic and non-atopic adults.[1] However, the increased serum IgE levels do not appear to cause allergic symptoms, said Arturo González-Quintela, MD, one of the study’s authors. Nevertheless, an association may exist between alcohol and certain allergens, stated Dr. González-Quintela, a researcher at the University of Santiago in Spain.

He and his colleagues enrolled 460 consecutive adult patients in their study; 325 were atopic, and the remaining 135 were non-atopic. Of the atopic patients, 78% were sensitized to dust mites, 33% to grass pollen, 11% to weed pollen, and 4% to animal dander.

Patients’ alcohol consumption was monitored prospectively. Among atopic subjects, 54% regularly consumed alcohol (median intake, 30 g/wk). In addition, 63% of the non-atopic subjects regularly consumed alcohol (median intake, 70 g/wk). Overall, 2% of the subjects were heavy drinkers (they consumed more than 60 g/d of alcohol) and 44% were abstainers.

Not surprisingly, median serum IgE levels were higher in the atopic subjects than in the non-atopic individuals. Regular alcohol consumers had higher median total serum IgE levels than did the abstainers (290 IU/mL vs 213 IU/mL, respectively, in the atopic subjects and 131 IU/mL vs 61 IU/mL, respectively, in the non-atopic individuals). In both the atopic and non-atopic subjects, serum IgE levels correlated directly with alcohol intake, but the association was stronger in those who were non-atopic. This suggests, says Dr. González-Quintela, that atopy overshadowed alcohol’s influence on IgE in the subjects with allergies.

A specific association was seen between alcohol use and allergy to the house dust mite Dermatophagoides pteronyssinus; patients with this allergy had higher specific IgE concentrations if they were alcohol consumers (54 IU/mL) than if they were abstainers (25.7 IU/mL). The same association was not seen in patients with grass pollen allergy.

Dr. González-Quintela stated that the mechanism through which alcohol influenced IgE levels was enigmatic, but he speculated that it might be related to the changes that alcohol induces in T-helper cell 2-type cytokines, which stimulate B-cells to produce IgE. He told RESPIRATORY REVIEWS, “Several reports conclude that chronic alcoholism is associated with changes in cytokine levels and/or production. As it happens with almost every study of the cytokine network, results are somewhat puzzling. Alcohol is a powerful immunoregulatory drug that probably has effects on a wide array of cellular subsets.”

Dr. González-Quintela concluded that alcohol intake of more than 70 g/wk should be considered a culprit in serum IgE increases. He and his colleagues admit that at the moment, these findings are primarily of pathophysiological interest, rather than of clinical significance. Nevertheless, they hope that further study will reveal more about the relationship between alcohol and IgE levels and provide clues to the synthesis and function of IgE in allergic disease.

—Owen McCarthy