Multidisc RAST: a reliable method for screening of specific IgE antibodies in serum?

"Multidiscs" (md) are cellulose discs to which several allergens are coupled, allowing the simultaneous screening of several specific IgE antibodies. We compared RAST performed with md to RAST performed with the corresponding individual allergens coated on single discs (sd). One hundred and twenty-two RAST positive samples were analyzed for four different allergen groups: moulds, cereals, weed pollens and tree pollens. We found lower RAST sensitivity when screening with mds than with the individual sds in all allergen groups except cereals. In 30 to 70% of the samples, the results were concordant. In 25.5 to 66.7%, md values were lower and in 1.3 to 26.3% higher than sd values. When only qualitative results were considered, the loss of sensitivity appeared acceptable: only 6.7 to 16.7% of the sd positive samples were not detected by md screening. A cost-benefit analysis, calculated on local data, confirmed economic advantages.