Absorption of IgG does not enhance toxoplasma IgM and IgA immunoblotting.

Total IgG, IgM and IgA levels and toxoplasma IgG, IgM and IgA immunoblotting patterns were assayed in 10 sera before and after IgG absorption with Protein G-Sepharose 4. Removal of IgG (mean reduction 96%) was accompanied by a significant reduction in the level of IgM (mean reduction 56%) and IgA (mean reduction 53%) in nine of the 10 sera. The absorbed supernates showed fewer and weaker IgM bands in five sera, but IgA immunoblotting patterns were unaffected by absorption.

Suspected allergy: a sequential protocol for testing patients' sera.

Sera from 591 patients were examined for total IgE concentration and for reactivity against a panel of seven specific allergens, using the radio-allergosorbent test (RAST). As the total IgE increased, the frequency of positive RAST reactions increased (P less than 0.001); there were more multiple positive RAST reactions (P less than 0.