| Abstract: | In the present study, it was shown that allergen challenge in vitro produced an increase in the number of antigen-specific IgE-plaque-forming cells of peripheral-blood lymphocytes from grass- or ragweed-allergic patients. Thus, the blood lymphocytes of all twelve (four rye grass I and eight AgE) sensitive donors responded whereas the blood lymphocytes of five non-atopic controls were unresponsive to antigen challenge. Allergen challenge doses of 10(-10)-10(-12) g/ml were found to give the greatest number of plaque-forming cells whereas the number of plaque-forming cells at challenging doses between 10(-9) and 10(-7) g/ml were either the same or less than those obtained with unchallenged cells. The results are discussed as to whether this in vitro model system represents in vivo response to allergen of the allergic patient. |
