Cross-allergenicity among the grasses.

RAST inhibition was employed to determine the allergenic relationship of five common western grasses (brome, quack, western wheat, salt, and grama), three southern grasses (Bermuda, Johnson, and Bahia), and six common northern grasses (timothy, June, rye, red top, meadow fescue, and sweet vernal). The patterns of cross-allergenicity suggested by these studies were compared to those suggested by the botanical classification of these grasses. There was significant cross-allergenicity among the grasses studied. Brome, western wheat, and quack grasses demonstrated RAST inhibition patterns similar to the northern grasses. Salt and grama grasses exhibited close allergenic relationships to Bermuda grass, which was allergenically distinct from the northern grasses. Johnson grass appeared to share allergenicity with both the northern grasses and Bermuda grass. Bahia shared allergenicity with the northern grasses, but also possessed some unique allergens. Timothy and Bermuda grass appeared to account for all of the RAST-inhibiting activity contained in the other grasses studied with the possible exception of Bahia grass.