Skin test evaluation of tropical and temperate grass pollen in hay fever subjects in London

Abstract

Abstract Patients from the West Indies with a history of hay fever in that region were free from symptoms during their first two or three seasons in London. Europeans with allergic sensitivity to pooid grasses are free from symptoms when first exposed to tropical grass pollen. We therefore investigated the possible antigenic relationships between species representative of pooid and tropical grasses by the skin-prick test. It is shown by multivariate analyses (Reciprocal Averaging and Principal Components Analysis) that a reaction to one species has a limited predictive value for reactivity to others. Use of aqueous extracts shows a common antigenicity throughout the grasses, and studies on the antigenicity of grass pollen by both in vivo and in vitro methods are briefly reviewed. It is concluded that aqueous extracts lack species specificity and attention is drawn to the report of Stanford (1983) that the purified proteins of Mycobacterium tuberculosis when used as skin test reagents, cross-react with other species of Mycobacteria, contain little species specific antigen and that molecules of mixed specificity play the largest part in skin test reactions. It is suggested that species specific antigens in grass pollen may be lipid or lipid associated and this appears worthy of investigation both in relation to pollinosis and incompatibility reactions in grasses.