Family study HLA antigen and Ir gene linkage in ragweed and dust allergy.

A family was studied for HLA antigen Ir-gene linkage in ragweed and dust allergy by clinical history, skin test, mixed lymphocyte cultures, lymphocyte culture for cellular immunity to antigen E and dust allergens, RAST assay for ragweed and dust antigens and HLA typing. These results confirm previous observations that ragweed Ir genes are linked to the inheritance of the HLA complex. The Ir genes may map at some distance from the closely linked HLA and MLC genes. It is also of interest that Ir genes for dust allergy in this family appear closely associated with ragweed genes. The set of twins with identical HLA complexes but different expression of presumably identical Ir genes will bear watching.