Association of HLA-DR3 with human immune response to Lol p I and Lol p II allergens in allergic subjects.

Associations between HLA type and IgE or IgG antibody (Ab) responses to two well-characterized, antigenetically non-crossreactive components of Lolium perenne (rye grass) pollen extract, Lol p I (Rye I) and Lol p II (Rye II) were studied in two groups of skin-test positive (ST+) Caucasoid adults. By both nonparametric and parametric statistical methods, significant associations were found between Ab responses to both Lol I and Lol II and the possession of HLA-DR3. In view of the well-known associations of both DR3 and B8 (which are in linkage disequilibrium) with many autoimmune diseases, differences in anti-Lol I and anti-Lol II mean log[Ab] levels between B8+, DR3- vs B8-, DR3- subjects and B8+, DR3+ vs B8-, DR3+ subjects were investigated. No differences were found. Our data, along with recent RFLP and DNA sequence studies, suggest that an Ia molecule involved in immune recognition of a similar major Ia recognition site of both the Lol molecules may consist of a DR3 alpha-beta I pair. Abbreviations used: Ab: Antibody. HLA: Human leukocyte antigen. Lol p I, Lol I: Group I allergen from Lolium perenne pollen (Rye I). Lol p II, Lol II: Group II allergen from Lolium perenne pollen (Rye II). Mr: Relative molecular mass. Rx: Immunotherapy with grass pollen extracts. ST: Skin test.