The relationships between late cutaneous responses and specific antibody responses with outcome of immunotherapy for seasonal allergic rhinitis.

Mountain cedar (MC) (Juniperus ashei) causes a significant and isolated seasonal allergic rhinitis in south-central Texas during the winter months. Retrospective studies have indicated that patients segregate into two categories based on skin test reactions: single positive skin test to MC only and multiple positive skin tests. These two populations differed in age, personal and family history of atopy, levels of both IgE and total MC-specific IgE (sIgE), and symptomatology. It has been speculated that the subjects with only a single positive skin test may actually be nonatopic and develop an IgE response to MC because of some peculiarity of the antigen. In a prospective, randomized, controlled trial, we tested the efficacy of immunotherapy (IT) with MC extract in 51 subjects, 12 single positive skin tests and 39 multiple positive skin tests, to determine if these differences indeed exist and if IT is equally effective in both groups. We failed to demonstrate significant differences in age, sex, MC sIgE, total IgE, initial immediate cutaneous response, initial late cutaneous response, or personal or family history of atopy. IT was equally effective in both groups of subjects with no significant differences noted in response to MC sIgE, MC sIgG1, MC sIgG4, or with suppression of the late cutaneous response. In addition, we found that suppression of the late cutaneous response correlated significantly with cumulative dose of MC extract, postseasonal level of MC sIgG1 and MC sIgG4, and improvement of symptomatology. Suppression of the late cutaneous response may be a clinically useful parameter to follow in monitoring patients during IT. Caution is advised because this procedure may result in systemic reactions.