The most common cause of seasonal allergic rhinitis in Japan is the Japanese cedar (JC). Recently, a pullulan-conjugated antigen (CS-560) has been developed to reduce adverse effects and to enhance the effect of JC-specific immunotherapy (IT). If the mechanism of IT can be fully elucidated and the treatment can be used safely and with specificity, IT should be reconsidered as a superior treatment for JC pollinosis. Thirteen patients with JC pollinosis who received IT were compared to 10 patients who did not receive IT. All patients were followed through two pollen seasons by means of allergy diaries. Peripheral blood mononuclear cells (PBMC) were collected before IT and just before each pollen season, and these were stimulated with pollen extract. The concentrations of IL-4, IL-5, IL-13 and IFN-gamma in the culture supernatants were determined using an ELISA. Furthermore, messenger (m)RNA expressions of IL-4 and IL-5 from cultured PBMC were also studied. As a result of the allergy diaries, we confirmed the clinical efficacy of CS-560. The symptom-medication scores were significantly decreased by IT. The levels of IL-4, IL-5 and IL-13 declined only in the IT group. However, the level of IFN-gamma did not change in either group. IL-4 and IL-5 mRNA expressions were inhibited in the IT group compared to that in the non-IT group. In conclusion, specific IT for JC pollinosis using CS-560 clearly modified cytokine expression by PBMC.
