Syuji Yonekura

Present Situation of Cedar Pollinosis in Japan and its Immune Responses

Recent observations have suggested significant worldwide increase in the prevalence of allergic rhinitis and cedar pollinosis. In Japan, Japanese cedar (Cryptometria japonica) and Japanese cypress (Chamaecyparis obtusa) pollens are considered to be the major unique allergens and their extent of dispersal is quite large, travelling more than 100km and thus causing serious pollinosis. Cedar pollinosis is a typical type 1 allergic disease by an adaptive immune response that occurs through the induction of allergen-specific effector T cells from naïve T cells. We examined the number of Japanese cedar pollen specific memory Th cells in the peripheral blood of the patients and found that the cedar pollen specific IL-4-producing Th2 memory cells increased during the pollen season and decreased during the off-season. However, more than 60% of the cedar-specific memory Th2 cells survived up to 8 months after the pollen season. Natural killer T(NKT) cells represent a unique lymphocyte subpopulation and their activity is not restricted to MHC antigens. NKT cells play an important role in innate immunity, however, the participation in development of allergic rhinitis could not be clarified.

Increase of regulatory T cells and the ratio of specific IgE to total IgE are candidates for response monitoring or prognostic biomarkers in 2-year sublingual immunotherapy (SLIT) for Japanese cedar pollinosis

The aims of this study were to examine the therapeutic effects of sublingual immunotherapy (SLIT) and to identify potential biomarkers that would predict the therapeutic response in a randomized, double-blind, placebo-controlled clinical trial. The trial was carried out over two pollinosis seasons in 2007 and 2008. Carry-over therapeutic effects were analyzed in 2009. SLIT significantly ameliorated the symptoms of pollinosis during the 2008 and 2009 pollen seasons. Cry j 1-specific cytokine production in a subgroup of patients with mild disease in the SLIT group was significantly attenuated. The ratio of specific IgE to total IgE before treatment correlated with the symptom-medication score in the SLIT group in 2008. Patients with increased Cry j 1-iTreg in the SLIT group had significantly improved QOL and QOL-symptom scores. In summary, the specific IgE to total IgE ratio and upregulation of Cry j 1-iTreg are candidates for biomarker of the clinical response to SLIT.

A Randomized Controlled Trial of Sublingual Immunotherapy for Japanese Cedar Pollinosis

Background: Japanese cedar pollen represents an important and unique allergen. Sublingual immunotherapy (SLIT) has been suggested to be a highly effective route of desensitization against a variety of allergens. However, little information is available about its use in cedar pollen allergy. Methods: A blinded randomized, placebo-controlled trial employing SLIT for cedar pollinosis was conducted over a period of 6 months. Sixty-seven subjects were enrolled and the symptom scores during the pollen season were evaluated by a symptom diary, measurement of cedar-specific IgE and IgG4, and determination of Cry j-specific Th2 clones before SLIT and before and after the pollen season. Results: No major adverse effects were observed in either group. The serum-specific IgG4 activity increased significantly after SLIT in the active group. The active group also exhibited significantly lower symptom scores compared to the placebo. The specific Th2 clone sizes were not significantly different between the groups before the pollen season. However, an increase in the clone size was observed after the pollen season in the placebo group, but not in the active group. Conclusion: Use of SLIT for Japanese cedar pollinosis was found to be safe and associated with an increase in cedar-specific IgG4 levels. Such therapy inhibited the increase in Cry j-specific Th2 clone size induced by pollen exposure. Finally, use of SLIT resulted in significant improvement of the clinical symptoms of cedar pollinosis in this patient population. These observations suggest that SLIT may offer another safe approach to the management of cedar pollinosis.

Sublingual Immunotherapy with House Dust Extract for House Dust-Mite Allergic Rhinitis in Children

BACKGROUND House dust extract is used in conventional immunotherapy for house dust-mite (HDM) allergic rhinitis in Japan. However, an alternative administration route is desired. The aims of the present double blind, placebo-controlled trial were to evaluate the therapeutic efficacy and safety of sublingual immunotherapy (SLIT) with house dust extract in pediatric patients with HDM allergic rhinitis. METHODS The study population comprised 31 subjects (21 males and 10 females) aged from 7 to 15 years old. Twenty patients (the active group) received house dust extract and 11 received placebo via sublingual administration. Extract or placebo (1 ml) was administered at 10-fold dilution once weekly for 40 weeks. During the study period, the subjects recorded their daily nasal symptoms and use (dose and frequency) of other medications in a nasal allergy diary. RESULTS The symptom scores in the active group began to decrease about 24 weeks after initiation of treatment and significant differences between the active and placebo groups were observed after 30 weeks. The average scores for the last four weeks of the study were significantly lower than those for the first four weeks in the active group but not in the placebo group. The only local adverse effect was a bitter taste reported by one patient. There were no other local or systemic adverse effects associated with SLIT. CONCLUSIONS Our results suggest that SLIT with house dust extract for more than 30 weeks is safe and effective treatment for HDM allergic rhinitis in children.

Efficacy and Safety of Sublingual Immunotherapy for Two Seasons in Patients with Japanese Cedar Pollinosis

Background: Japanese cedar (JC) pollinosis is the most common seasonal allergic rhinitis in Japan. Standardized JC pollen extract is available for subcutaneous immunotherapy, but this treatment is limited by potentially serious side effects. The aim of this double-blind, randomized comparative study was to evaluate the efficacy and safety of standardized JC pollen extract in a new oral formulation (CEDARTOLEN®, Torii Pharmaceutical Co., Ltd., Tokyo, Japan) for sublingual immunotherapy (SLIT) for JC pollinosis. Methods: A total of 531 subjects with JC pollinosis were randomized into 2 groups at a ratio of 1:1 to receive daily sublingual administration of standardized JC pollen extract with a maintenance dose of 2,000 Japanese allergy units (JAU) or placebo for 2 consecutive pollen seasons. The efficacy was evaluated using the total nasal symptom and medication score (TNSMS) as the primary end point. Secondary end points included the total ocular symptom and medication score (TOSMS) and scores for individual symptoms and medication. Results: The TNSMS was significantly lower (p < 0.0001) in the SLIT group than in the placebo group in the peak symptom period by 18 and 30% in the first and second seasons, respectively. All secondary end points were also significantly lower in the SLIT group in both seasons. No systemic anaphylaxis occurred. Conclusions: SLIT with daily administration of standardized JC pollen extract was effective for improving nasal and ocular symptoms of JC pollinosis and reducing the use of relief medication. The JC pollen extract was well tolerated with only local adverse events.

The induced regulatory T cell level, defined as the proportion of IL-10(+)Foxp3(+) cells among CD25(+)CD4(+) leukocytes, is a potential therapeutic biomarker for sublingual immunotherapy: a preliminary report.

Background:Japanese cedar (Cryptomeria japonica) pollinosis is one of the most prevalent allergies in Japan. Recently, two reports described the positive effects of sublingual immunotherapy (SLIT) against Japanese cedar pollinosis. However, the therapeutic biomarkers for SLIT are still unclear. We performed this unblinded, nonrandomized, open-label study to identify therapeutic biomarkers for SLIT against Japanese cedar pollinosis. Methods:We performed an open-label study during one pollinosis season in 2007, enrolling 19 patients from in-house volunteers suffering from Japanese cedar pollinosis. Peripheral blood was obtained from all participants before SLIT treatment as well as before and after the pollen season. The plasma levels of an immunoglobulin specific to a major allergen (Cry j 1) were determined. We analyzed the induction of regulatory T cells (iTregs), namely IL-10+Foxp3+ cells in CD25+CD4+ leukocytes, by flow cytometry. The Th2-type responses were analyzed by cytokine production from peripheral blood mononuclear cells after stimulation with Cry j 1. Clinical symptoms were estimated using a quality of life questionnaire in the middle of the pollen season. Results: The difference in numbers of iTregs between the medium-only control cell culture and cells stimulat- ed with Cry j 1 was significantly decreased in the non-SLIT group but was unchanged in the SLIT group after the pollen season. The subgroup of the SLIT group with increased iTregs showed more attenuated Th2-type cytokine profiles, and symptom scores in the subgroup with increased iTregs were significantly lower than those in the subgroup with decreased iTregs. Conclusion:The antigen-specific iTreg level is a potential therapeutic biomarker that correlates with clinical pollinosis symptoms and may be involved in the therapeutic mechanisms of SLIT.

Interleukin-25 and mucosal T cells in noneosinophilic and eosinophilic chronic rhinosinusitis

BACKGROUND Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease of uncertain pathogenesis. Memory T cells acquire additional functions during the secondary response and play important roles in chronic inflammation. OBJECTIVE To investigate characteristics of tissue memory CD4(+) T cells obtained from patients with noneosinophilic CRSwNP (NECRS) and eosinophilic CRSwNP (ECRS) by focusing on the influence of interleukin (IL)-25. METHODS Pro-allergic cytokines in tissue homogenates were measured using enzyme-linked immunosorbent assays. NP mononuclear cells and CD4(+) T cells were isolated from NPs from patients with CRSwNP. Cytokine expression and CD4(+) T-cell subpopulations were analyzed using enzyme-linked immunosorbent assay, flow cytometry, and real-time polymerase chain reaction. RESULTS The IL-25 level in NPs increased in patients with ECRS. IL-5 and IL-9 mRNA levels expressed by tissue CD4(+) T cells were significantly elevated in patients with ECRS. Most infiltrating CD4(+) T cells in ECRS and NECRS expressed CD45RO; however, regardless of the atopic status, high IL-17RB levels were detected in CD4(+) T cells from patients with ECRS. IL-17RB mRNA levels expressed by tissue CD4(+) T cells significantly correlated with the number of eosinophils in NPs. Elevation of IL-5 and IL-9 production was found in NP mononuclear cells from patients with ECRS, but not in those from patients with NECRS, by stimulation with IL-25 under T-cell receptor stimulation. CONCLUSION Interleukin-25 and a subpopulation of tissue T-helper type 2 and 9 cells that express increased IL-17RB levels could contribute to infiltration of eosinophils in NPs and could have produced the pathologic difference between NECRS and ECRS.

The Influence of Environmental Exposure to Formaldehyde in Nasal Mucosa of Medical Students during Cadaver Dissection

BACKGROUND Environmental exposure to formaldehyde is commonly associated with clinical symptoms such as mucosal irritation and olfactory disorders. However, the impact of such exposure on the development of mucosal inflammation and its outcome has not been carefully evaluated. METHODS The observational non-comparative study was planned. The study population consisted of group of 41 medical students who had signed up for a cadaver dissection course as part of their gross anatomy teaching at the school of medicine Chiba University in Japan. During such dissection course, the students are exposed to variable levels of environmental formaldehyde routinely employed for the preservation the cadavers. The subjects were evaluated by a detailed medical examination. We measured their serum IgE levels. In addition, an olfaction test and nasal mucosal sensitivity to histamine was serially determined, immediately before and after the course and 6 months after the completion of the course. RESULTS Olfactory abnormalities were observed in 13/41 (32%) subjects and increased nasal mucosal hypersensitivity to histamine was observed in 17/41 (41%) during and immediately after completion of the course. These subjects had evidence of preexisting allergic rhinitis. 6/41 (15%) other students with no prior evidence of allergic rhinitis also exhibited formaldehyde associated clinical symptoms during the dissecting course. However, the symptoms disappeared upon completion of the course in all subjects studied. CONCLUSIONS Temporary abnormalities in the olfaction test and increased nasal mucosal hypersensitivity to histamine were observed in a few students with preexisting allergic rhinitis after environmental exposure of high concentrations of formaldehyde. These effects appeared to be transient.

Effects of daily intake of Lactobacillus paracasei strain KW3110 on Japanese cedar pollinosis.

Japanese cedar pollinosis is an important contributor to allergic rhinitis in Japan. Lactobacillus may be useful as an immunomodulator and is used widely as a foodstuff. The purpose of the study was to examine the effects of daily intake of the Lactobacillus paracasei strain KW3110 in patients with cedar pollinosis. The effects of daily intake of KW3110 in patients with cedar pollinosis were investigated in 126 patients who received KW3110 or a placebo in a double-blind study. The study began 1 month before the start of the pollen season and lasted for 3 months. A significant reduction of nasal symptoms and the serum level of eosinophil cationic protein and improvement of quality of life scores occurred in the patients who received KW3110 when pollen scattering was low. However, the effects were limited during the peak period of pollen scattering. Intake of KW3110 may reduce allergic inflammation, but the effect is limited.

Cedar and Cypress Pollinosis and Allergic Rhinitis: Quality of Life Effects of Early Intervention with Leukotriene Receptor Antagonists

Background: Allergic rhinitis involves inflammation of the nasal passages. The use of nasal steroids is generally very effective in providing significant symptom relief. However, compliance for their use is sometimes poor. Methods: To examine the efficacy of early intervention (before pollen dispersal) with oral cysteinyl leukotriene receptor antagonists (LTRA) on pollinosis in patients with allergy to cedar and Japanese cypress pollens, groups of subjects were treated with LTRA or a placebo for 4 weeks at the beginning of the cedar pollen dispersal season. Subsequently, all patients received nasal steroid therapy concomitantly with LTRA throughout the remaining period of the pollen dispersal season. The effects of such early treatment with LTRA on pollinosis were investigated using symptom scores from an allergy diary and quality of life (QOL) scores. Results: Sneezing and nasal congestion scores were significantly lower in the LTRA-pretreated subjects than observed in the placebo-pretreated patients between weeks 4 and 6 and weeks 3 and 5, respectively. QOL scores improved significantly in all domains after concomitant therapy with nasal steroids. The percent improvement in the nasal congestion score after the concomitant therapy was significantly higher in the LTRA group (69%) than in the placebo group (41%). Conclusion: Significant differences observed in symptoms and in QOL effects between LTRA- and placebo-pretreated patients and the absence of major adverse effects noted in these studies suggest that early intervention with LTRA is beneficial and safe and should be considered in the management of pollinosis-associated allergic rhinitis.