Reduced anaphylactic potential of denatured pullulan-conjugated Cry j 1.

Japanese Cedar (JC) pollinosis is the most common seasonal allergic rhinitis in Japan. Throughout the JC pollen season, patients suffer from the allergic symptoms, resulting in a reduction of quality of life. Allergy immunotherapy (AIT) is an established treatment option for a wide range of allergens that unlike symptomatic treatments (e.g. antihistamines) may provide sustained immune tolerance. However, AIT, especially subcutaneous immunotherapy (SCIT) has a fatal anaphylaxis risk due to the use of crude allergen extracts. Consequently, development of allergen derivatives with substantially reduced anaphylactic potential is desirable. An allergen derivative that showed reduced IgE-binding and anaphylactic potential was developed through conjugation of native Cry j 1 (n Cry j 1), a major JC allergen, to the polysaccharide pullulan followed by chemical but non-covalent denaturation. The resulting Cry j 1 allergen derivative, Dn p-Cry j 1, showed reduced IgE-binding and IgE-mediated effector cell activation in vitro using an ELISA competition assay and a mast cell activation model (EXiLE). Reduced anaphylactic potential of Dn p-Cry j 1 in vivo was demonstrated using the rat passive cutaneous anaphylaxis (PCA) assay. The difference in anaphylactic potential of Dn p-Cry j 1 compared to n Cry j 1 in wild-type rats was of the same magnitude as the difference seen in the anaphylaxis reactions obtained with n Cry j 1 in wild-type rats and mast-cell deficient rats, indicating a dramatic reduction in anaphylactic potential of Dn p-Cry j 1. These results indicate that Dn p-Cry j 1 is a promising candidate for next-generation JC AIT.

Long-term oral administration of transgenic rice containing cedar pollen T-cell epitopes potentially improves medication- and allergy-related quality-of-life scores.

Background: We previously developed a transgenic rice that contains seven linked human predominant T-cell epitopes (7Crp) derived from Japanese cedar (JC) pollen allergens Cry j 1 and Cry j 2. Oral administration of 80 g of transgenic rice for 20 weeks suppressed allergen-specific T-cell proliferation in participants with JC pollinosis, but their clinical symptoms did not improve. Objective: We examined the clinical efficacy of low-dose (5 g and 20 g) intake of the transgenic rice administered for two successive seasons. Methods: In this randomized, double-blind, placebo controlled study, transgenic rice seeds (5 g or 20 g) were orally administered to the participants for 24 weeks in each of two successive JC pollen seasons. We analyzed T-cell proliferation and cytokine expression, and monitored symptom and medication scores during the pollen season. Quality of life (QOL) was evaluated by using the Japanese Allergic Rhinitis Quality of Life Standard Questionnaire (JRQLQ). Results: Specific T-cell proliferation after stimulation with 7Crp, Cry j 1, and Cry j 2 was significantly suppressed in the second JC pollen season. No significant differences were found among the three groups (5 g, 20 g, and placebo) with regard to clinical symptoms or medication scores in the first season. However, the medication scores and face scale for overall condition of JRQLQ improved in the 5-g transgenic rice group in the second season, although careful re-examination with a large sample size is necessary to confirm the results. Conclusion: Low-dose oral administration of transgenic rice that contains 7Crp significantly reduced allergen-specific T-cell responses and improved medication scores during the second season of administration. Thus, oral intake of the transgenic rice has the potential to induce immune tolerance to JC pollen allergens when administered for at least two successive seasons.

Recent development on the use of sublingual immunotherapy tablets for allergic rhinitis.

OBJECTIVE: Allergic rhinitis (AR) is an immunoglobulin (Ig) E-mediated inflammatory condition that causes sneezing, nasal congestion, rhinorrhea, and nasal itch. Although subcutaneous immunotherapy for the treatment of AR has been in use and well established as a treatment modality, sublingual immunotherapy (SLIT) is increasingly considered to be the safer and more convenient alternative. Thus, the objective of this review is to describe recent findings pertaining to the use of SLIT tablets (SLIT-T) for AR. DATA SOURCES: A database search (PubMed.gov) for articles published between January 1, 2017, and February 9, 2021, was conducted using the following key words: "allergic rhinitis," AND-ed "sublingual immunotherapy." Included were randomized placebo-controlled trials. Other experimental design studies were excluded. STUDY SELECTIONS: A total of 11 randomized placebo-controlled trials were selected for full-text review and included in the analysis. All studies investigated the use of SLIT on patients with seasonal AR (4 tree pollen, 1 grass pollen, and 1 Japanese cedar) or perennial AR (3 house dust mite). RESULTS: Our review of 7 recently published randomized placebo-controlled trials with 2348 subjects receiving SLIT reported increased efficacy, safety, supportive immunologic parameters (IgE and IgG4 pre- and posttreatment levels), and improved quality of life. All studies excluded subjects with overlapping seasonal or perennial allergens, a history of moderate-to-severe uncontrolled asthma, or reduced lung function. CONCLUSION: Our review highlights that SLIT is a safe and effective treatment that considerably reduces symptoms and medication requirements in AR and improves quality of life.

Japanese cedar and cypress pollinosis updated: New allergens, cross-reactivity, and treatment.

Pollen from many tree species in the Cupressaceae family is a well-known cause of seasonal allergic diseases worldwide. Japanese cedar pollinosis and Japanese cypress pollinosis, which are caused by pollen from Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa), respectively, are the most prevalent seasonal allergic diseases in Japan. Recently, the novel major Japanese cypress allergen Cha o 3 and the homologous Japanese cedar allergen Cry j cellulase were identified, and it was shown, for the first time, that cellulase in plants is allergenic. Although the allergenic components of pollen from both species exhibit high amino acid sequence identity, their pollinosis responded differently to allergen-specific immunotherapy (ASIT) using a standardized extract of Japanese cedar pollen. Pharmacotherapy and ASIT for Japanese cedar and cypress pollinosis have advanced considerably in recent years. In particular, Japanese cedar ASIT has entered a new phase, primarily in response to the generation of updated efficacy data and the development of new formulations. In this review, we focus on both Japanese cypress and cedar pollinosis, and discuss the latest findings, newly identified causative allergens, and new treatments. To manage pollinosis symptoms during spring effectively, ASIT for both Japanese cedar and Japanese cypress pollen is considered necessary.

Sublingual immunotherapy for 4 years increased the number of Foxp3+ Treg cells, which correlated with clinical effects.

OBJECTIVE: At least 3 years of sublingual immunotherapy (SLIT) is required to achieve long-term clinical tolerance for allergens. However, immunological changes with more than 3 years of SLIT have not yet been elucidated in detail. The present study investigated whether the numbers of regulatory T (Treg) cells and regulatory B (Breg) cells increased with 4 years of SLIT and if these increases correlated with clinical effects for pollinosis. METHODS: Seven Japanese cedar pollinosis patients received SLIT in 2014 or 2015 and continued treatment until May 2019. In May 2017 and May 2019, peripheral blood mononuclear cells (PBMCs) were collected from the patients, and analyzed by flow cytometer. RESULTS: (1) The visual analogue scale (VAS) was significantly higher in 2019 than in 2017. (2) The percentages of Foxp3+ Treg cells, type 1 regulatory T (Tr1) cells, and Breg cells in PBMCs were significantly higher in 2019 than in 2017. (3) The percentage of Foxp3+ Treg cells in PBMCs positively correlated with VAS, whereas those of Tr1 cells and Breg cells did not. CONCLUSIONS: These results suggest that 4 years of SLIT is needed to achieve sustained increases in Foxp3+ Treg cells, which are closely associated with the efficacy of SLIT.

Increased Thrombin-Activatable Fibrinolysis Inhibitor in Response to Sublingual Immunotherapy for Allergic Rhinitis.

OBJECTIVES/HYPOTHESIS: The objective of this study was to determine the role of thrombin-activatable fibrinolysis inhibitor (TAFI) as a candidate biomarker for therapeutic efficacy of sublingual immunotherapy (SLIT) and to identify the role of TAFI in the pathogenesis of allergic rhinitis (AR). STUDY DESIGN: Retrospective cohort study and laboratory study. METHODS: Serum was collected from patients with allergies to Japanese cedar pollen before, during, and after treatment with SLIT. We measured the levels of immunoreactive TAFI, C3a, and C5a in serum by enzyme-linked immunosorbent assay (ELISA) and assessed their relative impact on a combined symptom-medication score. We also examined the impact of TAFI on mast cells and fibroblasts in experiments performed in vitro. RESULTS: Serum levels of TAFI increased significantly in response to SLIT. By contrast, serum C3a levels decreased significantly over time; we observed a significant negative correlation between serum levels of TAFI versus C3a and symptom-medication score. Mast cell degranulation was inhibited in response to TAFI, as it was the expression of both CCL11 and CCL5 in cultured fibroblasts. CONCLUSIONS: High serum levels of TAFI may be induced by SLIT. TAFI may play a critical protective role in pathogenesis of AR by inactivating C3a and by inhibiting mast cell degranulation and chemokines expression in fibroblasts. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:2413-2420, 2021.

Intranasal levels of lead as an exacerbation factor for allergic rhinitis in humans and mice.

BACKGROUND: Air pollutants are suspected to affect pathological conditions of allergic rhinitis (AR). OBJECTIVES: After detecting Pb (375 µg/kg) in Japanese cedar pollen, the effects of intranasal exposure to Pb on symptoms of AR were investigated. METHODS: Pollen counts, subjective symptoms, and Pb levels in nasal epithelial lining fluid (ELF) were investigated in 44 patients with Japanese cedar pollinosis and 57 controls from preseason to season. Effects of intranasal exposure to Pb on symptoms were confirmed by using a mouse model of AR. RESULTS: Pb levels in ELF from patients were >40% higher than those in ELF from control subjects during the pollen season but not before the pollen season. Pb level in ELF was positively associated with pollen counts for the latest 4 days before visiting a hospital as well as scores of subjective symptoms. Intranasal exposure to Pb exacerbated symptoms in allergic mice, suggesting Pb as an exacerbation factor. Pb levels in ELF and nasal mucosa in Pb-exposed allergic mice were higher than those in Pb-exposed nonallergic mice, despite intranasally challenging the same amount of Pb. Because the increased Pb level in the nasal mucosa of Pb-exposed allergic mice was decreased after washing the nasal cavity, Pb on the surface of but not inside the nasal mucosa may have been a source of increased Pb level in ELF of allergic mice. CONCLUSIONS: Increased nasal Pb level partially derived from pollen could exacerbate subjective symptoms of AR, indicating Pb as a novel hazardous air pollutant for AR.

Possibility of Japanese Cedar Pollen Causing False Positives in the Deep Mycosis Test.

Because Japanese cedar pollen (JCP) contains beta-1,3-d-glucan (BG), there is concern that its lingering presence in the atmosphere, especially during its scattering period, may cause false positives in the factor-G-based Limulus amebocyte lysate (LAL) assay used to test for deep mycosis (i.e., G-test). Hence, we examined whether the LAL assay would react positively with substances contained in JCP by using the G-test to measure JCP particles and extracts. BG was purified from the JCP extract on a BG-specific affinity column, and the percentage extractability was measured using three different BG-specific quantitative methods. The G-test detected 0.4 pg BG in a single JCP particle and 10 fg from a single particle in the extract. The percentage extractability of JCP-derived BG was not significantly different among the three quantitative methods. As the JCP particles should technically have been removed during serum separation, they should be less likely to be a direct false-positive factor. However, given that the LAL-assay-positive substances in the JCP extract were not distinguishable by the three BG-specific quantitative methods, we conclude that they may cause the background to rise. Therefore, in Japan false positives arising from JCP contamination should be considered when testing patients for deep mycosis.

Long-term sublingual immunotherapy provides better effects for patients with Japanese cedar pollinosis.

OBJECTIVE: Japanese cedar pollinosis is an endemic disease affecting a large proportion of Japan's population. Five seasons have passed since sublingual immunotherapy (SLIT) for Japanese cedar pollinosis was included in the public insurance coverage in Japan. In this study, we evaluated the clinical effects of long-term SLIT for Japanese cedar pollinosis on upper respiratory symptoms primarily represented by nasal symptoms and inflammation of the respiratory tract in the 2019 season, in which considerable amount of cedar pollen was dispersed. METHODS: This study involved 95 patients who were undergoing SLIT for Japanese cedar pollinosis after the initiation at some point between 2014 and 2018, and this group of patients was compared with a control group comprising 21 patients receiving preseasonal prophylactic treatment (with a second-generation antihistaminic drug). We evaluated the patients' nasal/eye symptoms, total nasal symptom and medication score (TNSMS), and quality of life according to relevant guidelines. In addition, the levels of peripheral blood eosinophils, serum total IgE, Japanese cedar antigen-specific IgE, Cryj1-specific IgG4, and fractional exhaled nitric oxide (FENO) were measured as objective indices. RESULTS: From the fourth season (SLIT4), nasal discharge, sneezing, nasal obstruction symptoms, and TNSMS significantly decreased compared with those in the preseasonal prophylactic treatment and SLIT1 groups. In the patients suspected to have eosinophilic airway inflammation (with a baseline FENO ≥25 ppb), the interannual variability of FENO levels significantly reduced after 5 years of treatment. CONCLUSION: The efficacy of SLIT was noted from the first year of treatment, even in a year when pollen profusely dispersed. Thus, long-term continuous treatment with SLIT may alleviate nasal symptoms as well as eosinophilic airway inflammation.

Effects of sublingual immunotherapy on nasal symptoms and sleep disturbance in patients with Japanese cedar pollinosis.

OBJECTIVE: Japanese cedar (JC) pollinosis is the most common seasonal allergic rhinitis (AR) in Japan. AR reduces the quality of life not only because of nasal symptoms but also because of sleep disturbance. In the present study, we investigated the effects of sublingual immunotherapy (SLIT) with a standardized JC pollen extract on nasal symptoms and AR-related sleep disturbance in patients with JC pollinosis. METHODS: In the present non-randomized controlled study, we assigned thirty-one patients with JC pollinosis who received SLIT into the SLIT group, and another thirty-eight patients with JC pollinosis who visited our hospital without treatment into the untreated group. We evaluated nasal symptoms and sleep disturbance using the classification of the severity of AR symptoms and the Athens Insomnia Scale, respectively. RESULTS: The nasal symptom scores and the Athens Insomnia Scale scores of patients in the SLIT group were both significantly lower than those of patients in the untreated group. There was a significant correlation between total nasal symptom scores and the Athens Insomnia Scale scores. CONCLUSIONS: These findings suggested that SLIT with JC pollen extract suppressed nasal symptoms in patients with JC pollinosis, leading to improvements in AR-related sleep disturbance and daytime troubles with daily life.

Immunological and Symptomatic Effects of Oral Intake of Transgenic Rice Containing 7 Linked Major T-Cell Epitopes from Japanese Cedar Pollen Allergens.

BACKGROUND: A rice-based peptide vaccine containing 7 linked human predominant T-cell epitopes (7Crp) derived from Japanese cedar (JC) pollen allergens, Cry j 1 and Cry j 2, was developed. Here, we examined the efficacy and safety of this transgenic rice in JC pollinosis patients. METHODS: Transgenic rice (5, 20, and 80 g) was administered orally. We measured the T-cell proliferative activity against 7Crp, Cry j 1, and Cry j 2; the cytokine expression levels; and specific IgE and IgG4 production levels. In addition, the symptom and medication scores were monitored during the pollen season, and quality of life (QOL) was evaluated. RESULTS: T-cell proliferative activities to Cry j 1, Cry j 2, and 7Crp were significantly depressed in a dose-dependent manner. Oral intake of 80 g transgenic rice for 20 weeks resulted in significant suppression of allergen-specific T-cell proliferation with downregulation of IL-13 and upregulation of IL-10 levels but no changes to specific IgE and IgG4 levels. The QOL symptom scores for allergic rhinitis were not significantly improved. CONCLUSIONS: Allergen-specific T-cell responses were significantly reduced by oral intake of transgenic rice in a dose-dependent manner. However, neither medication score nor QOL symptom scores could be improved during the JC pollen season with oral intake of transgenic rice for 20 weeks.

Formation of IgE-Allergen-CD23 Complex Changes in Children Treated with Subcutaneous Immunotherapy for Japanese Cedar Pollinosis.

BACKGROUND: Subcutaneous immunotherapy (SCIT) is used to treat Japanese cedar (JC) pollinosis. The formation of IgE-allergen-CD23 complex after SCIT for JC pollinosis has not yet been fully elucidated. OBJECTIVE: The objective of this study was to investigate the formation of IgE-allergen-CD23 complex after SCIT for JC pollinosis. METHODS: Eleven patients were treated with 3-year SCIT for JC pollinosis at Sa-gamihara National Hospital from 2013 to 2014. Nasal and ocular symptoms (in terms of symptom scores) during the scattering of JC pollen and immunological changes were investigated. Levels of JC pollen-specific antibodies (IgE and IgG4) were measured by ImmunoCAP assays. To detect the changes in allergen-presenting ability of B cells, the levels of IgE-allergen-CD23 complexes in serum were measured by a cell-free, enzyme-linked immunosorbent-facilitated antigen-binding assay. RESULTS: The median (interquartile range) age of the subjects was 8 (6-10) years. Three patients (27%) had comorbid atopic dermatitis, and 5 patients (45%) had comorbid bronchial asthma. Before starting SCIT, the total IgE level was 373 (75-2,870) kU/L, and the level of JC pollen-specific IgE was 77.2 (15.4-528) kUA/L. Symptom scores improved significantly from the year after treatment. JC pollen-specific IgE levels did not change after 3 years of treatment. JC pollen-specific IgG4 levels increased significantly throughout the treatment period. The levels of IgE-allergen-CD23 complexes decreased significantly after 3 years of treatment. CONCLUSION: The ability of IgE-allergen complexes to bind to CD23 decreased after SCIT, suggesting that increasing levels of IgE-blocking antibodies, including IgG4, may play an important role in the mechanism of SCIT.

Allergen Stability and Immunological Reactivity during Co-dissolution and Incubation of House Dust Mite and Japanese Cedar Pollen SLIT-Tablets.

Japanese allergic subjects are commonly sensitized to both house dust mite (HDM) and Japanese cedar pollen (JCP) and combined treatment with sublingual immunotherapy (SLIT) tablets is desirable. However, mixing extracts of two non-homologous allergens may compromise allergen stability and affect the clinical outcome. Therefore, we investigated the stability of major allergens and total allergenic reactivity of HDM and JCP SLIT-tablets following dissolution in human saliva or artificial gastric juice. Two fast-dissolving freeze-dried SLIT-tablets were completely dissolved and incubated at 37 °C. Major allergen concentrations and total allergenic reactivity were measured. After mixing and co-incubation of HDM and JCP SLIT tablets in human saliva for 10 min at 37°C, there were no statistically significant changes in major allergen concentrations. In addition, no loss of allergenic reactivity of the mixed two SLIT-tablet solutions was seen. In contrast, complete loss of allergenic reactivity and detectable major allergen concentrations occurred when the two SLIT-tablets were dissolved and incubated in artificial gastric juice. These results demonstrate that HDM or JCP major allergens and the total allergenic reactivity of both SLIT-tablets measured here remain intact after dissolution and co-incubation in human saliva, supporting the possibility of a dual HDM and JCP SLIT-tablet administration regimen if clinically indicated. The complete loss of allergenic reactivity after incubation in artificial gastric juice can furthermore be taken to indicate that the immunological activity of the allergen extracts contained in the two SLIT-tablets is likely to be lost or severely compromised upon swallowing.

Eicosanoids seasonally impact pulmonary function in asthmatic patients with Japanese cedar pollinosis.

BACKGROUND: Condition of asthma in patients with asthma and concomitant seasonal allergic rhinitis (SAR) deteriorates during the Japanese cedar pollen (JCP) season. However, the underlying mechanisms remain unclear. METHODS: We analyzed seasonal variations in eicosanoid levels in the airways of patients with asthma and concomitant SAR sensitized to JCP (N = 29, BA-SAR-JCP group) and those not sensitized (N = 13, BA-AR-non-JCP group) during the JCP season. The association between changes in eicosanoid concentrations and pulmonary function was assessed. Exhaled breath condensate (EBC) was collected, and pulmonary function tests were performed during the JCP and non-JCP seasons. The cysteinyl leukotriene (CysLT), thromboxane B2 (TXB2), prostaglandin D2-methoxime (PGD2-MOX), and leukotriene B4 (LTB4) levels in the collected EBC were measured via enzyme-linked immunosorbent immunoassays. RESULTS: The log CysLT levels significantly increased in the BA-SAR-JCP group during the JCP season compared with the non-JCP season (1.78 ± 0.55, 1.39 ± 0.63 pg/mL, mean ± standard deviation, respectively, p = 0.01) and those in the BA-AR-non-JCP group during the JCP season (1.39 ± 0.38 pg/mL, p = 0.04). Moreover, the log TXB2 levels seemed to increase. However, the log LTB4 and log PGD2-MOX levels did not increase. The changes in the log CysLT levels during the two seasons were negatively correlated to forced expiratory volume in one second (FEV1) in the BA-SAR-JCP group (r = -0.52, p < 0.01). CONCLUSIONS: In the BA-SAR-JCP group, seasonal increases in eicosanoid levels in the airway likely promoted deterioration in pulmonary function despite optimal maintenance treatment.

Safety and efficacy of rice seed-based oral allergy vaccine for Japanese cedar pollinosis in Japanese monkeys.

Japanese cedar (Cryptomeria japonica) pollinosis　(JCP) is one of the major seasonal IgE-mediated type I allergies from February to April each year. Not only human patients but also Japanese monkeys (Macaca fuscata) are afflicted with this pollinosis in Japan, which exhibit similar clinical allergic symptoms such as allergenic rhinitis and conjunctivitis. Therefore, monkeys naturally sensitized to JC pollen allergens are expected to serve as a suitable animal model for exploiting the allergy vaccine for JCP, since allergen-specific immunotherapy is the only curative treatment for allergy diseases. We generated transgenic rice containing the hypoallergenic JC pollen Cry j 1 and Cry j 2 allergen derivatives as tolerogen. In this study, safety and efficacy of transgenic rice seed were evaluated by oral administration to Japanese monkeys. Healthy monkeys were not sensitized to Cry j 1 and Cry j 2 allergens, even　when administered for one to ten months. By contrast, peripheral blood mononuclear cell　(PBMC) proliferation and IgE antibody specific　to these allergens were reduced in Japanese monkeys with JCP. Especially, suppression of allergen-specific PBMC proliferation was observed within only two months after administration. These findings indicate that this transgenic rice acts as effective tolerogen to induce oral immune tolerance against JC allergens.

Decreased numbers of metachromatic cells in nasal swabs in Japanese cedar pollinosis following sublingual immunotherapy.

BACKGROUND AND OBJECTIVE: Nasal symptoms were reduced following allergen-specific sublingual immunotherapy (SLIT) for allergic rhinitis. The mechanisms underlying the effectiveness of SLIT for Japanese cedar pollinosis are poorly understood. We studied changes in the numbers of metachromatic cells, eosinophils, and neutrophils following SLIT for Japanese cedar pollinosis. METHODS: Nasal swabs were taken in the preseason (n = 32) and in pollinosis season (n = 49) from subjects given sublingual drop immunotherapy for an average duration of 1.5 years. The numbers of metachromatic cells (mast cells and basophils), eosinophils and neutrophils were determined and compared with those from untreated subjects in preseason (n = 65) and in season (n = 54). RESULTS: SLIT subjects had a significantly reduced frequency of moderate to most severe symptoms in comparison to untreated subjects in preseason (P < .001, the Mann-Whitney U test), and (P < .00001) in season. Metachromatic cell counts in nasal swabs of SLIT subjects in preseason and in season were lower than those of untreated subjects (P = .014, the Mann-Whitney U test) and (P = .00001) respectively. Eosinophil numbers in SLIT subjects were not significantly different than in untreated subjects in both preseason (P = .29) and in season (P = .09). However, when SLIT subjects in season were divided into those with greater than or equal to 1.5 years, or <1.5 years of SLIT duration, the degree of eosinophilia in those with SLIT greater than or equal to 1.5 years was significantly lower (P = .011) than in untreated patients, but not in those with SLIT less than 1.5 years (P = .9). There were no significant differences in neutrophil numbers in nasal swabs between untreated and SLIT subjects in preseason and in season. CONCLUSION: One of mechanisms underlying the effectiveness of sublingual drop immunotherapy for Japanese cedar pollinosis is a reduction of the number of metachromatic cells in preseason and in season. Eosinophilia was also reduced in season in those given SLIT for greater than or equal to 1.5 years.

Allergen-specific subcutaneous immunotherapy for Japanese cedar pollinosis decreases the number of metachromatic cells and eosinophils in nasal swabs during the preseason and in season.

BACKGROUND AND OBJECTIVE: Nasal symptoms of allergic rhinitis can be reduced with allergen-specific subcutaneous immunotherapy (SCIT). However, the mechanisms underlying the effectiveness of SCIT for Japanese cedar pollinosis are not well understood. We studied changes in the numbers of metachromatic cells, eosinophils and neutrophils in nasal swabs following SCIT for Japanese cedar pollinosis. METHODS: Subjects were either untreated or given SCIT for 0.5 to 13 years duration. For the 2019 seasons, nasal swabs were taken in the pollinosis preseason (immunotherapy n = 36; untreated control, n = 62) and in the pollinosis season (immunotherapy n = 45; untreated control n = 46) and the numbers of mast cells, eosinophils and neutrophils assessed by microscopy. RESULTS: There were significant improvements in symptom severities following SCIT in comparison to untreated subjects (P < .0003, the Mann-Whitney U test) in preseason, and (P < .00001) in season. Metachromatic cell counts from nasal swabs of SCIT subjects in preseason and in the season were lower than those of untreated subjects (P = .0029 and P = .031, respectively). Eosinophil numbers in nasal swabs of subjects given SCIT were lower than in untreated subjects (P = .0031) in season, but not in preseason. There were no significant differences in degrees of neutrophilia between untreated and SCIT subjects in preseason and in season. CONCLUSION: One mechanism underlying the effectiveness of SCIT for Japanese cedar pollinosis involves a reduction in the number of metachromatic cells in nasal swabs in the preseason and an inhibition of increases in the number of metachromatic cells and eosinophils in season.

Sustained effects of intralymphatic pollen-specific immunotherapy on Japanese cedar pollinosis.

BACKGROUND: Intralymphatic immunotherapy (ILIT) for allergic patients requires only a few intralymphatic injections of the allergen. However, the effectiveness and safety for Japanese cedar pollinosis are unclear. The objectives of this study were to clarify whether and how long ILIT is effective for pollinosis, and its safety. METHODS: In an open pilot investigation followed by a double-blind, placebo-controlled study, patients with Japanese cedar pollinosis received 3 intralymphatic inguinal injections of the pollen extracts before the first pollen season. The symptom medication score (SMS), nasal provocation testing and scoring visual analogue scale (VAS) were assessed after the first-third seasons. RESULTS: (1) Although mild adverse events were induced at the injected site, severe adverse events were not noted. (2) During the latter part of the first season, ILIT-treated patients (n=12) tended to show improved SMS compared to placebo-treated (n=6) without statistical significance. When assessed by nasal provocation testing and VAS scoring after the first season, the effectiveness of ILIT was significant. (3) The effects of ILIT continued until the second or third season. (4) Neither allergen-specific antibodies nor Treg/Breg cells changed in the peripheral blood. CONCLUSIONS: ILIT was safe and effective for Japanese cedar pollinosis. The clinical effects remained for 1-2 years.